ESE's works engine tuner

[F5 Dave]

Thanks, interesting. 1st one doesn't look like its reached its potential with that shaky line, suspect its worse than stock.

[bucketracer]

271000

Gigglebuttons 20.5hp FXR150, cams. carb and tuned length pipe.


its nice to see 30 hp (2-Stroke) buckets, but it seems far less than that is required to win races .… 22-25 HP at 10,500 and that, from my experience is not only feasible, but race winning as well.

Possibly, lets look at that.

270998

Chambers put TeeZees original 22.6hp @ 9,800 rpm Magic Vacuum Cleaner Engine on the dyno yesterday.

270999

And the 2-Strokes 22.6 3K power spread looks pretty short compared to the FXR's 7K spread.


270997

the "first finished run".... I am confident with the other exhaust system I would see 25 PS no problem.

It might be a high torque 2-stroke but with such a limited (2.5-3K at best) power spread compared to a FXR, are you sure the extra 2 or 3 peaky hp will help very much, a broader spread may be the way to go.

Hi torque without a decent power spread is not going to do the business either. Not without a lot of clutch slipping and gear leaver wiggling.

270996

Even something like TeeZees broad 4k power spread and 28.6hp might not be enough against the 25+hp FXRs that have long linear power spreads.


My opinion is that a 28PS 25 NM air cooled two stroke 125 would currently clean up in NZ buckets.

Hmmmm ....

271005

But maybe something like TeeZee's 30hp with a "variator" to keep it on the peak over a wide road speed range could do the trick.

[wobbly]

I know I go on about this every now and then, but everyone seems to forget that NoMates comes out on occasion with his 28Hp RGV100 from 6 years ago and absolutely destroys everyone, or crashes, or buggers it.
Good engine, good chassis, good rider - three titles in a row,lap record,what else is there to say.
I am just about to put an Ignitech on it,for ignition and powervalve, so will put the dyno result up on here when its done.

[richban]

I know I go on about this every now and then, but everyone seems to forget that NoMates comes out on occasion with his 28Hp RGV100 from 6 years ago and absolutely destroys everyone, or crashes, or buggers it.
Good engine, good chassis, good rider - three titles in a row,lap record,what else is there to say.


Did he have to walk to school in the snow and rain on a gravel road back then. Living in the past is ok.:innocent:

[wobbly]

I would put serious money on the fact that the RGV100 that was built properly 6 years ago,with 28Hp and a 4K spread could be ridden by a good rider tomorrow and easily beat anyone.
No one is going faster now than that thing did back then - 2T or 4T.
So it will be interesting to see what can be done , as the cylinder has been plated to stop bridge wear ( making it reliable again ) and a modern ECU fitted to drive the spark and the PV.

Nigel was left in a shoe box on the Southern Motorway as a child, so gravel roads, snow and rain would be chicken shit to him as no one loved him back then,and no one does now.

[TZ350]

I know I go on about this every now and then, Good engine, good chassis, good rider -

Agreed, its the complete package ..... Nigals was the first, but I think there are a few good packages coming along with the potential to keep him honest.

[F5 Dave]

. . .A good rider that could take the riding position. Cramped RS seat position & sit up MX bars, a normal person can hardly change gear -but he's a pervert I guess.

Did he find some more cases?

[Moooools]

I would put serious money on the fact that the RGV100 that was built properly 6 years ago,with 28Hp and a 4K spread could be ridden by a good rider tomorrow and easily beat anyone.
No one is going faster now than that thing did back then - 2T or 4T.
So it will be interesting to see what can be done , as the cylinder has been plated to stop bridge wear ( making it reliable again ) and a modern ECU fitted to drive the spark and the PV.

Nigel was left in a shoe box on the Southern Motorway as a child, so gravel roads, snow and rain would be chicken shit to him as no one loved him back then,and no one does now.

$200/3 = $66.67

The amount payed per lap at Hampton Downs before your two stroke shits itself.

I will stick with the FXR thanks.

(It did keep up with the pointy end of the hyosungs very well for those laps though. Although the FXR wasn't far off matching the pace. I needed more balls in the bends. Maybye next time...)

[TZ350]

Because I was asked, more FXR150 graphs.

271091

14hp modified exhaust and bigger carb but needs sorting.

271040

17hp Std Cams bigger carb tucked in after market muffler.

271037

18hp Akuner cams bigger carb tucked in after market muffler.

271038

20 hp CrazyMan cams bigger carb tuned length exhaust and tucked in after market muffler.

271036

25hp full house FXR and there are at least two or three of these bikes around. This is an older graph and I expect things have moved on since this was done.

[andrew a]

I rember the first GP I did. On the restart no mates just pulled away with no effort. It would have been an easy win except it expired. Very fast bike. Same as young Diprose. No 4t has gotten near his lap times.

[jasonu]

I am just about to put an Ignitech on it,for ignition and powervalve, so will put the dyno result up on here when its done.

You'll have to fix it first. I heard it blew up at HD last weekend...

[wobbly]

Yea it shit itself at Hampton, I was there with Discombe.
Thats what happens when you leave tuning to the rider,I hope to make it Foolproof with the new Ignition and an EGT gauge that works.
Bottom line still is though,it ran fine for 3 of the 6 years without being touched, and he wondered why it then became unreliable.

[TZ350]

271126

A certain RS/GP being prepared for Mt Welly, Sunday week.

271127

271128

[wobbly]

Shitbags, I want a dynogirl as well - as my wife would say "dirty old bastard".

[Brian d marge]

Here is a look into fins if anyone needs it

Stephen

[TZ350]

Thanks for that, I see 8mm is the most effective fin pitch for a moving cylinder.

[Buckets4Me]

Shitbags, I want a dynogirl as well - as my wife would say "dirty old bastard".

271151 are you sure ? she can be rough on gear

[husaberg]

Here is a look into fins if anyone needs it

Stephen

Neat thanks Stephen

Another subject i thought i had posted a while back was something Suzuki did with their intake bell mouths on the GSXR100 was to cut slots on the bellmouths they claimed it would dampen out intake pressure waves, resulting in smoother throttle response at midrange and higher revs.
Applicable to 2 strokes?

I asked a while back what the optimum water temp was. no answers
I think i found an answer for 4 strokes..... But What about the two strokes..........

[dinamik2t]

I think there was a petite discussion on this topic at Pitlane, with Jan Thiel. I think it might have been the FPE kart @ Technique, Husaberg.
(by the way there are some very interesting pics of rsa's cylinder cast molds in that thread)

[wobbly]

I thought I had answered the water temp question.
50* exiting the head is the shit,above that you loose power big time.
The 125 Kart engines run best down at 40*, but use alot bigger initial bore clearance.

[Neal]

271151 are you sure ? she can be rough on gear


Is this the same chick from the dyno ? One tough chick there !

[husaberg]

Is this the same chick from the dyno ? One tough chick there !

http://www.avalonbiddle.com/2012/03/29/avalon-heads-to-italy-for-remainder-of-2012/


I thought I had answered the water temp question.
50* exiting the head is the shit,above that you loose power big time.
The 125 Kart engines run best down at 40*, but use a lot bigger initial bore clearance.
I must have missed it thanks, the other question was calculating radiator size requirements.
i guessed i could just size one of a RS125 and decrease it by in engine capacity so 80% of the area and capacity as a rough guide?
RS125 NF4

350mm x 168mm x 30mm
<img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=265374&d=1340325420" width="340px"/><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=265376&d=1340325460" width="340px"/><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=265373&d=1340325404" width="340px"/>

Brand new, performance aluminum radiator for a Yamaha Raptor YFM660 or YFM660R 2001-05.
http://www.trademe.co.nz/Browse/Listing.aspx?id=519192715
http://images.trademe.co.nz/photoserver/tq/50/148305250.jpg
- Overall (mm): 374H*225W*38T

- Core (mm): 296H*218W*26T
A bit too big but struggling to find anything closer.....

[speedpro]

Duct (duck) tape, it aint hard. Or you could go smaller and fit the radiator into a duct. You could even use it to produce thrust like on spitfires for example, 30lbs in that particular case if I remember. The radiator doesn't have to be at the front.

[bucketracer]

A thread search on "Thrust" brought these two posts up.


Exhaust and cooling air were mixed and dumped overboard over the trailing edge of the wing. It was claimed that 500 pounds of thrust and 20mph resulted from this innovation.


Spitfire used radiators so cleverly designed (in terms of flow through the heat exchanger and the exhaust diffuser) that the underwing radiators generated something like 150 lb's of thrust by themselves.

[FastFred]

271200

http://www.aafo.com/racing/news/98/intrepid.htm

The radiator scoop for the later model P-51’s was well designed. While the scoop caused some profile drag, the heated air exiting the exhaust expanded and created enough thrust to compensate for the drag anytime the air was heated above 170 F. The stock P-51 radiator is large, being 14’ deep and 21" wide by 28" high, and it was sized to cool the engine at 3800 RPM and 55 lbs. of manifold air pressure (MAP). Racers go to 4,000 RPM and 120+lbs. of MAP, so additional cooling is required. Rather than add an even larger radiator, racers added cooling water spray bars in front of the radiator to accomplish the same thing. Spraying cooling water onto the P-51 radiator is necessary but reduces the thrust created in the exhaust because it also cools the air, decreasing hot air expansion.

271199

The question for Hal was how to turn this disadvantage into an advantage. By looking at the picture below you will see Mr. Dantone’s design which answers that question. It both reduces profile drag and in theory will produce a considerable amount of thrust. In summary, it takes the heat and momentum of the engine exhaust and applies it behind the radiator to turn the cooling water into steam, creating a large amount of thrust in the augmenter tube in an effect similar to that of a jet afterburner: a steam afterburner . The term "Steam Afterburner" may be an oxymoron, but it creates the right image. Cooling water enters the augmenter tube and is flashed to steam by the engine exhaust causing it to expand and create thrust much like fuel which is pumped into the afterburner of a jet engine where the heat of the exhaust burns it causing expansion and thrust. As Hal describes it, "The idea is to take the typical radiator design, streamline its flows aerodynamically, and combine it with an augmenter tube similar to the one used on the Convair 440." The radiator is in the bottom of the fuselage directly behind an opening with only a small adjustable scoop that can be opened into the airstream. Inside the scoop are two spray bars to spray cooling water onto the front of the radiator. Behind the radiator, an augmenter tube flows straight back to the tail. Just behind the radiator, the hot, high velocity engine exhaust is emptied into the augmenter tube causing a vacuum by venturi effect: the higher the engine RPM, the stronger the vacuum. That vacuum pulls air into and through the radiator without the need for a scoop. Without the P-51 style scoop, there is less profile drag. Hal goes on to explain that "while the necessity for a scoop is eliminated, there is the probability that some amount of scoop will be beneficial by creating a type of subsonic ramjet effect. An adjustable scoop of about 8"opening 30 will be used so that
a) maximum thrust through ramjet effect can be obtained while racing, and
b) adequate cooling can be obtained at cruise power settings" .

The hot, high velocity engine exhaust (at 1500 - 1700 F) mixes with the air coming through the radiator, heating it and causing it to expand thus creating thrust in a manner similar to the P-51 exhaust, but with much stronger thrust due to the hotter temperature. Note that this will produce more thrust than the P-51 radiator even before the introduction of cooling water. Of greatest import, the engine exhaust also mixes with the cooling spray water, turning it into steam and creating what could be a "significant" amount of thrust. This extra thrust is essentially free since the engine exhaust is otherwise discharged to the airstream and the water must be used to cool the radiator. Mr. Dantone also explained that "sizing the exhaust, augmenter tube and exhaust nozzle to obtain the maximum thrust is very important. It could be done mathematically, but modeling is more accurate and dependable. A professor in the Aerospace Engineering Department at Texas A&M University has assigned this problem as a project to two graduate students to build a model and find the optimum sizes: their assistance is invaluable and greatly appreciated. When they complete this study, the predicted thrust from this steam afterburner will be accurately calculated and published".

Jet engines with afterburners optimize thrust with exhaust nozzles that constrict the area of the exhaust thus increasing the velocity of the flow and the thrust created. The augmenter tube will be approximately rectangular in shape so that the aft portions of the side walls can be made into adjustable flaps to perform this nozzle function. Note that the end of Intrepid’s fuselage (ref. to the 3D rendering) is an opening rather than coming to the traditional closed point. This is the exhaust opening, and the flapper valve nozzles are on each side.

[wobbly]

No such thing as a rad thats too big.
If it fits into the chassis space then use it.
Add a bypass thermostat and it will control the temp at 50* all day, no matter what the air temp is.
No need for tape, or worry if it gets real hot during a race meeting.

[Ocean1]

The radiator scoop for the later model P-51’s was well designed.

Cheers, good read. Always worried me, throwing away all that heat energy with the exhaust. Wonder if the mass of the water would make it worthwhile for buckets. Might at least make racing in the rain a competitive advantage...

[husaberg]

No such thing as a rad thats too big.
If it fits into the chassis space then use it.
Add a bypass thermostat and it will control the temp at 50* all day, no matter what the air temp is.
No need for tape, or worry if it gets real hot during a race meeting.

yes we had a little play a while back and came up with this stuff i guess the rover one might be able to be made to work (with a suitable thermostat but probably not worth the effort.
The pic you display is not the Guhl one though is it?


Found this for RS125 and similar. But from memory some bikes ahad a remote theromsats (VT i think) and probably lots of cars as well. But then again you don't want to do the thermostat route. I suppose.
<img src="http://www.rscycles.com/images/therm_guhl/install_info.gif" width="340px"/>
http://www.rscycles.com/images/thermostat/therm_guhl.htm
(http://www.rscycles.com/images/thermostat/therm_guhl.htm)

The Guhl bypass thermos are great, I used one on my RS125 when I was racing that, never bothered pissing around with tape again, but at around $250NZ to get one its bloody expensive in terms of buckets!
If you can find a 55-60 degree thermo stat you could make one pretty easy though, I think aprillia RS125s thermostats are at around that temp.

252990 252991
My guess the temp is in deg F and 130 F is about 54 C

snooping around I found these Rover stuff.
<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman";} </style> <![endif]--> Pressure Relief Remote Thermostat
From TechWiki
Jump to: navigation (http://wiki.seloc.org/a/Pressure_Relief_Remote_Thermostat#mw-head#mw-head), search (http://wiki.seloc.org/a/Pressure_Relief_Remote_Thermostat#p-search#p-search)
A Pressure Relief Remote Thermostat (PRRT), or sometimes just PRT, is used to increase the amount of coolant flowing around the engine. The PRRT has a bypass valve opening when the coolant pump is flowing too much coolant for the radiator circuit. This valve is reducing pressure difference inside the whole circuit, achieving at the same time a more constant temperature inside the engine.
Note: The acronym PRT means Pressure Relief Thermostat. This setup was developed by Bill Hutchins and used by Rover, MG and Landrover, it has been in use in mid engined cars for 25 years, and an Elise system was previously developed by Simon Scuffham when racing his k-series engined elise. PRRT is actually a misnomer (albeit harmless), allegedly invented by one of the members of the Seloc forum. The PRRT acronym may not actually be recognised by anyone outside of the Seloc forum (including anyone involved in the design, manufacture or assembly of the device) though is perhaps a more accurate description as the second R refers to remote.
<!--[if !mso]> <style> v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} </style> <![endif]--><!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman";} </style> <![endif]--> http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=253027&stc=1&thumb=1&d=1324193035 (http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=253027&d=1324193312)
remote stat with by-pass BMW/Rover SD1 2600/etc
http://www.mgfcar.de/thermostat/Water_System_Mods.htm

Hello
I use this, works great.
http://www.hvg-engineering.com/index.php?action=article&group_id=10000015&aid=127&lang=NL
http://www.hvg-engineering.com/data/articles/images/b_127.jpg

Compare two cooling systems, A and B. In system B the water flows three times as fast and picks up only half the amount of heat per liter, compared to system A.
Then system B removes 50% more heat than system A! And provided your piston clearance is OK, you just cannot have too much cooling. In the Aprilia RSA125 the water pump circulates 160 liter per minute. That is 3 liter per HP per minute!

Nowadays we have a fine solution for avoiding corrosion; it's called plastic. Saves weight too.

I don't know exactly how the NZ dollar is doing, but that sum will probably buy you two of these:
http://www.hvg-engineering.com/index.php?action=article&group_id=10000015&aid=127&lang=NL

Core height Core width Core depth Model

254mm 98mm 40mm Honda cr85
215mm 118mm 40mm crf250
235mm 128mm 40mm crf450
235mm 118mm 40mm crf450 09-12
217mm 118mm 40mm KX250F 06-08
252mm 110mm 36mm KTM various
270mm 118mm 40mm DRZ400 07-09
216mm 128mm 40mm RMZ450
218mm 108mm 40mm YZF250f 03-06
236mm 118mm 40mm YZF450/426 00-05
sizes for single side should be the one with the filler but was in a hurry
http://www.mishimoto.com/kawasaki-radiator-powersports.html

of course the car boys now V mount the intercoolers and rads so....

[wobbly]

Na, the Guhls are stupid price, I made a stack of them.
Available in all colours as long as its staggeringly excellent red anodise for 150 NZ notes ex stock.
The pic is another Aprilia with RZ410 Athena kit for road bike I have nearly finished.

[dmcca]

KTM offroad bikes have a 55* thermostat with bypass... They can be had very cheap on eBay as its common to remove them and fit fully sikkkk colored silicon hoses for extra awesomeness.

[quallman1234]

No such thing as a rad thats too big.
If it fits into the chassis space then use it.
Add a bypass thermostat and it will control the temp at 50* all day, no matter what the air temp is.
No need for tape, or worry if it gets real hot during a race meeting.

I have a bypass thermostat on my RS125, have had it for a few years. Has been bloody fantastic! Zero issues with it and keeps the temp at 55* without thinking about and saves the hassles off duct tape strips! Do it get one.

[bucketracer]

271238


Is this the same chick from the dyno ? One tough chick there !

Yess ...

<iframe src="http://www.youtube.com/embed/GWqWbMHQZL8" allowfullscreen="" frameborder="0" height="315" width="420"></iframe>

Chasing Av at HD

271239

[husaberg]

KTM offroad bikes have a 55* thermostat with bypass... They can be had very cheap on eBay as its common to remove them and fit fully sikkkk colored silicon hoses for extra awesomeness.

Thanks they seem to start around 2000 on, with the 4 smokes
<img src="http://www.ktmpartfinder.com/pictureDisplayHandler.ashx?photopath=ktm_images/05548351.gif&width=800&height=600" width="340px"/><img src="http://i619.photobucket.com/albums/tt275/generationcycle1/105/106/107/021510187.jpg" width="340px"/><img src="http://i619.photobucket.com/albums/tt275/generationcycle1/105/106/107/021510188.jpg" width="340px"/>
<img src="http://www.twostrokeshop.com/custom_bypass_thermostat.jpg" height="300px"/><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=271202&d=1349552977" height="300px"/><img src="http://www.hvg-engineering.com/data/articles/images/b_127.jpg" height="300px"/>

Wobs look nice, Do they also come in red:shutup:
The one Frits and C_Wolf posted only weigh 78gms.


MZ
Below some old 2 stroke interestingly the same thing that was done to the ignition, was also done by JAP on the Speedway bikes in a last ditch effort to stay competitive (in this case in effort to lower parasitic losses) I must admit i never actually considered how much hp , those wasted spark 4 strokes set ups cost. Actually wasn't the LC250/350 wasted spark as well?

[wax]

I have one but its inline. Im not really sure how its going to open with no water movement due to it being closed. I Like the bypass setup alot more
It looks like this so its not a bypass

http://2smoked.com/LC421_engine_files/img6758medium.jpg

[Frits Overmars]

No such thing as a rad thats too big. If it fits into the chassis space then use it. Add a bypass thermostat and it will control the temp at 50* all day, no matter what the air temp is. No need for tape, or worry if it gets real hot during a race meeting.Amen to that.

[twotempi]

Question mainly for Wobbly and Fritz.

The water flow within an early TZ 250/350 - in one side of the head and out the other - seems a bit odd.

Would it be better to introduce the cooling water around the exhaust port area using a fabricated manifold, and then discharge at the back of the head ( normally the inlet !! )

The TZ's are known to run hot - and often use larger radiators in Australia.

Comments, or have you done this before ??

thanks

[wobbly]

When you change the head to inserts you can also change the water flow with a fitting for the cold water in on the back of the cylinder - under the head face.
Having cold water flow over the Ex is NOT what you want at all.
Keeping the transfer ducts outer walls cold is the prime target.
A TZ will struggle to run under 70 at the best of times with the stock rad,but Hintoes replacement unit is alot better - even though it is simply just thicker..
It is easily possible to add 30mm to each side of a TZ rad and still fit it into the fairing, but the best workaround would be to change the flow completely.
Put the tanks on the ends and make it crossflow with a divider on the RH side.
Hot water in at the RH top, out at the RH bottom, using a bypass - exactly as per the pic I posted back a little.
Then run it at 50* like a good little 2T should be.

[TZ350]

Page 620 ...

Big post by Bucket on setting up carburation with an EGT probe.


And Just for you TeeZee I waded back a hundred pages or so and collected up Wobs comments on setting up 2-Stroke carburation.

More on port radiuses


I have just completed a back to back test on the Ex port radius in a TM 125 kart engine.
The cylinder from the factory was a special "tuned "expensive part number, and I was given a stock one to modify.
For sure the two were very different, the stock one being alot lower timing.
This was fortuitous,in that it enabled alot of room to be used to move ports.

First test was the stock cylinder with the main EX at 194, I put a big radius on the roof giving effective timing at 196.5 ( the trick cylinder was the same at 196.5 )
This instantly picked up power everywhere from 8000 to 14000, with alot better overev power, being 6Hp up at 14000
The next test involved dropping the cylinder,removing the chrome and regrinding the ports to the reverse stagger layout.
The A port being the lowest, to allow alot bigger Aux ports.
The main Ex port now opened around 192,with effective at 195 but the Aux opened at the same time, giving better blowdown area, as well as the flow enhancing radius on all 3 ports.

With the reverse stagger giving better transfer area ( as the B,C ports being high with alot of width compared to the previously high A port ) the engine now made 2 Hp or more than the factory trick cylinder
but was now 8 Hp up at 14000 and gained 400 rpm of usable overev, as previously it dropped dead at 13800 on track.
This setup proved to be quite insensitive to jetting and timing changes, allowing alot more static advance giving much better off corner power without killing revs as this would normally do.
Thus the enhanced blowdown flow of the radius at low port openings,allowed those much lower timings to be used effectively, enhancing power everywhere, but most importantly in the overev,where blowdown is most needed.

Frits is right when he says that the Italian factories are 3 years behind,as they still havnt started to use much of the technology developed at Aprilia even now.

