ESE's works engine tuner

[Hemi Makutu]

Sometime ago Hooser got me excited. Nah, nothing to do the (or his?) whole chicken thing, but labyrinth seals (see pic). HP just waiting to be unleashed?
So, got a Ø20*Ø35*7 teflon lipped seal and wrapped it with a paper strip, slid it over a crank and weighted it up so it was enough to overcome static friction and slowly rotate around the shaft with a 90 gm weight. (see pic).
Working backwards, this level of friction equates @ 14k rpm, to equal 0 .0226 kW. Stuff all really.
However, this is without and pressure acting on the seal. I guess the next step would be to mount 2 seals in a sleeve with varying applied pressures from within a drilling in the shaft. See pic. I guess one could do this based on crank angle vs pressure and do some sort of averaged calc of the frictional power over the full 360 deg cycle
325069325070325071

Ken, 2T oil generally contains high levels of ZDDP ( zinc-phosphate) to compensate for the loss of TEL ( lead)
lube from road-legal petrol, if you were serious about a research project, you could sacrifice a top-end, & seal up
a crank-in-case ( having cut off the con-rod above the big-end, & sealed on a blanking plate) to test it,
back to back, all-metal lab' seal vs current teflon low-loss resilient-type, on a powered spintron set-up, eh...

[ken seeber]

Ken, 2T oil generally contains high levels of ZDDP ( zinc-phosphate) to compensate for the loss of TEL ( lead)
lube from road-legal petrol, if you were serious about a research project, you could sacrifice a top-end, & seal up
a crank-in-case ( having cut off the con-rod above the big-end, & sealed on a blanking plate) to test it,
back to back, all-metal lab' seal vs current teflon low-loss resilient-type, on a powered spintron set-up, eh...

Hemi, I was always under the impression that zinc and phosphorous were additives specific to 4 strokes as these acted to provide resistance to the high pressure scuffing in cam followers. Unfortunately both these are considered poisonous to catalysts, hence the need for good oil control. However as 2 stroke oils do not contain these, the typical crankcase scavenged total loss lubrication system is quite ok. Could be wrong though.
As to your suggestion, it does offer a method of holding the seals, although with bearing friction to be allowed for, but it does allow one to fit alternative sealing arrangements in.

[husaberg]

TZ inline 4's used their 1-1 jackshaft for ignition on one end, & clutch pinion on the other...
Maybe Yamaha should've used that jackshaft as a balance shaft too..

Yes they did but that was to minimise the width, they did a two up two down config likely more to lower costs.
The jackshaft costs HP, not and issue in 750 but not ideal for a 125.

[Hemi Makutu]

If you fact check, there were G.P. 125's which utilized jackshafts.
Yamaha went basic to stick a pair of twin 180 degree cranks into the 4s rather than go to 90 degree/even firing.

Note the length/wheelbase saving shaft-stacking done by KTM, so really,
- it would depend on the value of crank rotation/gyroscopic forces - if a crank turning in reverse to wheel was wanted.

[husaberg]

If you fact check, there were G.P. 125's which utilized jackshafts.
Yamaha went basic to stick a pair of twin 180 degree cranks into the 4s rather than go to 90 degree/even firing.

Note the length/wheelbase saving shaft-stacking done by KTM, so really,
- it would depend on the value of crank rotation/gyroscopic forces - if a crank turning in reverse to wheel was wanted.

JAW......... all over again.
The words used were not ideal. No such words as never used.
The TZ twin for instance did the jackshaft to reverse the crankrotation only to increase piston life over a 100KM or so.
As i said in regards to the TZ750 to save cost. PS Thanks for you imput James.

[Hemi Makutu]

Hemi, I was always under the impression that zinc and phosphorous were additives specific to 4 strokes as these acted to provide resistance to the high pressure scuffing in cam followers. Unfortunately both these are considered poisonous to catalysts, hence the need for good oil control. However as 2 stroke oils do not contain these, the typical crankcase scavenged total loss lubrication system is quite ok. Could be wrong though.
As to your suggestion, it does offer a method of holding the seals, although with bearing friction to be allowed for, but it does allow one to fit alternative sealing arrangements in.


Among the highest ZDDP additive counts for 4T oil is the H-D specific type, due to their high load rolling element
bottom ends, & high ring-land/bore contact friction long-stroke designs.

But feel free to check, 2T oils use it for the same reasons...

[koenich]

hey guys,

not a regular poster rather a reader. as it's off season now in Europe I'd like to build some pipes for my Conti RX356...

I stumbled upon this drawing in the thread, is it for 50cc Wobbly?

Diameters seem to be a bit bigger than usual but length is way more (usually I end up in the 670 mm range).

[Hemi Makutu]

JAW......... all over again.
The words used were not ideal. No such words as never used.
The TZ twin did the jackshaft only to increase piston life over a 100KM or so.
As i said in regards to the TZ750 to save cost. PS Thanks for you imput James.


As it happens, you've got a bit to learn yet, eh fella.. see the 1960's 4 cyl 2T G.P. 125s..

& as such see the 2-stroke thread current on the F1 Technical Forum, wherein the value of a even-fire multi 2T engine is discussed.
(Its in the engines, transmissions... section)

[husaberg]

As it happens, you've got a bit to learn yet, eh fella.. see the 1960's 4 cyl 2T G.P. 125s..

& as such see the 2-stroke thread current on the F1 Technical Forum, wherein the value of a even-fire multi 2T engine is discussed.
(Its in the engines, transmissions... section)

Thanks J.A.W.
Alas If only you could actually read what was posted rather than just trying to be a know it all.
Adds to ignore list. Suggest's all others do the same.

[Hemi Makutu]

Adds to ignore list. Suggest's all others do the same.

Off topic/zero value post or what, eh fella...

Ah well, I also "suggests all others " go back to discussing items of actual 2T technical merit

Husa will likely back edit his ludicrous statement claiming that TZ twins used a jackshaft to enable their pistons to last 100 Km...

( & meanwhile Husa's calling card of leaving a negative reputation ranking & "total dick" comment - says heaps about his limitations).

[Hemi Makutu]

The TZ twin for instance did the jackshaft to reverse the crankrotation only to increase piston life over a 100KM or so.



1, TZ twins never - "did the jackshaft" at all, but won many G.P. races well in excess of 100 Km in length.

2, TZ fours "did the jackshaft" - to utilize a pair of twin cranks geared together inline, with centre PTO.

3, TZ fours won the Daytona 200 mile ( ~320 Km) race 9 times in a row.

[Frits Overmars]

TZ inline 4s used their 1-1 jackshaft for ignition on one end, & clutch pinion on the other...
Yes they did but that was to minimise the width, they did a two up two down config likely more to lower costs. The jackshaft costs HP, not and issue in 750 but not ideal for a 125.

As it happens, you've got a bit to learn yet, eh fella.. see the 1960's 4 cyl 2T G.P. 125s.. & as such see the 2-stroke thread current on the F1 Technical Forum, wherein the value of a even-fire multi 2T engine is discussed.Forgive me for asking Hemi, but weren't you the one starting a discussion about inline 4s? None of those 1960s rotary inlet fours were inline.
And since you mention it, judging by their comments, nobody on the F1 Technical Forum appears to have any hands-on experience with the Yamaha inline fours.
None of those engines had a 1 to 1 crankshaft / jackshaft ratio because of their hunting-tooth layout, so no way could this jackshaft have been used as a balance shaft, nor carry the ignition on one end as you claim.
The jackshaft itself propelled another shaft that carried the ignition. And this ignition shaft rotated with crankshaft rpm. Feel free to enlighten the F1 Technical people:
38 teeth on the crankshafts, 39 teeth on the jackshaft, one more 39 teeth gear on the jackshaft, 38 teeth on the ignition shaft.
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TZ twins never - "did the jackshaft" at allDon't tell me you've never seen a 1981 TZ250H, a 1982 TZ250J, a 1983 TZ250K or a 1984 TZ250L...
325085 325086 325087

[Frits Overmars]

got a Ø20*Ø35*7 teflon lipped seal and wrapped it with a paper strip, slid it over a crank and weighted it up so it was enough to overcome static friction and slowly rotate around the shaft with a 90 gm weight. (see pic). Working backwards, this level of friction equates @ 14k rpm, to equal 0 .0226 kW. Stuff all really.I must admit this is less than I expected, because we've experienced that the very first parts to heat up in a running engine are the places where the seals run.
So I did some backwards working too. Here's what I did:
circumferential force at radius 0,035/2 = 0,09 * 9,81 = 0,883 N
Preservation of torque gives:
circumferential force at radius 0,020/2 = 35/20 * 0,883 = 1,545 N
Circumferential velocity at radius 0,020/2 = 2*pi * 0,02/2 * 14000/60 = 14,66 m/s
friction power = force * velocity = 1,545 * 14,66 = 22,6 W = 0,0226 kW.
So I shouldn't have bothered. Next time I'll just believe whatever you say, Ken :p.

Of course most engines have more than one seal, and the direct power loss caused by the seals is converted to heat which causes additional indirect power losses in a two-stroke. And the fact remains that labyrinth-type seals are practically frictionless and bulletproof.

[wobbly]

The only TZ to have piston issues was the 250G, as it had a ludicrous inlet port width and shape - along with a short skirt to suit the lifted port.
As Frits rightly points out, all the engines directly after that had the crank spin backwards with a jackshaft, thus enabling a big
inlet setup with no piston issues.
Obviously the race division got a right kicking in the arse over the G affair, and fixed it for good.
I guess Yamahas accountants had more sway than the engineers doing the 500 and 750 inline 4 cylinder layout,but as it turned out
the big bang 180* firing and reverse spinning crank was never considered a technically backward step, and they certainly weren't noted as being
prone to vibrations enough to annoy riders or crack frames.

[wobbly]

The 50cc pipe shown is an early version ( based on Aprilia style cones ) done for a customer that wanted peak power at only 13,000,and that translates to a tuned length
in the 760 ballpark.
Later more powerful versions of that pipe were even fatter,and had a single rear cone , but the length remained similar to suit the powerband requested.

[rodg]

325089325089

Two curves from my RS125 on the ESE dyno. The one with the dip is V Force reed block. The other curve is stock reeds. V Force reeds and block in good condition. As they say, stock is best!

[Muciek]

Any other mods in engine?

[wobbly]

RS125 with VF3 makes no better ( less ) power as the petal frequency is wrong, but if you can find a VF2 then thats worth an extra
between 1 and 2 Hp everywhere.

[Hemi Makutu]

Forgive me for asking Hemi, but weren't you the one starting a discussion about inline 4s? None of those 1960s fours were inline.
And since you mention it, judging by their comments, nobody on the F1 Technical Forum appears to have any hands-on experience with the Yamaha inline fours.
None of those engines had a 1 to 1 crankshaft / jackshaft ratio because of their hunting-tooth layout, so no way could this jackshaft have been used as a balance shaft, let alone carry the ignition on one end as you claim.
The jackshaft itself propelled another shaft that carried the ignition. And this ignition shaft rotated with crankshaft rpm. Feel free to impress the F1 Technical people:
38 teeth on the crankshafts, 39 teeth on the jackshaft, one more 39 teeth gear on the jackshaft, 38 teeth on the ignition shaft.

Thanks Frits, mea culpa, I was being a bit naughty.. to provoke a knowledgeable response.

I knew someone would show the pix ( knowing the TZ 4 ignition was driven from a gearing corrected aux shaft),
and that without the qualifier 'contemporary' to match the early TZ twins with the 4's the later jackshaft ones would be noted.

I was a bit mean I suppose, to show Husa that his 'backlash' reason for non gear driven ignition didn't apply.
But I figured his "100Km" piston life idea - was too funny to let slide.

But nevermind the fun, did you see the research links?

Here is Kevin Cameron on 'wrenching' (rebuilding) the TZ 750.

www.cycleworld.com/2016/01/18/yamaha-tz750-racing-motorcycle-engine-development-and-analysis-kevin-cameron-insights

[Hemi Makutu]

I guess Yamahas accountants had more sway than the engineers doing the 500 and 750 inline 4 cylinder layout,but as it turned out
the big bang 180* firing and reverse spinning crank was never considered a technically backward step, and they certainly weren't noted as being
prone to vibrations enough to annoy riders or crack frames.


Yamaha did have big troubles with their 4T 750 twin 'omniphase balancer' TX at that time too, although
the TZ racing engineers likely would've laughed at all the chain stretching/oil frothing horrors..

[Hemi Makutu]

May be of some interest to those dealing with injectors.

www.diva-portal.se/smash/get/diva2:460049/FULLTEXT01.pdf

[rodg]

Any other mods in engine?

Just a VHM head. 250km Old piston. We found another 1 HP by retarding ignition 1 degree after this

[rodg]

RS125 with VF3 makes no better ( less ) power as the petal frequency is wrong, but if you can find a VF2 then thats worth an extra
between 1 and 2 Hp everywhere.

