ESE's works engine tuner [Archive] - Page 13

TZ350

18th November 2010, 06:01

From page 181

Thomas and Bucket have got the generator system working OK now, using two coils with 420 turns of 0.6mm enameled wire on each and wired in parallel. The system was made with a new $15 pit bike rectifier/12v-regulator from Trademe and two rolls of 0.6 wire from JayCar at $11 each.

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10.74 AC Volts from the generator, 13.9 DC Volts from the Pit Bike Rectifier/Regulator.

To find DC Volts from an AC source and full wave rectifier and smothing capacitor, multiply AC volts by 1.44, less 0.5 to 1.0 Volt for the forward resistance through the regulator........

How are you guys powering the ignition units?
12v battery?

Hi Koba, as you know, we made our own generator by rewinding the ignition coils so they put out about 14 Volts at 2.5A and used a cheap Pit Bike rectifier regulator to charge a 12 Volt battery.

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We used one of these jell type batteries they work well on the CB125T's up here at Mt Welly, but the vibration of our 2-stroke killed it.

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So in a moment of brilliance I grabbed the 14 Volt battery from a Black and Decker battery drill.

Worked great, lasted all day on the dyno, then after a while the battery lost power and the ignition started playing up.

When the 14Volt batteries voltage dropped the ripple voltage from the generator was false triggering the ignition and we were getting multiple sparks per revolution...... and we could easily see this with a timing light.

It only took Thomas and Bucket a few moments to relise my mistake.

A 12 Volt charging system dosn't work well with 14 Volt batteries......:Oops:

Our next move is to try a capacitor instead of a battery, a 24V 100,000 uf electrolytic should do it, our IgniTech ignitions will run any where from 10-18Volts and draw about 0.2A at idle and 0.8A flatout, so the 12 Volt charging system and capacitor could be OK.......

koba

18th November 2010, 06:33

ahh, true! I lost that in all the information!

Thats damn smart.

Henk

18th November 2010, 06:49

I have heard of people running big caps instead of batteries and charging systems in the past and going total loss that way, not sure how it would work for a long race though. If you go for a huge cap instead of a battery and still run the charging system it may pay to slap a smaller cap in parrallel, electrolytics tend to be a bit slow so you may need something else to knock the spikes off.

bucketracer

18th November 2010, 06:55

it may pay to slap a smaller cap in parrallel, electrolytics tend to be a bit slow so you may need something else to knock the spikes off.

That was the problem with the nearly flat battery, its internal resistance made it a bit slow too and the charging system could develop voltage spikes (ripple voltage) across it.

Yow Ling

18th November 2010, 14:58

I have heard of people running big caps instead of batteries and charging systems in the past and going total loss that way, not sure how it would work for a long race though. .

Its not total loss if you still have the charging system. Caps are great but wont initially power up the electronics. I have a zeeltronic that likes a battery , it is only the signal processor and will start without a battery but goes into panic mode with no battery at 6k , a revlimiter at that speed is not very impressive. Battery wire fell off in the dipper at ruapuna, I thought it was seizing.

F5 Dave

18th November 2010, 16:52

Bert

19th November 2010, 06:15

Yes the square GP port is a problem, 70% did not allow much rounding of the window, 75% was as much about improving the shape as increasing port time area.

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Sorry for dredging this up,
though i fully understand your problems with square ports (thanks Suzuki), I was actually referencing the work done on the port itself (red circles, as seen in earlier photos). maybe a bit more rounding in these areas might provide less pressure/whatever on the piston/ring: you have plenty of bore to work with.

now here is a ring gobbler (something like 77-78% of bore):
http://www.kiwibiker.co.nz/forums/album.php?albumid=2701&attachmentid=203280

TZ350

19th November 2010, 07:12

Thanks Bert, you have a lot of interesting pictures on your site, http://www.kiwibiker.co.nz/forums/album.php?albumid=2701

I did not know you had posted about your build, very interesting, I will have a good look through it.

If anyone else has posted their work I would love a link so I can read through it..........

TZ350

19th November 2010, 07:19

Yeah I've had to put on a bigger battery with my Zeel, they are pretty thirsty & need a decent buffer. For a racebike I just want to push & go. Batteries are just a pain & another reason not to finish a race. Seen it again & again with people running total loss. How to ruin your day in several drawn out episodes with lots of swearing, adult situations & self flagellation.