Case Comp and Pipes


Case com is a very complex subject but a few rules of thumb apply.
The higher the bmep of an engine then the higher the delivery ratio, thus a larger case can store the higher volume of ingested air at a higher pressure and this is then available to the transfer ducts.
But the quality of the duct and port geometry also affects the case com required.
The smaller the case vol (higher ratio) the greater the pressure rise in the case as the piston drops - this suits compromised transfer ducts with little or no inner wall shape, as it helps force the flow around thru the ducts quicker.
Good duct/port geometry allows the use of a bigger case as they dont need a large pressure ratio across the port to initiate good flow.
Lastly is the effect of the pipe geometry, the diffuser sucks like hell on the Ex port around BDC, pulling flow thru the transfers, and it is important to match the pipe diameter ( and thus the diffuser included angles) to the transfer port/duct geometry.
Suck too hard on crap transfers and they loose directional control - giving greater short circuiting out the Exhaust port.

Thus you have a Catch22 in that you need a small case to speed up the flow, but this limits the available stored mixture, and you want to suck on the transfers as much as possible, but no so much as to loose the control of the flow direction - or to speed up the loop velocity excessively thus reducing the trapping efficiency..

One myth that needs busting here is that the bulk of the flow thru the transfers is initiated by the piston dropping.This happens in lawn mowers, not racing engines.

Pipe diffuser suction when the piston is around BDC forces the bulk of the flow volume, NOT the pressure in the case forcing flow up the ducts.
When the transfers open there is more pressure in the cylinder than in the case.
Thus we get flow reversal at the initial transfer opening point.
This also means that the transfer port that opens first - flows last, as it has the greatest flow reversal affect,down the duct.

In general, high bmep engines that by default will have good port/duct geometry, will like a case com down near 1.3:1, lower performance engines with crap transfer/duct geometry will perform best with the ratio higher, up near 1.4:1.
Thus as you develop an engine, increasing its efficiency with better porting, then this will allow the use of a bigger case, and bigger pipe diameter/vol, to work with that - the two go hand in hand.


Another curly one to deal with. It would seem that staggered transfer timing would have real flow advantage rather than just taming a too peaky motor.
I figure that with this reversal of flow that the boost port would open first as this would allow the flow from main and aux to potentially reach the rear of the cylinder before being directed up, like wise the aux would open next ensuring the main flows first thus limiting short circuiting out the exhaust??????
Anyone got a spare KE125 cylinder (preferably with aux exhaust ports), mine is heading for the bin!


Honda first used the staggered transfer setup with the RS125/250 and was developed by Helmut Fath ( my hero) as was Exhaust stinger nozzles,for the factory teams.
With the big T port they opened the main first by around 2*, the secs and boost ports last.
Aprilia later came along with a 3 port Exhaust setup with huge aux Ex ports, they now have the mains lower to allow much bigger aux Exhaust area, with the secondarys and boost opening first.
All have the axial angles set at around 22* - 12* - 55* to clear out as much residuals from within the loop area as possible.
The big hooks on the secondarys also flips the flow over on itself under the boost, to clear this area out as well.
Greater flow reversal occurs when there is insufficient blowdown STA,and the TZ250 sacrificed blowdown for more transfer area, something we now know is a mistake - but with limited transfer port area you take your pick of what to compromise.


Only Yamaha stuck with the wank flat roof scenario way after the use by date, and got their arses kicked for years in GP.
Till they finally bought a CNC controlled Jante machine from Czech, went square bore/stroke and using the 500 cylinders on the 250 easily won the champs in 2000 with Olivier Jaques.

The secondarys facing each other relatively flat will always collide, but the hooks rotate the flow under the boost as it exits the port ( easy to see with the tap water Jante trick),clearing out a big "dead" area
in front of the rear port.

All modern race engines have a nozzle restriction at the flange face, as big T ports and tripple Exhausts loose alot of velocity going into the header.
Rule of thumb is a 75% of the effective EX area at the flange.
Stepped oval duct into a round flange does work, but I have used a CNC oval to round transition in the spigot for years, as has Honda in A kit, and Aprilia factory engines, this works way better.
Here is a sim showing my new 400cc F3 engine, with and without the spigot nozzle.

The stinger nozzle effectively removes the stinger tube length from the equation - it was developed for Spencers NSR that had one stinger 150 long, the other was 450.
The nozzle is around 2 to 3mm smaller than the tube stinger .


This is great, maybe not as pertinent to the single port commuter engines we are playing with, but still very interesting. Any chance of an example picture?



So assuming I had a 200mm 18mm ID stinger but didn't have the space for it & could replicate it with a 16mm section a couple of cm long & then just run a 209mm section to the pipe to the muffler? A 16mm stinger is 50cc size & would be certain piston crown doom to run on a 100. Is this what you are saying?

I had heard that tapered venturies apparently used on GP bikes?


Here is an oval to round spigot for Robs GP100 with RGV cylinder.
36mm pipe ID, oval shape at the duct exit is 36 wide by 27 high = effective area of a 31mm round..
This nozzle effect doesnt work on single port engines - I have tried.


Re stinger nozzles - if running a 18mm nozzle on a 100cc then you could connect a 20mm stinger tube to it in basically any length and this would not affect the power at all - in fact using the nozzle with a tapered section out to the bigger tube makes more power.
Aprilia/Derby twins do this as the top pipe has a stinger 60mm long, the bottom one is closer to 220, but the effect works on any 2T.


All but impossible to show properly the scavenging pattern without one of the CNC controlled Jante screenshots but imagine looking out from inside the duct,the piston is the "floor" in front of you.
The flow attached to the septum wall blows straight past your left ear, and the flow hitting the hooks on your right side, rotates clockwise underneath this left side flow,the bottom attaching to the piston - the upper flow pushing upwards.


The FPE superkart engine that won the NZ road title at Manfield a few weeks ago makes 92 RWHp on the Dynojet 168 I use.
Still not quite as good as the RS250 setup we did that won at Laguna Superkart Worlds a couple of years ago.

The powerjet carb is controlled by the Ignitech with a combination of throttle position and rpm in a "truth table".
In general the solenoid is activated with 12V ( no fuel flowing) below 4000 rpm and 75% throttle on the TPS.
Above 75% and around 12400 rpm it is activated again to lean off the fuel curve over the top of the pipe.
Looks like you will be able to reverse the fuel exit, blocking off the hole on the throttle bore side, and take off fuel from the outside bung, thru a needle jet and into the top of the venturi next to the slide.


Well funilly enough that Kawasaki piston gave rise to the idea of a toroid shape.
I think they were trying to get the plug closer to the centre of the combustion area, but of course it shagged the squish action as well as the transfer flow regime.
The toroid shape does everything right and there is no reason to use anything else.

[twotempi]

Page 620 ...

Wobbly - Thanks for the reply. It makes sense to keep the transfers as cool as possible to maintain the inlet charge density.

The reason I mentioned the inlet for the cooling to be around the exhaust port was to minimise the temperature difference around the cylinder to reduce any distortion.

So in order of flow of cool water does 1) transfers first 2) than exhaust, 3) inlet area - make sense ??

[husaberg]

One Day i will stop chocking the thread with articles about old stuff.......
But its not today.
Note the induction controlled by reed and rotary valves.

[bucketracer]

These are great, love reading the old articles, I hope you have plenty more.

[wobbly]

If you feed cold water in over the rear of the cylinder it will cool that side first, you then have to control the flow to prevent it filling the head too soon and bypassing directly
to the outlet.
Having the water forced to flow across the cylinder,rear to front, then up into the head,flowing front to rear, and out at the highest point is what you are trying to achieve.

[twotempi]

If you feed cold water in over the rear of the cylinder it will cool that side first, you then have to control the flow to prevent it filling the head too soon and bypassing directly
to the outlet.



What you have described is exactly how the circulation is for an early TZ !! The entry for the water is at the back of the head ( highest point !! ) and exit at the front of the head via thermostat. The cylinder just takes its chances

Hence the "how can it be done better" query.

Will have a think and play to see how your suggestions can achieved so thanks for your comments

[husaberg]

These are great, love reading the old articles, I hope you have plenty more.

Last thing you want to do is encourage an anorak.
Yes a few more left.
Including a very interesting gearbox configuration on a works Kreidler 50cc.
The suzuki 50cc here has an Alloy frame (always wondered why Suzuki's welding was so chunky)
Updraft on the carbs and also note the shape of the crank-wheels.
I have always thought the 60's Suzuki's were functionally pretty.
oh yeah the carbs in thew last 50cc twin nearly bigger than what you are allowed on the Air cooled 125 Rob.
In fairness your power spread is a little wider though:yes:

[husaberg]

more clogging........
More well balanced than most articles i have seen credits a lot more people than some.
But at the end of the day it would have been a team effort.
Shame they didn't have better metallurgy and sponsorship.

[husaberg]

Early Suzuki's mmm...
When one of the riders you pay to race your bikes. nicknames your bike whispering death it can be hardly confidence inspiring can it..........

[chrisc]

Thanks Husa, I love these old articles too. Don't stop putting them up!

[husaberg]

<img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=250785" width="340px"/>

An interesting look at a Kreidler transfer passage.
An interesting look at a Kreidler transfer passage.

[QUOTE=Frits Overmars;1130196393]The Kreidler engine shown by TZ350 was cutting edge technology in 1962, but I do not think any of you want to copy transfer passages that, together with twin rotary disks and a twelve-speed gearbox, produced all of 10 HP out of 50 cc.
In case you wonder: the transfer timing was 142°; the single exhaust was way over 200°. Don't try this at home....
Below are some more pictures of the same engine, showing the twin carbs and the screwed-in caps that gave access to the transfer ports for easy modification.
You can also see the hand-operated three-speed gearbox behind the foot-shifted four-speed box.
<img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=250812&d=1321437686" width="340px"/>http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=250811&d=1321437680<img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=250807&d=1321437117" width="370px"/>


These are great, love reading the old articles, I hope you have plenty more.


Thanks Husa, I love these old articles too. Don't stop putting them up!

Thanks for the nice comments. Good to know some people enjoy them shame most people missed the MZ a page back
Frits (and Robs) original post has some nice pics of the engine and the carb and Overdrive set up.
I find the 3 speed OD box quite interesting. No doubt an economical solution. it would also make the down changes faster if not a little confusing.

[Frits Overmars]

I find the 3 speed OD box quite interesting. No doubt an economical solution. it would also make the down changes faster if not a little confusing.Forget about 'a little'. Imagine coming down a long straight in gear 4C, braking at the limit for a hairpin and having to shift down to 2A. Or was it 1C? Or 2B? Or 3A?
Later Kreidler substituted the 4*3-box with a 6*2-box; also twelve speeds, but a little easier to keep count.
As a friend who rode these tiddlers, told me: "Most of the time I hadn't got a clue what gear I was in. All I needed to know was, how often to change down with my foot for a corner, and how to move the hand shifter. You had to get that into your head for every corner. And the tracks were a little longer then: the original Nürburgring had 187 corners..."

[husaberg]

Forget about 'a little'. Imagine coming down a long straight in gear 4C, braking at the limit for a hairpin and having to shift down to 2A. Or was it 1C? Or 2B? Or 3A?
Later Kreidler substituted the 4*3-box with a 6*2-box; also twelve speeds, but a little easier to keep count.
As a friend who rode these tiddlers, told me: "Most of the time I hadn't got a clue what gear I was in. All I needed to know is, how often to change down with my foot for a corner, and how to move the hand shifter. You had to get that into your head for every corner. And the tracks were a little longer then: the original Nürburgring had 187 corners..."

;) do you have any more pics Frits.
The little was unfortunately my sense of humour.

That pic of the engines is a nice diasembled is a nice example of why 2 strokes are so great esp when you compare it to this.(sorry couldn't find a 5
<img src="http://www.vf750fd.com/Joep_Kortekaas/honda_race_history/rc166-2.jpg" width="370px"/><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=271421&d=1349859077" width="480px"/>

The Suzuki twin write up a while back has how Ansheidt dealt with the multi speed gearbox's.
I can imagine huge problems with over revving, on over run when the rider got even a fraction wrong.
I seem to remember Hugh Anderson as being quoted something along the lines that even if the wheel lifted off the ground for a second the Suzuki's could also do a big end. That's not to mention the tucking in at all costs the imminent threat of siezure and plus the fact that they were also racing. It makes my head hurt.

[richban]

Forget about 'a little'. Imagine coming down a long straight in gear 4C, braking at the limit for a hairpin and having to shift down to 2A. Or was it 1C? Or 2B? Or 3A?
Later Kreidler substituted the 4*3-box with a 6*2-box; also twelve speeds, but a little easier to keep count.
As a friend who rode these tiddlers, told me: "Most of the time I hadn't got a clue what gear I was in. All I needed to know is, how often to change down with my foot for a corner, and how to move the hand shifter. You had to get that into your head for every corner. And the tracks were a little longer then: the original Nürburgring had 187 corners..."

Amazing things them 50's. I wonder what we would have now if they were still racing at top level. GP level that is not buckets. Would you get by with just 8 gears. I wonder. I spent lots of time on 50's when I was a teenager. A50 CB MT GT MB RD.

[F5 Dave]

ahh some old killjoy would have made them 100cc diesels by now anyway,

I'm keeping the flag flying as much as I can.

[Frits Overmars]

Amazing things them 50's. I wonder what we would have now if they were still racing at top level. GP level that is not buckets. Would you get by with just 8 gears.We would get by with 6 gears like we did in the 125 cc class until Dorna killed it last year. Don't be misled by the Aprilia's power valves. They were there because the same cylinders had to be used on the 250 twins, which would have been too vicious without them. The 125s did not really need them. And having many gears to cope with is a big disadvantage. Not only does each gearshift interrupt the power, bringing unwanted movement in the bike and distracting the rider, it also interrupts the gas dynamic processes in the engine which means full power won't be available right after each shift.

[Drew]

That pic of the engines is a nice diasembled is a nice example of why 2 strokes are so great esp when you compare it to this.(sorry couldn't find a 5


Prolly be a better visual comparison, with a single next to a single though aye. Possibly even a two stroke with power valves too, since the current four strokes have fewer parts these days, and the two strokes more.

[richban]

The 125s did not really need them. And having many gears to cope with is a big disadvantage. Not only does each gearshift interrupt the power, bringing unwanted movement in the bike and distracting the rider, it also interrupts the gas dynamic processes in the engine which means full power won't be available right after each shift.

Yes well I do think a good 4 speed box on a Kart track would be good. I use 5 on the local track but the ratios are crap. Looking into fixing that.

[F5 Dave]

On my 50 I use all 6 & still have to abuse seven shades out of the clutch.

but secretly I just like inflicting pain on small circular oil drenched machine parts.

[jasonu]

On my 50 I use all 6 & still have to abuse seven shades out of the clutch.

That is because you have a 206deg exhaust port...(among other things)

[TZ350]

271426
... a nice example of why 2 strokes are so great ...

I always thought they had two carburetors so there was a symmetrical gas flow into the crankcases. But looking at the rotary valves one can be seen to have more extreme timing than the other so it looks like one carb was opened first then when the rev's were up I guess the other side with the radical timing was opened for top end and over rev.

[husaberg]

Prolly be a better visual comparison, with a single next to a single though aye. Possibly even a two stroke with power valves too, since the current four strokes have fewer parts these days, and the two strokes more.

It was a bit unfair, but the comparison was valid, as it was 1960's vs 1960's.
lt should have probably should have used this one though.
<img src="http://www.vf750fd.com/Joep_Kortekaas/honda_race_history/rc166-2.jpg" width="520px"/><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=258580&d=1330250986" width="350px"/>
Although in fairness to the Honda they had pulled out by then and the completion for the title was the V4 Yam plus the rider and the handling of the Ossa was its secret weapon.

Below, for Rob. Note the builder .The way the twin carbs was done was better than the Factory IMO

[F5 Dave]

That is because you have a 206deg exhaust port...(among other things)10 degrees off (and not in that direction smartarse)

[kel]

It was a bit unfair, but the comparison was valid, as it was 1960's vs 1960's.

Not a big fan of the 4 strokes but the Honda 166 is exceptional, damn I love that bike. 6 cylinder 18k open megaphones - hear me HOWL!

http://www.youtube.com/watch?v=eaRop_ZMwo0&feature=related

[husaberg]

Not a big fan of the 4 strokes but the Honda 166 is exceptional, damn I love that bike. 6 cylinder 18k open megaphones - hear me HOWL!

http://www.youtube.com/watch?v=eaRop_ZMwo0&feature=related

You can have it as a ringtone here.....
http://world.honda.com/MotoGP/history/RC166/ringtones/index.html
The other galleries section show and sound the NR500 the nsr500 http://world.honda.com/MotoGP/history/NSR500/video/02/index.htmlrc211v rc166,rc142 etc.


Amazing things them 50's. I wonder what we would have now if they were still racing at top level. GP level that is not buckets. Would you get by with just 8 gears. I wonder. I spent lots of time on 50's when I was a teenager. A50 CB MT GT MB RD.


They would get by because they have no options. When the FIM brought in the rules for how many cylinders limiting at first the 50's (later 80cc's)to one. The 125's to two (later one) and the 250's and 350's to two 500's two four the one common rule was gearbox's with no more than 6 gears were allowed.
Remember the speed (155 to 160mph) i posted for the Yamaha 250V4 it took years for that to be matched with the more restrictive rules.
Suzuki when they pulled out in the 60's had been testing the 50cc/3 with god know's how many gears(at least 18) The riders were faster on the twin though.

[chrisc]

Not a big fan of the 4 strokes but the Honda 166 is exceptional, damn I love that bike. 6 cylinder 18k open megaphones - hear me HOWL!

http://www.youtube.com/watch?v=eaRop_ZMwo0&feature=related

Ah god dang I love the RC166. Here's a photo:
http://www3.images.coolspotters.com/photos/670364/mike-hailwood-and-honda-rc-166-gallery.jpg

And click here for 10 minutes of NSR/NS (http://www.youtube.com/watch?v=uLUex1BssgY&feature=related)

[TZ350]

for Rob. Note the builder .The way the twin carbs was done was better than the Factory IMO

Thanks for that.

271436

The GP did not make any more real power when I tested it with a bigger carb the other day so I figure that something else is restricting it and EngMod2T points to the rotary valve window so I am making a set of cases with a bigger disk and window.

271438 271437

[bucketracer]

Prolly be a better visual comparison, with a single next to a single though aye. Possibly even a two stroke with power valves too, since the current four strokes have fewer parts these days, and the two strokes more.

Maybe a fair comparison would be a Moto 3 single with the Honda RS125 they replaced.

Looking at them, I think the 2-stroke still has less parts and made more power per liter, whats your thoughts?

[Frits Overmars]

Maybe a fair comparison would be a Moto 3 single with the Honda RS125 they replaced. Looking at them, I think the 2-stroke still has less parts and made more power per liter...More than double the power per liter.

[F5 Dave]

Well here's my latest project-ette.

I've borrowed RA dentist tools before & they can do the job but very slowly as they have micro bits.

I came across new old school (sorry I hate that expression) dentist drills that are lower speed but rotary driven & with bigger bits. Maybe I figured I could drive one from my dremel flexidrive & use these diamond bits I bought years ago in the chance that I could find something like this.

Good RA cutters small enough to fit in 50cc barrels or even 100s are more $ than I can justify. So how much for the dentist drill head brand new? Surely more? $25NZ landed to door. Yep that's right, free shipping ebay special.

OK so all was not simple dimple. How to interface the drive for a start. I made a fugly holder out of the end section of a diffuser & welded it to a bit of steel that was tapped (thanks Mike) to fit the dremel flexi (1/2" unf or some crazy tap I didn't have).

The other issue is the bits I'd bought were bigger shank than they said they were so I got a chap to turn them down (my lathe was too big), machine a retainer groove & a flat.

First try out tonight. It spins & is easy to use, but the bits aren't much chop, may have to sacrifice some tungsten dremel ones & the drive started slipping but I had a bent ended old bit to drive the coupling, I really need to weld a decent mating bit to slip into the coupling. Will update how sucessful this all is.

[Drew]

Maybe a fair comparison would be a Moto 3 single with the Honda RS125 they replaced.

Looking at them, I think the 2-stroke still has less parts and made more power per liter, whats your thoughts?


More than double the power per liter.I'm not arguing that the four stroke is superior, was just saying it was a tad unfair to the diesel to picture them such.

I have a two stroke, it just happens to be shit.

[richban]

I'm not arguing that the four stroke is superior, was just saying it was a tad unfair to the diesel to picture them such.

I have a two stroke, it just happens to be shit.

Also the last picture is not the KTM moto3 engine. Its the dirt engine they were talking about in the press when the class was first announced. Not to pedantic for yah.:bleh:

[FastFred]

it looks like one carb was opened first then when the rev's were up I guess the other side with the radical timing was opened for top end and over rev.

Almost a rotary valve version of Frits's swing up out of the way at resonance 24-7 reed valve concept.

[FastFred]

271459 271460


just saying it was a tad unfair to the diesel to picture them such.

Maybe not, if you are comparing the effort a 4-stroke has to go to to be competitive with the same size 2-stroke.

[FastFred]

I have a two stroke, it just happens to be shit.

Here is your chance, apply some skillful talent and unshit it.

[F5 Dave]

Unshit it. Nice turn of phrase. But alas, if he did that; what else would he have to complain about?

. . . oh right. pretty much everything.

[Drew]

Here is your chance, apply some skillful talent and unshit it.Got another guy's pipe dimensions. That and some time on the rolling road to tune it should considerably unshit it.


Unshit it. Nice turn of phrase. But alas, if he did that; what else would he have to complain about?

. . . oh right. pretty much everything.I'm just misunderstood.:cool:

[FastFred]

I'm just misunderstood.:cool:

True.


Got another guy's pipe dimensions. That and some time on the rolling road to tune it should considerably unshit it.

I have a soft spot for the Suzuki GT125, please keep us posted.

[Drew]

True.



I have a soft spot for the Suzuki GT125, please keep us posted.There's a thread about my bike. The stuff I'm doing doesn't really warrant being in this thread.

[husaberg]

I'm not arguing that the four stroke is superior, was just saying it was a tad unfair to the diesel to picture them such.

I have a two stroke, it just happens to be shit.

Nah ya not getting off that easy, no way.
You you wanted me, instead of comparing 60's 4 stroke GP bike to a 60's 2 stroke gp bike engine. You wanted me to compare a 2000's gp 2 stroke to a mx motor that had been forced on the gp fields (to save money haha) One that was twice the size more costly to run heavier and slower.....ok you are right Drew..........

Morbidelli 500

Right first up, Rossi Yes he is his dad. Talent i guess riding talent runs in the family.
The rest maybe our European corespondents can add to?