Thanks Wobbly. One of the pieces of knowledge that would have been useful prior to that acquisition

[Frits Overmars]

Thanks Frits, mea culpa, I was being a bit naughty.. to provoke a knowledgeable response. I knew someone would show the pix ( knowing the TZ 4 ignition was driven from a gearing corrected aux shaft), and that without the qualifier 'contemporary' to match the early TZ twins with the 4's the later jackshaft ones would be noted.
I was a bit mean I suppose, to show Husa that his 'backlash' reason for non gear driven ignition didn't apply. But I figured his "100Km" piston life idea - was too funny to let slide. But nevermind the fun, did you see the research links? Here is Kevin Cameron on 'wrenching' (rebuilding) the TZ 750. www.cycleworld.com/2016/01/18/yamaha-tz750-racing-motorcycle-engine-development-and-analysis-kevin-cameron-insightsI knew the article about the opposed-piston HCCI two-stroke but it was not the most informative paper I ever read.
I also saw the link to the Snowmobiler magazine that you posted in the Oddbike-section but it didn't work for me. Luckily I had already received the same information from Rotax.
You're right about putting the Rotax 850 cc E-Tec engine in a motorcycle chassis. Somebody at Rotax may have had a similar idea, because about a year ago Rotax presented their 600 cc E-Tec engine, combined with a six-speed gearbox instead of the usual CVT. But when I made further inquiries, it appeared that the engine did not really exist; it was just a teaser, published in order to fathom the interest in such a unit.
325100 325101

Regarding Kevin Cameron's TZ750-article: yes, I knew it. I love reading whatever Kevin writes. Did you know that once upon a time we were colleagues?
Kevin impersonated a technical editor at Cycle World and I was doing the same at the dutch Moto73 magazine.


A counter balance shaft might be okay for a generator side of things i had that idea myself, but i think it would be not so great for timing as it would have a fair bit backlash built in. thus the timing could be a little eratic. The Aprilias had a pickup sensor built into the crank wheel...
The TZ twin for instance did the jackshaft to reverse the crank rotation only to increase piston life over a 100KM or so...
The jackshaft costs HP, not and issue in 750 but not ideal for a 125.Husa was of course exaggerating about the piston mileage in the Yamaha TZ250G but apart from that I must agree with him on all accounts.
The TZ250G was remarkable. Power-wise its cylinder block was a big step forward, with better transfer ducts, smaller exhaust duct volumes and the huge inlet ports that were detrimental to piston life.
The following year Yahama reversed the direction of crankshaft rotation by means of the jackshaft, but we'd already found a much simpler solution: we reversed the cylinderblock on the 'G': piston problem solved.

[Hemi Makutu]

Thanks Frits, I appreciate the considered reply,

I had meant actual research as per posts # 23745, #23746 & # 23771.
It goes to show the difference between Kaaden-type racer-engineers & academic thesis writers..

Although KC does write so nicely, I also find, he's always worth reading.
I do note his view that the 180' rocking couple was responsible for TZ 4 crankcases fatigue failure,
( not that Yamaha likely ever expected them to do so many Km)...

Here's a fresh KC blog, giving his 'big bang' appraisal.

www.cycleworld.com/why-single-and-twin-cylinder-motorcycle-engines-are-good-in-the-dirt


Sorry, that link won't , for some reason, but tjbw has kindly put it up on post #23783, if you want to view it.

[husaberg]

IHusa was of course exaggerating about the piston mileage in the Yamaha TZ250G but apart from that I must agree with him on all accounts.
The TZ250G was remarkable. Power-wise its cylinder block was a big step forward, with better transfer ducts, smaller exhaust duct volumes and the huge inlet ports that were detrimental to piston life.
The following year Yahama reversed the direction of crankshaft rotation by means of the jackshaft, but we'd already found a much simpler solution: we reversed the cylinderblock on the 'G': piston problem solved.

Although it might appear to be flippant, I actually wasn't Frits, it was out of McKellar’s Yamaha twins book, he lists 80-120 KM piston mileage and cranks not much more. With 53 Rear wheel hp 43mm inlet port width and a 4mm Sinusoidal port roof. More curving yet flat roofed transfers
Slightly larger Front forks were added as well.
The official recomended replacement of pistons on the G i believe was per race.
Along with the Jack shaft and the changed bore and stoke the H was also the first year of the PV, it has bigger big ends, lighter crank wheels and a different crankshaft coupling resulting in less crankshaft flex.
Base mounted cylinders 44mm intake port width 23mm ex port height and 55 HP. But of course more importantly much greater reliability.

Funny enough as you know yamaha, eventually followed you. (and MZ)

[Frits Overmars]

Here's a fresh KC blog, giving his 'big bang' appraisal. You may have to scroll down some, to the subject feature if it doesn't pop up
www.cycleworld.com/why-single-and-twin-cylinder-motorcycle-engines-are-good-in-the-dirt?src=offramp&loc=region-2&lnk=imgYet another link that didn't work for me. All I got was "The page you are looking for no longer exists". Is it just me or does this look familiar to you guys?

[trevor amos]

Yep, I got the same response Frits, so it`s not just you!

Wob, with VF2`s being rarer than chicken`s teeth, and VF3 not as good, what would your recommendation be for the next best thing in place of the VF2 for the Honda RS 125?

Cheers, Trevor

[adegnes]

My newly started "vlog" about the Spx etc.
Keep your expectations low.


http://youtu.be/yFYhwpGaniw

http://youtu.be/HMCmlB2KXlI

[wobbly]

Yep, that page doesnt exist Frits.
Re the reeds for RS125.
I have done a huge test program on the SKUSA CR125 that makes near on the same power as the RS does.
The reed block is pretty much identical, but the big difference is that the CR inlet manifold is bent 30* to the left.
Thus I "rebend" the flow such that I get almost identical flow ( tested with a probe on a Superflow ) from each of the upper reed windows by using 3 different backups.
On the bottom a single blade works the best to help direct flow upward toward the piston.
I hope to get another test session in before the Vegas Worlds in November, so send me a PM and I will try to do a some runs with your block before I go.

[TZ350]

My newly started "vlog" about the Spx etc.

I love it, actually I like all the good discussions on here, but your blog and workshop is stuff I can relate too ....... :niceone:

[adegnes]

I love it, actually I like all the good discussions on here, but your blog and workshop is stuff I can relate too ....... :niceone:

Thank you!

[tjbw]

Yet another link that didn't work for me. All I got was "The page you are looking for no longer exists". Is it just me or does this look familiar to you guys?

I think this is the correct link:

http://www.cycleworld.com/why-single-and-twin-cylinder-motorcycle-engines-are-good-in-dirt

[Frits Overmars]

Adegnes, I liked it a lot!

[adegnes]

Adegnes, I liked it a lot!

Thank you!

[twotempi]

Originally Posted by Frits Overmars t
IHusa was of course exaggerating about the piston mileage in the Yamaha TZ250G but apart from that I must agree with him on all accounts.
The TZ250G was remarkable. Power-wise its cylinder block was a big step forward, with better transfer ducts, smaller exhaust duct volumes and the huge inlet ports that were detrimental to piston life.
The following year Yahama reversed the direction of crankshaft rotation by means of the jackshaft, but we'd already found a much simpler solution: we reversed the cylinderblock on the 'G': piston problem solved.



I have a TZ250G with the inlet port about the same size as the bore. My solution was to weld a 6mm wide vertical bridge in the inlet port which was then shaped into an old cylinder that needed to be re-plated. Early days but this seems to give better support to the rear face of the piston to guide it down the correct hole .l My reasoning also included that since it was in direct line of the conrod there was little reduction in effective port area.

Reversing the cylinder would mean new pipes etc so this solution have the least effect on the rest of the bike. Also wanted the bike to look "original". Also managed to find a stash of 30 "G" pistons which are 54.25 mm rather than 54.00mm !! And no - I do not want to sell any.

Comments anyone ? ( Especially Frits Overmars )

[Hemi Makutu]

This may help: www.greencarcongress.com/2016/08/20160805-anltribo.html

It may even assist with 2T engines with cylinder ports making a production road vehicle comeback,
if improved durability on lower oil consumption/HC emissions are part of the DLC tribofilm deal.

[wobbly]

I did the same trick of putting a bridge into the intake on a 350G - 6 port cylinder, as it now has reed boxes on the back.
This allowed a much wider intake width, and then I added an extra pair of boost ports up each side of the welded in bridge.
Works well.
Hummel and Chevalier did some cylinders for the 250 with a bridged intake that worked well also.

[lodgernz]

I love it, actually I like all the good discussions on here, but your blog and workshop is stuff I can relate too ....... :niceone:

Me too. Good stuff Alex.
It looks like you don't have a clutch on the variator or the driven pulley. Are you using the engine movement to act as a clutch?

[twotempi]

If you are only permitted to use fuel commercially available at the pumps does Gull Force Pro E85 fit this definition ?? 85% Ethanol / 15% Petrol

This is available at the Gull Forrest Hill direct from their forecourt fuel pumps as advertised on the Gull website and the roadside signage .

Also available from other Gull service stations as well.

[adegnes]

Me too. Good stuff Alex.
It looks like you don't have a clutch on the variator or the driven pulley. Are you using the engine movement to act as a clutch?

Thanks!
Actually there is a centrifugal clutch on the driven pulley, I'll make shure to include it in the next video.

[TZ350]

If you are only permitted to use fuel commercially available at the pumps does Gull Force Pro E85 fit this definition ?? 85% Ethanol / 15% Petrol

This is available at the Gull Forrest Hill direct from their forecourt fuel pumps as advertised on the Gull website and the roadside signage .

Also available from other Gull service stations as well.

Looks good.

I would be pretty interested in what others think. This type of fuel will be more and more available at the pump everywhere in time. Metholated spirits is available at hardware stores everywhere now and 8.5 L of metholated spirits and 1.5L of 96 is the same thing as Gull pro. So should fuels becoming available to the public at the petrol station pump be allowed for general use in Buckets?

There has been a thread started over here by Fastfred:- http://www.kiwibiker.co.nz/forums/showthread.php/181239-Gull-Pump-Fuel?p=1131007011#post1131007011

[Hemi Makutu]

Looks good, there has been a thread started over here by Fastfred:- http://www.kiwibiker.co.nz/forums/showthread.php/181239-Gull-Pump-Fuel?p=1131007011#post1131007011

I would be pretty interested in what others think, should any general pump fuel available to the public allowed in Buckets?

No, OH&S/material safety regulations state that gas containers must be of approved type, not allowed to pour in a bloody bucket.

( heheheh...)

& since racebikes are 'not for highway use' then avgas ( it is pump gas at aero-clubs) oughta still be ok..
2T's like a bit of TEL, & it is still available as an additive 'Kemco Octane Supreme 130' if you want to do a bit of blending.

www.hi-flow.com/hp016aOS.html

When was the last time anyone's bucket race-gas was protested/analysed?

[Grumph]

If you are only permitted to use fuel commercially available at the pumps does Gull Force Pro E85 fit this definition ?? 85% Ethanol / 15% Petrol

This is available at the Gull Forrest Hill direct from their forecourt fuel pumps as advertised on the Gull website and the roadside signage .

Also available from other Gull service stations as well.

Yeah, but only where Gull has outlets - which at the moment AFAIK is limited to the Auckland area. Certainly only in the NI anyway.

Remember that it was a couple of National racers bringing their own Gull fuel South to the Southern national meetings that caused the shitfight over fuel a season or so back. Personally I'd like to see open fuel come back but that won't happen....But I'm sure that if guys bring this fuel South there will be protests. Missing from the definition is "available nation wide"
As an amusing aside, 98 is not available in Invercargill to my knowledge at present - but LL100 is.

[Frits Overmars]

I have a TZ250G with the inlet port about the same size as the bore. My solution was to weld a 6mm wide vertical bridge in the inlet port which was then shaped into an old cylinder that needed to be re-plated. Early days but this seems to give better support to the rear face of the piston to guide it down the correct hole .l My reasoning also included that since it was in direct line of the conrod there was little reduction in effective port area.
Reversing the cylinder would mean new pipes etc so this solution have the least effect on the rest of the bike. Also wanted the bike to look "original". Also managed to find a stash of 30 "G" pistons which are 54.25 mm rather than 54.00mm !! And no - I do not want to sell any. Comments anyone ? ( Especially Frits Overmars )Welding a bridge in the G's inlet port will certainly improve piston life, but it will also cause extra turbulence, reducing the effective flow area. The con rod is directly behind that bridge alright, but the inlet flow has already expanded by the time it encounters the rod, so the rod is less of an obstacle.