I totaly agree, even with the very low current draw of the IgniTech CDI Ignition total loss can be a problem. We will be looking at improving the charging system.

Easyish to make a 12 Volt one using some 12V Rectifier/Regulator unit but a bit tricker to make a 14 Volt one from scratch.

Henk

19th November 2010, 14:27

Charging voltage for a 12V system is up around 14 vols in any case. Might not be as hard as you think.

F5 Dave

19th November 2010, 15:01

some regulators are set higher than others. Used to run ~ 13.7 but newer ones on some brands try to get away with higher voltages probably to account for voltage loss through nasty contacts etc so have been creeping up to 14.5.

Of course if you don't have the output power it will sag under load to less than regulated voltage. Add to this cheap small batteries vibrating their plates apart & creeping internal resistance. Those non adjustable MX CDIs are looking good again despite their compromised curve.

Bert

20th November 2010, 06:57

Modifying an analogue CDI (if you can get them apart). some might find this interesting:
http://www.geocities.com/a57ngel/moto/CDI.html
http://www.geocities.com/a57ngel/moto/CDI-mod.html

TZ350

20th November 2010, 07:57

Modifying an analogue CDI (if you can get them apart). some might find this interesting:
http://www.geocities.com/a57ngel/moto/CDI.html
http://www.geocities.com/a57ngel/moto/CDI-mod.html

Thats interesting Burt, if one had the stator part of a MX ignition they could follow the schematic and make the CDI part.

Another usefull kit from JayCar. Kit number KC5466 $29 aprox. Its a CDI kit to replace a bikes blown CDI. This could be adapted in all sorts of ways.It uses the bikes own high voltage stator coil to charge it and the trigger coil to fire it.

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It would be worth looking at the Jacar CDI kit's to see if they can be modified to give an ignition curve too .........

Hmmmmm thats got me thinking about them again.

Bert

20th November 2010, 09:57

It would be worth looking at the Jacar CDI kit's to see if they can be modified to give an ignition curve too .........

I maybe wrong but I think Skunk has build one of these for his RD/ZXR project
http://www.kiwibiker.co.nz/forums/blog.php/2010-Skunk

the kit has potential as it has a fixed pulse (no advance/retard) but requires a trigger (from a Hall effect sensor etc). now surely it is not that difficult to have it set at the most retarded setting & have some smarts sitting between the trigger and the trigger input of the CDI (that could be changed at different RPM = pulse frequency) which acts as a advance/retard emulator by controlling the timing of the trigger...
go back 50 odd pages and I think we have had this conversation before...:facepalm:

TZ350

29th November 2010, 15:09

Modifying an analogue CDI (if you can get them apart). some might find this interesting:
http://www.geocities.com/a57ngel/moto/CDI.html
http://www.geocities.com/a57ngel/moto/CDI-mod.html

Hi Bert

The Jaycar kit looks like it could be modified to have a retard curve as shown in the link on your post.

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It also looks like it could be made to run without a seperate trigger coil.

Although a trigger coil could be fitted, and it could even be as simple as a few turns (60?) of wire around the main HV generator coil.

TZ350

29th November 2010, 15:18

The complete how too......... of the Jaycar CDI kit

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Bert

29th November 2010, 18:25

Hi Bert

The Jaycar kit looks like it could be modified to have a retard curve as shown in the link on your post.

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It also looks like it could be made to run without a seperate trigger coil.

Although a trigger coil could be fitted, and it could even be as simple as a few turns (60?) of wire around the main HV generator coil.

Hadn't actually compared both of them side by side:facepalm:.

but yes it looks as if it can be modified to do just that. nice; good spotting
(I'll have to have a play with mine and see what we can get out of it).

I quite liked the idea of a separate trigger, a little pic micro sitting in-line would enable programming of the advance curve.

was thinking about one of these:
http://newmanz.co.nz/shop/index.php?main_page=product_info&cPath=66&products_id=205
question is could the pick-up coil be modified to generate enough voltage at hig RPMs??? if so a lathe would sort out the rest...

TZ350

29th November 2010, 21:56

I quite liked the idea of a separate trigger, a little pic micro sitting in-line would enable programming of the advance curve.

was thinking about one of these:
http://newmanz.co.nz/shop/index.php?main_page=product_info&cPath=66&products_id=205
question is could the pick-up coil be modified to generate enough voltage at hig RPMs??? if so a lathe would sort out the rest...