<img src="http://www.motalia.de/174_Morbidelli-12www.jpg"width="340px"/><img src="http://www.motalia.de/174_Morbidelli-11www.jpg"width="340px"/><img src="http://www.motalia.de/174_Morbidelli-10www.jpg"width="340px"/>
<img src="http://www.motalia.de/174_Morbidelli-14www.jpg"width="340px"/><img src="http://www.motalia.de/174_Morbidelli-13www.jpg"width="340px"/><img src="http://www.highsider.com/bildlager/Pelletier_lager/Pelletier_82_04.jpg"width="380px"/>
<img src="http://img12.imageshack.us/img12/1200/morbidelli5002.jpg" width="370px"/><img src="http://img600.imageshack.us/img600/349/morbidelli5006.jpg" width="310px"/><img src="http://img251.imageshack.us/img251/9568/morbidelli5001.jpg"width="420px"/><img src="http://img820.imageshack.us/img820/7294/morbidelli5005.jpg"width="275px"/><img src="http://img304.imageshack.us/img304/3715/motoremorb0gv.jpg"width="350px"/><img src="http://img225.imageshack.us/img225/4203/morbidelli5004.jpg"width="495px"/>

[Drew]

Nah ya not getting off that easy, no way.
You you wanted me, instead of comparing 60's 4 stroke GP bike to a 60's 2 stroke gp bike engine. You wanted me to compare a 2000's gp 2 stroke to a mx motor that had been forced on the gp fields (to save money haha) One that was twice the size more costly to run heavier and slower.....ok you are right Drew..........
Don't make me sully a properly educational thread with my stupidity man!

[husaberg]

Don't make me sully a properly educational thread with my stupidity man!

Actually you make a great point when was the last time a 4 stroke won a world championship on an equal footing since the mid 70's.MV 500's
I can think only of the open MX class maybe enduros as well. 1995-2002 ish.

Although the Husaberg's did have a 2 stroke based bottom end, at least at first.Plus no one was making a serious open class mx 2 stroke by then anyway.

350 Scott racer 1966

Not as modern as the Morbidelli 500 above but the i think the inlet pictured on the last page is interesting. Had me fooled for a while.
The date is a typo the engine was designed in 1964.
You do have to wonder why the Birmingham "Holder" Scott Squirrel road bikes were liquid cooled yet the racer was to be air cooled, Fashion?

[chrisc]

Last thing you want to do is encourage an anorak.
Yes a few more left.
Including a very interesting gearbox configuration on a works Kreidler 50cc.
The suzuki 50cc here has an Alloy frame (always wondered why Suzuki's welding was so chunky)
Updraft on the carbs and also note the shape of the crank-wheels.
I have always thought the 60's Suzuki's were functionally pretty.
oh yeah the carbs in thew last 50cc twin nearly bigger than what you are allowed on the Air cooled 125 Rob.
In fairness your power spread is a little wider though:yes:

I saw this in the August 2012 issue of Classic Bikes (http://classicbikebooks.com/catalog/images/cb201208.jpg), page 65 if anyone wants to check it out for a similar read

http://christophercain.cc/b/d/bikes/_MG_4287.jpg

[husaberg]

So how much mass do we need in a drum for an inertial dyno for up to say 40hp engines?
would a couple of Petter diesel flywheels do the job ?



Did anyone anwser this post mike something i am interested in as well.
I seen this today, obviously a little large for a bike, but the approach has some merit.
Built in brakes. Bearing that should be up to it.not to mention a convenient shaft for the starter.(Truck ones and real 4wd's normally have the provision to lock the diff also before some points out it will spin one wheel.)
<img src="http://cache.jalopnik.com/assets/images/12/2011/06/img_0121.jpg" width="335px"/><img src="http://ls1tech.com/forums/attachments/multimedia-exchange/23250d1107226248-homemade-dyno-homade-dyno-2.jpg" width="335px"/><img src="http://cache.jalopnik.com/assets/images/12/2011/06/xlarge_img_0340.jpg" width="460px"/>

Free dyno software
http://www.dynamometer-info.co.uk/download-free-automotive-inertia-dyno-software.htm


http://www.dynamometer-info.co.uk/diy-dynamometer.htm
A really heavy roller or drum(s) - This needs to be heavy enough to give a long enough period with even a really powerful car or bike to allow fuel flow, boost etc to stabilize properly. It also needs to be 16 inches diameter or above to prevent losses, tyre damage, and maximise traction to give good accuracy. It must be very free running, and of a known (mathematically calculated) inertial value. This needs serious consideration and testing to find the best size and mass. Our own Motorcycle one for example, finished up at 402mm Diameter x 562mm wide and solid turned steel.(weighs 2/3rds of a ton) Two of these are fine for up to 600 or 700 BHP cars as well. This gives almost twice the inertial value of the then popular DynoJet Dynamometer for bikes. And about 3 or 4 times as much as some current "dynamometers"! Smaller diameter = tyre slippage, and frictional losses, Smaller width = not enough load to fully test powerful drag bikes or to load up even modern stock bikes in lower gears.

A Computer interface timing card / board, to accurately measure both engine RPM and time each drum revolution to a VERY high degree of accuracy. This level of accuracy must be far more precise than a computer or soundcard at 44k sample rate could ever achieve! There are many Dynamometers out there that use the computer to time the drum! They do NOT work accurately enough, and because of this need to use lots of data averaging on the graphs, This is very obvious when you look at the number of data points plotted on the screen on some so called "dynamometers"... The data they produce is pretty useless. This data card part is difficult - much more so than you could ever believe. Its also why the majority of small companies Dynamometers do NOT read real time RPM data during the run, as well as needing to use a HIGH level of data averaging in their graphs... This disguises the real issues, but stops you from seeing what really did happen during the run! BE VERY CAREFUL! This applies to a lot the inertia Dynamometers sold! Unless you are an electronics expert, and also a programmer they you are going to need to find one! If you get a dyno graph print out that gets more spiky in taller gears, and at the top "high power part of the curve, be very suspicious!

A Drum sensor! Sounds easy but the timing accuracy required is far greater than at first glance would seem to be required! A simple hall effect device or a shaft encoder is NOT accurate enough. A gear position, dual hall effect latching sensor is, provided you are looking only at a single point (every 360 degrees) point on the drum.

A Computer... cheap, buy anywhere!

Some dyno software! Mine took 3 years of development and rewriting to finally get everything right and as we needed, with database, auto graph scaling, etc. Be warned, its easy to produce a graph, MUCH harder to produce a final finished useful bit of software with all the facilities you actually need! If you are not good with C programming, and physics, forget it!

A dyno chassis to mount the car / bike / drum(s) into! This is obviously the easiest bit by far!

Stuff like cooling fans, exhaust extraction, gas analysers, etc too, but technically these are not really part of the dyno system.

[wobbly]

I have built several inertial dynos for 40 Hp engines ( engine dyno, not roller for a bike ) and the steel wheel were all sort of around the same dimensions.
Depending on what scrap I could beg ,borrow or steal.
Last one was 525 by 60 thick, new one is 450 by 80 thick.
Depending upon what gear you use you can vary the spin up time, thus the acceleration rate very easily to get the test length in the ballpark.
One thing not mentioned in many build descriptions is that you must use an overun clutch to prevent the inertia wheel from driving the test motor forward, after a test or
more importantly, if it fails on the dyno.
Imagine the mess if it siezes, and it is forced to keep running whilst you are frantically jumping on the brake.
Im just about to assemble my new setup, so will take some pics when its up and running.

[husaberg]

One thing not mentioned in many build descriptions is that you must use an overun clutch to prevent the inertia wheel from driving the test motor forward, after a test or
more importantly, if it fails on the dyno.
Imagine the mess if it siezes, and it is forced to keep running whilst you are frantically jumping on the brake.
Im just about to assemble my new setup, so will take some pics when its up and running.


sweet

This site http://www.tractordata.com/articles/technical/overrunning-clutch-powered.gifhttp://www.dtec.net.au/Inertia%20Dyno%20Design%20Guide.htm (http://www.dtec.net.au/Inertia%20Dyno%20Design%20Guide.htm)
which has been quoted some-where has thede
Being an ex farmer esp one that had driven a non "live drive tractor before"i should have thought about the "overrun clutch"

Overrunning Clutch
A one-way (or overrunning) clutch allows the engine to come to a stop whilst the flywheel continues to come to a gradual stop.
This device is only needed if the engine or vehicle does not have a clutch to disconnect its drive force from the flywheel. After the flywheel has been accelerated and the engine throttle is closed the flywheel will continue to turn, the engine is forced to act as a brake (this is where a clutch would be used if one is available to effectively separate the engine from the flywheel).
Excessive engine braking is very hard on an engine due to internal stresses and a critical issue is that 2 strokes get their lubrication inducted with their fuel/air mixture; this is not present or at very least minimal under closed throttle conditions.
It is not enough to rely on the flywheel braking fast enough (read “braking” section for the dangers of this) and centrifugal clutches fitted to some applications won’t function when the output is doing the driving, they are designed for the engine to be applying the torque.
Whilst we are discussing clutches, a one–way clutch does not negate the need to decouple the engine for starting; this is no problem on motorbikes etc. with conventional clutches. Trying to start an engine whilst it is driving the flywheel is difficult unless it has very low inertia (so therefore probably unsuitable for using anyway), the centrifugal clutch fitted to the engine (assuming it has one) should remain in place to allow starting and warm up but it should be adjusted to ‘lockup’ at low enough rpm to allow testing across the whole useful RPM range.
Bearing supply companies have many overrunning drive options (also known as a ‘cam clutches’ in industrial applications) but prices can be ridiculous, particularly for assemblies that are ‘bolt on’ options. If you are prepared to be inventive then basic ‘cam clutch’ bearings are available, but you will need to design a housing to adapt to the dyno application.
An approach widely used is the fitment of a modified PTO (Power Take Off) over-running clutch from farm equipment suppliers; they are extremely heavy duty and are fitted to farm implements such as ‘mowers’ that are driven from the tractor directly, these implements have enough inertia to cause some tractors to drive forward if they suddenly slowed down (the blade will continue to turn). The units will typically need machining to remove the internal splines to take your shaft in one side (female) and have the male sectioned machined down to fit inside your other shaft (male). The difficulty in mounting is offset by the cost, they can be found easily for less than AU$400 (we’ve seen them <$150!)
http://www.dtec.net.au/images/Dyno%20Design%20Guide/PTO%27s.jpghttp://www.tractordata.com/articles/technical/overrunning-clutch-powered.gifhttp://www.tractordata.com/articles/technical/overrunning-clutch-diagram.gifhttp://www.tractordata.com/articles/technical/overrunning-pto-clutch.htmlhttp://www.tractordata.com/articles/technical/overrunning-clutch-freewheel.gif

PTO overrunning clutches
Do not use automotive starter motor drive pinions as overrunning clutches on small dynos, they will fail! They are designed to operation for short durations (seconds) in normal use and they quickly overheat and seize. A more robust option may be to adapt one of the one-way pulleys from an automotive alternator; these are often used now on passenger sized diesel applications (and some petrol) to decouple drive forces for bearing life, less belt whip, less loading and inertial energy recovery.
An alternative option we have seen is a small custom ‘dog clutch’ designed to disengage the motor at the end of a test. It can be fairly simple design just sliding on the shaft as it sees only intermittent use.

[Yow Ling]

Heres a bit more enginge dyno stuff, they are using Datamite software which is what I have bought and customs are holding to ransom.

http://www.tdkmotorsports.com/mechdyno.html

[TZ350]

Kel is still unable to ride so the Beast stayed in the shed.

The high point for Team ESE at Mt Welly today was Gigglebuttons FXR with Glen aboard winning an "A" grade pre lim race and a bike tuned by Speedpro with Dave M riding winning the first "A" grade points round. It looks like the lap times at the pointy end of A grade are now often under 30 seconds.

The track was mostly dry for the racing but a good shower of rain in one of the races saw at least half the field drop their bikes, there was so much carnage that the race was Red Flagged, thankfully no real injures.

[wobbly]

I use a tractor PTO overun clutch as Husaberg showed above - around $150.
Cut off the splined shaft and weld the drive sprocket to that face with an additional ball race inside for support on the shaft.

[bucketracer]

271702

a dyno like this?

An old post with more interesting dyno pics.....

[husaberg]

Carrillo

Not sure it happen exactly the same these days or even the ownership is the same. I had an idea they were now part of the conglomerate that owns wiesco etc

My father still walks with a limp from a aluminum alloy rod breaking on him over 25 years ago.
So what was the engine single cylinder aluminum alloy rod. (not an Enfield either Stephen)
Virtual chocolate fish to the first correct answer.

[husaberg]

Some other Aussie ones

I guess they did read the same articles as posted above.
MMC seem to be one of the fashionable materials these days. With selected rods available for the 4 stroke crowd
http://www.mxcomposites.com/con_rod.php
The MMC calipers that AP used to do were ridiculously light.

Last picture might jog a few memories of a bucket from the past.

<img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=271739&d=1350297984" width="340px"/>
The attachment is much much clearer

[2T Institute]

Ha Ha Argo, their best rod is the one they make for Mazda Rotaries. I had a need for a custom rod they said yeah no worries we can machine one out of 4140. I asked how did you get the big and small end eyes hardened up to >62HRc ????? We don't do that we would just press in hardened sleeves from the bearing shop...................................:rolleyes:

[husaberg]

Ha Ha Argo, their best rod is the one they make for Mazda Rotaries. I had a need for a custom rod they said yeah no worries we can machine one out of 4140. I asked how did you get the big and small end eyes hardened up to >62HRc ????? We don't do that we would just press in hardened sleeves from the bearing shop...................................:rolleyes:

As do the the Cornish and Carrillo ones Lozza..............:scratch:


The interesting thing is that the MMC ones are run direct on the crank-pin.They reputedly last for a seasons racing.
So at 900 euro the $1430 NZD or $1136 Aussie beer tokens(plus vat and freight as well) those 4 strokes sure are cheap to run......



http://www.ret-monitor.com/articles/1138/metal-matrix-composite-rods/
In my previous article on the subject of con rods I asked, “Can we manage without big-end bearings?” and went on to look at the various attempts to do this and the possible future options. The article briefly mentioned the benefits of not having a bearing, and observed that there is one currently successful application of bearing-free technology being raced.
In the application concerned - four-stroke, single-cylinder race engines with ‘assembled’ cranks, where the crankshaft isn’t a single piece but is assembled with the con rod in place - there is an advantage in terms of design simplicity: the con rod can be a single piece rather than an assembly split at the big end. This means that there is neither a requirement for bolts to secure a cap, nor dowels or pins to ensure correct rod-to-cap alignment.
The con rods in question are made of metal-matrix composites (MMCs), and an early Race Engine Technology Monitor article goes into some detail regarding the properties of such materials and their application to con rods.
There are obvious advantages to using such materials for con rods, even if we can’t dispense with the big-end bearing. The low mass of the con rod means transient engine response should be improved, and indeed power output should also be improved because of the lower frictional loads due to the lighter rod. There is potentially further scope for optimisation by further lightening the crankshaft based on the lighter rod.
MMC properties are due to the addition of small particles of silicon carbide to the aluminium matrix. These additions, however, have the unpopular side-effect that the material becomes difficult to machine. This is partly why some of the more popular rods are made from near net-shape forgings.
The machining of the material is also a very specialised process, using special tooling and a high-speed machining technique originally developed by Saab. Isaksson says, “High-speed machining is one of the keystones in this process, as are the special tools being used.”
In many ways motocross is an ideal arena in which to test a rod without a bearing. The engines are simple but highly tuned, and are stripped and rebuilt regularly, giving ample opportunity to gauge the condition of the internals. The move away from the standard needle roller came because it was felt that the original big end of the rod was rather large, so there was a desire to see if the needle roller was really required. From the work undertaken, it appears that there are cases where the needle-roller may be dispensed with.
With these motocross rods running a hydrodynamic bearing, but without a shell, how long will it be before we see this technology more widely applied?

http://www.ret-monitor.com/articles/123/mmc-finds-more-motor-sport-applications/This article spotlights the properties of one specific MMC (AMC-225xe) and some of its varied uses in motor sports. These uses include pistons, cylinder liners, con rods, rocker arms, valve spring retainers and suspension uprights.AMC-225xe is 75% (volume) high-strength Aluminium-Copper alloy (AA-2124) and 25% Silicon Carbide. It’s manufacture is based in powder metallurgy techniques, and includes (a) steps to produce ultra fine (2-3 micron) particles of the metal and the ceramic components, (b) the proprietary high-energy mixing process which assures an extremely homogeneous distribution of the components, (c) the HIP-based compaction of the mixture into billets, (d) the forming of the final product (forging, rolling, extrusion), and (e) the appropriate heat treatments.Table One shows the physical properties of AMC 225xe compared to certain other high performance materials. (AlBeMet-162 (62% Beryllium), which was outlawed for political reasons several years ago, is included in the table to illustrate the extremes of MMC technology.)
http://www.ret-monitor.com/articles/wp-content/uploads/2009/05/mmc-table.jpg


Table One: Comparison of Key PropertiesCompared to 2618, the coefficient of thermal expansion (CTE) is 32% less and the thermal conductivity is about 7% greater. These properties make it clear why an MMC piston can be designed either for the same life with a much-reduced weight, for much longer survival at the same weight, or some combination of greater life with reduced weight.Several years ago, one CART team began using cylinder liners from 225xe to address a longevity problem in that highly-turbocharged application. The new liners lasted so well that they could be re-used during two rebuild cycles. Currently, a major piston manufacturer has developed a big-bore kit for motorcycle engines using a 225xe liner.One company offers a line of 225xe con rods for popular 250, 450 and 650cc single-cylinder 4-stroke motorcycle racing applications. These one-piece rods, for built-up crankshafts with roller bearings, originally came with a pressed-in steel outer race for the rollers. Next, they eliminated the pressed-in steel race and ran the rollers directly on the con rod MMC surface. The current products now run with NO rollers. The MMC big-end surface forms a hydrodynamic bearing against the journal, without any coatings.While no steady-state power gains have been attributable to the use of these conrods, there has been a dramatic improvement in transient acceleration performance. They are nearly half the weight of the steel pieces they replace, which allows the counterweighting on the crankshaft to be lightened dramatically in the rebalancing, significantly reducing the mass moment of inertia of the crankshaft. That reduction also serves to reduce the gyroscopic moment which the engine generates during yaw and roll manoeuvring. Some teams report being able to eliminate the counterbalance shaft which some of the engines use to reduce engine vibration. Drivers report that the engines-sans-balance shaft are no worse than the original setup
I have posted the last 4 attachments before but they include the use of MMC sleeves shame they are to big 68mm plus.
The cost was far more reasonable than the rods but still much more than a alloy sleeve or iron.

Sorry for choking the thread someone talk about the uniflow 100 would ya
did you see the Barker Headless above
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=263654&stc=1&thumb=1&d=1336897776http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=271739&stc=1&thumb=1&d=1350297984

[2T Institute]

Feel free to run that Vanessa , never seen a Carrilo 2T rod

[Fooman]

(AlBeMet-162 (62% Beryllium), which was outlawed for political reasons several years ago, is included in the table to illustrate the extremes of MMC technology.)

Funny use of the word political, when they probably meant "fucking good" - Beryllium is highly toxic and carcinogenic. On the nastyness scale it is very similar to brown asbestos. You would not want to do any work (i.e. machining or grinding) that would release dust or particles. Shame really, because it is a really useful alloying addition for some metals.

Cheers,
FM

[husaberg]

Feel free to run that Vanessa , never seen a Carrilo 2T rod

Sorry just has an Aprillia (roadbike) rod not ideal as its 19mm little end od, but what can you do.
When you think about it. have i seen or heard of a 2T Carrillo rod. But why the negativity towards the bearing sleeves. There would hardly be a bevel duke running around Aussie that didn't have them (other than the Mille's)


Funny use of the word political, when they probably meant "fucking good" - Beryllium is highly toxic and carcinogenic. On the nastyness scale it is very similar to brown asbestos. You would not want to do any work (i.e. machining or grinding) that would release dust or particles. Shame really, because it is a really useful alloying addition for some metals.

Cheers,
FM

Thanks I guess killing people is politically incorrect (unless they are non Americans or poor)
isn't Beryllium still used in valve seat or is it a coating only?

[speedpro]

We had a berrylium-copper tool kit for working on the radar transmitters on the orions when I was in the Air Force. Non magnetic but strong tools for working anywhere within about a foot of the Cross Field Amplifier magnets. They made magnetron magnets look wimpy. The tools came with serious health warnings regarding breakage or modification.

[Yow Ling]

OK while you guys have been debating the merits of MMC, Ive been in the shed messing with my dyno, assembled the drum tonight, very hard work for a feeble office worker. data box and bits should arrive tomorrow

271848

271846

271847

[husaberg]

your threads gone viral TZ
Av's a hit also it seems.

Someone must know something about the Barker Headless is it a uniflow?

[Yow Ling]

Someone must know something about the Barker Headless is it a uniflow?

It appears not to be a uniflow just 2 normal 2 stroke engines sharing a common combustion chamber , hence the 4 exhaust pipes

http://thevintagent.blogspot.co.nz/2010/07/mystery-racer.html

[husaberg]

It appears not to be a uniflow just 2 normal 2 stroke engines sharing a common combustion chamber , hence the 4 exhaust pipes

http://thevintagent.blogspot.co.nz/2010/07/mystery-racer.html

Not so sure but who knows about the normal configuration a few split singles had 2 exhausts (i think).
<img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=271859&d=1350297984" width="370px"/>
It appears to only have 2 crankshafts. Plus the crankcase looks narrow?. Interstingly the pic i posted came out of the classic bike mag they quoted in the replies to the blog.It looks like the blog was from NZ.


If I remember correctly (1926 is some time back) the Garelli 350 Competizione was a split single allright, but unlike the later DKW split-single racers it did not have forked or articulated conrods. The Garelli was a normal 360° (both pistons rising and falling simultaneously) parallel twin with three transfer ports in the left cylinder and two exhaust ports in the right cylinder. Both cylinders shared a common combustion chamber. Each piston commanded two carburetters. Also unlike the DKWs, the Garelli had no auxiliary pump cylinder or blower of any kind.
I do like the look of the Garelli's exhaust pipes. It is the oldest bike I know of with such modern-looking pipes. Using diffusers to promote suction was not yet common practice then, and adding end cones would be regarded as revolutionary 26 years later! But I suspect that neither the exhaust timing nor the blowdown time.area of the Garelli did the end cones much justice; they were probably shaped like this just to accomodate the fish-tails.


<img src="http://coskys0.tripod.com/VintageMotorcycles/89afaa00.jpg" width="410px"/><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=253649&d=1324799993" width="370px"/><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=253650&d=1324799993" width="350px"/>



The Garelli is a real oddball split single. Most are tandem cylinders with either two rods or a forked rod. the garelli is side by side with a very long gudgeon pin. You're looking at the right hand cylinder which has the inlet ports at the bottom and two exhausts - one at the front of the cylinder and one at the back. No problems doing that as the transfers are all in the other cylinder.
So - sucks in on the right hand pot, transfers in the left hand one from a common crankcase , common combustion chamber , exhausts from the right hand pot as it's transferring fresh mix up the left barrel.....
Wob would approve of the long blowdown possible - and the uncontaminated fresh charge.
Frits - I see we overlapped - no factual differences which is pleasing - and no, I'm not old enough either.