We wanted to avoid welding and the according cylinder distortion, and we wanted to make our own pipes, which became a lot simpler with the reversed cylinder block.
We had to make an airbox for the carbs sitting directly behind the front wheel, but that was no extra work because even if we hadn't reversed the cylinder we would have made an airbox in order to keep the engine from inhaling hot air from the radiator.
And we didn't care about the bike looking original because it wasn't a classic back then. It should win races, never mind the looks. And the best combination proved to be a reversed G cylinder block with 38 mm carbs on RD400 crankcases with their extra case volume. That bike really flew.

[jasonu]

And the best combination proved to be a reversed G cylinder block with 38 mm carbs on RD400 crankcases with their extra case volume. That bike really flew.

Buggar. Now I wish I had kept my RD400...

[wobbly]

Yep Frits, RD400 cases are the go to get some case volume, especially with a TZ400 with reeds added ,made from a stroked Banshee crank
and 66mm Wossner pistons in a 350G cylinder, with 8 transfers.
Because they are period legal as well, 40mm flat slide Lectrons flow way more air than the old round slide Mikunis ever did
I was astounded to find that Yamaha had made the 400 with practically the same side cover fixing as the earlyer 250 based case.

[husaberg]

I was astounded to find that Yamaha had made the 400 with practically the same side cover fixing as the earlyer 250 based case.

The actual crankcase cover used from the TZ C model on up until about the H was based on the production RD400 cover pattern. According to the details i have, They previously they used a DS7 cover pattern modified for a water pump in place of the Autolube pump with other changes as required.

[ief]

Looking at this picture made me wonder again...

http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=325082&d=1476359225

Placement and size of the piston windows, anyone with some ideas about the what and the why ?

(in this case they seem small, sometimes they are higher up, these are low etc.)

I've alluded to this before and if I remember correctly Wob stated they are for inlet only (I can imagine they could also be of use on the downstroke in aiding flow to the C-port.)

Ps, love the video's Adegnes!

[adegnes]

Ps, love the video's Adegnes!

Thanks! Recording E3 tonight, will be about the variator, clutch and pipe + I got a request for showing how I measure the balance factor of my crank(method learnt from TZ's great writeup starting on page 70, I'll of course credit him and leave a link in the description)

[Frits Overmars]

Looking at this picture made me wonder again... Placement and size of the piston windows, anyone with some ideas about the what and the why ? (in this case they seem small...)They are small Ief. Compared to smaller competition two-strokes the TZ750 is not a racing engine at all; it's a tourer. But that was what was needed to do the job.
You can't beat cubes, as the merikans say, but the cubes can beat you, if you let them.
The TZ750 had to be very forgiving, so all port timings were mild and the reeds were barely big enough for a 50 cc racer. We tried to 'correct' this once, putting TZ350-stuff on the TZ750 cases.
Takazumi Katayama rode it, once. The bike had at least 30 hp more than anything else on the track, but it was unrideable. While everybody else could start opening the throttle after mid-corner, Takazumi had to wait till the bike was completely upright, and then he had to concentrate on not flipping over backward.

[husaberg]

They are small Ief. Compared to smaller competition two-strokes the TZ750 is not a racing engine at all; it's a tourer. But that was what was needed to do the job.
You can't beat cubes, as the merikans say, but the cubes can beat you, if you let them.
The TZ750 had to be very forgiving, so all port timings were mild and the reeds were barely big enough for a 50 cc racer. We tried to 'correct' this once, putting TZ350-stuff on the TZ750 cases.
Takazumi Katayama rode it, once. The bike had at least 30 hp more than anything else on the track, but it was unrideable. While everybody else could start opening the throttle after mid-corner, Takazumi had to wait till the bike was completely upright, and then he had to concentrate on not flipping over backward.

Frits a few years ago you mentioned playing with a Kawasaki KR1
Did you window the piston?
I was looking at a cylinder map picture the other day, i noticed it had a odd port arrangement?
With what is by the look of it a blind gully port?
http://i189.photobucket.com/albums/z125/maccas125/utf-8BSU1BRzA4NjYuanBn.jpg

[Frits Overmars]

Frits a few years ago you mentioned playing with a Kawasaki KR1. Did you window the piston? I was looking at a cylinder map picture the other day, i noticed it had a odd port arrangement? With what is by the look of it a blind gully port?That port map of yours doesn't look like the KR1S I worked on. There was no blind gully port and the auxiliary exhaust ports were 2 mm higher than the central exhaust.
And I didn't window the pistons; I replaced them with Yamaha TD2B racing pistons: lighter, one ring instead of two, and 1 mm less compression height which gave me the desired transfer timing without having to do anything to the ports.
Other mods: head inserts to compensate for the lower TDC, raising the central exhaust by 2 mm (which was the maximum that was allowed under the regulations), shortening the inlet rubbers as much as possible (6 mm I think it was) while keeping the standard 28 mm carbs (regulations again) and fitting own pipes. It produced 73 rear wheel-HP; quite enough for the then standard 400-class. 400 cc four-cylinder four-strokes against 250 cc two-stroke twins; let's show them how unfair that is :D.

[jfn2]

adegnes:
Videos look very good. Stay with the rum. Insights come easier.

[adegnes]

adegnes:
Videos look very good. Stay with the rum. Insights come easier.

Thanks!
+1 for rum noted.

[Fabio15]

I've seen a lot of mention of water temps being between 50-60 C. Where exactly is the measurement being taken? ( I assume this is after the radiator before entering the engine?). Also, where is the most ideal spot to place a temp sensor on 2 strokes?

[Frits Overmars]

I've seen a lot of mention of water temps being between 50-60 C. Where exactly is the measurement being taken? ( I assume this is after the radiator before entering the engine?). Also, where is the most ideal spot to place a temp sensor on 2 strokes?The quoted temperature should be the highest temperature of the water in the cooling system, so it should be measured directly after it exits the cylinder head.
Often the sensor is mounted in the head which gives about the same reading.

[wobbly]

There is an answer on here somewhere about inlet piston porting for reeds.
As there is no intake flow until the timing edge approaches TPC, the piston skirt position should be as high as possible ( greatest port duration ) and
the holes should be as low as possible to promote the initial start of the intake process.
The 250G we were talking about had the whole port lifted, to straighten out the duct ( a good mod to earlyer TZs as well was to recut the flange face
thus steepening the carb angle - and thereby reducing the abrupt downward bend at the face ).
Then the piston skirt on the G was shortened to get the correct timing with the higher floor position.

Re water temp, its near on impossible to have too much radiator, or too much water flow.
The KZ2 125 kart engines are fastest down at 45* exiting the head, but its very hard to achieve this with ambient above 20*.
And PS - Flettner has nearly finished the bypass thermostats that several readers are waiting for.

[JanBros]

Frits a few years ago you mentioned playing with a Kawasaki KR1
Did you window the piston?
I was looking at a cylinder map picture the other day, i noticed it had a odd port arrangement?
With what is by the look of it a blind gully port?
http://i189.photobucket.com/albums/z125/maccas125/utf-8BSU1BRzA4NjYuanBn.jpg


That port map of yours doesn't look like the KR1S I worked on.

that might be correct Frits, as that is a KR1 cylinder map, allthough probably from a tuned cylinder. the give-away is the port underneath the C-port. probably the one that makes Husaberg wonder if you windowed the psiton.

here is an original KR1S map, and as you notice : from the S onwards, they ditched that port (S cylinders are supposed to be the cylinders from the racing kit of the KR1)

http://i57.tinypic.com/k2fzmg.jpg

anyone have any idea about the purpose of the port under the C-port ?
as a sidenote : on mine the brigde between both (C and below) got missing (damn you Woessner :spanking:), so I removed it in the other cylinder also, never noticed any difference in performance.



edit : you don't happen to know CR ratio/squish ratio and height/... of that engine Frits ? How many rev's to get those 73HP ?
I use YZ125 '89 piston's in mine for the same reason, as they also have 1mm less compression height

[ief]

anyone have any idea about the purpose of the port under the C-port ?


wob > to promote the initial start of the intake process.

Perhaps?

Didn't work I guess :)

[wobbly]

It depends upon the C ports duct and the flow regime below the entry from the case.
In the early Rotax twins it was found that a big " 1/2 moon " cylinder cutaway under the C duct along with a hole in the piston gave a good power increase.
Rotax didnt believe our dyno numbers till we sent a heavily ground sample along with the new JL pipe I did for them to test.
Very quickly the factory engines added this idea, but put a tall 1/2 moon in the piston skirt instead of just a hole.
That cylinder 1/2 moon cutout idea even survived into the Aprilia.
Several other engines like RM125 have a long slot in the piston that allows thru piston flow easier access to the C duct entry.
I even tried cutting slots thru the all transfer inner walls and the piston on a Rotax,thinking that the boost port idea would work on all of them.
Sadly all it did was cost my boss a weeks wages ( at Zipkarts ) and a new cylinder, it was the trickiest thing I have ever seen that worked so badly.

[Hemi Makutu]

Arctic Cat features piston slots, see here: www.snowgoercanada.com/reviews/277-arctic-s-new-600-c-tec2

[Muciek]

Wobbly what was the difference in power using that JL pipe and rotax vsk that was made by factory, to go that year with engine?

[Hemi Makutu]

Want to have a go at a DIY? See here: www.engapplets.vt.edu/fluids/CDnozzle/cdinfo.html

[Hemi Makutu]

http://www.industrial-electronics.com/engineering-industrial/images/process-plant-mach_5-9.jpg

[JanBros]

It depends upon the C ports duct and the flow regime below the entry from the case.
In the early Rotax twins it was found that a big " 1/2 moon " cylinder cutaway under the C duct along with a hole in the piston gave a good power increase.


in the KR1, piston's didn't have any sort of hole or whatever that came in front of that port below C-port

[wobbly]

The so called JL "Silverstone " single rear cone pipes for the Superkart twins made an extra 4 +Hp at peak.
Best of all though was the overev power,they made some 14 Hp more at 13,000 with usable rev on to 13400.

This was the pipe that we spent months at JL in England, trying to get a blown version of to replicate the power made by the cones.
No matter how we went about it, including using a clam shell bridge to hold the dwell to size, we could never get closer than
4 Hp down nearly everywhere ie the blown pipe made the same peak power as the Rotax VSK design.
Hines used them to win his World title, and then sold those pipes exclusively for something like 1800GBP.

[peewee]

And PS - Flettner has nearly finished the bypass thermostats that several readers are waiting for.

just in time as ill be needing it :niceone:

[Hemi Makutu]

I even tried cutting slots thru the all transfer inner walls and the piston on a Rotax,thinking that the boost port idea would work on all of them.
Sadly all it did was cost my boss a weeks wages ( at Zipkarts ) and a new cylinder, it was the trickiest thing I have ever seen that worked so badly.

Good on ya for trying it in metal though, W.

Not all R & D ideas are gonna pan out, but the worthwhile ones need hard work too.

Have you ever tried, or seen done - transfer ducts with full or partial - internal lateral flow fences
( for aero, not structural reasons), air-straightener honeycombs, venturi-type cross-sections/organic nozzle shapes
- or boundary layer control devices - such as dimples/vortex generators & /or director vanes/Coanda effect?

[adegnes]

Have you ever tried, or seen done - transfer ducts with full or partial - internal lateral flow fences
( for aero, not structural reasons), air-straightener honeycombs, venturi-type cross-sections/organic nozzle shapes
- or boundary layer control devices - such as dimples/vortex generators & /or director vanes/Coanda effect?

Laminar flow nozzles in the transfers and exhaust? Like used in water fountains. I was thinking about it a while back. Maybe not so good for a/f mixing, and hard to make enough room(and keep enough volume), especially in the transfers.

[husaberg]

That port map of yours doesn't look like the KR1S I worked on. There was no blind gully port and the auxiliary exhaust ports were 2 mm higher than the central exhaust.
And I didn't window the pistons; I replaced them with Yamaha TD2B racing pistons: lighter, one ring instead of two, and 1 mm less compression height which gave me the desired transfer timing without having to do anything to the ports.
Other mods: head inserts to compensate for the lower TDC, raising the central exhaust by 2 mm (which was the maximum that was allowed under the regulations), shortening the inlet rubbers as much as possible (6 mm I think it was) while keeping the standard 28 mm carbs (regulations again) and fitting own pipes. It produced 73 rear wheel-HP; quite enough for the then standard 400-class. 400 cc four-cylinder four-strokes against 250 cc two-stroke twins; let's show them how unfair that is :D.


that might be correct Frits, as that is a KR1 cylinder map, allthough probably from a tuned cylinder. the give-away is the port underneath the C-port. probably the one that makes Husaberg wonder if you windowed the psiton.

here is an original KR1S map, and as you notice : from the S onwards, they ditched that port (S cylinders are supposed to be the cylinders from the racing kit of the KR1)

http://i57.tinypic.com/k2fzmg.jpg

anyone have any idea about the purpose of the port under the C-port ?
as a sidenote : on mine the brigde between both (C and below) got missing (damn you Woessner :spanking:), so I removed it in the other cylinder also, never noticed any difference in performance.



edit : you don't happen to know CR ratio/squish ratio and height/... of that engine Frits ? How many rev's to get those 73HP ?
I use YZ125 '89 piston's in mine for the same reason, as they also have 1mm less compression height

Yes its the KR1 rather than the KR1S
On std 28mm carbs thats pretty impressive.
Some of the ones we got had 35mm PWK's

i will see if i can find another pic
325124

i found this that says it goes nowhere and might need a hole in the piston to work.
325125

[Hemi Makutu]

Laminar flow nozzles in the transfers and exhaust? Like used in water fountains. I was thinking about it a while back. Maybe not so good for a/f mixing, and hard to make enough room(and keep enough volume), especially in the transfers.