Hi Bert

Jaycar have a small Velleman (kit VM111) PIC programming board with software.

I have had a look at the ignition from Newmans before, I think it should work OK with the Jaycar CDI. The problem for me was that the rotor taper was to big for the GP which is quite small, smaller than a MB100 or CB/SL125.

If the trigger works ok at low rpm then it should be ok at higher rpm too as the voltage increases the faster the magnetic field cuts the windings in the coil, ie, voltage goes up as rpm increases untill the magnetic flux through the iron core saturates.

Anyway an ignition firing every revolution at 12,000rpm is running at 200Hz, (12,000/60=200), not much above base speaker frequency, so not very fast in electrical terms.

I think Shellracing has used one of those ignition units from Newmans. So lots of interesting CDI bits to play with........:D

TZ350

30th November 2010, 15:46

This is my XL spreadsheet for the basic design of an expansion chamber, based on work by someone who knows their stuff.........

The spread sheet......

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And the Maths...........

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Bucket used the spread sheet to design a series of chambers who's tuned length ranges from 820 to 920mm, there will be five chambers in the series.

We could have used mid section slip joints but as the cones themselves vary in length with changes in the tuned length we wanted to have a series of chambers that could more represented what the final design should look like.

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Three of Buckets chambers compaired with the GP/RM pipe that NedKelly uses on his 23rwhp Suzuki GP125 (see Page 200).

Things that affect the tuned length are:-

Higher RPM: shorter tuned length. as there is less time for the wave to get there and back.

More exhaust port duration: longer Tuned Length, as there is more time for the wave to get there and back.

More Power (higher BMEP indicating more heat) at the same RPM, longer Tuned Length: as the exhaust gas is hotter and the wave travels faster so gets there and back quicker.

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Bucket making up the cones.

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Bucket getting his hand in at TIGing them up.

Finding the right Tuned Length is a bit of the Chicken and Egg thing, you don't know the exhaust temp untill you have made a pipe and dynoed it. Then you can work backwards from the hp and calculate the BMEP which you need to know if you wan't to accuratly design a new pipe.

We had an idea of the style of pipe we wanted, medium GP race and expect that having this series of chambers covering the range of Tuned length variables that we will be able to close in on the best option quickly.

These pipes are pretty generic and will be usefull for testing with other engines too.

kel

30th November 2010, 16:46

Bucket used the spread sheet to design a series of chambers ... These pipes are pretty generic and will be usefull for testing with other engines too.

:woohoo: hope they have a 37mm header

TZ350

1st December 2010, 18:01

richban

1st December 2010, 18:13

.

Blue line, a front running FXR150

Shouldn't that be a near standard FXR? I will have mine on the dyno on saturday so will post a graph on the weekend. Used to make 24 Old engine that is, same engine that ran Taupo last year. It 2 has a wobbly pipe now.

speedpro

1st December 2010, 18:43

richban

1st December 2010, 19:11

I've just negotiated an exclusive contract with Wobbly for next year.

This is the text of an email I got recently from him:

"I got an email from Kevin Bann complaining to some bastard had got 29 out of an MB100.
I told him 30 was going to be easy and that 4 strokes were shit."

He's another guy who will never cross to the dark side. :yes:

Yes I got the same email. The good thing is that Kevin and Wobbly are now at war trying to make lots of power out of bucket engines. That means some of the most talented engine developers around are now putting all there knowledge and technology into buckets or should 1 say F4. Looks like I was lucky to get his input into the megaphone before the war started. New FXR engine will be together next week. Then of to Manifield to run it in. Then to the dyno. Don't under estimate the power of the dark side.

ac3_snow

1st December 2010, 19:43

That means some of the most talented engine developers around are now putting all there knowledge and technology into buckets or should 1 say F4.

hmmm guess thats good news.. or it may make life a whole lot harder trying to keep up?

RMS eng

1st December 2010, 21:17

.

Another dyno graph from the Mt Eden Motorcycles Dyno.

Blue line, a front running FXR150

Red line, my old Suzuki GP125

Green line, Speedpros new Wobbly designed MB100

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Speedpros bike is indeed a beast........:facepalm:...... Taupo is looking serious........

would greens MB100 still make 29 HP if the dyno was set to SAE HP,Jasons KE100 makes 24.8HP on the SAE sheets i have but would be 25.55 HP in DIN
chris p

Damien_Toman

1st December 2010, 21:23

Great workshop photos :). I always find workshops fascinating - the place where ideas take shape :).