[TZ350]

OK while you guys have been debating the merits of MMC, Ive been in the shed messing with my dyno, assembled the drum tonight, very hard work for a feeble office worker. data box and bits should arrive tomorrow

271848 271846 271847

Its great to see this project coming along, with all these dynos being built, Buckets is getting serious.

[TZ350]

271866

I have been using EngMod2T to try and develop a new engine plan that will give lots of over rev but I get this shape of graph and it is something I have seen on the dyno too.

There is a power peak and then the beginings of another peak, whats that about? I have tried different exhaust/transfer and inlet STA's and opening points. The changes move the second peak around but nothing I have tried blends the two into the one long curve that I want.

271867

I suspect the pipe, the header and diffuser sections are in the ball park %%% wise but are they too steep? What should they be.

[Brian d marge]

OK while you guys have been debating the merits of MMC, Ive been in the shed messing with my dyno, assembled the drum tonight, very hard work for a feeble office worker. data box and bits should arrive tomorrow





I hope the drum will be mounted to the frame, a little bit stronger , Im not sure what you have in ming , and I couldnt see it from the photos

Stephen

[wobbly]

The pipe is a complete mess both % wise and taper wise - not even close to being too steep - as an Aprilia pipe is 124 or so diameter.
And expecting an engine to make serious power up at 14,000 with a 196 Ex port is a "pipe "dream.
The dip in power is due to a big mismatch in spec,that is synergistic at some points , but self cancelling at others.

[Neal]

Where can I read some info on squish area ratio ? I have ordered some vhm heads and would like to experiment with them . What is the best compromise - 50% ? 40% ? 30% ?
Thanks

[F5 Dave]

Dentist drill update

Well I've made an interface using an old bit & a washer welded to it & grind to shape. It drives well.

The weak point is the bevel drive inside the dentist unit so I'll have to be careful not to get it hung up or push too hard. But so far it is a success & quite easy to use, these cheapo bits seem to work well in the liner so when I have time I'll lower the transfers, but first tickle up worked well & seemed to shift some material.

something a bit like this, price seems to have gone up, but the free shipping helps. Avoid ones with too small a bits.

http://www.ebay.com.au/itm/Dental-Low-Speed-Handpiece-Contra-Angle-Latch-E-type-/160757338552?pt=LH_DefaultDomain_0&hash=item256de251b8


[edit] Spent a couple of hours yesterday lowering some transfers 1.2mm & it worked a treat. I did bit side at a time in case it failed, but was still going strong & happy with the result. I just noticed this morning a bit of a ridge at the interface of the cut but I'll bend a riffler a bit more to ride that bit off.

They may or maynot have a limited life, but they are cheap enough, its a pity there isn't an easier way so you could replace the heads in case one wears out as you could buy a set of 3 for $78. the way I have it I'd have to make some careful cuts & reweld.

[wobbly]

Short answer re squish in a race engine - 50% and the minimum clearance just short of the piston hitting when in overev.
ie 0.65mm in a 125 is safe at 14500.
I have seen a 100cc ( 50 by 50 ) with 0.45mm rev to 16000 and not hit.

[ief]

I was under the impression mr. Darcy knows his stuff as well...

and was curious what the exhaust did on my sim. Not to shabby if you ask me, red line is the last (I think, bin a while) exhaust I 'made'.

edit, one more try, shortened the mid a couple of cm's... darcy2

[F5 Dave]

Not wanting to take this too far off track, but a true story & I wonder if you could Sim this?:


This morning I was sitting on the throne waiting to ablut :pinch: (if that is a bone-fide shortening of the word ablution - and I'm Verbing a Noun) either way I felt a sneeze coming on.

Ah
Ah
ACHOOO. instantly followed by Bududududduda.:blink:

Oh, I guess I'm done.:confused:

So the exhaust port was opening but just preceding this event the intake was violently expelling a pressure relief, but still there was pressure to expel the exhaust charge.

It was most confusing.

[TZ350]

shortened the mid a couple of cm's... darcy2

Good tip, I will try it.

[husaberg]

Not wanting to take this too far off track, but a true story & I wonder if you could Sim this?:


This morning I was sitting on the throne waiting to ablut :pinch: (if that is a bone-fide shortening of the word ablution - and I'm Verbing a Noun) either way I felt a sneeze coming on.

Ah
Ah
ACHOOO. instantly followed by Bududududduda.:blink:
Oh, I guess I'm done.:confused:
So the exhaust port was opening but just preceding this event the intake was violently expelling a pressure relief, but still there was pressure to expel the exhaust charge.
It was most confusing.

I disagree. I fact i think you are talking shit.:yes: Was that your Friday musical interlude?



The dip in power is due to a big mismatch in spec,that is synergistic at some points , but self cancelling at others.

This mismatch is seen in some highly tuned 4 stokes with sometimes 3 sets of peaks and throughs.All corresponding
It is this reason i believe you see interesting things like the 2 different bell mouth lengths on Honda CBR400r's which is if i am not mistaken is the factories attempt to mitigate/Balance the resonance effects. compromise.
I seen somewhere where they tried for short bell mouths and then 4 long ones results the to top end and bottom power were as expected, but the peaks and through moved and got larger as well.

[TZ350]

271935

Took another look at the Carb tonight.

271937

Machined the front off and lost 8mm from the total length.

271936

And fitted some Keihin 393 series main jets, now I have an easily changed air correction jet and instead of a pilot air screw I am going to use another Mikuni main jet.

Unfortunately it looks like, with the jets sticking out like that, they are going to disrupt the air flow and I will need to counter sink them into the bellmouth.

271934

By loosing the pilot air screw and blocking the pilot side off from the air correction side I can fit an air solenoid to bring in additional air correction at max revs. The objective is to maintain the correct air/fuel ratio and prevent things from becoming to rich during over rev.

Or the soleniod could be used for a little bit of water injection to cool the incoming air/fuel mixture.

[husaberg]

http://www.jetsrus.com/FAQs/FAQ_identify_that_jet.htm

But any small allen headed bolt Alloy and a Number drill bit.
http://www.nitrous.info/images/jetdrills-pipes/jet-drills.jpg
http://www.trademe.co.nz/building-renovation/tools/hand-tools/drills/auction-524115307.htm
http://www.trademe.co.nz/toys-models/models/tools-supplies/auction-523651806.htm

28mm PWK needles
http://www.jetsrus.com/a_jets_by_carburetor_type/needle_keihin_N427-46.html

[Frits Overmars]

....Or the soleniod could be used for a little bit of water injection to cool the incoming air/fuel mixture.You'll find that water is quite stubborn; it is too thick to flow through small orifices. But you can reduce its surface tension by adding a few drops of washing-up liquid. Just don't let the missus catch you, or you'll be doing the dishes for the rest of your life :shifty:.

[TZ350]

You'll find that water is quite stubborn; it is too thick to flow through small orifices. But you can reduce its surface tension by adding a few drops of washing-up liquid.

Thanks for the tip.

[ief]

Not sure how the actual carb looks but could adding something like the green help raising the resonance higher up without disrupting flow?

[TZ350]

could adding something like the green help raising the resonance higher up without disrupting flow?

271973 271972

I have tried that, it worked OK and made good power but I found that it was hard to get the overall length shorter.

271974

The taper bored OKO carb has worked out a bit better on the dyno.

[ief]

I have tried that

Figures ;)

[TZ350]

271934
I can fit an air solenoid to bring in additional air correction at max revs. The objective is to maintain the correct air/fuel ratio and prevent things from becoming to rich during over rev.

Recently I tried a 30mm carb to see if it would make any more power than my 24, it didn't but the 30 did show a little better over rev. The engines inlet when fitted with the 30mm carb would have had a different resonant response compaired to the 24 and possibly by luck the 30 may also have had a better fuel curve.

By shortining the 24 and adding the air correction jets I hope to increase its resonant level and also be able to more accuratly dial in its fueling curve.

272011

As a two stroke is basically a resonant system I would expect the ideal torque curve from a perfect engine to be bell shaped and symmetrical about the point of maxima.

In a real engine things like increasing friction with rpm, carb richining with increasing air flow and different natural frequencies of components can change the picture.

272013

These resonant differences could be used to advantage to strech or bend the curve but the highest peak will be obtained when they all work together.

Because power is torque times rpm the power curve won't be symmetrical or flat unless the torque curve is distorted in some way.

271978

If you look at the 30mm carbs torque curve (Blue line) between 10 to 13K it appears fairly symmetrical and I am sure the 24mm carb (Red line) can be adjusted to match it by improving the fuel curve with air correction and/or shorting the inlet tract to raise the resonant response of the inlet system to match that of the 30.

[TZ350]

Some of Blairs thoughts on the important features in an expansion chamber.

272017

I have been wondering about the static working pressure inside an expansion chamber but I did not see the answer there that I am looking for.

Clearly in a well tuned engine the pipe is at the right internal working pressure around peak torque, but does it continue to build up as the revs climb? And if it builds up, is high internal pipe pressure one of the things that stifles the torque curve on over rev.

Certainly reducing the pipes internal pressure on low throttle openings is a good way to avoid detonation during overrun into a corner or just trickling around the track.

So now the big question is, can we also get more over rev by moderating the working pressure in the expansion chamber?

[husaberg]

First bit i see you ran the 30mm Carb Rob, but why so small...... why not at least a 34mm?

Here is some real Aronak stuff the intersting things in there for me was the Rat and Mouse trap carbs discussed ages ago.
Plus the Stewart precision carb. Which is a very intersting concept that i had never seen
Lastly it is interesting that nearly all the current carbs owe much to the humble Villiers carb from the 1920's.Origionaly made by Mills.
<img src="http://www.andybuysbikes.com/images/Bike%20images/BSA/5380bsa/The%20Mills%20carburettor.jpg" width="308px"/><img src="http://www.users.globalnet.co.uk/~pattle/nacc/arc0596i.jpg" width="390px"/><img src="http://www.users.globalnet.co.uk/~pattle/nacc/arc0596n.jpg" width="320px"/>


STEWART MODEL "25" CARBURETOR USED ON DODGE BROS. CAR
This carburetor is a metering valve, expanding type. The air and fuel are both metered by a combination of the metering valve and metering pin.
It is located on the left-hand side of the engine and is fed from the vacuum tank on the engine.
Construction
Float chamber: Fuel enters the carburetor at (A), passing up through the strainer (B), into the float chamber (C), through the needle valve (D). The valve (D) is actuated by means of the float (E), operating through the counterweight levers (F).
As the fuel flows into the float chamber the float rises and, acting against the levers (F) forces the needle valve down and closes same.
As the float rises the valve closes until the float reaches a certain predetermined level at which the valve is entirely closed.
1 From instruction books of Stewart carburetor issued by the Detroit Lubricator Co., Detroit, -Mlich. (manufacturers).
If the float falls below this level, because of the diminishing supply of fuel in the float chamber, the valve is automatically opened and more fuel is admitted to bring the level up to correct height.
From the above it will be seen that the float chamber constitutes a reservoir of constant supply, in which the height of fuel is always at the same level. This contributes to efficient metering.
Dashpot chamber: From the float chamber the fuel flows through passage (G) into the dashpot chamber (H). It also passes through the holes (I) in the valve piston into the central space (J) which surrounds the tapered metering pin (W).
The metering valve has a piston (L) at its lower end and which operates in the dashpot chamber.
The object of the dashpot is to improve the performance of the carburetor by steadying the action of the metering valve during acceleration and low speed operation of the engine.
Name of Parts
A, fuel supply inlet; B, strainer; C, float chamber; D, gasoline needle valve; E, float; F, counterweight levers; G, gasoline passage; H, dashpot chamber; I, gasoline passage; J, gasoline passage; K, dash adjustment lever; L, riashpnt piston; M, metering valve head; N, metering valve stem; 0, as-pirating tube or nozzle; P, primary air passage; Q, metering valve seat; R, mixing chamber; S, fuel metering orifice; T, metering pin rack carrier; U, adjustment lever clamp screw ; V, adjustment screw; W, metering pill; X, gear housing; Y, pinion shaft; Z, low throttle stop screw; AA, strainer plug; BB, air inlet; CC, throttle valve.
The metering valve consists of a conical shaped head (M), CC stem (N), and piston (L). This is the only moving part in the carburetor proper. It slides up and clown in its guide, formed in the body of the carburetor. The upper part of this valve contains a jet or nozzle (0) and primary air openings (P).
When the engine is at rest, the conical head of the metering valve seats in the carburetor body at (Q). When the engine is running, however, the metering valve is always floating in some higher position, thereby forming an annular or ring-shaped air opening between_the conical head and its seat (Q).
Fig. 1. Stewart model "25" carburetor, 1" size, with rack and pinion dash adjustment used on Dodge Bros. car. Side, or horizontal outlet.
1261
Action of Carburetor
The action of the carburetor is as follows: The suction created by the down-ward stroke of the engine pistons draws air into the mixing chamber (R) through the primary air openings (P). The same suction draws a fine spray of atomized fuel from the nozzle (0) into the mixing chamber. The air thus mixing with the fuel forms a combustible gas for the engine. As soon as the engine begins to rotate, the metering valve lifts sufficiently to allow the main air supply to pass into the mixing chamber between the conical A head (M) and the seat (Q).
Fuel is metered in an annular shaped orifice near the center of the valve at (S) passing between the valve and the tapered A A portion of the stationary metering pin (W). As the metering valve lifts into the higher positions, it gives increasingly larger fuel openings due to the lifting of the valve away from the tapered metering pin, also larger air openings due to the
<img src="http://old-carburetors.com/images/1927-Dykes/1927-caburetor-030_600.jpg" width="530px"/><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=272025&d=1350726025" width="541px"/>
<img src="http://i.ebayimg.com/t/Dodge-Brothers-1920s-Stewart-Carburetor-/00/s/MTIwMFgxNjAw/$T2eC16FHJIkE9qU3iLdcBQb5RrmdQw~~60_57.JPG" width="370px"/><img src="http://i.ebayimg.com/t/Dodge-Brothers-1920s-Stewart-Carburetor-/00/s/MTIwMFgxNjAw/$(KGrHqNHJB8F!jcB3oF2BQb5RiFdd!~~60_57.JPG" width="370px"/><img src="http://i.ebayimg.com/t/Dodge-Brothers-1920s-Stewart-Carburetor-/00/s/MTIwMFgxNjAw/$T2eC16NHJHoE9n3Kd2kKBQb5RdLi(g~~60_57.JPG" width="370px"/>

[TZ350]

First bit i see you ran the 30mm Carb Rob, but why so small...... why not at least a 34mm?

Interesting info on carbs Husa.

The 30mm Carb fitted without having to modify any part of the inlet tract, making it easy to swap back to the taper bored 24.

[bucketracer]

I discovered the 135mm inlet rule of thumb on a TM125 MX engine used for 125 class kart shifter racing .

That length is for a reed - the RV needs to be alot shorter again.

Wobs comment on inlet tract length.

[bucketracer]

And Just for you TeeZee I waded back a hundred pages or so and collected up Wobs comments on setting up 2-Stroke carburation.


Lambda is not a reliable tool for any length of time in a 2T.
The heated ones last a bit longer but no matter what probe type is used they get contaminated and don’t read correctly in a very short time frame.

EGT is very simple.If you find peak power at say 1240* ,and know what the RAD was on the dyno, then its easy to construct a jetting pattern.

Every 3% rad = 1 jet size in a Kehin or Dellorto that use metric sized jet holes.

Always start on the rich side and jet down to the set EGT.

Best example I can give was at Vegas World Kart Champs. In practice we went down one or two jets every run - as long as we saw a temp rise around 50* per jet,and the ground strap mark was clean at 3/4 length, then we were making more power.

At RAD 101 we had 1260, going one more only raised egt about 20* so NFG going there.
This was a 162 jet before we changed.

On qualifying morning it was cool and RAD104 - up one jet to 165 and we saw 1255 - on the money, qualified 2nd by 0.003 sec.

First race after lunch was RAD98, down 2 jets, won the first heat easily and saw 1265* and immediately were accused of cheating,for blitzing the Yank Champ down the shute..
He hadnt jetted down enough for the hot afternoon RAD change.
Its that simple,once you have a baseline.
You can use the egt and the CHT as well, but thats another story.


Have tried the remote hose to the Lambda thing and although the probe lasted better it was slow responding to the extent that it is impossible to log the Lambda output against rpm/Hp on the printout.

The reading I think was about 2000 rpm behind the engine when accelerating at 300 rpm/sec.

Dynojet has an expensive add on kit that uses a pump to draw the gas thru a tube that goes in the muffler, this has a filter element in it so should make the probe reliable.

But it doesnt work on a 2T - even apart from having something affecting the test by altering the outlet area of the muffler itself..
I have seen one Dynojet session where the customer had to pay for 2 probes in a 4 hour test cycle. NFG.

Re using EGT and CHT.
The only probes that are worth shit come from Exhaust Gas Technologies.They guarantee them for 2 years,and I have had no problems since changing to them.

They sell probes to Nascar/IRL/F1/MotoGP teams with a guarantee - the only guys to do this with exposed tip,high speed temp sensors.
The company sells Digatron gauges on Ebay,and having just started to use one with 2 screens and 5 functions - im sold.

The ones sold by Mychron etc for kart use are crap, seen several brand new setup last two laps.

Using the two gauges together,especially if you have say a Digitron data logging gauge,makes jetting much easyer.

Basically when the jets are rich, both egt and cht will rise then fall together,when doing a full throttle all gear run.
You can keep dropping jets and be sure that all is well as long as they both rise together - with the one caveat I stated above.

One Keihin main jet size should lift the egt around 50*F, if you only get 20* rise from a previous jet then what is happening is this. There is only "x" amount of energy in the fuel ingested.This can end up in the trapped, expanding gas - making power.

It can end up in the water, via the head and cylinder wall,and depending upon the com or ignition point,alot simply exits the port and heats up the pipe.

BUT - as soon as you go overly lean,the combustion pressure/temp gets to a point where instead of heating the combustion charge, the flame front starts creating free radicals.

This uses a huge amount of the available energy,and instantly the egt drops.

Once free radicals have formed,they keep the process going,causing destructive deto to get worse and worse - thus the egt drops thru the floor.

You need exposed tip,fast probes to see this quick enough to save the engine.

Thus on the gauge,the CHT keeps rising fast,but the EGT slows and can drop down again.

In the above example I gave, the egt only rising 20*F pointed instantly to the fact that we were approaching deto point.

By watching the two temps track upwards together it is real easy to get a handle on what the engine wants, to make peak power - just short of deto.


CHT is dead accurate on a watercooled head as far as the rising temp is concerned.

The washer reads the heat load into the plug,its a bit slower than on an air cooled engine but the data is still valid.

More important is the fast response needed for EGT tracking,so you see immediately the temp slowing and then dropping when deto sets in.

The A/F meter is no different than the Lamda readout - the sensor soon dies due to contamination of the sensing surface.NFG.

The last injection setup I worked on we built an interface for the ECU that converted the EGT reading to the Lambda scale that the computer recognised.
This worked well on a Jetski setup,that is usuall all go or none.


You must take into consideration the fuel being used, and how the factory engineers approached the problem.

Unleaded ( FIM that needs gloves and a respirator ) will go to 15:1 but must be run VERY rich to achieve best power with that level of com.

Leaded was run up at 19:1 in GP engines and at the end of the day the result was that the advance curves changed very little.

The big advance was in using the powerjet solenoids.

The unleaded scenario uses BIG powerjets ( 60 + ) to turn off the rich mixture past peak power.
The leaded setup was very lean at peak power, so only needed small ( 35 ) powerjets to keep the pipe temp up, over the top of the pipe.

Later of course that bastard Thiel came along and did the clever thing of PWM controlling the powerjet, thus even closer continuously matching the A/F ratio to the pipe temp needed for max power.


The issue that your test doesn't address, is that with pump gas you may be able to get away with 13:1 com.

With AvGas its just starting to work properly at 15:1 and this attribute will always far outweigh any advantage flame speed or whatever may be contributing from the pump gas scenario.

The other issue is that unleaded fuel works best with plenty of advance, no com, and rich as hell.
AvGas loves com, loves running lean and hates advance, so you need to spend days on the dyno just optimising for the fuel.


Using a 10 plug there is 0.2 cc in the plug hole. When drawing a chamber in CAD, with a straight line across where the threaded hole would be, you add 0.2 cc to the calculated vol. A 9 series I would say was closer to 0.3cc.


Yep Mitre 10 is the simple answer to easy access to Acetone.
About a cup full in 5L does the job in AvGas.

Re the powerjet sizing the answer is NO NO NO.
Cant be bothered now but work out the AREA of a 160 main and subtract the AREA of a 0.35 powerjet.


Area 1.6 main = 2.010, less area 0.35 = 0.0962.
Main jet should now be 1.56,closest is 1.55 with the powerjet .
Try this without switching first to check equivalent egt to original setup.


Matters not how the best temp was derived, on track or on the dyno.
With the gauge running and say a 180 main, then going down to 178,if I only see a small increase in temp ( 20*F) then that instantly means that more heat energy is being used somewhere - not in heating the Ex gas to make power.

If the original temp was 1240, then that will be the ref temp for any air conditions on any day.
With the example I gave we had a 3 jet spread during the day, a very cool dense morning, and a very hot dry afternoon.

In both cases the egt settled at around the same mark. One jet leaner and we would be in the danger zone - one richer and we wouldn’t be the fastest by a mile as we were.



Each engine is different but if a setup has the optimum com and the timing in the ballpark of 15* at peak power, then Avgas or leaded racegas around the equivelant RON
will always be maxed out at around 1250* - @ 150mm min from the port.

Unleaded likes to be alot richer and makes more power with more advance so that setup makes best power at around 1050.

Not enough com or advance, and the peak safe egt will rise, but power wont, it will just rev on more due to the higher wave speed. But you still have it wrong about the air on the day.

You can jet to get the optimum egt, no matter what the RAD says, and it will be in the same state of tune - just using all the oxygen in the air available and mixing it with the correct amount of fuel.

On a hot day,or low Baro, it will hit 1250 but simply make less power, due to less oxy and thus less fuel = less BTUs burned.

The 400 F3 we thrashed on the dyno and at 12,000 held by the dyno for around 30 secs it settled at 12000* F - 96 Hp with no fade.

Thus this is a good safe baseline for the new owner who may not have the tuning smarts to determine what is good or not - but if he has to change jets 3 times during a day to see 1200 then he will be well on the way to learning what to do.

[Yow Ling]

http://www.youtube.com/watch?v=3aiyD9AxXqw

500cc flat 4 2t from 1942, homebuilt by Denny Jones

[husaberg]

500cc flat 4 2t from 1942, homebuilt by Denny Jones

Nice video Mike. Unfortunately the post war ban on supercharging limited it's use a bit though. So he build some 4 cylinder Diesels, like this one, afterwards.