Could be, unless you have enough space to mill away the existing transfers, ( while retaining cylinder integrity)
& bond in a designer-shaped, flow-optimised, & multiplex-tubed, pre-fab unit.

[jonny quest]

Wobbly, regarding hydroformed pipes. It may work both ways.
Thundercat 900cc triple, individual pipes. Straight pipes on the dyno worked amazing over stock. Hand-built to chasis... they made same as stock. Refit pipes to have the longest straightest headers we could fit... piwer came back slightly. Made stampings off these, power came back some more.
Company building hydroformed pipes wanted our business, they built a set based on our dimensions... made more power than the stanpings.

[ief]

What differences in power are you talking about then johny?

[Larry Wiechman]

Wobbly, some time ago you offered a DXF that showed how to construct one of your KT100 pipes. I'd like to roll one of these up and give it a try!
Did the header used with this pipe conform to the 75% exhaust area rule?
Would it be beneficial to cool the header near the exhaust port flange?
Is the pipe straight or a 90° diffuser?

Thanks,
Larry Wiechman
wiechman@charter.net

[Larry Wiechman]

Wobbly, regarding hydroformed pipes. It may work both ways.
Thundercat 900cc triple, individual pipes. Straight pipes on the dyno worked amazing over stock. Hand-built to chasis... they made same as stock. Refit pipes to have the longest straightest headers we could fit... piwer came back slightly. Made stampings off these, power came back some more.
Company building hydroformed pipes wanted our business, they built a set based on our dimensions... made more power than the stanpings.

Was the same material thickness used for all the pipes?

[jonny quest]

20ga for handbuilt. 19ga for hydro and stampings

[adegnes]

Episode 3 of my garage vlog is out.

https://youtu.be/15El7vUgack

[wobbly]

The pumped up pipes used the same material, so that wasnt an issue.
We finally made a press tool and made the U bend front pipe header in two 1/2 pieces, as this was the vast time consumer .
This setup made around 1/2 Hp more than the cones did.
I believe the problem with pumped pipes is that there is no way to get a definite angle change between sections.
This is especially important where the rear cone starts, as there is always a big blend area where the wave action must
be " smeared " slightly.
In effect making the rear cone shorter.
Clamping/restraining the mid section did help alot though.
Pressed pipes can be much more accurate,and have definitive angle changes.
Honda have used this method forever in racebikes, and the KTM ones built by Harolds team were stunning,with formed
header/first diffuser - the rest in cones.
My opinion would be that if pumped pipes made more power, then the actual shape was different enough that the real dimensions of the as built part,
were " better " than the drawing used

Re the KT100 pipe.This is dead straight, the bend was in the tapered header that had a machined nozzle as part of the plate flange clamp.
The reducer nozzle varied from 32mm to 36mm ( the duct being 38 ) and each engine tuner had his nozzle of choice depending upon the tune.
I will have to search for the old hard drive that has the dxf on it, I have it somewhere, but I vowed never to make another after over 2000 hand built ones,the first
500 or so i even cut the patterns and drilled the rear cone holes by hand.
CAD and Lasers were a god send financially and brain damage wise back in the day.

[wobbly]

OK, found the old drive - here is the dxf and a couple of pics.
Bugger - dxf not allowed, can admin change this please.

[Larry Wiechman]

Bugger - dxf not allowed, can admin change this please.


Looks good! :woohoo:

Can you attach the DXF to an email and send it to wiechman@charter.net?

[Muciek]

More pics of the Ktm frr parts there are 4 cyl heads carbs and reeds http://www.pit-lane.biz/t118p25-gp125-caracteristiques-ktm-frr

[TZ350]

325133

http://www.rzrd500.com/500phpBB3/viewtopic.php?f=3&t=11729&start=30

Interesting Engine build(S), lots of home brew and cunning ideas here.

[husaberg]

OK, found the old drive - here is the dxf and a couple of pics.
Bugger - dxf not allowed, can admin change this please.

Possibly.....
I thought i was on the list,
er no its not on the list.
Can you screenshot it as a word or Jpeg?
Word doc 2.00 MB

gif 768.0 KB

jpeg 768.0 KB

jpg 768.0 KB

kmz 2.00 MB

mp3 1.00 MB

pdf 2.00 MB


what is the size?
Request sent to MR T.

[TZ350]

.
The real deal, a performance 2T Two Stroke successfully running an electronic fuel injection system.


E85 at work


https://youtu.be/CnIemdISKrM

Kawasaki F86M BigHorn 350cc Air Cooled, E85 and Fuel Injected .......

325137


Here is the EFI at work.


http://youtu.be/ifSEql1X4R0

325138

F86M dyno graph.

[Frits Overmars]

Bugger - dxf not allowed, can admin change this please.Zip it Wob :shutup:
Oops, that may have come over pretty rude. What I wanted to say was: put everyting you want to post in a zipfile. That's an accepted file format. 325136

[TZ350]

Page 1590 .....


Aprilia closed their big end pins with conical plugs, but that wouldn't solve the aux/transfer short circuiting either.

Past experience tends to point into the opposite direction: circlips can be very good at causing disaster.

And what about that 3 piece pin? Well, what about acceleration values of 5000 g around BDC and 7850 g around TDC (Aprilia RSA at its 14500 maximum rpm)?

Do you think any built-up contraption would stay together long enough under that kind of stress? You're right about that, providing you use circlips at all. That is why I did away with them and click my plugs straight into the circlip grooves.

The issue is not the volume of the remaining space, but the cross flow area of the leakage path between auxiliary exhaust ports and transfer ports.

Turning to the simplest solution I could think of: leave the circlips out (saves weight) and click the plugs directly into the circlip grooves. They will work fine in combination with a normal piston pin (saves a huge amount of money compared to a Pankl pin) and it reduces the aux/transfer leak path better then even the latest domed Pankl pin, shown in the picture below-left. Right is my simple, very light plug.

There were never any lubrication problems, only a problem when someone used plugs, designed for a Simson piston, in a Kreidler piston which has different circlip goove dimensions. One plug came out, passing through the engine without doing any harm, but then the piston pin started wandering sideways, scraping the cylinder bore.

Most of the research went into finding the proper plug material. And since I don't expect I'll ever get rich from selling plugs, I'll let the cat out of the bag:
the plugs are made of Torlon. The stuff ain't cheap, but you'll get about 20 re-usable(!) plugs for the price of one Pankl pin.

326134 326135



Is it 4301? At least available easily enough.

http://nz.rs-online.com/web/p/plastic-rods/2577136/Yep, that's the stuff. Like I said, it ain't cheap.



With a pumper if you have over run richness, then the pop-off is too low and or the lever height is too high.


this my truing tool. 2 lasered vertical plates and 2 lasered v's:

326165

was only few bucks to get the stuff lasered and can be upgraded with small bearings + discs to balance cranks.

[Mental Trousers]

OK, found the old drive - here is the dxf and a couple of pics.
Bugger - dxf not allowed, can admin change this please.

As Frits said it's best to zip it up then upload it.

[FastFred]

.

https://youtu.be/JY9mrKR5SkA

Real racing ... MotoGP Historic Battles -- Rossi vs Stoner Laguna Seca 08'

[emess]

starting with blowdown and transfer STA matched to the targets in Engmod
then increasing transfer STA above the the target (keeping the same blowdown STA)
the simulator shows better midrange and peak power with no losses over the normal powerband
So the question is...
should you stick to target STA values or believe the sim results and go with the higher transfer STA?


Mick

[wobbly]

All depends upon the scavenging model you have assigned.
If you have crap transfer duct/port geometry then increasing the STA, over and above the code estimation, is what you should do anyway.
But if you are using the Aprilia scavenging model, then this has been proven to be accurate enough to believe as is.

[peewee]

A counter balance shaft might be okay for a generator side of things i had that idea myself, but i think it would be not so great for timing as it would have a fair bit backlash built in.thus the timing could be a little eratic.
The Aprilias had a pickup sensor built into the crank wheel as did the ROC/swissauto/pulse.

ill have some photos when I get a free moment. I want to take off the cylinder and side covers to have a look inside

[emess]

All depends upon the scavenging model you have assigned.
If you have crap transfer duct/port geometry then increasing the STA, over and above the code estimation, is what you should do anyway.
But if you are using the Aprilia scavenging model, then this has been proven to be accurate enough to believe as is.

Doh! Thank you Wob. I couldn't see the wood for the trees.
I do indeed have crap transfers in the sim as there is not much inner wall to play with.
Maybe a thicker liner would help.

[wobbly]

Yes its all to do with the effective Cd of the port sets.
An Aprilia sim would appear to favor the transfer STA over the all important blowdown.
But careful analysis shows that the big radius on the Ex roof dramatically increases the "real " STA as Jan developed the flow regime on
his test bench.
If the Cd is taken into account then the STA figures make sense completely.

[adegnes]

New episodes of my vlog out now!


https://youtu.be/P05qU984qXA

https://youtu.be/OaCS9Ppfqb8

Please let me know if I should quit posting links to my videos here, don't want to be a spammer!

[TZ350]

Very interesting, please keep posting about what you'er doing.

[trevor amos]

Adegnes, I`ve enjoyed your videos and much admire what you are doing, so carry on posting

[adegnes]

Very interesting, please keep posting about what you'er doing.


Adegnes, I`ve enjoyed your videos and much admire what you are doing, so carry on posting

Thanks! Means alot!

[wobbly]

Im a single malt guzzler myself, but whats the rum you are sampling ?

[adegnes]

Im a single malt guzzler myself, but whats the rum you are sampling ?

Ron Bucanero, cheap stuff I picked up in Denmark on vacation. Wish it was a bottle of Mount Gay.
I'm fond of single malts too, particularly the peaty stuff like Laphroaig.

[ken seeber]

After the last quick and dirty seal friction test, which was pretty rudimentary, I thought that we’d do better. So, turned up a bit of Delrin with a seal in both ends. This was slid over a length of stock chrome & ground Ø20 bar. This had been drilled so the inside cavity between the two seals could be pressurised. This was done using a diaphragm carb pressure tester. It was tested at atmospheric pressure and then 8 psi (sorry about the units). As you can see it was again a static test. Well almost static, as we based the torque required on its ability to break static friction and just lightly rotate. Shaft was well covered in oil prior to assembly.

325275


So, any thoughts on the results? Just the percentage difference in torque between atmospheric pressure and 8 psi (which is probably a bit above actual crankcase peak +ve pressures). Was it double or halved or the same or whatevered......?
No prizes though, as Australia is going through a financial crisis. :weep:

[tjbw]

About 54% higher?

[Frits Overmars]

It was tested at atmospheric pressure and then 8 psi (sorry about the units).At least you're aware of this hundredweight-furlong-fortnight foolishness instead of our civilized kilogram-meter-second units, so you're forgiven, Ken.


As you can see it was again a static test. Well almost static, as we based the torque required on its ability to break static friction and just lightly rotate.You could give the shaft a slight vibration with a violin bow.

EDIT: the weight pulling on the circumference of the Delrin part is also loading the seals, so in principle you should put a central bearing in that will take the weight away from the seals. Or, the larger you make the Delrin part diameter, the less weight will be required to create the necessary torque.

EDIT 2: never mind me and my bright ideas. Of course you could increase the diameter until the necessary weight approaches zero, but then the weight of the Delrin itself approaches infinity :facepalm:.

[Sketchy_Racer]

Hmmmm two seals just over 0.55 bar i'm going to go with 110%

[adegnes]

Thumbs up for performing the tests!
200% from me, go high or go home! :clap:

[wobbly]

The static lip seal friction I would have thought to be less than 1/3 of the pressurized value.

[Larry Wiechman]

Then do the same test with a few inches (sorry Frits) of vacuum. A worn seal will sometimes test OK under pressure. Vacuum changes the dynamic. Put a flowmeter between the test piece and the vacuum gauge. It's interesting to see how much depression it takes to overcome the seal.

[jacobson_se]

I have a Tz125 97/98 with cylinders from Bartol. Some of the pipes are stamped with MZB.
Wobbly do you have anything to do with the pipes or know who MZB is?