[husaberg]

Question for the panel
has any one ever done any research on other means of creating (a non engine related) positive wave or indeed negative wave to extend the effective rev range of a pipe. I am thinking of some alternate way of generating a pressure wave to argument the Kadenacy effect over a wider rev range perhaps possibly i don't know just musing acoustically?
But there would probably be other ways as well i assume
I understand 170 db is around 1psi
183 db is 6psi or their about's
193db is around 14psi

i realise it is likely unrealistic, but has anyone tried?
Blame a LPG powered bird deterrent cannon for this question.

PS does Frits have an update on the trombone pipe he posted earlier?

While i was having a poke around the net i came upon this http://en.wikipedia.org/wiki/Pressure_wave_supercharger


A pressure wave supercharger (also known as a wave rotor[1]) is a type of supercharger technology that harnesses the pressure waves produced by an internal combustion engine exhaust gas pulses to compress the intake air. Its automotive use is not widespread; the most widely used example is the Comprex, developed by Brown Boveri.[2] Ferrari tested such a device during the development of the 126C Formula One car. The system did not lend itself to as tidy an installation as the alternative twin-turbocharger layout, and the car was never raced in this form[3]. A more successful application was in the RF series diesel engine found in the 1988 Mazda 626 Capella; ultimately 150,000 Mazda diesel cars were fitted with a Comprex supercharger. Other users included Peugeot and Mercedes-Benz. The Greenpeace SmILE concept car uses a Hyprex pressure wave supercharger developed by the Swiss company Wenko AG.[2] NASA uses wave rotors in experiments attempting to increase gas turbine efficiency. The wave rotor is placed between the compressor, combustor and turbine sections in order to extract more energy from the combustion process
PrincipleThe process is controlled by a cylindrical cell rotor whose speed is synchronised with the engine crankshaft speed via a belt or chain. Individual cells alternately open and close the exhaust gas and fresh air apertures, when the aperture on the exhaust gas side is reached pressurised exhaust gas flows into the cell and compresses the fresh air there. As the cell rotor continues to rotate and reaches the aperture on the inlet side the compressed air flows to the engine. Before the exhaust gas can flow the aperture is closed again and the exhaust gas column is reflected before entering the engine. The exhaust gas exits at high speed sucking further intake air into the cell behind it repeating the process.

[edit] AdvantagesEnergy exchange in the pressure-wave supercharger occurs at sound velocity, resulting in good response even at low engine speeds, a common downfall of turbocharged engines. It combines the advantages of mechanical and exhaust gas supercharging.

[edit] Control systemA control system, to optimise performance, was patented in 1986 by Hachiro Aoki for Diesel Kiki Co. Ltd., Tokyo, Japan - United States Patent 4563997.[6]



well not exactly what i was looking for i found it interesting and i had never heard of the concept

oh Swissauto that rings a bell.....

[Yow Ling]

Heres an interesting thread on machining 2T stuff, covers resleeves, honing and other interesting stuff

http://forums.everything2stroke.com/threads/49513-How-It-s-Done-Trade-Secrets-inside?

[Bert]

Heres an interesting thread on machining 2T stuff, covers resleeves, honing and other interesting stuff

http://forums.everything2stroke.com/threads/49513-How-It-s-Done-Trade-Secrets-inside?

What a gold mine.. well worth reading.

[richban]

Yes I know this is a 2 stroke thread but I did say to Rob I would post the latest results from the dark side.

So here it is. Almost 2hp above the old fast engine. Lots to still do. I ran out of needle options so could not fix the hole at 8. I will try make a new needle today.

Also running the stock FXR ignition at this point so will be looking at the ignitech after I get a EGT and CHT Gauge.

But happy for now.


272215

[F5 Dave]

I imagine that torque curve would look entirely different if run up on a dynojet, far less dippy.

Funny how the Dyno Dynamics SW designers decided that the most important feature was a Max HP reading in a big box. Yet ease of storing of files wasn't a key feature.

[kel]

Almost 2hp above the old fast engine.



Damn who would have thought 27hp at 11k from a diesel. You'll be up for the first round of the NI series? I sure would like to see a true back to back on the ESE dyno.

[richban]

I imagine that torque curve would look entirely different if run up on a dynojet, far less dippy.

.

Thats the fuel ratio. he he.

[richban]

Damn who would have thought 27hp at 11k from a diesel. You'll be up for the first round of the NI series? I sure would like to see a true back to back on the ESE dyno.

Yeah back to back will tell the true story. I will try to come up. 27 at 11. What at 13? Lots of work to do. There should be power at the limiter so something is holding it back. Could be the stock ignition could be fueling. Will se with more time.

[TZ350]

... 27 at 11. What at 13?

Its looking good, my pick is, 27+hp @ 11 and at least 6k useable power spread when its sorted.

Maybe Rich will get 28-29 with a few more rev's, very much impressed.

[FastFred]

Damn who would have thought 27hp at 11k from a diesel.

and more to come too by the looks of it.


My opinion is that a 28PS 25 NM air cooled two stroke 125 would currently clean up in NZ buckets.

TeeZee has been talking about whats needed for a while now and has been showing the way.

Its only my opinion SS, but I think you might need to raise your sights a bit.

[Grumph]

and more to come too by the looks of it.



TeeZee has been talking about whats needed for a while now and has been showing the way.

Its only my opinion SS, but I think you might need to raise your sights a bit.

I'm starting to come to the belief that the limiting factor in air cooled 125 development may be the ability of an iron linered barrel designed for a commuter bike to handle the heat rejection levels required for those power levels.

i suspect both Frits and Wob may agree - Frits has said something similar I thnk.

A safe level may actually prove to be around 27 - 28 hp....unless you go to fan cooling....
Short dyno sessions are just that - races are actually quite different.

[husaberg]

and more to come too by the looks of it.



TeeZee has been talking about whats needed for a while now and has been showing the way.

Its only my opinion SS, but I think you might need to raise your sights a bit.

he started off mouthing with 24hp that was ample i think.

I'm starting to come to the belief that the limiting factor in air cooled 125 development may be the ability of an iron linered barrel designed for a commuter bike to handle the heat rejection levels required for those power levels.

i suspect both Frits and Wob may agree - Frits has said something similar I thnk.

A safe level may actually prove to be around 27 - 28 hp....unless you go to fan cooling....
Short dyno sessions are just that - races are actually quite different.

http://i.ebayimg.com/t/HONDA-ODYSSEY-FL250-FL-250-DG-SUNBURST-RADIAL-FIN-HEAD-BIN-10-24-/00/s/MTIwMFgxNjAw/$(KGrHqZ,!l!E-cYNe5ERBPqzvf(KoQ~~60_35.JPG<img src="http://t0.gstatic.com/images?q=tbn:ANd9GcS8MGub88EB96pNTaWGRY4YHGr0jlyUK i4pzX0f4SjuFDbtisCRKypl8UCt" width="295px"/><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=257856&stc=1&thumb=1&d=1329473248" width="165px"/><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=257848&d=1329471869" width="328px"/>
Dt175 which are common were similar head plus many others too i guess. that would be legal as well.
My iron Villiers had the fins turned off and alloy fins shrunk on. Yeah i know not ideal but neither was the iron cylinder either........

The AJS porcupine, well you can guess what the finning was like can't you.....
[R RATED]http://img142.imageshack.us/img142/672/p2090005mq7.jpg[/R RATED]

A lot of the 50's works bikes had a very very high proportion of Silver in them too.....

[bucketracer]

Yeah back to back will tell the true story. I will try to come up. 27 at 11. What at 13? Lots of work to do. There should be power at the limiter so something is holding it back. Could be the stock ignition could be fueling. Will se with more time.

Might be only one 27hp FXR at the moment but now the 4-stroke boys have the formula you can bet there will be some more high powered 4's soon.

Good effort.

[bucketracer]

I'm starting to come to the belief that the limiting factor in air cooled 125 development may be the ability of an iron linered barrel designed for a commuter bike to handle the heat rejection levels required for those power levels.

....unless you go to fan cooling....


272245
I cant immediately remember who, but near the beginning of this thread there was someone who tried to mock TeeZee http://www.kiwibiker.co.nz/forums/images/smilies/nyanya.gif for all the copper and his idea of using cpu heat sinks and fans for extra cooling I guess they were wrong.

[Kickaha]

I'm starting to come to the belief that the limiting factor in air cooled 125 development may be the ability of an iron linered barrel designed for a commuter bike to handle the heat rejection levels required for those power levels.

Would fitting an alloy liner and nicasil coating it be better then?

[bucketracer]

272240

I have already talked about sleeves with side exhaust ports as a way of improving ring and piston reliability


Would fitting an alloy liner and nicasil coating it be better then?

I think TeeZee is very interested in trying that.

Maybe if the alloy sleeve was extra thick the outside surface area would be big enough to transfer enough heat to the fins to keep the area around the exhaust port window cool.

[husaberg]

I cant immediately remember who, but near the beginning of this thread there was someone who tried to mock TeeZee I guess they were wrong.

I must admit Avril Lavigne helped a little bit with the lyrics...........

Ode to the scooterboy
TZ was a Man, SS was a Scooterboy..... Can I make it anymore obvious?
TZ was a tuner, SS did ballet What more can I say?
TZ wanted hp, And he'd Alway’s say, Secretly SS wanted hp as well…
But all of ESE friends, stuck up their nose as They had a problem with SS's scooterboy's derogatory prose....

SS was a Vespa boy, ESE said, "See ya later boy" SS wasn't well behaved for here,
SS had a Few idea’s But her head was up in space SS needed to come back down to earth...

Five years from now, SS sits at home... Stoking his Vespa, SS's is all alone....
SS turns on Computer, guess who he sees... TZ350 rocking up the thread with Team ESE
SS calls up his only friends, they already know And they've all got tickets to see TZ’s 30 hp ESE show....
SS tags along, snipes From afar and Looks up at the man that SS tried to tune down.

SS was a Vespa boy, Everyone said "See ya later boy" He wasn't good enough behaved for here ,
now he's a German Gaypornstar....Slamming on about his Lambertta.
He gets talked about, like he deserves anyone see what he's worth?
Sorry SS, but you missed out Well, tough luck, That boy's got 30 hp now has good friends.....
This is how the story ends

It's bad to see Scooterboy for the annoyance that Scooterboy could be.
There is more that meets the eye There was no humility that is inside
He's just a Scootertoy and the whole world can see.

Can I make it anymore obvious? He, himself is his only love, But he'll gladly share How he rock’s the scooter world?
Alone for the scooter boy, Everyone said "See ya later boy" He'll be backhome after the show,
TZ be at a workshop Singing the song I wrote About a Lamberetta girl we all used to know.

<img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=259007&d=1330681681" width="340px"/>

[richban]

I must admit Avril Lavigne helped a little bit with the lyrics...........

Ode to the scooterboy
TZ was a Man, SS was a Scooterboy..... Can I make it anymore obvious?
TZ was a tuner, SS did ballet What more can I say?
TZ wanted hp, And he'd Alway’s say, Secretly SS wanted hp as well…
But all of ESE friends, stuck up their nose as They had a problem with SS's scooterboy's Narcissistic drones....

SS was a Vespa boy, ESE said, "See ya later boy" SS wasn't good enough for here,
SS had a Few idea’s But her head was up in space SS needed to come back down to earth...

Five years from now, SS sits at home... Stoking his Vespa, SS's is all alone....
SS turns on Computer, guess who he sees... TZ350 rocking up the thread with Team ESE
SS calls up his only friends, they already know And they've all got tickets to see TZ’s ESE show....
SS tags along, snipes From the crowd and Looks up at the man that SS tried to tune down.

SS was a Vespa boy, Everyone said "See ya later boy" He wasn't good enough for here, now he's a German Gaypornstar Slamming on about his Vespa.
Does anyone see what he's worth?
Sorry SS, but you missed out Well, tough luck, That boy's got 30 hp now has good friends.....

This is how the story ends
It's Too bad that everyone could see Scooterboy for the annoyance that Scooterboy could be.
There is more that meets the eye There was no soul that is inside
He's just a Scootertoy and is still just a pill.

Can I make it anymore obvious? He, himself is his only love, But he'll gladly share How he rock’s the scooter world?
Alone for the scooter boy, Everyone said "See ya later boy" He'll be backhome after the show,
TZ be at a studio Singing the song he wrote About a Scootergirl we all used to know.

<center><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=259007&d=1330681681" width="740px"/><center>



While I appreciate the effort. Shouldn't you not be spending all available time building a motorcycle? I think you may have started before me and I am going racing on Sunday.;)

[Bert]

While I appreciate the effort. Shouldn't you not be spending all available time building a motorcycle? I think you may have started before me and I am going racing on Sunday.;)

I was thinking the same thing Rich.
I've built mine, raced it & blown it up and rebuilt it (and also now on its second colour scheme).
Sad thing not being able to go racing on sunday (after all the prep and hard work mainly by crazyman to make it)....:angry2:

What's actually holding things up Husa? is there some way we might be able to help?

[wobbly]

You know very quickly if an aircooled is thermally limited.
The power fades very quickly,and can be seen even doing an all gear run on the inertia dyno.
I spent 6 months testing pipes for KT100, and it was easy to make around 20 Hp, but this would drop 2 secs a lap as soon as it got hot, ie 2 laps.
You had to wind in fuel to cool it - not make power.
I ended up searching for power band width, pumping up the bottom end and overev power, keeping the peak well supressed to prevent the power fade from affecting lap times.
Ive sold over 2000 of those pipes now, and so far no one has bettered them on track.

[F5 Dave]

he started off mouthing with 24hp that was ample i think.
.....
Actually currently 24hp is ample to be competitive. I topped 1st qual at the GP with 24 (actually it was 1 or 2 less than that on the day) & it is about what young Nat was holding with his Dads Derbi (less with his) & looked to do the biz.

But clearly more is better.

[kel]

Actually currently 24hp is ample to be competitive.
Competitive maybe, complacent definitely.

[F5 Dave]

oh for sure, the right rider on the right bike with more mumbo is a shoe in, just that hasn't consistently happened. Yet. If for example Nige wasn't self employed it would have been a regular feature.

[FastFred]

Competitive maybe, complacent definitely.

Absolutely


oh for sure, the right rider on the right bike with more mumbo is a shoe in, just that hasn't consistently happened. Yet.

"Yet" but who wants to bet that it won't.

[husaberg]

While I appreciate the effort. Shouldn't you not be spending all available time building a motorcycle? I think you may have started before me and I am going racing on Sunday.;)

The trick is don't say nothing till you got lots of bits. All the bits came from different locations for mine. Frame Japan, Swing arm different guy Japan, front end and rear shock NZ. All the other bits I had in the shed ether on the floor or on the old 45. Back to the shed now got to make a new gear lever. I new that skill saw guide would come in handy one day.
She has gained some weight now complete. Need a lighter exhaust. Bike is 92kg now same weight as me. Lucky the quick engine is 2kg lighter and a new muffler should get it back in the 80's. Time to do my own MTB rear break conversion. Got all the bits, I just need the time.




I was thinking the same thing Rich.
I've built mine, raced it & blown it up and rebuilt it (and also now on its second colour scheme).
Sad thing not being able to go racing on sunday (after all the prep and hard work mainly by crazyman to make it)....:angry2:

What's actually holding things up Husa? is there some way we might be able to help?
Fair calls all around
I could give you a long tale of woe....
but simply its me holding it up. I blame apathy and chronic procrastination mostly.throw in a Masterbuilder who arn't so masterful. A registered plumber who learn's on the job at my cost and a misses who sees the bucket fund as an extension of her credit facilities. For good measure Add in in some SOE restructuring but as i said it's mainly procastination on my part.

oh the song 2-10 minutes to type and rewrite. It was worth it.. Maybe it's to early for me to go pro then?

[F5 Dave]

. . . ."Yet" but who wants to bet that it won't.

Well I'm trying to fit that gap, but I'm not 'covering myself with glory' if you know what I mean.

[jasonu]

oh for sure, the right rider on the right bike with more mumbo is a shoe in, just that hasn't consistently happened. Yet. If for example Nigels bike would hold together long enough to finish a race it would have been a regular feature.

Fixed it for ya;)

[TZ350]

.

Keith Biddle, Av's Dad, had been unwell lately and passed away peacefully this morning.

He was someone we enjoyed the company of very much and his passing is a great loss.

[Ned Kelly]

.

Keith Biddle, Av's Dad, had been been unwell lately and passed away peacefully this morning. He was someone we enjoyed the company of very much and his passing is a great loss.

R.I.P Keith. A good man has passed away well before his time. Enjoyed some great times with Keith and his family. Many good race days at the TRRS. Had a great time last year with Av, Keith and Bev at the Motogp at Phillip Island where we were invited to join them as part of there team when AV was a wild card rider in the 125's. An experience never to be forgotten. Seems a long time ago now.
Our thoughts and wishes to all of the family at this very sad time.

[F5 Dave]

Oh shit. I've been too scared to txt him as time has gone on, last time I talked to him he was too tired to talk long.

RIP mate.

[Buckets4Me]

one of the nicest guys you will ever meet.
272272

[RMS eng]

Oh shit. I've been too scared to txt him as time has gone on, last time I talked to him he was too tired to talk long.

RIP mate.

this is all a bit of a shock to me,done a few jobs for Keith over the years,nice guy,all my thoughts to his family RIP Keith

chris P

[wobbly]

A sad day for a top bloke RIP buddy.
He rang me a couple of months ago re bringing down the RS125 to sort the ignition, I wondered what had happened to that.
More than happy to help out if Av wants it done.

[jasonu]

.

Keith Biddle, Av's Dad, had been unwell lately and passed away peacefully this morning.

He was someone we enjoyed the company of very much and his passing is a great loss.

I'm very sorry to hear it. My thoughts and condolences are with all concerned.

[andrew a]

Sad news sorry to hear. All the best to Av will be some toughf times ahead. Keath seamed a nice guy from few times I had spoken to him.

[Rick 52]

It's a cruel world sometimes, a sad loss to everybody, a real gent !

[quallman1234]

A sad day for a top bloke RIP buddy.
He rang me a couple of months ago re bringing down the RS125 to sort the ignition, I wondered what had happened to that.
More than happy to help out if Av wants it done.

I was talking to James Jarman in the weekend. Keith got him to make a exhaust flange to suit the JHA chamber recently to get it ready for someone to use.

Such a massive loss, as they say couldn't of meet anyone nicer. Rest in peace mate. You will be massively missed.

[TZ350]

I'm starting to come to the belief that the limiting factor in air cooled 125 development may be the ability of an iron linered barrel designed for a commuter bike to handle the heat rejection levels required for those power levels.

A safe level may actually prove to be around 27 - 28 hp....unless you go to fan cooling....

At the moment the bike does not even have any real ducting, so yes, it might be time to fit some ducts and re visit fan cooling for purging hot air from between the roots of the fins.


Here's a pic of my head and a CPU fan/heat sink that I thought had possibilities. I was thinking of using 4 of these on the head with the idea that they switch on and off as the head heats or cools.


Copper with twice the thermal conductivity or half the thermal slope (less heat resistance), looks like it could remove heat from the combustion chamber surface much more efficiently (quickly) than aluminium.

I have talked before about using fans and copper for removing waste heat from the combustion chamber and the thermal gradient involved in pushing the heat to the outer fins.

272413

My latest idea is to sandwich a cooper sheet between two heat sinks in such a way that the copper is positioned very close to the combustion chamber shell and the heat is carried away from there to the outer fins much faster and that would keep the combustion chamber much cooler than if it was just an all alloy head.

If the fins aren't too deep then ducting and big CPU fans could be used to assist the natural airflow to move the cooling air along the fins and purge the fin roots of stagnant hot air.

Another possibility is to use a heat resistant gasket to thermaly isolate the head from the cylinder.

Yes, I think your right, some attention to fin spacing, some ducting and a fan or two would greatly improve the cooling.

[Ocean1]

I have talked before about using fans and copper for removing waste heat from the combustion chamber and the thermal gradient involved in pushing the heat to the outer fins.

You're unrestricted as far as home made parts is concerned?

Stupid question... why not a copper alloy head, with optimised fin mass/spacing?

[TZ350]

... why not a copper alloy head

Pure polished copper is a good reflector and heat conductor but from what I have read, too soft on its own for a head as the plug threads tend to give way and the head studs tend to crush and distort it.

And copper alloys are not as conductive as pure copper and often much worse than aluminum alloys.

Thermal conductivity of metals http://www.engineeringtoolbox.com/thermal-conductivity-metals-d_858.html

From experience, the other problem with polished copper is that it tarnishes in the combustion chamber and becomes the perfect heat absorber instead of reflector.

272429 1.5mm of copper sprayed on the head to transfer heat from the combustion chamber.

Polished aluminum does not tarnish in the combustion chamber like polished copper does, but a thin clear ceramic coating over the polished copper chamber surface might fix the tarnishing problem.

[Yow Ling]

From experience, the other problem with polished copper is that it tarnishes in the combustion chamber and becomes the perfect heat absorber instead of reflector.

.

are you trying to keep the heat in the engine or remove it?

[Grumph]

are you trying to keep the heat in the engine or remove it?

Actually, at some points it is profitable to try to retain heat whereas at others removal asap is necessary....

There are a number of heat barrier type coatings on the market now which are showing good results for piston crowns etc - some gains could be expected there.

The multi - metal, add a layer of copper approach is flawed as far as i can see, because every time you introduce another layer the juction between different layers is another barrier to heat transfer.

A well designed sunburst type head with the fin roots actually on the chamber does work well but can be hard to cast...

[TZ350]

are you trying to keep the heat in the engine or remove it?

I would like to keep it all in the super heated and expanding combustion products to help push the piston down but once any thermal energy has leaked into the combustion chamber shell, piston crown or cylinder walls through radiation or conduction the cooling system needs to shed it ASAP to avoid over heating the engine.

[TZ350]

A well designed sunburst type head with the fin roots actually on the chamber does work well but can be hard to cast...

272431

Yes I like the sunburst head as it has the fin roots right on the combustion chamber shell and hence a shorter thermal path than the conventional Suzuki GP125 head.

272432

On my Suzuki the copper fin extends right into the combustion chamber and forms the squish band area.

[Ocean1]

And copper alloys are not as conductive as pure copper and often much worse than aluminum alloys.

Thanks. I stupidly assumed there would be an alloy that was mechanically as rigid as aluminium yet retained most of copper's thermal properties.

And yes, radial finz is good, Mr Maico had a winner, there.

[F5 Dave]

Well while we are talking about cooling I’ll throw in my radiator questions.

I’m readdressing my 500 (2 cyl RZ350 with 496 CPI barrel) & its temp issues. I’m not concerned with city riding, just backroads, open road & occasional trackday.

All the testing I’ve done around back suburb roads had temp around 55 deg so I was never worried. But once I got it a bit more legal I took it out on the open road & it was cruising at 100 on part throttle but 70 deg. Gosh, didn’t expect that. Up the Takas & under load it was maybe a bit hotter. Then roadworks & down to a crawl & she just rose to 99 where I got to the top & let her cool off. Down the hill was better of course.

So part throttle over heating. The Zeel ign doesn’t have TPS so I’m wondering if my 12.5:1 compression is contributing to the heat. I can take some out but don’t want to if I don’t need as its harder to put back. 1mm squish which is for a 250 (x2) roadbike pretty safe.

So back to the Rad. Space is very limited. A custom Rad would help but it would be a complex one to avoid wheel & funds aren’t likely to allow even a Chinese one. Currently with a ZX4 rad, so how to make best of what I’ve got?

Head feeds up to thermostat, which outputs to left top of rad which has a tank on either side. Outlet bottom right to pump.

So I can try running water wetter & un-flattening some of the fins that are bent closed (about 5-10%) seeing if that helps enough.

With this style of rad it seems you are lucky of the tank feeds from one side to the other using all the area. But I’ve never cut one apart.

It would seem an improvement to have the tank separated in half on the right & the inlet & outlet on the same side so the water flows Right to left, then down the tank & back left to right in the bottom half of the rad.

Looking at Wobs 400 set up I wonder if this is the case?


If I could find a thin rad I wonder if I could place this onto the front of the original & weld straps & cunningly tube them together (Ideally without looking to Frankeinbike).

Thoughts?

[wobbly]

Yep, thats exactly what its got = crossflow radiator, right hand tank split.
The other issue is the dumb water flow regime that came from the original RZ/Banshee.
Only way to help this is to machine inserts that allow some water next to the plug threads, but still have the wall to stop flow short circuiting over the head.

[TZ350]

272458

A nearly definitive comparison of a RS125, Honda MC16 and MC21 frame weights.

272459

RS125 = 11.5Kg

(I estimate 12kg if it still had the rear axle adjusters swing arm bolt and other equivalent engine mount hardware thats still on the other frames)

272460

MC16 = 14Kg

272457

MC21 = 17Kg.

[richban]

272458

A nearly definitive comparison of a RS125, Honda MC16 and MC21 frame weights.

272459

RS125 = 11.5Kg

(I estimate 12kg if it still had the rear axle adjusters swing arm bolt and other equivalent engine mount hardware thats still on the other frames)

272460

MC16 = 14Kg

272457

MC21 = 17Kg.



But which one will give you the best lap times?

[husaberg]

I was going to ask about the frame now you have so many. But don't you have a NX4 in the ESE armory as well.
You may see what i mean about the MC16 being the pick of the Honda frames to mod.
Those straight rails scream (channel me) a
The MC22 CBR250 swingarm is within a couple of mm of being a bolt in as well to the MC16 (for that Doohanesk look) shame its a bit longer.
Interesting thing with the NF4 is the steering bearing size weird as. Plus i don't think Hondas planing on making any soon either.


Well got it today. Surprised how light it all is. Fame, Swing arm, Forks, Rear shock all bolted up is 23kg.
?NF5?

[kel]

But which one will give you the best lap times?

My monies on the 16. The NF4 is too small for anyone over 5'6, and the 21 is made for 60hp.
More than 1 NX4 Husi.

[Ocean1]

Well while we are talking about cooling I’ll throw in my radiator questions.

Got an oil cooler in there somewhere?

[husaberg]

My monies on the 16. The NF4 is too small for anyone over 5'6, and the 21 is made for 60hp.
More than 1 NX4 Husi.

weight comparison is?
My moneys on the NX4 but the problem with the MC16 is the real lazy geometry in std spec.
But the rider is far more important it comes down to a total package.


Got an oil cooler in there somewhere?

I PM'd him about adding a marine cooler as a supplementary cooler. i just Know he will hate it.
But size wise they are bloody efficent yeah will need a extra small rad and electric pump somewhere but if you shop around they are available for basically nothing
<img src="http://us1.webpublications.com.au/static/images/articles/i1077/107760_05lo.jpg" width="320px"/><img src="http://us1.webpublications.com.au/static/images/articles/i1127/112712_2lo.jpg"340px"/>

[jasonu]

272458

A nearly definitive comparison of a RS125, Honda MC16 and MC21 frame weights.

272459

RS125 = 11.5Kg

(I estimate 12kg if it still had the rear axle adjusters swing arm bolt and other equivalent engine mount hardware thats still on the other frames)

272460

MC16 = 14Kg

272457

MC21 = 17Kg.

Hey Chris, how about weigh my NX4 frame and SA and post the results.

[richban]

My monies on the 16. The NF4 is too small for anyone over 5'6, and the 21 is made for 60hp.
More than 1 NX4 Husi.

Unless you mod it to bits. ( probably easier to make a new frame ) you are dreaming. Check the spec. lazy pig I think you will find. Best option is to just lighten the shit of of the monster 21 swing arm job done. Also the fame can be lightened heaps. Already got dibs on the 21 if rob wants to let it go.
MC16
Castor:26°
Trail: 103mm
18" rear wheel

MC21
Castor:23° 15'
Trail: 87mm
17" rear wheel

[F5 Dave]

Yep, thats exactly what its got = crossflow radiator, right hand tank split.
The other issue is the dumb water flow regime that came from the original RZ/Banshee.
Only way to help this is to machine inserts that allow some water next to the plug threads, but still have the wall to stop flow short circuiting over the head.
Beauty! I've never cut a rad open so didn't know how the bigger ones worked. Seemingly they are just made big enough, but I'm glad the split idea works, I'll do that. I'll give you a buzz for a sht cct thermo when I have some bills sorted out, unexpected trips to Auckland etc.

I'll pull the head off too so it can meet mr lathe. Do you think com ratio is worth pulling back?

[F5 Dave]

If I had room I'd plumb another small rad under the pillion seat blanking cover & mesh it, but running rad hoses about the bike, - well there just isn't room. Its in a RG250 chassis which is heavily braced.

[TZ350]

But which one will give you the best lap times?

That is the million dollar question.....

For completeness I weighed up a FZR250 3LN frame like mine.

272497

Because the frame still had the triple clamp on it and I wanted a truer apples for apples comparison with the others.

272496

I weighed the frame with a spare triple clamp sitting on it then without and deducted the difference to get the comparative frame weight.

Yamaha FZR250 3LN 15.5 Kg

So now we have:-

RS125 = 12.0Kg
MC16 = 14.0Kg
3LN = 15.5Kg
MC21 = 17.0Kg



MC16
Castor:26°
Trail: 103mm
18" rear wheel

MC21
Castor:23° 15'
Trail: 87mm
17" rear wheel

[Buckets4Me]

For completeness I weighed up a FZR250 3LN frame like mine.



Because the frame still had the triple clamp on it and I wanted a truer apples for apples comparison with the others.

272496

I weighed the frame with a spare triple clamp sitting on it then without and deducted the difference to get the comparative frame weight.

Yamaha FZR250 3LN 15.5 Kg

So now we have:-

RS125 = 12.0Kg
MC16 = 14.0Kg
3LN = 15.5Kg
MC21 = 17.0Kg

can you re weigh the 3ln without the side stand and back brake master cylinder etc :) I'm sure there is another kg or 2 to loose there :killingme

[husaberg]

Unless you mod it to bits. ( probably easier to make a new frame ) you are dreaming. Check the spec. lazy pig I think you will find. Best option is to just lighten the shit of of the monster 21 swing arm job done. Also the fame can be lightened heaps. Already got dibs on the 21 if rob wants to let it go.
MC16
Castor:26°
Trail: 103mm
18" rear wheel

MC21
Castor:23° 15'
Trail: 87mm
17" rear wheel
Yokes with more offset sort the trail (and Visa Versa) no problems the steering head angle should be remembered is also an attribute of the set up with the respective ride heights and tire profiles by juggling both the geometry can be sorted.
The weight distribution is more problematic the reason i chose the MC16 frame (Rob has it now) was its straight narrow rails that made a simpler proposition to shorten correct the geometry.

I planned to jig a std NX4 frame to get the correct geometry. Then make the MC16 fit the jigged positions.

In the end i came across a NF4 frame not ideal (i would much rather have a NX4) chassis, but beggars can't be choosers.
Honda only made about 500 per year.
<img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=272460&d=1351574534" width="390px"/><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=266882&d=1343252313" width="240px"/>


That is the million dollar question.....

For completeness I weighed up a FZR250 3LN frame like mine.
I weighed the frame with a spare triple clamp sitting on it then without and deducted the difference to get the comparative frame weight.

Yamaha FZR250 3LN 15.5 Kg

So now we have:-

RS125 = 12.0Kg
MC16 = 14.0Kg
3LN = 15.5Kg
MC21 = 17.0Kg

Actually surprised at the FZR esp considering it has the side stand still fitted.
Weight of course is only one factor. Yes you wont get it to the weight of the NX4 though because they are real light gauge.
The Alloy used in the MC16 also won't require heat treatment after welding. the very late model Honda's supposedly do. Not sure re the MC21 though.
MC16's are also cheap and readily available.

I have glossed over eccentric inserts trail adj yoke yokes with the steering stem re-angled etc

[Bert]

I've got a few to weigh in;
Tz125 4jt.
Rgv vj19 (lighter than the 22/23)
Cbr which I can nearly get too now all the woods gone from the woodshed.

And of course the GPR (which was lighter than the nx4)..:2thumbsup

[richban]

And of course the GPR (which was lighter than the nx4)..:2thumbsup

And go around corners the same if not better. Instead of playing with old Ali junk just get scott to build you 4 frames. I am sure he would do a bulk deal.

[Bert]

And go around corners the same if not better. Instead of playing with old Ali junk just get scott to build you 4 frames. I am sure he would do a bulk deal.

Just think if it was capable of taking a bigger motor as well you could do all sorts of racing.
That's right it can!!:drool:

Just get in line; I want another one...:motu:

[TZ350]

Page 630 ....

A Big post about Wobs views on pipes, more can be found on page 620


Well thats one of those old wives tales ( or tuners tale if you like).
The depression created in the case by the diffusers outgoing + wave,sucks like hell on the cylinder, via the Ex duct, around BDC.
That is, if its properly designed for maximum effect at peak torque.
There is simply insufficient time for this effect to suck mixture thru the transfers, empty the case, and then start sucking the reeds open.
It just doesnt happen.Its lies, a myth,not reality at all.
And to make it worse, if the diffuser is designed correctly, when it works best, there is the least time period ie full noise.
In a race engine at peak torque (same as peak power in many cases)the reeds do not start to crack open until the piston is travelling upward and is covering around 1/2 the transfer height.
So in this respect this is about the only similarity a race engine has with your dads old lawnmower,in that the rising piston creates some of the depression needed to initiate intake suction.
As I have posted before,this can be "tuned" in as much as correctly timing the wave return at the reeds as + just as the case starts to go -, you create the max effect possible by using free energy to open the reeds.
Sure, the better the pipe, the sooner the case goes below a zero pressure ratio, and this has only a minor effect on the reed opening point - but there is NO FLOW created by the pipe "sucking" on the reeds, its bullshit.
Rotary valve intake tuning is highly affected by resonance effects due to the very "sharp" open/close scenario,creating high amplitude "shock" and standing waves in the carb - but inherently the pipe is working with the cylinder contents, not the case vol, and thus the design parameters are to all intents identical.


Look again at the F3 engine I am building - the reed tip lift is only just starting to allow real flow, when the transfers are closed.
When in full resonance mode ( in this case its designed to work best in the overev ) the reeds open a little earlyer, and stay open alot longer due to intake "ram" but there is little evidence of pipe effects, even the reed closing side of the trace has nothing to do with "pipe suction"..


Only the middle reed opened - wow, a real odd artifact you would never expect,but that sort of shit happens all the time.
I would get a migraine trying to fathom that one.

One other point to mention here, one I have posted before somewhere.
If you look at the delivery ratio of a race engine, then calculate how much actual mixture is transmitted thru the transfers into the cylinder - compare that to the swept vol of the transfers, you realize that in most engines,what is sitting in the ducts is more than the vol going to the cylinder.
So where is all this so called case flow that supposedly opens the reeds, it aint there at all.
This is why new technology has the transfer ducts getting smaller and smaller,the stored volume has less inertia and gets into the cylinder quicker with the same pressure ratio across the ports.


TZ mentioned how the Honda RS pipe inlet is larger than the GP exhaust port outlet, while this is common place on 4 strokes for the purpose of AR I wasnt aware it was used on 2 strokes but on reviewing RSA photos I came across this
239992
239993
Jan Thiel "One wants the pressure wave coming back into the cilinder but NOT the burned gases that are hot and can cause detonation!"
Makes sense.


Mild steel pipes will always rust and or go black,the only way to help keep them looking OK is to use Castrol R.
You have to rub it on with a rag every time the bike is run, and eventually it will burn in like a wok surface preventing rust, but you cant stop the header going black.

All the common big end sizes are available in the newer flat cage design, as this type is used in all current road and race engines.
And who is going to say to you that your engine is illegal coz its got a modern cage design.

And re the step in a Honda exhaust duct.
When using a T port or a properly designed tripple port exhaust, the area just outside the port is way too big during the blowdown phase,and alot of velocity is lost.
I have found that a good rule of thumb is to gradually reduce the duct exit at the flange, to around 75% of the total chordal area.
This will often equal the area of just the main port in a tripple setup.
If you make the duct exit the width of the header, and then reduce the height, forming an oval to give the correct area, a heap of power is created, in part due to the much better flow from the outer parts of the port width of a T or the
aux ports in a tripple..
Steps work OK, but a CNC formed oval to round transition in the flange works best.
Note well, this technique DOES NOT work in a single Ex port engine, no matter how big it is.


The only connection between Rotax and Aprilia was that the race team used the 250 V twin cases from Rotax at the beginning of their attack on that class.
Very quickly they made their own cylinders, and later their own cases as well.
Then they got sick of the crap gearboxes and did their own, as the original design by Bombardier was for a 125, and this got used even on the 250cc single, with predictable results there as well.
The early Rotax had 20mm pins that were too small, and the later design had 22mm - when Hondas bulletproof cranks were 24 and 25mm.
So yes the uprated design you mentioned probably had some actual QC done on the parts, unlike the Rotax shit - they should have been shot very early on and prevented millions of dollars and grief being spent on broken engines for no good reason.

The nozzle is part of the Exhaust duct, you can weld the duct or counterbore it and press in a sleeve to be ground out to the right shape.
Honda use a cast oval to round transition male spigot flange in the A kit 125 engines, as well as some years of the 250 V twin design.
And yes the RS125 header size is way big for a 100 - but having the correct size oval shape in the duct would reduce its volume and increase velocity and power a heap.
The design I have just done for the RGV100 has an oval duct nozzle the area of a 31mm circle,that transitions out to a 36 diameter round header bore in the flange.
This matches an Ex port area capable of achieving an easy mid 30Hp number.


Removing the step from a Honda means you remove the oval nozzle restriction before the header, that increases duct velocity.
Bigger is certainly not better.
As an example when I did testing for the new Luyten 125 cylinders, I counterbored the duct and made inserts to change the oval size.
It started with 41 by 37, I dropped it to 41 by 35 then 41 by 32.The change was worth around 2Hp everywhere, but especially in overev.
Then I added a hand ground 41 by 32 oval, to 41 round, transition in the spigot - and picked up another 1.5 Hp, putting that cylinder over 50 RWHP for the first time.

The Rotax Tandem twin was the first 250 class engine, but it was way too long to get good chassis geometry, they then did the V twin for Aprilia, carrying on making the tandem for karting.

A747 is a synthetic hybrid with caster added, it doesnt work on pipes ( just as well at the price).Probably still the best 2T oil you can use.


Another good source for big ends is Thompson - I use these in KT100 crank rebuilds as the needles are already graded.
The rear cone nozzle in the old Honda manual is well out of date.
A later version was developed by Helmut Fath and was first used on Fast Freddys 250 where one stinger was 150 long the other was 450 long.
This better design has a short 10mm "nozzle" of the correct size to create the pressure restriction, then a short taper, up to a stinger tube approx 2mm bigger in diameter.
The bigger stinger and the reverse taper basically remove this resonant tube from the equation, and the stinger length becomes irrelevant.
Under normal conditions the wave action bouncing up and down the stinger ,off the open end to atmosphere, creates varying bad effects on the reverse cone waves.
The pic shows a section of one for F3 - 400.
Rear cone welds onto LH side, stinger pushes into RH side and welded as well.
Another side effect is that there is no welding ( dags) to affect the flow where the rear cone is attached to the tube.

Dont know about Loris and his anal action, but I was with Benson and the team at Cowes one year having diner on the corner, where Max had a new "girlfriend" that night.The next night the same "person" was on his lap,as a man.
Tell his new wife that one, and see if the bulge in the back of his pants is stronger than the one in front.


In the testing I have done, the volume of the resonator chamber isnt critical, once you have reached a certain size.The best place to start is equal to the cylinder displacement, and this will "work" every time.
Fitted to a world champ ski engine, these chambers, operated by a flat, throttle slide plate,added over 30% more power at 1/2 peak rpm.
They seem to work very similar to a PV, in that the pipe effects are dramatically reduced in the area where the wave action is way out of phase with the port.
This is seen in the sim, and on the dyno, in that you can change the pipe dramatically, and it has little effect when the PV is down, or the chamber is open.


If you wana talk pipes, take a gander here.
Prototype set for my 100Hp+ F3 - 400 RZ in Aprilia 250.
Though personally I like the radial Brembos with adapters better.

Having sharp corners, even up at the center section kills power big time - better to have 3 small cuts than one sharp one.


Been there tested that on Ti pipes, if you have ever tried to hammer Ti or Stainless you will know its all but impossible.
As long as the angle changes are small like the sections in the pipes shown, with fusion only welds,then hammering the joins makes no difference to power.
Nigel is anal about the hammering and does a real good job just to be better at it than me,but as the testing showed its not needed with quality fusion welds,it makes my customer pipes just a bit more affordable.
If I hammered every weld of a single pipe, it would take 3 days instead of 2.
But even he wanted to have sex with the first set I made for the RS500.
The venturi is 27mm the stinger ID is 28.6


Yep, 304 Stainless, a real bitch to roll and work with, but easy to weld.
I hate doing them in SS, and now get Tyga to do the production pipes off my patterns, as 90% of the work is in getting the shape and cuts correct.
Another small point about weld hammering is that if its done "too well" then you get the same issue as found with blown pipes.
The angle changes become smeared and you loose power.
Especially at the interface of the header end, and the rear cone to the mid, these have to be a "sharp" angle change, different issue to a too sharp angle cut, that isnt a change in pipe section.


Interesting, This probably accounts for the works pipe I Have see on the interweird with blown headers and the rest welded.


What about Fleck , Hiroshi Naito (1971) and Robinson in regards to STA

http://www.suzuki-rg500.com/water.htm

WATER INJECTION
By Randy Norian
SAE paper 931506, expanding the torque curve of a Two Stroke Motorcycle race engine by exhaust water injection", by Robert Fleck at QUB. In this paper, they built a simple system to inject water into the headpipe of a 125cc test motor and recorded power gains of up to 24% in the lower midrange. I decided to copy their setup and was able to reproduce their results on the dyno. After that, I decided to built a usable system that would function smoothly on my streetlracebike.
But first, some numbers.
Fleck recorded pipe temps at several points along the exhaust pipe. In the diffuser, without water injection, he recorded gas temps rising from 425 deg Cat 9000rpm, to 510 deg Cat 10800 rpm.
With the water injection active, the same sensor recorded temps of 150 degrees Cat 9K RPM, rising to 420 deg Cat 10800 rpm.
Lets go back to the equation for tuned length.
If we consider a stock RG500, this distance is about 84cm, (33 inches) and Eo is 188 degrees. Using Vs of 1700 fps, this formula predicts a peak power RPM of 9684 RPM. This is a pretty good estimate, as my bike peaked at 9500 rpm in stock form.
Now we consider Vs with water injection active, let’s say we have a mean 200 degreee C drop in gas temps. If we use Vs of 1700 fps with no water, this figures to a new Vs of about 1430 fps with water. Plug that into the equation for tuned length, and our same exhaust pipe is now tuned for a peak of 8150RPM. So we have been able to shift our peak power down almost 1500 rpm, by injecting water. Obviously, this will reduce the peak rpms of our motor, so the trick here is to turn off the water at some point and let the engine rev out normally on top.
If we were able to cool the pipes all the way down to room temperature, the stock Gamma would have a peaking RPM of just 6270 RPM. Clearly, pipe temperature has a huge role in determining the rev range of a pipe/port combination.
Controlling pipe temperature is an effective way to alter the tune of a 2 stroke

I note Aprilia used use carbon sleeves to raise the temp of the pipe for top end


I was in the pit at Philip Island when Doohan tested the NSR with the water solenoids on the headers.
He did 3 laps, immediately full noise as he always did.
Came in and said it was a piece of shit till 1/2 way down the straight, but had heaps of power off the bottom and lost around 1000 rpm on top.
They plugged in the laptops, and I assume wound back the squirt volume.
Another 3 laps, and he said it now came on song much earlyer, but had lost most of the bottom end, and was still 800 rpm down on top speed..
More festering on the laptop, back out again.
This time no useable gain in bottom end,slow to come on the pipe, and still no overev power.
Mick just said - "maaaete,turn the fuckin things off and give it a go."
Went out and put it on pole,easily.
Talking to Burgess in the Cowes pub that night he said it seemed that to get enough water into the pipe to do some good for the bottom end, it took too long for the temp to rise back to "normal" again, so they had ripped the whole thing off, and binned the idea.
Adjusting the PV curve gave better, repeatable results.


I was just pointing out that the idea of using water, great as it may be in theory, and on a dyno when looking for bottom end, it "works" just fine.
But in a controlled test to see if its was usefull, it failed, as the systems effect had to be reduced so much that any gain in bottom end was still offset by a loss in the top end.
As Burgess said,when the effect was usefull,it took too long to reheat the pipes.
My thoughts,from the testing I did with a PV and ATAC operated separately ( instead of combined together as many MX engines have now) is that this works real well with no down sides at all,and is easy to implement.

If you or someone can refine the original idea - then great.


Im not allowed Chokky Fish bugger it as I have type 2,that is under control with diet and single malt.
But the powerjet switched with a solenoid is done just after peak power,as the engine is most efficient at peak torque,where it needs the most fuel.
But the carb doesnt know about efficiency, only bulk flow past the main jet - and the flow keeps rising as do the revs,so the mixture goes rich over the pipe ( thus reducing the temp).
By switching off some of the orifice area ( PWM is way better) we can lean down the fuel curve into the overev and heat the pipe up way more than is possible at peak torque.
On a HRC - RS250 for example the solenoids are activated at 12200 to 12800 ( adjustable plugs in the loom) and it will rev hard to 14000.
Without the powerjets it falls dead just past peak power at 12000.