/Christer

[Lef16]

Hey guys,
I have a problem,trying to set up ignitech on a wr200 engine(tuned).
What I want to know is what feels like when the bike is over advanced and what when advance is too low.
What I feel from the bike on the road,is like it can't release it's full potential power,and from 9500 power is dropping off,at 10000 the bike is dead like it has a rev-limiter there.
And in some cases it is not hitting the power band at all and it's having momential blackouts.
Advance is 25* maximum,14* at 9000 and 11* at 10500.
I'm pretty sure this is not fuel problem,but electrical.
Please answer me as soon as possible,
Cheers

[F5 Dave]

Straight line 15deg and check static timing is right. Also it should run smoothly like that if somewhat weak at lower revs, but that confirms if its not fueling, check battery voltage while you run it up.

[wobbly]

Dave is right.The WR200 will time at 1.18mm for 15*,so set the piston there and mark the rotor and stator
in an easily seen position.
Strobe it with a 15* straight line program and check that the base timing is correct.
But depending upon the mods, too much advance will kill overev power dead.
Easy way to check what it likes , once the base timing is verified, is to add say 3* of base - this will retard the whole curve 3* from "actual ".
If it then revs better, you know what to do with the curve.
Then of course if the egt drops in the upper rpm, you have too much advance or com for the fuel, and deto is just around the corner.

MZB is a huge parts supplier, mainly for scooters, but no I have not done any designs for them.

[wobbly]

I know this isnt the correct forum for this but a bunch of people on here wanted a bypass thermostat urgently.
They are done, and I have a few not going to be anodised.
If you want one send me a PM with delivery info.

[Hemi Makutu]

No solenoid, and really? Better than a Keihin? A dirty mikuni?

No one seems to have taken on Smartcarb.

This: https://technologyelevatedco.com

[Flettner]

This: https://technologyelevatedco.com

Just another carburetor, same shirt different day.

[jacobson_se]

Wobbly, do you have some more stories to tell about Bartols work with Yamaha regarding the tz125 and tz250.

/Christer

[ken seeber]

SEAL FRICTION TEST RESULTS ARE NOW IN !!!!!!!!!!

At atmospheric pressure, the twin seal set up required 138 gm on Ø40.6 = 0.0275 Nm. The power required to overcome this friction at 14k rpm = 0.0403 kW. Remember this is for 2 seals. Note slightly less friction than before, mainly I think due to the better finished shaft surface.
A couple of points:

1. This is a quasi-static result and maybe things might change with running at actual speed. This could be tested with running the shaft between two bearings and two seal packs on the shaft. One would be used to measure the torque and the other used to apply pressure to the test piece, a passage interconnecting the two cavities inside the seal packs. See sketch below.

325290


2. As Frits correctly pointed out, there is a radial force imposed on the seals, equal to the measured force. However, I feel that this force is relatively small in relation to the seeming stiffness of the seal moulding. Notwithstanding, this could be overcome using the method shown in the sketch.

3. Larry W suggested the effects of lower than atmosphere and we could do this, but content with the results.

Now, I’m sure that most won’t believe the results, but we did it quite a few times. I expected differently as well. So, if you are still sceptical, feel free to drop in this Friday arvo and have a play yourself. We’ll provide the beer, single malt whatever, E85 or even Marsala ice cream.

Oh, the results you might ask. The friction at 8 psi was exactly the same as at atmospheric. No change. Bugger, we had a really neat labyrinth set up designed for KZs.

Back to the Slider engine.

[husaberg]

SEAL FRICTION TEST RESULTS ARE NOW IN !!!!!!!!!!

At atmospheric pressure, the twin seal set up required 138 gm on Ø40.6 = 0.0275 Nm. The power required to overcome this friction at 14k rpm = 0.0403 kW. Remember this is for 2 seals. Note slightly less friction than before, mainly I think due to the better finished shaft surface.
A couple of points:

1. This is a quasi-static result and maybe things might change with running at actual speed. This could be tested with running the shaft between two bearings and two seal packs on the shaft. One would be used to measure the torque and the other used to apply pressure to the test piece, a passage interconnecting the two cavities inside the seal packs. See sketch below.

325290


2. As Frits correctly pointed out, there is a radial force imposed on the seals, equal to the measured force. However, I feel that this force is relatively small in relation to the seeming stiffness of the seal moulding. Notwithstanding, this could be overcome using the method shown in the sketch.

3. Larry W suggested the effects of lower than atmosphere and we could do this, but content with the results.

Now, I’m sure that most won’t believe the results, but we did it quite a few times. I expected differently as well. So, if you are still sceptical, feel free to drop in this Friday arvo and have a play yourself. We’ll provide the beer, single malt whatever, E85 or even Marsala ice cream.

Oh, the results you might ask. The friction at 8 psi was exactly the same as at atmospheric. No change. Bugger, we had a really neat labyrinth set up designed for KZs.

Back to the Slider engine.


Ken hook engine crankshaft crankcase assembly to lathe,run at speed measure current draw.
Repeat with telfon seals
Then totally remove seals and repeat test (i think you will be surprised)
The Old style spring gater seals used in pommy shitters were HP killers, modern ones i would expect would be far better.

[tjbw]

SEAL FRICTION TEST RESULTS ARE NOW IN !!!!!!!!!!

...

Oh, the results you might ask. The friction at 8 psi was exactly the same as at atmospheric. No change. Bugger, we had a really neat labyrinth set up designed for KZs.

Back to the Slider engine.

I won, I won, well I was closest, I claim the prize of 'nothing' from Australia ;)

Ken, is there any leakage at 8 psi?

[wobbly]

So the friction created by the backup radial spring on the seal lip far outweighs that of the case pressure - man that
is so counter intuitive, just like most things in a 2T.

Re Harolds work on the Yamaha.
He was the team boss for them in 125 with Ui, and he had ( sorry, he told me he had ) done a huge amount of work on a Jante developing a cylinder
that bolted straight onto the TZ125 that already had over 50 Hp.
This made me super depressed at the time ,as the cylinder we had done for the BSL500, made 55Hp ( 166cc ) at 12,000 so I thought I was well off the pace bmep wise.
Yamaha wouldnt let him use it on the team bike ( that was very slow ) but looking at the nicely made cylinder it appeared just like a RS125, except it had
the oval to round transition header off the 250 factory bikes.
As it later transpired the thing had nowhere near 50 Hp when it was tested on the Derby dyno, so his boasting to me ( and Derby obviously ) was largely bullshit.
This became obvious to me when we sent a 3D printed plastic cylinder to him to test/modify on the Jante - and we never saw a result, let alone any more power.
Much of his cylinder " design " work then went to KTM 250, as did the so called A Kit Honda pipe design.
That engine was in my opinion very well conceived as a symetric parallel twin ,firing at 90* with a balance shaft, but as with Derby, the cylinder and pipe were the Achilles heel
in that Jan at the same time had made huge steps forward, initially with Harolds Derby reed, and then with the Aprilia.

[adegnes]

Thumbs up for performing the tests!
200% from me, go high or go home! :clap:

Crap, I knew I should have gone home...


https://www.youtube.com/watch?v=Gf_vP0SiOS0

Nothing in it for a crowd of seasoned bucketeers I guess, but you could watch it for a laugh!

[jonny quest]

So 2 standard crankshaft seals rob .054hp

[wobbly]

On your advice Adegnes, Im into a Friday night rum session.Only 1/2 way so far but feeling pretty good at this point.

[adegnes]

On your advice Adegnes, Im into a Friday night rum session.Only 1/2 way so far but feeling pretty good at this point.

:2thumbsup

[breezy]

so , between the small end of a 2t conrod and the big end , conrods have a familiar shape.. would anybody in the know tell me why its shaped like this? is there any reason why this is?:sherlock::sherlock:

[wobbly]

The norm is a non symmetric H section and this deals with the max stress concentrations of compression/elongation on the outer edges.
The only variation I have seen was earlier Rotax rods that were elliptical in shape ( for aero efficiency i assume ) , and a few 100cc kart engines that were slightly H
in section with the center hollowed out.
I always assumed this was to help the disrupted flow from the side RV, the reason Jan looked into putting the RV on the back.

Edit - Makr has given the correct term of I beam - not my idiot idea of a non symmetric H, sorry.

[husaberg]

so , between the small end of a 2t conrod and the big end , conrods have a familiar shape.. would anybody in the know tell me why its shaped like this? is there any reason why this is?:sherlock::sherlock:

For different shapes look at an ariel Arrow or a Alpha conrod as used in 1960 villiers conversions like the Greeves silverstone.
325341325342325343
The reasons i believe for the shapes were increased primary compression, which was of course all the rage back then. as the two strokes had cavernous crankcases and half cycle cranks.
In Irvings tuning for speed, they cover modifying two stroke rods for improved steamlining
The streamlined arrow rods were made and used in the IOM bike Herman Meier construsted were actually cheaper to make so it went into mass production.

Sorry i can't find a decent picture of any.

[Hemi Makutu]

If of interest: http://60sclassicmotorbikes.blogspot.com.au/2014/02/ariel-golden-arrow-engine-strip-part-2.html

[TZ350]

325334325335

Arrow Crank and Rods

[Hemi Makutu]

http://www.kawtriple.com/mraxl/files/crankrebuild.pdf

Note the collar/spacer the seals bear upon, was this the type included - in your seal friction test - Ken?

[husaberg]

325334325335

Arrow Crank and Rods

pic two is the origional style pic one is a nice pic, good find:niceone:

[TZ350]

325338

Tales from my recent pilgrimage to worship at the Team GPR Temple of speed.

325340

It is always great to get a look around someone else's work space. Scott's Barn is high up in the hills with a stunning vista of the valley below. Scott and Reagan were great to spend some time with. They made David and myself very welcome and allowed us to poke around and discover all sorts of interesting bikes.

325339

The first thing I came across in my tour of this very interesting place was the number one GPR rider inspecting their new bike.

The current GPR bikes are great examples of motorcycle engineering art and frame building but it was the bikes from back in the day that opened my eyes to how much effort that has always gone into putting a competitive front running Bucket together.

325346

Behind the latest examples of GPR racing machinery was what was Scot's first bike from back in the day. There were lots of bikes from yesterday, bikes that show how much effort and competitive thinking has always been put into this class.

325345 325344

I think this is Ziffles old bike and Pete Sales RG50 front end. Both very fast bikes and clever for their day. Pete's front wheel complete with alloy disk brake rotor.

[TZ350]

Pilgrimage - 2

325347

It wasn't all Buckets, here is a rear right hand chain drive VMX Honda 125 in the process of being restored to near new condition.

325348

And a 300cc NSR MC28 in a special Team GPR frame.

325352 325350

The home built Team GPR dyno. These home built dynos appear to be expertly engineered and read a lower but more accurate figure than our Dynojet. That makes their mid 20's hp FXR150's very frightening and puts them on a similar BMEP level as F1 race car engines.

325351

More examples of cleverly engineered RG50's from back in the day. They could be resurrected and still be a very fun ride today.

325349

Discovered among the Buckets in the dyno room was this Ariel Square Four.

[TZ350]

Pilgrimage - 3

325353 325354 325358

Lots of special air cooled engines that had been converted to water cooling.

325359

An air cooled 50 fitted with a water cooled head.

325355 325360

It's not all Buckets, there was an old Harley and the latest KTM in a special GPR frame.

I really loved visiting Team GPR, I hope I got most of the details right and many thanks to Reagan and Scott for their hospitality.

[Hemi Makutu]

I thought you'd been to 'Shangri La'
& found 120 y/o ex-Nazi fluid dynamics scientists still hard at work.. as sent by SS Kammler..

http://www.dw.com/image/16166342_303.jpg

( & FYI, Kawasaki, who also had Nazi science input, had plasma sprayed Al-alloy racebike discs - back in the `70s).

[breezy]

so , between the small end of a 2t conrod and the big end , conrods have a familiar shape.. would anybody in the know tell me why its shaped like this? is there any reason why this is?:sherlock::sherlock:

thanks for all the info :psst:

[peewee]

hey guys im near completetion on this engine and hope I can get some input for the head, im using methanol fuel by the way. cylinder is bolted to the crankcase and ive got a rough cut done on the head, ill check all measurements and do another final cut. because im using Honda piston with longer stroke crank I cut almost 2mm higher into the head and cut the squishband 17* to match the piston. where im needing help is on the comp ratio, width of band and piston to head clearance. heres what I was thinking for a approximate starting place. 16:1, 1.27mm piston head clearance, 50% of area band, dimensions are 90.5mm x 82mm, expected top rpm around 8,000 or so. does these head figures sound about right ? included is photos of piston at bdc and tpc. while im thinking of it I cant remember if I showed my newest bike yet either :2thumbsup

[Makr]

so , between the small end of a 2t conrod and the big end , conrods have a familiar shape.. would anybody in the know tell me why its shaped like this? is there any reason why this is?:sherlock::sherlock:

I-beam is the strongest and most efficient shape to manufacture. I-beam for the simple engineering principle of getting the mass as far away from centerline as possible.