To get around 38 crank Hp from an RGV100 ( to create mid 30RWHp) the T port needs to be up at 198 duration.
This is governed entirely by the blowdown available when the transfers are in the right place as well.
Having the T port as well as the aux ports may allow the exhaust port to be dropped a few degrees in duration,this then increases the range where the pipe is in resonance,giving a wider spread and no drop in peak power.
I need to measure one up though to see what is possible when it is sleeved back from the 56 bore to 50mm

Edit, its 54 bore,so has a stroke of 54.5 unlike the earlyer engines.


"MSV is high at 25M/Sec", forget all that old shit - here is the go with squish.
In any race engine the squish height should be set at the minimum achievable,just shy of the piston tapping the head when overeved.
In a bucket where the norm is "only" 13000 there is no reason to have any more than 0.6mm.
The squish width based on MSV is a theoretical number of little relevance when we are running the piston in the powerband just short of hitting the head.
But with a parrallel squish ( ie curved same as piston dome rad - or a straight cut with minimal divergence) then in most cases we can use 40 to 45% squish area.
This generates MSV numbers in the high 30 M/Sec region.It has been stated in a few references that " high"squish velocity will bump up mid power and reduce the top end.
Yes, in a limited view of things it does.But now that we have digital programmable ignitions thats rubbish.
The high MSV increases turbulence in the end gases, this increases flame speed, and has the same effect as high com or too much advance.
Simply retard the timing and the rpm comes back, but you keep the power generated by better turbulence burning up more of the end gas trapped in the squish.

One point to remember is that the best radius on the squish corner into the bowl is no radius at all.A sharp corner with just with a rub of sandpaper to get rid of the ragged knife edge, works best.
And with any of the race type plugs we are using approx 1mm of unthreaded plug end should be protruding into the chamber.
The old B10EGV was originally designed to be used this way by NGK, but nowdays the trick plug is a R7376-10, this plug makes more power than any other tested with around +2 Hp better than an expensive Denso equivalent, here is the test i have shown before.

Here is a pic of one of several "form tools" I have used for years cutting chambers.
Now there are plenty around I always use CNC to generate a toroid insert, based on a CAD construction of the chamber, as its simply too hard to get a good shape ( and is a prick to measure properly) when doing it by hand.

Page 305


Whats inside your head then.
KTM250 open kart engine for reference.
CNC toroidal,0.8mm squish,38M/Sec MSV 13.5:1 on pumpgas.


The Starmaker shape was stolen from diesel tech, but as it shrouded the squish from the main body of mixture in the chamber, it was doomed from the onset.
The material is aluminium bronze, I would use beryllium bronze if cost wasnt an issue, the stock head itself I machined away to suit the insert.
In this case we attack all the relevant issues involved, with small detail tricks.
The squish band has a very highly heat conductive bronze surface that runs cool and keeps the end gases from overheating and thus forming radicals that lead to thermal runaway - deto.
Bronze inserted "rings" only do 1/2 the job as they have a heat joint barrier no matter how well fitted they are.
The one piece insert is far stronger than plain aluminium in such a big bore, thus the water can be run much closer to the places its needed, in the squish area , and around the plug threads, reducing thermal hysteresis.
And lastly, the chamber only is coated with a clear ceramic heat reflective, that retains the high temp in the chamber as the combustion gases are expanding.
Creating more gas expansion is the holy grail to pushing the piston down harder , with less wasted heat into the water - on the other side of the insert.
Same with the piston - only the chamber area is coated, if you coat the whole piston, the heat reflective surface becomes hotter than the raw piston underneath, again this will create deto in he squish band area.

Offset chamber heads were patented by a dirty Doctor from EMC who sold the idea to Yamaha, that used it for one year on a TZ and in some industrial shitters, then dropped it.
It didnt work then, and wont work now.
As it means in effect that the once beautifully symetrical chamber of a 2T has a MSV of 60M/Sec on one side and virtually zero on the other,the end gases have no chance of getting out, overheat ,and cause deto real fast - bugger.
And if you move the plug over as well you have just created a bigger bore in one direction, again - dumb idea.
Never seen a fast 250G with a stock head - ever.


My take on the copper in the head would be to have it extend only to the edge of the bowl.
Then have the alloy bowl ceramic sprayed.
This pulls heat out of the squish, but keeps the heat in the combustion area to do some work.
Only issue is the same as bronze inserts, there is still a joint face that will dramatically slow thermal conduction between the copper and the alloy.


.

The 1987 Honda RS250R had the ATAC system ........... its got to be worth a try in a Bucket


Fast Freddies 500 tripple had them on 2 cylinders as well, but I found that the combo of independent atac and PV was the shit.
Adding them to a non PV cylinder is an easy way to gain a heap of free bottom though.
The clear ceramic coating I have NOT being using for years on KT100 pistons and chambers where its illegal, nor in World Champ winning stock class jet skis at Lake Havasu.
Several tech inspecting teams have commented about how lean the middle of our pistons run in comparison to the squish band,I told them that was all in the jetting of course.


The material depends upon the application.
Bronze is quite "strong" and can be used to create a complete insert, or just bands pressed in.
Copper is softer than poo so wont hold its shape, but has better thermal conduction.
I believe the best setup would be a combination, but always keep in mind about boundary joints forming a big barrier to heat transmission.


Generally, the more pure the alloy, the better the thermal conductivity. As noted, the more pure the alloy, the weaker it is.

Bog std copper (unalloyed) has a thermal conductivity of ~380 W/m/K
8% Aluminium bronze - 70 W/m/K
5% Tin Phospher bronze - 80 W/m/K
Al/Ni/Fe bronze - 38 W/m/K
357 Al casting alloy (bit of a guess at a typical cast alloy) - 152 W/m/K
1100 (99% pure Al) billet (strong as mashed spud) - 221 W/m/K

If you want to improve the heat transfer over the boundary, use an insert with a greater thermal expansion than the body of the head - the additional pressure at the interface improves thermal conductivity. There may be an issue with thermal cracking in the head however...


FM


Three Bond 1104 Liquid Gasket Grey is available from Northern Accessories, the very best and is copied as Yamabond etc.
You must remember that ANY RTV based goop is NOT fuel resistant, so will not seal anything properly that is exposed to petrol long term.
The red hi temp RTV works well on exhaust spigots etc, even works to kill noise, when beads of it are run along a chamber.


I did a heap of testing for karts to try and get the noise below the newly set Db limits.
The best muffler core material is a trade off between open area - greater open area enables the packing to absorb more "noise",and the issue of the packing being blown out thru the holes.
In the end I settled on commercially available perforated 1mm sheet steel that is easy to roll up and tack weld along the joint.
Anything with approx 2mm holes on 3mm centers is the go.
The only packing that works properly and wont get blown out easily is called SilentSport muffler packing.Its easily the best and can be bought from MotoWorks in ChCh.
The other issue tested is power.Anything but a densely packed muffler will loose power,and making the core ID the same as the OD of the stinger seemed to be the best setup as well.


The ring pinned on center setup is the best way to do it.
As the ring drops into the Ex port at its widest point, then is pushed back in by the corner rads,having the gap dead opposite the Ex means the ring moves symetrically in the groove.
The ring ends contact the pin at the same time,thus preventing any issues with one end banging on the pin continually from one side.
As long as the boost has a nice chamfer on its top edge all is fine with the ring ends.


With todays technology the bar can now be raised to around 40 crank Hp without too much drama involved, and thus achieving around 35 RWHp.
Its just a matter of careful parts selection and very careful assembly.

The alloy inserts for the TZ350 was the customers choice - once its all proven, and we get a handle on what the engine likes, then I will do some bronze ones.

AvGas in NZ is all LL100, this is low lead 100 octain.But the rating is defined differently in avaition.Its approx equiv to 100 "pump" gas, but has a lean rating of 100 and a rich rating of 130.
MNZ Appendix E defines avgas as max 112 MON amd max 108 RON.

Avgas, or any leaded "race" fuel reacts completely differently to unleaded pump gas.
In general terms the unleaded hates compression, but loves timing.Avgas is the opposite in that it makes more power up to the knock limit with more com.
Unleaded makes better power when run rich,avgas makes more the leaner you go.
Tuning in the old days with RS and TZ engines meant using lean mains and small powerjets ( 35 ) as turning off a big jet over the top would mean being too lean in the overev.
Nowdays the unleaded fuel runs rich at peak power, then uses a big powerjet ( 55) to create some heat in the pipe over the top.


Race gas bought in drums really is" low lead race gas", nothing wrong with it - but hard to get the same stuff in many places.
The stuff in tanks at stations/tracks is "old" avgas.The best, and only way to be sure of what you are getting is to go to any local airport and buy Avgas - it is tested regularly and is guaranteed to be fresh and to spec - has to be, or the Lycomings would all fall out of the air - bad.


Having multi cone sections gives the designer the ability to shape the power curve to the desired application.
Add to this 2 stage headers and you can achieve any wave amplitude correction needed with a 3 stage diffuser.
Here is a design I did for a Euro champ winning 50cc Malossi,it has a nozzle in the exhaust duct with an oval to round transition in the flange.
A two stage header, 3 stage diffuser with the steepest angle in the middle.
A killer pipe for the cylinder porting as it was used for long track racing only.
Graph is crank Hp

Quotes about pipes from pages 282 to 330 posted here on page 630, more to come on page 640

[TZ350]

can you re weigh the 3ln without the side stand ...

Good spotting .... but because the 3LN did not have a back axial and chain adjusters like the other frames did. I left the side stand on in the hope its weight would approximate the missing parts.

[TZ350]

I've got a few to weigh in; Tz125 4jt. Rgv vj19 (lighter than the 22/23) Cbr which I can nearly get too now all the woods gone from the woodshed. And of course the GPR (which was lighter than the nx4)..:2thumbsup

It will be interesting to see the results, then we can add them to the list.

[TZ350]

OK, posted because someone asked about what "O" ring we used for a head gasket.


The split ring held the cylinder central and the pull back held it secure and square in the chuck. The pull backs foot is across the main transfer ports and the threaded rod goes right through the lathes head stock and is pulled up with a nut and spacer at the back.

The post links to some pictures of how I setup to skimm and "O" ringed the cylinder.

"O" rings are measured on their inside diameter, ID and thickness.

We have used a mixture of 70mm and 73mm Imperial 1/16th (1.78mm) and 72 Metric 2mm Viton "O" rings

The "O" ring groove was cut 1.5mm deep by 2mm wide for the Imperial "O" ring and 1.75 by 2.5mm for the metric, if we messed up the imperial cut we could go deeper and wider to suit the metric size.

The 70mm grove fits snug around the iron liner and the 72-73mm grove leaves some alloy between the liner and groove as seen in the picture.

Head clearance volume for 7.2:1 corrected comp ratio. 10cc for Ex Closes 83 deg ATDC, 9.5cc for 80 and 9.25cc for 78.5 ATDC.

Using a flat top piston made it easier to machine the head. I have not bothered re cutting the squish, but re cutting with a deg or two taper could be worth while.

[F5 Dave]

Just as it is a sore point, there are engineering tables for the appropriate sizes of grooves. many people (comapnies?) seem to ignore these.

O-rings are not supposed to be compressed or squashed in the groove, they are supposed to be 'displaced' & the groove allow the space for it to deform. Which is, as appears TZ's grooves do allow.


My CPI barrels for example follows the classic mistake of being too narrow. May help retain the o-ring for assembly, but squashes it too much so most times they come off they need replacing. My GasGas is the same. My 50 however has the same o-ring from 2004 & 1 or 2 rings a year.

[Ocean1]

O-rings are not supposed to be compressed or squashed in the groove, they are supposed to be 'displaced' & the groove allow the space for it to deform.

Depends. Lots of variables, is static or dynamic seal, what material, temp, pressure differential.

It's not hard, though: http://oringcalculator.eriksgroup.com/

Note that as you get up in pressures you should be making with a slight radius across the root of the groove, and surface finish becomes critical.

[twotempi]

A VERY BIG word of warning guys.

Viton "O" rings become VERY/EXTREMELY toxic if they get burnt as in if they get overheated in service. The resulting mess will burn into your skin, and keep on attacking the skin/flesh/ bone ( in that order ) even if flushed with copious amounts of water.

So be very careful and use a spike or latex gloves to remove the "O" ring if there are any doubts to its condition. They are very cheap so replace rather than reuse.

I use a smear of high temp silicone between the combustion chamber or cylinder bore edge to further protect the "O" ring from any possible direct flame

What ever you do DO NOT rub your eyes until you have washed your hands like a surgeon before he operates !!

[wobbly]

I complained about the Oring grooves being "wrong " in CPI cylinders, and was told I had it wrong.
Even pointing out that every major manufacturer in the world had it right had no positive effect, so I also resorted to using imperial O rings in the "wrong" metric grooves.

[Ocean1]

I complained about the Oring grooves being "wrong " in CPI cylinders, and was told I had it wrong.
Even pointing out that every major manufacturer in the world had it right had no positive effect, so I also resorted to using imperial O rings in the "wrong" metric grooves.

Did you notice that imperial Orings are about 5 times the price? What is it with that?

[F5 Dave]

A VERY BIG word of warning guys.

Viton "O" rings become VERY/EXTREMELY toxic if they get burnt as in if they get overheated in service. The resulting mess will burn into your skin, and keep on attacking the skin/flesh/ bone ( in that order ) even if flushed with copious amounts of water.

So be very careful and use a spike or latex gloves to remove the "O" ring if there are any doubts to its condition. They are very cheap so replace rather than reuse.

I use a smear of high temp silicone between the combustion chamber or cylinder bore edge to further protect the "O" ring from any possible direct flame

What ever you do DO NOT rub your eyes until you have washed your hands like a surgeon before he operates !!
OK that's scary, so don't use them in exh joints for sure. Ideally this situation should not occur unless you have a head warp or machined the groove too close to the bore, but I'll take heed of your warning.

[F5 Dave]

I complained about the Oring grooves being "wrong " in CPI cylinders, and was told I had it wrong.
Even pointing out that every major manufacturer in the world had it right had no positive effect, so I also resorted to using imperial O rings in the "wrong" metric grooves.
Well to be fair you are wrong; its every manufacturer except CPI AND GasGas:lol:.


. . . & probably a few others, but certainly the Japs always get it right.

I used to work for a company that had a designer that always got it wrong, so it always stuck in my mind. We now have products that can take 30M immersion with plain nitrile rings but yes you do need to watch surfaces.

and thanks for the suggestion of the imperial size, its close enough without the option of remachining it seems, not that mines got many miles on it since I put those in.
Any thoughts on compression vs water temp? I'm about to pull the head off this week & try your insert modification.

[husaberg]

OK i are now confused. I always thought the rubber o-rings were more for water sealing yet rob has one.
I remember the first time it was mentioned with the Air cooled two stroke singles and i always assumed it was referring to the stainless wire 4 stroke style or that or a fire ring.

wouldn't a simple spigot serve Rob better esp as he already has a defacto copper head gasket. (Possably missing something simple here)

I remember these Minarelli and i guess some of the other ones will do too. esp the Europeans.
Apologies for using a web picture as i can't be arsed driving 20 km and taking the head of the Indian ME125 at my dads place.
The pics i have unfortunately doesn't show the underside of the cylinder head (edit does now)where the small gasket fits.(only this is the aluminum one from a fifty)
But it does give an indication to how big the finning was on a Italian 1970's two stroke 125 with a 55mm bore.
<img src="http://i.ebayimg.com/t/NOS-Indian-Motori-Minarelli-Head-Gasket-MT-MI-MS-175-cc-dirt-bike-/00/s/MTIwMFgxNjAw/$(KGrHqZ,!nME63S99g!QBP!7bByQ-g~~60_57.JPG" width="249px"/><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=272640&d=1351923333" width="249px"/><img src="http://i.ebayimg.com/t/NOS-Indian-Motori-Minarelli-Race-Cylinder-Piston-ME-MT-SS-125-cc-model-125-5-/00/s/MTA2NlgxNjAw/$T2eC16FHJIIE9qTYI5bDBQ!5RT4fCg~~60_12.JPG" width="282px"/><img src="http://i.ebayimg.com/t/NOS-Indian-Motori-Minarelli-Race-Head-ME-MT-SS-125-cc-model-125-5-dirt-bike-/00/s/MTA2NlgxNjAw/$T2eC16NHJHEE9ny2qThdBQ!5ioqU6!~~60_12.JPG" width="282px"/>
As a whole the engine looks like this as a whole bike (the Indian ME125) is spectacularly ugly in a seventies angular kind of way.pic on right is what it should look like
<img src="http://www.indiandirtbikeparts.com/sitebuilder/images/Indian_ME-125-896x597.jpg" width="570px"/><img src="http://farm2.staticflickr.com/1261/533703228_fb00643e4f_z.jpg?zz=1" width="550px"/>


OK virtual chockyfish question. Name this flying web crankshaft (it may be a tricky one)
It caught me out. Could be posible to make an interesting engine out of it too with a few mods. ESP as they made quite a few of them over the decades it was in production

[twotempi]

We ditched the copper/fibre head gaskets which used to leak on our Benelli aircooled twin and used Viton "O" rings in a machined groove in the head instead and cured the problem. Not one leak in many seasons.

However a friend machined the groove in the cylinder instead with a too narrow groove and manged to implode the cylinder wall back inside the cylinder. There was not enough material left between the groove and the cylinder bore to support excessive pressure from the crushed "O" ring.

Robs table of "O" ring groove dimensions is available from Seal Imports Ltd. I have found that Murray at the Lower Hutt branch is very helpful - he is also a bike nut which helps - and although I am in Auckland he is only a $4 courier parcel away.

The viton "O" rings are available in two grades - the red one is a higher temp version.

Also there is a "Super Viton" ring available good for a very high temp but very pricey @ $100+ each. Maybe NASA has some shuttle ones left over ??

[speedpro]

Pipeline industries on Rosebank Road have pretty well every regular size viton o-ring made and they are real helpful. They have like a room with racks and racks of orings in plastic bags on hooks.

[Haufen]

One some of the o-ring manufacturers' homepages there are online o-ring groove calculators. Never had a problem if the groove was designed by one of these programs. They also take tolerances of the o-rings into account.

[dinamik2t]

Hello Wob,
I have a question, if you have some time.
Searching backwards, I met with your post here about EGT with Avgas/Unleaded (http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130362060#post1130362060).

How this relates to the bulk temp of the gases in a pipe, in a pipe calculator?
Neels describes the parameter in help files like this:

The software uses this value to calculate the tuned length and it is the average bulk temperature of the exhaust gas in the pipe from the piston face to the tailpipe entry over a complete cycle at the design rpm value.
If the EGT value can be used for this parameter (given avgas/leaded is +200*F over unleaded), does it mean that a pipe designed for unleaded must be shorter?
I have no idea, a 200*F/90*C difference results in ~40mm difference in TL, according to Engmod.


My question is driven by the dyno results of this engine (http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130402485#post1130402485) (running pump unleaded). I got my hands on the graph and it's like this
272674 ,
-about 1500rpm off- so I immediately thought of lower EGT.
Still, I was able to look at the AFR graph and it was around 13.5~13.7, only past 11k it went through the roof. I tested a little in Engmod to try and produce such a 'deviation'. It seems that such an AFR situation, with ~14adv around 10.5k, could have this effect in power. So I ended up that it was either tuned by a stupid carb/adv tuner or really a lower EGT.
.. so confusing the art of tuning after all. :confused:

[wobbly]

Unleaded fuel to make best power likes to be rich and have plenty of advance with low com.
Thus in general a shorter pipe would be needed, as you say due to the lower egt.
But as usuall there is a fly in the ointment in that the FIM race fuel that needs gloves and a respirator, acts differently,and ends up with the same tuned length as was used with ELF124.
But the bulk pipe temp isnt what the egt probe reads in the header, its the average temp and is alot lower overall.

[dinamik2t]

Ok Wob, thank you. Is there a way of tricking EngMod into predicting the right rpm for top power, when using unleaded fuel? So far it seems to predict the rpm range as if the egt was around 650C.

[wobbly]

The biggest thing to realise is that the pipe wall temp seems to work best in the 0 to 100*C range.
I use 50* for most engines running on Avgas.
This is a fudge that Neels hates but works very well.

[TZ350]

More than you ever wanted to know about "O" rings

http://www.parker.com/literature/ORD 5700 Parker_O-Ring_Handbook.pdf


O-rings are not supposed to be compressed or squashed in the groove, they are supposed to be 'displaced' & the groove allow the space for it to deform.

True....

272706

Static "O" ring groove design.

[F5 Dave]

Wow that looks like a read & a 1/2, I'll need to find some time to go through that, good post.

[TZ350]

272755
Originally posted by Husa

The variator interests me as I would like to fit one to the Beast.

272756

By moving my engine forward the variator assembly looks short enough to fit into the chassis with a jack shaft for the chain.

If anyone knows what this one is off I would love to know.

[husaberg]

272755
Originally posted by Husa

The variator interests me as I would like to fit one to the Beast.

272756

By moving my engine forward the variator assembly looks short enough to fit into the chassis with a jack shaft for the chain.

If anyone knows what this one is off I would love to know.

http://www.aaenperformance.com/snow_clutch_parts.asp
http://www.aaenperformance.com/snow_clutch_roller.asp

bUT look under snowmobiles failing that Argo or john deere (can't remember what the old 6 wheeler was)(later gator the old 6 wheelers) they all have similar CVT's hp'ed to suit. i remember the argo are set to rev real high and had a 2 stroke std (well some of them did)
Before you start though try going around corners in netural to see if you like it though.
interestingly I was going to post some stuff on the 70's Husky 4 speed auto set up but can't find all the info. I haven't googled it though.
Why not a slipper KTM 50 style always on the pipe. Much like a chainsaw setup.

[speedpro]

Snow mobile.

I've already investigated them. The Canadians have some lovely billet stuff with roller bearings and different ramp angles etc etc. Some of their snowmobiles are making over 300hp using turbocharged 2-strokes.

Check this place out - http://www.aaenperformance.com/snow_clutch_roller.asp

They run the sleds on the drag strip as well using titanium tracks with rubber bits on the outside.

Check out the 1&5/8th belt good for over 300hp and also their racing engines.

[richban]

272755
Originally posted by Husa

The variator interests me as I would like to fit one to the Beast.

272756

By moving my engine forward the variator assembly looks short enough to fit into the chassis with a jack shaft for the chain.

If anyone knows what this one is off I would love to know.




Try find yourself a Gilera runner 180 one. Should cope with the hp fine. Also lots of good bits for them. I might have an old vespa one in the shed will have a look. I replaced it with an adjustable malossi one. Was never beaten when the lights went out. They are quite big and heavy. Even the fancy ones.

You will need a nice rear brake. If you are hoping to make it easier to ride think again. Corner entry and exit are hard work. Also the delay from throttle to drive is a bitch. When you set the clutch up to launch hard for starts it also means that it can be quite brutal when you twist it on to full noise.