[jasonu]

Pilgrimage - 3

325353 325354 325358

Lots of special air cooled engines that had been converted to water cooling.

325359

An air cooled 50 fitted with a water cooled head.

325355 325360

It's not all Buckets, there was an old Harley and the latest KTM in a special GPR frame.

I really loved visiting Team GPR, I hope I got most of the details right and many thanks to Reagan and Scott for their hospitality.

The buggars could have at least swept the floor before a celebrity such as yourself arrived...

[Frits Overmars]

16:1, 1.27mm piston head clearance, 50% of area band, dimensions are 90.5mm x 82mm, expected top rpm around 8,000 or so. does these head figures sound about right ?The compression ratio is something for Wobbly, he has way more experience with methanol than I have. The squish clearance seems rather big to me.
Are you going to use that piston in combination with auxiliary exhaust ports?

[wobbly]

The combination of 8000rpm and the 82 stroke gives a piston speed of 22M/Sec, so thats getting up there with such
a big heavy piston.
But yes I believe as Frits says that closer to 1.2mm will be approaching the mechanical limit and this then gives a MSV close to 38M/Sec with 48% squish area.
Methanol at 16:1 will be fine in this engine, closest I have simmed was 78/72 for Land Speed and it was safe as, so you could go a bit higher for short track use.

[mr bucketracer]

The buggars could have at least swept the floor before a celebrity such as yourself arrived...was part way through a clean up , mind you it did not get much better lol , was good to catch up with rob and met his friend :scooter:

[jasonu]

was part way through a clean up , mind you it did not get much better lol , was good to catch up with rob and met his friend :scooter:

Part way thru a clean up, yeah right...Tui etc.
I didn't see my CBR150 motor anywhere.

[peewee]

Are you going to use that piston in combination with auxiliary exhaust ports?


yes why do you ask? dont tell me i made a mistake some how :D

wob your suggestions sound like a decent place to start so ill give it a try. i figure 2* advance on the base timing is good to start with? i have no idea what the curve looks like

[wobbly]

No - dont advance the ignition.
The Methanol setup works best with the same curve as petrol - but using the high octane and latent heat to generate power with compression.
Once you have a working safe setup, and when you find out what the ignition is, you can then decide to raise the com or change the curve.

[Larry Wiechman]

yes why do you ask? dont tell me i made a mistake some how :D




Won't those cutouts on the side of the piston (wristpin area) link the exhaust sub ports directly to the transfer ports?:shit:

[peewee]

yes they will link but because the aux is tear shape it will keep linking to a minimum. unfortunatly there was no other piston choice as far as i know

[Hemi Makutu]

yes they will link but because the aux is tear shape it will keep linking to a minimum. unfortunately there was no other piston choice as far as i know

What piston are you using?

Wiseco list 'em up to 91mm as OS for the 2T Sea Doo 950,
if its a goer, dimensions compatibility-wise - they might do a custom unit from one for you.

[peewee]

its 90.5mm cr500 piston. far as i know prox, oem, wiseco, wossner all have the piston sides sliced off. maybe other engines also use 90.5 but what is the wristpin height and pin diam ? this piston has long side skirting which keeps the aux from linking to the crankcase at tdc. other than the large side cutouts, i think this piston will be fine.

[Hemi Makutu]

Wiseco will likely respond to an info/custom request ( they have a template for this - on their site) & give the dimensions.

Or, ask one of the 'Bucket foundry' blokes here to fill your inconvenient piston cavities with a metal-foam matrix?

www.azom.com/article.aspx?ArticleID=5940

[peewee]

wiseco gladly does special requests but they have a minimum order. ive talked with them about special stuff before. ill just use what I have for now and if I find a better alternative later I can swap out the piston easy enough

[Hemi Makutu]

Sure P-W, try what you have, but asking Wiseco to see the 91mm piston's vital stats shouldn't cost you..
( & what you have is impressive, so thanks - for sharing)

Likely a PWC forum/local rebuild shop could show you one too.

[SwePatrick]

As there are somany experianced tuners writing in this thread i must apologize for asking.

But is there any good quality 66.4mm bore piston with piston ring dowelpin at 6 o clock?
Ofcourse single pistonring.

Rgds
Patrick

[41juergen]

Peewee: Woessner makes pistons to your desired design, it only cost a bit more ... :msn-wink:

[Hemi Makutu]

As there are somany experianced tuners writing in this thread i must apologize for asking.

But is there any good quality 66.4mm bore piston with piston ring dowelpin at 6 o clock?
Ofcourse single pistonring.

Rgds
Patrick

If that piston you seek is for a Yamaha, you could be in luck..

[wobbly]

Most all the 66.4 engines can be had in a single ring design, and yes Wossner make plenty of them in flat top and domed
for everything from KTM to CR250

[Flettner]

Peewee: Woessner makes pistons to your desired design, it only cost a bit more ... :msn-wink:

I too would be more inclined to use a Woessner, with a comparison on the pistons I use, the Woessner is by far the better piston over the Wiseco and slightly more cost effective too. Next order will be a batch of 10, with this number Woessner will make the changes I want.

[2T Institute]

hey guys im near completetion on this engine and hope I can get some input for the head, im using methanol fuel by the way. cylinder is bolted to the crankcase and ive got a rough cut done on the head, ill check all measurements and do another final cut. because im using Honda piston with longer stroke crank I cut almost 2mm higher into the head and cut the squishband 17* to match the piston. where im needing help is on the comp ratio, width of band and piston to head clearance. heres what I was thinking for a approximate starting place. 16:1, 1.27mm piston head clearance, 50% of area band, dimensions are 90.5mm x 82mm, expected top rpm around 8,000 or so. does these head figures sound about right ? included is photos of piston at bdc and tpc. while im thinking of it I cant remember if I showed my newest bike yet either :2thumbsup

Will rev to more like 6000-6500 unless you like rebuilding big ends and your teeth haven't all fallen out from the vibrations

[Hemi Makutu]

http://motocrossactionmag.com/bike-tests/we-ride-donny-emlers-kx500ktm-250sx-hybrid-two-stroke-project-bike

As the reviewers say, if KTM built a current factory version, it'd sell..

500's aren't really too annoyingly vibey to ride, & for sure - they won enough long desert races - in the day.

[peewee]

Will rev to more like 6000-6500 unless you like rebuilding big ends and your teeth haven't all fallen out from the vibrations

it will turn up more than 6500, i know this for sure. hard to say how long big ends will last but its using the prox cr500 conrod assembly. with the old topend that used 92.25 piston, most the vibration seemed to be in the middle rpm range. above and below wasnt all that bad

[TZ350]

325383

Team ESE has taken on a cylinder porting apprentice.

[TALLIS]

325383

Team ESE has taken on a cylinder porting apprentice.

Must be a dentist or tattoo artist :Punk:

[husaberg]

325383

Team ESE has taken on a cylinder porting apprentice.

Tell the apprentice she will get fired/disowned/Introduced to Donald Trump, if she doesn't put on her Safety glasses.
325384

[peewee]

hemi im glad you like what ive done but most these guys have accomplished way more impressive things. besides, i only copied old hat that i found around this site. none of it was my own ideas

[Hemi Makutu]

hemi im glad you like what ive done but most these guys have accomplished way more impressive things. besides, i only copied old hat that i found around this site. none of it was my own ideas


Peewee, what you have kindly shared is interesting, esp' doing it with a big cylinder,
& showing the port/time/area issues of getting it to breathe well, rather than just 'tractor' about..

Maybe you could ask Flettner to do a bolt-on P-V for it?

[wobbly]

Listen you perverts, instead of doing that buy her one of these.

http://www.ccspecialtytoolstore.com/cylinder-head-brace-swivel-p/bv1.htm

Makes porting a doodle even for dirty old men bucket racers.

[Frits Overmars]

Tell the apprentice she will get fired/disowned/Introduced to Donald Trump, if she doesn't put on her Safety glasses.

Listen you perverts, instead of doing that buy her one of these. http://www.ccspecialtytoolstore.com/cylinder-head-brace-swivel-p/bv1.htmYeah, that will do her eyes a lot of good. That head-swivel is a fine tool, but it won't be much use to a blind tuner.
Come to think of it: judging by the pictures there must be more than one blind tuner around. 325400 325401

[adegnes]

Yeah, that will do her eyes a lot of good. That head-swivel is a fine tool, but it won't be much use to a blind tuner.
Come to think of it: judging by the pictures there must be more than one blind tuner around. 325400 325401

Would love to know the story behind that wooden piston in there!

[wobbly]

The FPE disaster pics reminds me of running in the very first recieved Rotax twin on the Zipkarts new dyno.
Rotax QC was non existent back then, and the very first time I did a full power test, it threw a rod and cut the front of the case
completely in 1/2.
We had to buy 100 big end bearings, and I sat for hours with a 4 digit micrometer and put together sets of needle rollers
within 1 uM of each other - then it was reliable.

[SwePatrick]

If that piston you seek is for a Yamaha, you could be in luck..

It´s actually for an Kawasaki, but it has 18mm pin and pistonheight isn´t very important as i already has a spacer to move the cylinder upwards to fit the long rod i use.
I can just make an another spacer or shim of the one i have.

The imprtant thing is the locking pin for the ring.
I want it at six o clock so i can port out the B-transfers a lot more.
As i can see with wiseco´s 'racers choice' piston for KX250 the single ring is ~7 o clock, not good.

[adegnes]

E8 is up!
https://youtu.be/NAYQyAf0rdY


https://youtu.be/NAYQyAf0rdY

[Frits Overmars]

A port map is fine for recording the number of ports, but that's about it. As you say, radii and chamfers will distort the map, so you can't take reliable port height measurements from it. But you cannot take reliable port corner radii measurements from it either, so why bother making a port map at all?

Having gotten that off my chest, I want to say that I enjoy your vlogs more and more. A lot of familiar tips are passed on in a relaxed, understandable way.
Keep up the good work Adegnes :niceone:.

[adegnes]

A port map is fine for recording the number of ports, but that's about it. As you say, radii and chamfers will distort the map, so you can't take reliable port height measurements from it. But you cannot take reliable port corner radii measurements from it either, so why bother making a port map at all?

Having gotten that off my chest, I want to say that I enjoy your vlogs more and more. A lot of familiar tips are passed on in a relaxed, understandable way.
Keep up the good work Adegnes :niceone:.

Thanks! Means alot!
Anyone with ideas for better ways of measuring the port corner radii?

[Frits Overmars]

Thanks! Means alot!
Anyone with ideas for better ways of measuring the port corner radii?The pictures show Jan Thiel's 'coins-on-a-stick' that were mainly used for feeling the passage width of ports but that can also be used to check radius diameters.
325429 325430

[adegnes]

The pictures show Jan Thiel's 'coins-on-a-stick' that were mainly used for feeling the passage width of ports but that can also be used to check radius diameters.
325429 325430

Thanks! I'll fabricate a set!

[Frits Overmars]

Thanks! I'll fabricate a set!You can make those coins-on-a-stick like Jan had, but for radius checking it could be even more useful to have a set of balls-on-a-stick.
If I need to measure a radius in a port corner, I usually check with a drill shaft. After all I've got those lined up with 0,1 mm diameter increments.

[adegnes]

You can make those coins-on-a-stick like Jan had, but for radius checking it could be even more useful to have a set of balls-on-a-stick.
If I need to measure a radius in a port corner, I usually check with a drill shaft. After all I've got those lined up with 0,1 mm diameter increments.

Clever! Good thing I've just ruined a bunch of drill bits on hardened stuff!

[Reedyspeedy]

Hello all,

This might be a far fetched question, but does anyone know or know of anyone, who has/can alter dynojet software to increase the resolution of the analog inputs? Or is there a third party software/hardware that can run in-line with dynojet software to able to data log and have the logs plotted along with the software plots?

Hope that makes sense.

Thank you

[JanBros]

Would love to know the story behind that wooden piston in there!

a friend of mine once made a wooden piston for a moped. the challenge was that it needed to run 100m. didn't make it that far, but he managed +/- 65m.
his was very basic though, even the "ring" was made on the lath, part of the same piece of wood.

[adegnes]

a friend of mine once made a wooden piston for a moped. the challenge was that it needed to run 100m. didn't make it that far, but he managed +/- 65m.
his was very basic though, even the "ring" was made on the lath, part of the same piece of wood.

:clap::clap::clap:

[Drew]

325383

Team ESE has taken on a cylinder porting apprentice.
Is that Sharn? Met her at the Cliffhanger hill climb in March. Has she gone bucket racing?

[TZ350]

Yes. She has had her Bucket bike in the workshop fettling it for the 2-Hour.

[Grumph]

a friend of mine once made a wooden piston for a moped. the challenge was that it needed to run 100m. didn't make it that far, but he managed +/- 65m.
his was very basic though, even the "ring" was made on the lath, part of the same piece of wood.

The late Norm Hayes of Invercargill NZ made an all wooden engine - which ran.
He was one of Burt Munro's main supporters and a pretty good engineer in his own right. It was done for a bet - with another Invercargill engineer, Oyster who posts on here occasionally. That side of the bet was to produce an engine with everything visible except the combustion chamber. I've seen that one running and Norm's wooden engine was on display at the Hayes family hardware store last time I was down there. Clever guys.

[wobbly]

I have used the Wossner piston with a single ring pinned at 6 from a CR250 in flat top, and the same for a KTM 250
with a dome - both off the shelf,Wossner part numbers.
All the 250 MX engines are 66.4 with 18mm pins, varying deck heights - so plenty to choose from.

[peewee]

all the late model ktm 250 pistons have the peg at 6oclock, how many years this design goes back I don't know. I would assume the cr250 from '02-'07 likely has the 6oclock peg also, before '02 is likely 5 and 7 position. the other japs mostly used cylinder reed valves so I would guess they were 5 and 7 also but im not sure. should be able to google search piston images and get a idea or check photos on ebay

I never made a tool for measuring angles after the fact but I did make some templates for cutting in new aux exh passages and it worked very well. basically I took some measurements in the cylinder of the existing exh passages then drew the new desired exh ducting I wanted on stiff paper and cut it out. then i just grinded the passage floor until the template fit nice. the template was for the aux floor because once you establish that, the walls and roof can be grinded much faster. saved me a lot of guess work and time. unfortunately I must have erased the actual photos of the exh templates I had but heres more or less how I did it. also I made some inner and outer trans wall templates that saved me a ton of time. without templates as a guide it would of been near impossible for me to do the work I did

[jasonu]

I have used the Wossner piston with a single ring pinned at 6 from a CR250 in flat top, and the same for a KTM 250
with a dome - both off the shelf,Wossner part numbers.
All the 250 MX engines are 66.4 with 18mm pins, varying deck heights - so plenty to choose from.

What sort of wood is it made of?

[husaberg]

What sort of wood is it made of?


https://www.youtube.com/watch?v=MfU-oSTDt2I

[peewee]

325383

Team ESE has taken on a cylinder porting apprentice.

no safety glasses. no respirator. :shit:

[F5 Dave]

I've seen some of Jason's allymininium welding and it was pretty good.

[Ocean1]

You can make those coins-on-a-stick like Jan had, but for radius checking it could be even more useful to have a set of balls-on-a-stick.
If I need to measure a radius in a port corner, I usually check with a drill shaft. After all I've got those lined up with 0,1 mm diameter increments.

I've even seen tiny french curve sections on a stick.

But these are better: https://www.youtube.com/watch?v=rxFJfbdCT_k

And becoming almost reasonably priced...

[Ocean1]

The late Norm Hayes of Invercargill NZ made an all wooden engine - which ran.
He was one of Burt Munro's main supporters and a pretty good engineer in his own right. It was done for a bet - with another Invercargill engineer, Oyster who posts on here occasionally. That side of the bet was to produce an engine with everything visible except the combustion chamber. I've seen that one running and Norm's wooden engine was on display at the Hayes family hardware store last time I was down there. Clever guys.

This one? <iframe width="560" height="315" src="https://www.youtube.com/embed/hyYznnQCVWY" frameborder="0" allowfullscreen></iframe>

It's still there. Still works.

[SwePatrick]

I have used the Wossner piston with a single ring pinned at 6 from a CR250 in flat top, and the same for a KTM 250
with a dome - both off the shelf,Wossner part numbers.
All the 250 MX engines are 66.4 with 18mm pins, varying deck heights - so plenty to choose from.

Man, i have searched and searched, looked at pictures, i haven´t been able to find anyone yet.
Can i ask you for an example with domed top?

Edit: oh.. i read too fast.. you actually gives two examples,, sorry ;)

Edit2: is it this one?
https://www.amazon.com/Wiseco-824M06640-2-Stroke-Off-Road-Piston/dp/B000GVBJU8
don´t mind the wiseco,, just the motorcycle model i´m after.

[mr bucketracer]

Yes. She has had her Bucket bike in the workshop fettling it for the 2-Hour.i should let her ride a real bike , my 4 stroke lol :laugh:

[marsheng]

Yes, 909 will settle out in AvGas after only a few minutes of mixing it up - did exactly that to me on the dyno.
We tested for probably 20mins,stopped for a cup of tea,and it would not restart,I could see straight oil in the bowls of the Lectrons.
But add a cup of acetone in 5L and no issues after that.
Motul Kart GP does not do this in Avgas.

The 909 and Avgas "mixing fog" got really bad in Winter. No problems with 98. Just checking that you would recommend Motul Kart GP for the Maico.

Thanks Wallace.

[tjbw]

https://www.youtube.com/watch?v=rxFJfbdCT_k

Thanks for that link Ocean1, very nice tool, in fact I'm going to write a letter to Santa ;)

[adegnes]

all the late model ktm 250 pistons have the peg at 6oclock, how many years this design goes back I don't know. I would assume the cr250 from '02-'07 likely has the 6oclock peg also, before '02 is likely 5 and 7 position. the other japs mostly used cylinder reed valves so I would guess they were 5 and 7 also but im not sure. should be able to google search piston images and get a idea or check photos on ebay

I never made a tool for measuring angles after the fact but I did make some templates for cutting in new aux exh passages and it worked very well. basically I took some measurements in the cylinder of the existing exh passages then drew the new desired exh ducting I wanted on stiff paper and cut it out. then i just grinded the passage floor until the template fit nice. the template was for the aux floor because once you establish that, the walls and roof can be grinded much faster. saved me a lot of guess work and time. unfortunately I must have erased the actual photos of the exh templates I had but heres more or less how I did it. also I made some inner and outer trans wall templates that saved me a ton of time. without templates as a guide it would of been near impossible for me to do the work I did

Great tips! I don't think I've ever seen someone modify a cylinder as extensively as you have!

[lohring]

For small engines I use a set of templates for porting. Since we usually deal with the same style of industrial engine, I just need templates for the two bore sizes typically used. The transfer and exhaust ports are very similar across a series of manufacturers. They have one piece cylinders so measuring the template to set port heights is a lot easier than measuring the cylinder. The extended screw goes through the plug hole and is secured with another nut. It takes one template for the transfers and one for the exhaust. This style reduces the grinding errors, but flat slugs can also be used. The complete article on the method and measurement calculations is in the article Zenoah Porting 101 (http://www.namba.com/content/library/propwash/2016/April/). See the pictures below.

Lohring Miller

325451 325452 325453 325454

[FastFred]

Very Clever. Thanks for the tip.

[wobbly]

Wossner 8090DA is single ring flat top
Wossner 8082DA is single ring domed.

[Hemi Makutu]

Here's a current 'off the shelf' 2T unit, which with a power tune, might make an interesting bike engine.

www.recpower.com/3703%20-%203%20cylinder%20-%202%20cycle.htm

[peewee]

thanx for the nice words adegnes. if you ever seen these cylinder before modification, the power is very low.

[SwePatrick]

Wossner 8090DA is single ring flat top
Wossner 8082DA is single ring domed.

Thanks Wobbly,, many many thanks =)

[adegnes]

Very Clever. Thanks for the tip.
+1 Great tip! I think someone else on here have made something similar too. Seems very useful!

Edit: Almost forgot:

E9 is out.
https://youtu.be/NdXS79Le3pw


https://youtu.be/NdXS79Le3pw

Made a "channel trailer" too.
https://youtu.be/bhI70X5caeo


https://youtu.be/bhI70X5caeo

Yes I know, pressing + welding the slugs in would be better, but I don't own a tig welder, don't know what alloy the "tungsten" slugs are, and I wanted to get it done fast. It'll be fine! :wacko:

[Frits Overmars]

Yes I know, pressing + welding the slugs in would be better, but I don't own a tig welder, don't know what alloy the "tungsten" slugs are, and I wanted to get it done fast.
It'll be fine! :wacko:Famous last words :D.
I hope that at least you used high-temperature epoxy. But I wouldn't put my trust in it. I've seen pressed-plus-glued slugs move about and nibble at the con rod.
Screwing-plus-loctiting them in would ge a better way, but cutting a thread on the slugs might be a bit of a problem. Tack-welding would be best.

[adegnes]

Famous last words :D.
I hope that at least you used high-temperature epoxy. But I wouldn't put my trust in it. I've seen pressed-plus-glued slugs move about and nibble at the con rod.
Screwing-plus-loctiting them in would ge a better way, but cutting a thread on the slugs might be a bit of a problem. Tack-welding would be best.
.... And with my track record of epoxy related engine failures I should know better... Here we go again! :laugh:

World leader in entertainment at my own expense!

[ken seeber]

Just goes to show, you can't trust the media these days...:banana:

325488

[jasonu]

Just goes to show, you can't trust the media these days...:banana:

325488

If you can afford it that is...
http://www.nzherald.co.nz/business/news/article.cfm?c_id=3&objectid=11740760

[wobbly]

I know is being smart arse but its the old story of "fools rush in ".
Not that Im saying you are a fool, far from it, but using epoxy, just to get it done "in a rush " is false economy.
And I know without a TIG you are buggered, but the slugs material is Tungsten with sometimes a few small % of other shit,but you dont need to
worry about the welding technique of it as all you do is crank up the amps and fusion melt the flywheel and slug together.
A small amount of any steel filler rod can be used when just simply creating a small arc of weld.
And as the balance factor still isnt correct at 48%, dont fuck about , get on with the job of doing it properly - take out the epoxy and add some more Mallory.

[adegnes]

I know is being smart arse but its the old story of "fools rush in ".
Not that Im saying you are a fool, far from it, but using epoxy, just to get it done "in a rush " is false economy.
And I know without a TIG you are buggered, but the slugs material is Tungsten with sometimes a few small % of other shit,but you dont need to
worry about the welding technique of it as all you do is crank up the amps and fusion melt the flywheel and slug together.
A small amount of any steel filler rod can be used when just simply creating a small arc of weld.
And as the balance factor still isnt correct at 48%, dont fuck about , get on with the job of doing it properly - take out the epoxy and add some more Mallory.

You are right, and as it is winter in Norway and at least 5-6 months until I can take it for a test ride, I will listen.
Must be growing up... You wont believe how many times I have learned(can't really say that can I...) the hard way, especially when it comes to epoxy!

I could just buy a new stock replacement crank too, they're balanced to 55% and fairly cheap.

[190mech]

adegnes ,I'm enjoying your vids!
Perhaps you could burn the epoxy off with a heat gun and get it TIG welded at a welding shop?
You mentioned getting a stock crank,can it handle the extra stresses from your modifications?Maybe installing a quality racing rod kit on stock crank wheels would be a good alternative..

[adegnes]

adegnes ,I'm enjoying your vids!
Perhaps you could burn the epoxy off with a heat gun and get it TIG welded at a welding shop?
You mentioned getting a stock crank,can it handle the extra stresses from your modifications?Maybe installing a quality racing rod kit on stock crank wheels would be a good alternative..

Thanks!
Yep, was planning on using a propane torch though, thinking the epoxy will turn to ash long before the heat is high enough to mess up the hardening.

I share your concern about the stock crank(if the Doppler is any better is questionable, seeing how they screwed up with the balance factor), and a rod kit is a good idea.

[adegnes]

The answer is probably obvious to the more experienced in welding and metallurgy, but what's the reason I can't just use my mig to tack the slugs in there?

[ken seeber]

I was also going to suggest the MIG. If you ground away the Mallory (tungsten) pieces locally in a couple of appropriate edge spots, you could just MIG in these areas so the weld overlapped the interface. No hardness loss hassles. Should be able to do this in less than 5 months.

[adegnes]

I was also going to suggest the MIG. If you ground away the Mallory (tungsten) pieces locally in a couple of appropriate edge spots, you could just MIG in these areas so the weld overlapped the interface. No hardness loss hassles.


Sounds like it could work! Any objections?



Should be able to do this in less than 5 months.

:clap::clap::clap:

[wobbly]

Yep, a couple of small chamfers on the Mallory, and crank up the heat so you for sure melt into the flywheel material as well as
filling the crevice with weld.
But MIG is for bridge building, a small TIG is cheap as these days and much more suited to doing pretty welds on racebike frame/crank/pipes etc.

[adegnes]

Yep, a couple of small chamfers on the Mallory, and crank up the heat so you for sure melt into the flywheel material as well as
filling the crevice with weld.
But MIG is for bridge building, a small TIG is cheap as these days and much more suited to doing pretty welds on racebike frame/crank/pipes etc.

I think I'll give the mig a go then!
E10 is uploading, doing a few test welds with the mig(and flux core, no less) on a scrap crank. Didn't work very well, but that crank is cast iron(I think), and the Doppler is forged steel.
A tig is definitely on my wish list!