When I raced my scooter I spent the whole time wishing I had gears.

[husaberg]

Try find yourself a Gilera runner 180 one. Should cope with the hp fine. Also lots of good bits for them. I might have an old vespa one in the shed will have a look. I replaced it with an adjustable malossi one. Was never beaten when the lights went out. They are quite big and heavy. Even the fancy ones.

You will need a nice rear brake. If you are hoping to make it easier to ride think again. Corner entry and exit are hard work. Also the delay from throttle to drive is a bitch. When you set the clutch up to launch hard for starts it also means that it can be quite brutal when you twist it on to full noise.

When I raced my scooter I spent the whole time wishing I had gears.

I have no doubt posted the Monotrack stuff somewhere if not i will do. it had one back in the early 70s based on a snowmoble were avant-garde at the time (Mag monoque disk all around mag wheels funny air forks belt rear drive etc)but no match for the TZ750's. From memory the rokon had one (probably the same guy) i think the weird 2wd bike about the same time as well had on too.

[wobbly]

Forget that shit - get a 30Hp aircooled on track that runs like a clock all day!!

[Frits Overmars]

.... I was going to post some stuff on the 70's Husky 4 speed auto set up but can't find all the info....Maybe because the Husky I rode was a 3-speed auto....

[richban]

Maybe because the Husky I rode was a 3-speed auto....

How was that to ride?

[F5 Dave]

Tri-Matic Bro!:laugh:



sorry, a bit of island humour for our offshore chaps

[Frits Overmars]

How was that to ride?For me it was great; I almost started liking motocross. I did not have to worry about shifting down when I got into deep sand or up steep slopes.
But a pro MX rider who knew what he was doing, might not have benefited as much as yours truly.

[F5 Dave]

I'd read about some 'Mercan winter bog enduro race (about '80) & some top rider scooped it using an auto & said it was almost like cheating, along with the heated hand grips.

Never seemed to come to any more though.

[jasonu]

Forget that shit - get a 30Hp aircooled on track that runs like a clock all day!!

Where are you going to find one of those???:no:

[TZ350]

Posted because someone asked me how to mount a GP engine into a RS chassis.

272790

The rear engine mounts make use of the original RS mounting points without any modification to the frame there.

272787

We used a piece cut from the original GP frame for the front mount.

272789

We found that where the front mount attached to the RS frame it would break away and we had to glue and screw some hefty bracing there.

And now we also have the bolt where the front mount attaches to the frame bracket running through a red nolathane bush to absorbe some of the vibration.

272788

We had to cut one head fin off and trim the back of the cylinder fins to clear the frame because the motor had to be shifted about 15mm to the right to get good chain alignment.

[F5 Dave]

Stop it! You'll only encourage her:msn-wink:

[husaberg]

Maybe because the Husky I rode was a 3-speed auto....

For me it was great; I almost started liking motocross. I did not have to worry about shifting down when I got into deep sand or up steep slopes.
But a pro MX rider who knew what he was doing, might not have benefited as much as yours truly.

I'd read about some 'Mercan winter bog enduro race (about '80) & some top rider scooped it using an auto & said it was almost like cheating, along with the heated hand grips.
Never seemed to come to any more though.

I found it although it seems Frits and me are both right. (Nothing new for frits but a rare husa moment)
I did a google search the production ones were both 3 and 4 speed and the Swedish army were a big buyer of them.They made them for 12 years all up. (Likely longer for the military)
The test rider here attached (1976)below (a non pro)says basically exactly what Frits assessment was, also what Dave said about them. I was more interested how it worked.The interesting thing was how it could help the non pro plus the consistency
I know very little about auto trans. but the drag racers love them (no corners to contend with either though)

http://www.motorcycle-usa.com/290/1097/Motorcycle-Article/Memorable-MC-Husqvarna-390-Automatic.aspx
http://www.bikeexif.com/husqvarna-automatics

The Husky Auto was a serious race bike but it came about as a spin-off from a Swedish Army contract. In essence, the contract specified that raw recruits, who had never ridden a bike before, had to achieve complete motorcycle competency in a week. However, the Swedish Army didn't want recruits merely to cruise up and down the highway wearing mirror shades, looking cool and waving to the girls. No, they had in mind full blown enduro riding skills - and on snow and packed ice too.
Husky's answer was a 250cc, fully automatic motorcycle complete with the option of permanent skis for winter terrain. The squaddie merely sat on the Army bike, opened the throttle and away he went - and over killer difficult terrain too.
Husqvarna was a small factory but was packed full of clever engineers and, unlike the Japanese, very used to working on micro budgets. The Auto racebike reflected this low budget approach to engineering.
Most of the bike was a direct lift from existing Huskys. This included the reed-valved, single-cylinder two-stroke engine and all the chassis. Only the gearbox was unique to the Auto and this fitted inside a regular Husky engine case.
A 384cc two-stroke Single, the Husqvarna 390 Automatic featured a gearbox with a centrifugal clutch and a series of dog clutches.
The heart of the gearbox was the clutch mechanism. Initially, drive was taken up by a centrifugal clutch - like a Honda 50 Cub - and then a series of a dog clutches engaged sequentially locating higher gears. It was brilliantly simple and even more brilliantly effective with bomb-proof reliability and faultless changes even under full power.
When the throttle was closed, the engine free-wheeled and the clutches disengaged so that the correct gear was available when the rider need to accelerate again. If the bike had a problem, it was the freewheeling element.

Hill descents became a real, hardcore thrill. Not only was there no engine braking available - a very, very scary experience for the first time auto rider - but the rear wheel stability which even mild two-stroke braking provided was absent. Although the Auto had state-of-the-art handling for its day, it skated and skittered downhill in a very disconcerting manner.

The lack of engine braking was exacerbated by the brakes - or lack of them. It's worth remembering that, at this time, dirt bikes had drum brakes - not the discs of today. The Husky's brakes were as good as anything around at the time but once the linings were wet, they didn't work for some time afterwards. Get the wrong combination of a river crossing followed by a steep hill and Auto riders could crack walnuts between the cheeks of their bottoms on the way down


Automatics have a strong following in the four-wheeled offroad world, so it’s not surprising that they’ve been tried in dirtbikes. And Husqvarna got it mostly right from the start: according to VMX’s writer Rob Shoemark, “The first commercial release of the Automatic was in 1976 and the last was 1988. Throughout that whole time the transmission was basically the same with only minor design enhancements.”
Since 1980, Husqvarna has been supplying the Swedish Army with auto all-terrain bikes that can be ridden proficiently by new recruits after just one week of training. And how does it work? “It is mechanically simple,” VMX reports. “Based around a centrifugal clutch, drive is firstly taken up by that clutch, then a series of a dog clutches engaged sequentially, locating higher gears. It was not only simple but very effective and reliable. What about changing back down? Once the throttle is closed, the engine goes into free-wheel mode. Once you apply the throttle again the gearbox was ‘told’ what gear it should be in by the speed of the back wheel.”

Initial reports from the motorcycle media varied. But the good outweighed the bad, and sales were strong enough to merit twelve years of non-military production. “The 1988 430 water-cooled automatic was the last automatic model released,” says Shoemark, “and it was the automatic at its best. Finally without any doubt, and with proper maintenance, the Automatic was a truly great competitor in any enduro field—and was campaigned accordingly by the factory. It was a gem. Interestingly, that last model was also a three-speeder—all the auto versions up to that point, from 1976 onward, had utilized four speed gearboxes.”


<img src="http://www.bikeexif.com/wp-content/uploads/2010/09/husqvarna-automatic-4.jpg" width="300px"/><img src="http://www.bikeexif.com/wp-content/uploads/2010/09/husqvarna-automatic-3.jpg" width="370px"/><img src="http://www.bikeexif.com/wp-content/uploads/2010/09/husqvarna-automatic.jpg" width="370px"/>


Oh great to have you back Frits too. Is there any update in regards to the FOS cylinder and the Trombone pipe you posted from a associate?

[Frits Overmars]

... How does it work? “It is mechanically simple,” VMX reports. “Based around a centrifugal clutch, drive is firstly taken up by that clutch, then a series of a dog clutches engaged sequentially, locating higher gears".False. A better descrition is given in the second page that Husa posted above. In case you missed that: each gear has its own centrifugal clutch, and all gears except the highest gear have unidirectional freewheels (called dog-bone clutches because of the shape of the locking elements in them) so they can be overriden by a higher gear.

No news about the FOS cylinder, except that everything takes way more time than it should.
The trombone pipe works a treat and the sealing is bullet-proof now, but with a six-speed gear box you hardly benefit as far as lap times go. On our kart tracks fewer gears might actually yield better lap times; Richard Maas is investigating that now.

[FastFred]

The trombone pipe works a treat and the sealing is bullet-proof now.

How is the sealing done?

[Frits Overmars]

How is the sealing done?That's not for me to divulge. Maybe Richard will tell.

[wobbly]

I have recently lost a couple of customer engines due to plug failures.
Initially it was blamed on deto causing the issues, but now I find out there is a recall from NGK due to faulty manufacture.
The local importer is desperate to keep this quiet, im not.

[2T Institute]

For me it was great; I almost started liking motocross. I did not have to worry about shifting down when I got into deep sand or up steep slopes.
But a pro MX rider who knew what he was doing, might not have benefited as much as yours truly.

There is only deep and very deep sand on Dutch mx tracks :laugh:

Been using Denso plugs for a fair few years after I had a few new-out-of-box NGK failures.

[twotempi]

Have a box of new-in-the-packet B9EGV's NGK plugs coded 1Hx5 which are on the list.

Who do i see to get these replaced ??

And who is the NZ stockist of Nippon Denso plugs ??

Most people gave up on the Champion brand for the same reason. Seems that NGK have the same issue.

[kel]

Have a box of new-in-the-packet B9EGV's NGK plugs coded 1Hx5 which are on the list.

Who do i see to get these replaced ??

And who is the NZ stockist of Nippon Denso plugs ??

Most people gave up on the Champion brand for the same reason. Seems that NGK have the same issue.

You can get the Denso IW plugs from most Kart shops. I also have a couple of NGK's to be returned, cheers Wobbly for bring this to our attention

[wobbly]

These are old style shitter plugs, but still no excuse for crap quality from NGK.
The newer iridium/platinum versions are way more expensive but way better for info to help with tuning both mixture and advance.
I have dyno tests that prove conclusively that the best NGKs make more power than any of the alternatives from Denso.
Anyway Darbys are the importer, and they are ultimately responsible, but claims must be made thru the supplying retailer.
Fear not, several complete engine destruction claims are already on the table.

[SS90]

These are old style shitter plugs, but still no excuse for crap quality from NGK.
The newer iridium/platinum versions are way more expensive but way better for info to help with tuning both mixture and advance.
I have dyno tests that prove conclusively that the best NGKs make more power than any of the alternatives from Denso.
Anyway Darbys are the importer, and they are ultimately responsible, but claims must be made thru the supplying retailer.
Fear not, several complete engine destruction claims are already on the table.

Darbis (or NGK for that matter) Shelling out for competition engine failures? Seems unlikely at best. Over the last 20 years I have seen plenty of situations where competition components have failed, and manufactureres have no legal obligation to pay for someone elses fun.

It is a bitter pill to swallow, but the sad reality.

Best I have seen is replacement of part..... no good if the supplied part is made in the same production run, but normally it is more than their obligation (which is none)
Add to this the amount of people buying plugs from the net, and I suspect there will be a few customers left out in the cold when it come to replacement

[FastFred]

.

Any reason for this mind numbing advice????

[wobbly]

In this country we have the Consumer Guarantees Act that protects the purchaser,with a "fit for end use " requirement.
Plus for NGK there is no legally binding disclaimer printed on the product ,thus consequential damages is a viable legal option.
Add to this the fact that there is a public ( though kept quiet ) general recall of the product, and here at least, they havnt a leg to stand on.
The EGV range is very old,and cheap, but the 7376 range is so superior and reliable,there is really no reason not to be using them apart from price.

[SS90]

In this country we have the Consumer Guarantees Act that protects the purchaser,with a "fit for end use " requirement.
.

Understood, but don't forget that the consumer guarantees act covers "private consumers", and, specifically excludes businesses from any "warranty"

A guy on his Harley (Road Bike) may have a Shot at getting some assistance (I doubt they would get anything other than a new set of plugs) but a business building competition engines, not so.

Over this way, you wouldn't have a shit show of getting anything, these plugs are for competition, and that's the end of the discussion.

NGK would do well not to piss you off, as this sort of thing, in a small country like NZ would soon (most likely) result in serious sales drops for NGK (although, as usual, NZ probably represents less than 1% of their entire world wide sales ( car and bike combined)

I notice that most people over here use Bosch or ND more than NGK, but in the UK, NGK is the big one.
I used to run cheap B10.5EGV in my 125's and replace them every meeting, and they never let me down, the old ones I used to chuck in a water cooled DT100 I had, so I felt I got my moneys worth, but everyone I know that ran them for long in a 125 had electrodes fall off.

I would be interested to hear what solution they offer in your case.

[wobbly]

The people who run the plugs in their KT100 or NSR250 road bike all are "private consumers".
They can go direct to the shop and make a claim, and they will pass this on to Darbi, who will ultimately pass it on as well I assume.
But Darbi must have liability insurance, being as they are a registered LTD,so I cant see it being an issue.

I cant go direct to Darbi and claim as a business, on behalf of my customers under the CGA, but I can sue them - and thus their insurer.

[FastFred]

the old ones I used to chuck in a water cooled DT100 I had

Its not everyday we have an Industry man experienced with dynos talking about an F4 type engine of his own.

I would be very interested to see a dyno graph or know the statistics for your water cooled DT100 and how it compares to TeeZee's efforts.

[twotempi]

Spoke to Darbi regarding the plug issue and was told to return the plugs to them and they will replace them free-of-charge even if used on a competition engine.

They have a shipment of replacement plugs due end of November. Note "replacement" plugs - not a free "upgrade" to EIVX grade

So it looks if "Consumer Guarantee" or commercial commonsense/pragmatism worked, and good on Darbi's for a positive response.

[diesel pig]

Its not everyday we have an Industry man experienced with dynos talking about an F4 type engine of his own.

I would be very interested to see a dyno graph or know the statistics for your water cooled DT100 and how it compares to TeeZee's efforts.

That would be a wast of time, He didn't build it. All he did with was lose it.

[FastFred]

the old ones I used to chuck in a water cooled DT100 I had.


SS90 I would be very interested in a dyno graph to see how it compares to TeeZee's efforts.


That would be a wast of time, He didn't build it.

Pity or tune it I guess ... I suppose SS just wanted to make an impression.

[husaberg]

That's not for me to divulge. Maybe Richard will tell.

mmm.....how do we get him to do that? does he come visit this thread sometimes......
Will a virtual chocky fish lure him into posting.......
http://learningagents.files.wordpress.com/2010/02/spoonfulofsugarjpg3312.jpg

Actually i was surprised no one had a go at the last chocky fish question.



OK virtual chockyfish question. Name this flying web crankshaft (it may be a tricky one)
It caught me out. Could be possible to make an interesting engine out of it too with a few mods. ESP as they made quite a few of them over the decades it was in production

[FastFred]

.

Four stroke???

[husaberg]

.

Four stroke???

.......... what could be.......

[twotempi]

4 stroke outboard motor ??

have also seen an air rock-drill motor crankshaft that was similiar but unlikely on this forum.

[SS90]

Spoke to Darbi regarding the plug issue and was told to return the plugs to them and they will replace them free-of-charge even if used on a competition engine.

They have a shipment of replacement plugs due end of November. Note "replacement" plugs - not a free "upgrade" to EIVX grade

So it looks if "Consumer Guarantee" or commercial commonsense/pragmatism worked, and good on Darbi's for a positive response.

As expected, the reference to competition engines was Wobbly lodging a claim for engine damage as a result of faulty plugs, I am very interested to hear of the result of that one, as I said, NGK would (in my experience with wholesalers) not most likely not offer compensation of any sort for that. It remains to be seen.

Replacement plugs, for sure, I wonder if the claimants have to prove they where purchased from a NZ reatailer or not, given so many people buy of the Bay of E these days.

[dinamik2t]

Actually i was surprised no one had a go at the last chocky fish question.

How much cocoa in that fish?

Could it one of these -2CV? :psst: linky link (https://www.google.gr/search?tbs=sbi:AMhZZiv4pPjusu3mO2N_1RZ_1K1WYhInqOf vmIPwPrMY9l0zQOZnBh9Ja7We04ViwijM8votM2LmXp2yN9zDB mdyZcnVOYGHg8xE4ixSSnvN7CITQIPkVHk8RMut7PGZ7W8DuS9 KPyFhnUY9IpglbWPCiKjQMF8Xkye7z9MKEIIQF4BACQdrthJgU XPogszcIzQy2bDH2aJOqiOBHH8AmM4U1l7uJA4NU4kniUO1DE7 y1RpiyV1DyuO0JBVNFGKrAUAkEmXGCcaUikSrg29sxVzI06f20 d6w-rDyLWWN_1pJrzgKelKXTuj1ZKgde8l9NWhx24IEBWJNtzkSs2t oUw1Lat1CH2uJWoDUrtDpw6ABOFlodIhtpC6HAwvYbRedhFYL4 FRX2pEekxEQAZ31fYJV7VstJDDzeggPxdEfgd0vJ-Gfo3HY00wA4flXr1i0YBaEemLWzPF4CXW2nBy8t0yE84kF9pOf 0cfSRWrIsprc4EGtyev8q86hARngIlokaKUriqYpdl0xLdxjB4 4yyZRy4B-0pXa_1eg4qtySNDl419VJd_18GdaX5cX5ZV89CqnG5Osahoy79 qHswjM8VPI3D4WQPGsAmvnMj6pmddT0SdedjQIb_1_19QZZ8A7 zLSEbrqbG-jQcQmTZVHszs_1pzma6DXDCKNFCCY39GKDZGV4AJHQNhgEmSVP 3HG6JZdIwiSRvArOyMEzfBu7konRnc1KUqhLVj0HANMMn0ssoN NyzXOlwDl0ZKF35rtY_17msAPVxE4vOPANhwz6cFqHg6M1SCcv uW2NAvs3jVVNUPsJZYZPWjJVgKAeVG_1usifg1yiDTauDmy1HC WCAfeGitb_1ih3K4toluP_10EOPC3Xx1I1oLCLe_1cAwUdlH3a YJGQfFKm77n98awkLW89tJrWTyXLzWB1hmpO9yRRpVDkgJTwfv nVVb6CkdMK5so2sx3g1DElKKP00ZAJiZORKkszCZtcZNJ9dRbD dSCifot51GaAREVg27NtBRZypaUY5KHn5qxXpVtewo6_1yCuu6 YOuyzIpOxNOJnfCa5Ymu_1OhZFNIoj-TnBCJ9jWkUORdVtDHnDFyyD67rKXRCi_1BiQg3D7lMZsPafBHz kkXFloR6nyGAfAqyNxY9zGS-a3TwFHlLvIKbDHrSRVg4P0bqBFfkooJlaGYZsUe-97m3EiL_1gUwo3hhaolDxCW03ZeVv7gNdCEs1UgeVjGAubX-ORfDdxoVLcEFihkut80s-c-mfEOZ3yEbiVhKHewaeoCLdTfJOb4vmt95qim39ehXOv6ih32Da wj1aXy143a2Wn0VGqn5_1_1XcOBnYwdki5CYnaI&num=10&hl=el&bih=474&biw=1190)

[husaberg]

How much cocoa in that fish?

Could it one of these -2CV? :psst: linky link (https://www.google.gr/search?tbs=sbi:AMhZZiv4pPjusu3mO2N_1RZ_1K1WYhInqOf vmIPwPrMY9l0zQOZnBh9Ja7We04ViwijM8votM2LmXp2yN9zDB mdyZcnVOYGHg8xE4ixSSnvN7CITQIPkVHk8RMut7PGZ7W8DuS9 KPyFhnUY9IpglbWPCiKjQMF8Xkye7z9MKEIIQF4BACQdrthJgU XPogszcIzQy2bDH2aJOqiOBHH8AmM4U1l7uJA4NU4kniUO1DE7 y1RpiyV1DyuO0JBVNFGKrAUAkEmXGCcaUikSrg29sxVzI06f20 d6w-rDyLWWN_1pJrzgKelKXTuj1ZKgde8l9NWhx24IEBWJNtzkSs2t oUw1Lat1CH2uJWoDUrtDpw6ABOFlodIhtpC6HAwvYbRedhFYL4 FRX2pEekxEQAZ31fYJV7VstJDDzeggPxdEfgd0vJ-Gfo3HY00wA4flXr1i0YBaEemLWzPF4CXW2nBy8t0yE84kF9pOf 0cfSRWrIsprc4EGtyev8q86hARngIlokaKUriqYpdl0xLdxjB4 4yyZRy4B-0pXa_1eg4qtySNDl419VJd_18GdaX5cX5ZV89CqnG5Osahoy79 qHswjM8VPI3D4WQPGsAmvnMj6pmddT0SdedjQIb_1_19QZZ8A7 zLSEbrqbG-jQcQmTZVHszs_1pzma6DXDCKNFCCY39GKDZGV4AJHQNhgEmSVP 3HG6JZdIwiSRvArOyMEzfBu7konRnc1KUqhLVj0HANMMn0ssoN NyzXOlwDl0ZKF35rtY_17msAPVxE4vOPANhwz6cFqHg6M1SCcv uW2NAvs3jVVNUPsJZYZPWjJVgKAeVG_1usifg1yiDTauDmy1HC WCAfeGitb_1ih3K4toluP_10EOPC3Xx1I1oLCLe_1cAwUdlH3a YJGQfFKm77n98awkLW89tJrWTyXLzWB1hmpO9yRRpVDkgJTwfv nVVb6CkdMK5so2sx3g1DElKKP00ZAJiZORKkszCZtcZNJ9dRbD dSCifot51GaAREVg27NtBRZypaUY5KHn5qxXpVtewo6_1yCuu6 YOuyzIpOxNOJnfCa5Ymu_1OhZFNIoj-TnBCJ9jWkUORdVtDHnDFyyD67rKXRCi_1BiQg3D7lMZsPafBHz kkXFloR6nyGAfAqyNxY9zGS-a3TwFHlLvIKbDHrSRVg4P0bqBFfkooJlaGYZsUe-97m3EiL_1gUwo3hhaolDxCW03ZeVv7gNdCEs1UgeVjGAubX-ORfDdxoVLcEFihkut80s-c-mfEOZ3yEbiVhKHewaeoCLdTfJOb4vmt95qim39ehXOv6ih32Da wj1aXy143a2Wn0VGqn5_1_1XcOBnYwdki5CYnaI&num=10&hl=el&bih=474&biw=1190)

yip........

[andrew a]

Nice to see some 2CV stuff on ESE thread. The late model 2CV a full 602cc.

[F5 Dave]

You guys are sick