[jasonu]

I think I'll give the mig a go then!
E10 is uploading, doing a few test welds with the mig(and flux core, no less) on a scrap crank. Didn't work very well, but that crank is cast iron(I think), and the Doppler is forged steel.
A tig is definitely on my wish list!

Doing it with a mig is asking for a ruined part. Don't be a tight arse, pay a shop a few bucks to do it correctly and properly with a tig.

[190mech]

Also if the tungsten slug is a 'push fit' and tacked from the outside of the crank wheel,what keeps it from walking into the con rod as Frits said??

[DoldGuy]

It´s actually for an Kawasaki, but it has 18mm pin and pistonheight isn´t very important as i already has a spacer to move the cylinder upwards to fit the long rod i use.
I can just make an another spacer or shim of the one i have.

The imprtant thing is the locking pin for the ring.
I want it at six o clock so i can port out the B-transfers a lot more.
As i can see with wiseco´s 'racers choice' piston for KX250 the single ring is ~7 o clock, not good.

If this is for a KX cylinder, the other 66.4 Pistons will expose the auxiliary exhaust ports at TDC. The port floors would need to be raised a minimum of 4 mm & shaped very much like the ports of the KTM 250 Wobbly ported and posted pictures of.

[adegnes]

Also if the tungsten slug is a 'push fit' and tacked from the outside of the crank wheel,what keeps it from walking into the con rod as Frits said??

I was planning to get a couple of tacks on the inside of the webs too. I think I can reach in there with flux core and no gas nozzle.

E10 is up!
https://youtu.be/blwUtIKaZn4


https://youtu.be/blwUtIKaZn4

[peewee]

I think miller and Lincoln have some smaller tig welders that aren't terribly expensive. they don't have all the bells and whistles but it might do the job your looking for. then again if you end up needing to weld other stuff you may need a machine with more functions.

[peewee]

Patrick if you still need a 66.4 piston I have a cast vertex from '13 250sx. had about 3hrs runtime when removed. pegs at 6 and im quit sure theres no chance of the aux popping open at tdc no matter what cylinder you put it in or how low you drop the aux. bad news is its 2 ring . pay the freight and its yours if you want it

[SwePatrick]

If this is for a KX cylinder, the other 66.4 Pistons will expose the auxiliary exhaust ports at TDC. The port floors would need to be raised a minimum of 4 mm & shaped very much like the ports of the KTM 250 Wobbly ported and posted pictures of.

Aha, thanks for the info.
But mine KX250(1996 engine) is downstroked to 61.1mm stroke from 72mm(the piston is at tdc about 11mm down from the original position(72mm stroke) with correct squish)
It runs in a special 'outlaw' mopedracing class in Sweden.
Maximum cc allowed is 212cc, mine is 211.47cc
I also run a 137mm long rod (Maico/Yamaha 490) to make it take the rpm´s with ease.

With that said, i have a special insert in head to move the chamber 11mm down into cylinder.

[SwePatrick]

Patrick if you still need a 66.4 piston I have a cast vertex from '13 250sx. had about 3hrs runtime when removed. pegs at 6 and im quit sure theres no chance of the aux popping open at tdc no matter what cylinder you put it in or how low you drop the aux. bad news is its 2 ring . pay the freight and its yours if you want it

Nice!
I could use it as mockup to measure things, and in spare if something happens.
I live in Sweden, check freight and come back to me =)
How to solve payment?
Paypal?

Pm me.

Rgds
Patrick

[trevor amos]

Adegnes, I have to say that your video diary is becoming essential viewing, don`t worry too much about the small mistakes and errors made, we all have done that. Keep it up you must a world wide following by now all willing you on, terrific stuff , thanks!

Trevor, in GB.

[adegnes]

Adegnes, I have to say that your video diary is becoming essential viewing, don`t worry too much about the small mistakes and errors made, we all have done that. Keep it up you must a world wide following by now all willing you on, terrific stuff , thanks!

Trevor, in GB.

Thank you for the kind words!

[wobbly]

The reason I chose the CR250 piston to go into the KTM ( apart from the single 6 o'clock ring pin ) I did was purely due to the skirt cutout below the small end pin
on that model was lower than than others I looked at.
This gave plenty of coverage over the Aux port bottom edge at TDC, preventing any short circuiting issues.

[2T Institute]

............ but what's the reason I can't just use my mig to tack the slugs in there?
You should be shot for suggesting that , you will be tempted to use it on engine cases, frames etc

[F5 Dave]

First the epoxy now the mig. Blah blah. I can't preach. You should have seen my LC head for my MB when I asked myself; gee I wonder if I can get it to hang together devcon the outside jacket on if I key it right?

And you know what? It worked great. Poopoo the naysayers.

Think it made it through practice. Not so much the first race before a side fell off.

Great believer in learning from others mistakes. But some you are destined to make yourself. Sometimes that can lead to unexpected results.

[Hemi Makutu]

First the epoxy now the mig. Blah blah. I can't preach. You should have seen my LC head for my MB when I asked myself; gee I wonder if I can get it to hang together devcon the outside jacket on if I key it right?

And you know what? It worked great. Poopoo the naysayers.

Think it made it through practice. Not so much the first race before a side fell off.

Great believer in learning from others mistakes. But some you are destined to make yourself. Sometimes that can lead to unexpected results.

Basic bodge 1001... & work in some metal scourer pad material - as a matrix while you are at it too, L.O.L...

[F5 Dave]

Just can't help yourself J.A.W.

[Hemi Makutu]

Bloody superglue on a clutch cable - in lieu of solder - has got me home before, always keep some in the tote bag..

[adegnes]

You should be shot for suggesting that , you will be tempted to use it on engine cases, frames etc
Yeah, can't really say I've changed can I...

A part of me still want to try the epoxy... All my epoxy failure experience is on old cast aluminium, no steel. Never used it on moving parts either.

[Haufen]

Anyone got a handy hint on why my engine keeps doing this to my beloved r7376 spark plugs?
This is the third one, and I'd prefer spending my racing budget on other stuff than plugs to be honest.

326079

[jasonu]

Anyone got a handy hint on why my engine keeps doing this to my beloved r7376 spark plugs?
This is the third one, and I'd prefer spending my racing budget on other stuff than plugs to be honest.

326079

Ham fisted wrench man???

[wobbly]

Yep its the wrench.
Some plug sockets have a step down inside, and this means the porcelain is supporting that smaller diameter.
When you lean on the wrench, you are leaning on the porcelain - and not being flexible at all, it cracks off the resistor tube.
Change sockets.

[adegnes]

The shit has hit the fan.

[F5 Dave]

The fan has shorted out, the shit has caught fire and the orphanage is ablaze.

[husaberg]

The fan has shorted out, the shit has caught fire and the orphanage is ablaze.

With a bit of luck he might have two strokes.

[adegnes]

:laugh::laugh::laugh:

[TZ350]

Page 1600 ...


Aprilia closed their big end pins with conical plugs, but that wouldn't solve the aux/transfer short circuiting either.

Past experience tends to point into the opposite direction: circlips can be very good at causing disaster.

And what about that 3 piece pin? Well, what about acceleration values of 5000 g around BDC and 7850 g around TDC (Aprilia RSA at its 14500 maximum rpm)?

Do you think any built-up contraption would stay together long enough under that kind of stress? You're right about that, providing you use circlips at all. That is why I did away with them and click my plugs straight into the circlip grooves.

The issue is not the volume of the remaining space, but the cross flow area of the leakage path between auxiliary exhaust ports and transfer ports.

Turning to the simplest solution I could think of: leave the circlips out (saves weight) and click the plugs directly into the circlip grooves. They will work fine in combination with a normal piston pin (saves a huge amount of money compared to a Pankl pin) and it reduces the aux/transfer leak path better then even the latest domed Pankl pin, shown in the picture below-left. Right is my simple, very light plug.

There were never any lubrication problems, only a problem when someone used plugs, designed for a Simson piston, in a Kreidler piston which has different circlip goove dimensions. One plug came out, passing through the engine without doing any harm, but then the piston pin started wandering sideways, scraping the cylinder bore.

Most of the research went into finding the proper plug material. And since I don't expect I'll ever get rich from selling plugs, I'll let the cat out of the bag:
the plugs are made of Torlon. The stuff ain't cheap, but you'll get about 20 re-usable(!) plugs for the price of one Pankl pin.

326134 326135



Is it 4301? At least available easily enough.

http://nz.rs-online.com/web/p/plastic-rods/2577136/Yep, that's the stuff. Like I said, it ain't cheap.



this my truing tool. 2 lasered vertical plates and 2 lasered v's:

326165

was only few bucks to get the stuff lasered and can be upgraded with small bearings + discs to balance cranks.

[ken seeber]

326104

2 strokes live on........

[Frits Overmars]

Adegnes, I have to say that your video diary is becoming essential viewing, don`t worry too much about the small mistakes and errors made, we all have done that. Keep it up you must a world wide following by now all willing you on, terrific stuff , thanks!Adegnes, I like the way that you don't edit your mistakes out of your videos but just show them so we can all learn from them, like putting a clamp on that slug only after we all could see it coming that it wouldn't work without a clamp.
I also like the somewhat shorter length of that last video. But I have to say that you'll never make a good politician; you're too honest :rolleyes:.

By the way: most mass-production crankshafts are forged but that doesn't mean they are cast-iron.

[adegnes]

Adegnes, I like the way that you don't edit your mistakes out of your videos but just show them so we can all learn from them, like putting a clamp on that slug only after we all could see it coming that it wouldn't work without a clamp.
I also like the somewhat shorter length of that last video. But I have to say that you'll never make a good politician; you're too honest :rolleyes:.

By the way: most mass-production crankshafts are forged but that doesn't mean they are cast-iron.

Thanks! I try to make them as entertaining as I can and feel the mistakes help with that!

E11 is out, shorter, more mistakes and now with an intro/outro!
https://www.youtube.com/watch?v=_xVmPj0h7Yc


https://www.youtube.com/watch?v=_xVmPj0h7Yc

[Haufen]

Ham fisted wrench man???


Yep its the wrench.
Some plug sockets have a step down inside, and this means the porcelain is supporting that smaller diameter.
When you lean on the wrench, you are leaning on the porcelain - and not being flexible at all, it cracks off the resistor tube.
Change sockets.

Thanks for the tip! I will double-check the wrench and sockets. But I think this one even has a rubber inside.
At least the last one of the spark plugs had only been in contact with an open ended wrench, so no chance of contact with the porcelain. Unfortunately it showed the same damage.
The other two plugs have been tightened with both the conventional spark plug socket and an open ended wrench. But maybe the open ended wrench is the cause, as I started tightening the plugs with it about the same time the damage started.

If you have any other ideas, please let me know.

[wobbly]

So Adegnes, I thought we had finally " got thru ".
The Tungsten is welded in, as you say maybe not pretty ,but the balance factor is still bloody miles off.
You have done all this work,yet the thing is not even close to being done right - i need to come over there and belt you
over the head with an empty Rum bottle, maybe better a plastic bag full of bigger Tungsten's.

[adegnes]

So Adegnes, I thought we had finally " got thru ".
The Tungsten is welded in, as you say maybe not pretty ,but the balance factor is still bloody miles off.
You have done all this work,yet the thing is not even close to being done right - i need to come over there and belt you
over the head with an empty Rum bottle, maybe better a plastic bag full of bigger Tungsten's.

And it seems like while working on the "half assing", personal issue #2 has surfaced; absent-mindedness(if that's a word)
As I often do, I got carried away and forgot about the weight being too low. :facepalm:

Ok, enough. I'll recheck the bf, assemble the engine and try it. It wont be perfect, but at least then I know how it reacts to that specific balance factor - I can pretend the mistakes made were in the name of science.

This video series has turned into a tragicomedy!
I've obviously opened up a can of worms here, what's next?

[Hemi Makutu]

Dynafocal engine mounts?

http://patentimages.storage.googleapis.com/US6871820B2/US06871820-20050329-D00005.png

[husaberg]

Thanks! I try to make them as entertaining as I can and feel the mistakes help with that!

E11 is out, shorter, more mistakes and now with an intro/outro!
https://www.youtube.com/watch?v=_xVmPj0h7Yc

https://www.youtube.com/watch?v=_xVmPj0h7Yc

I enjoy your videos Plus your english is great, esp considering its likely your second or third language.
Most kiwis struggle with one.
I must ask though, Did you consider pressing the crank apart and then welding?
ps youre out of ethanol.

[adegnes]

I enjoy your videos and your english is great considering its likely your second or third language
I must ask though, Did you consider pressing the crank apart and then welding?

Yep, as an afterthought of course... Trying to stay in character here!
Edit: Oops, forgot to say thank you!

[adegnes]

ps youre out of ethanol.

Need to do something about that!