TZ350

1st December 2010, 21:25

would greens MB100 still make 29 HP if the dyno was set to SAE HP,Jasons KE100 makes 24.8HP on the SAE sheets i have but would be 25.55 HP in DIN chris p

Yes your right there is a difference I will see if there is an SAE graph, we prefer SAE ourselves but used DIN so as to compare apples with apples as other graphs posted here were in DIN or PS. DIN = PS = 735.5W and hp (UK) = 745.7W

29.6 DIN converts to 29.2 HP, using this handy converter, http://www.statman.info/conversions/power.html

But whatever, Speedpros effort has got to be the stuff of legends.

F5 Dave

2nd December 2010, 10:31

Yeah but the ESE bike whips it up until ~10,500. Enforce a Bucket revlimiting std CDI in the next rules update.:shutup:

What make of dyno is the Mt Eden one? My old aircooled 125 (which I ran at Taupo in '06 was clearly outpowered by RG150s, which should have 26-28hp) ran 24hp on a dyno here in wgtn, but it only managed 19 at my usual dynojet one with no changes.

bucketracer

2nd December 2010, 12:04

What make of dyno is the Mt Eden one? My old aircooled 125 (which I ran at Taupo in '06 was clearly outpowered by RG150s, which should have 26-28hp) ran 24hp on a dyno here in wgtn, but it only managed 19 at my usual dynojet one with no changes.

Dyno Jet, WinPep software version 6.03.01, autocorrecting for RAD and Humidity too, I think.....

jasonu

2nd December 2010, 12:47

...But whatever, Speedpros effort has got to be the stuff of legends.

Mike, if you don't beat the coal burners I will send my wife over there to kick yr ass!!!

jasonu

3rd December 2010, 13:10

Here are my hand drawn dynojet 100 runs from 1997 on top of Greens latest posted graph. Mike Green was also there that night running his T Macintosh.
Bike KE125 bottom end with RG400 cylinder, D bored 28mm flat slide mikuni.
The graph labeled RS, same motor with a modded 1991 RS125 pipe.
The graph labeled TZ, same motor with a TZ500 pipe. This was the last run of the night and the only dyno run with this pipe.
When riding with the RS pipe the bike easily pulls from 8k, hits 11k and signs off abruptly. 22HP peak @ 10500
When riding with the TZ pipe it will pull from 8k but doesn't really get going until 9k. It runs hard to 12k and will over run nicely to about 12600. 24.8HP peak @ 12000

Looking at Greens graph, it seams 10k+ will be the order of the day and it should really rip. I am sure you lot will be looking at improving the low end power, you may loose a pony or two up top but with 29.8 you can afford it.

kel

3rd December 2010, 13:43

. It runs hard to 12k and will over run nicely to about 12600. 24.8HP peak @ 12000.
Yeh but the FXR makes more power at 7k, I dont want to play any more. :sick:

speedpro

3rd December 2010, 15:52

you'd be one of the people voting for standardised ignition systems with a rev limit, say 8,000rpm?

If the other advantage the sludge brigade have, motors that are half as big again as the real race motors, was taken away we'd still toast you.

Yow Ling

3rd December 2010, 17:02

Standard ignition that fires every other stroke, that should give parity with the diesels

richban

3rd December 2010, 18:55

If the other advantage the sludge brigade have, motors that are half as big again as the real race motors, was taken away we'd still toast you.

Does that mean I can go make mine a 200. 100 2 stroke 200 4 stroke. Nice round numbers always look better. I think we should be fine with a 150. All the fast weed whackers blew up last year.

koba

4th December 2010, 09:04

Does that mean I can go make mine a 200. 100 2 stroke 200 4 stroke. Nice round numbers always look better. I think we should be fine with a 150. All the fast weed whackers blew up last year.

The last two years have been won by Diesels after reliability issues with some fast two strokes.

richban

4th December 2010, 12:00

Well just got back from the Dyno. Mixed bag really. The biggest improvement has been the Mega designed by Wobbly. I has fattened up the middle nice. After a few carb changes the throttle slide cover gasket gave up the ghost and ended the session. I am quite sure that with out the big exhaust gas probe up its bum it would still top out at 24 as it did a year ago. Still to rich on the pilot and a little on the needle but happy with the main jet. Well thats the old engine still going strong after a year of racing. The new one is almost finished and is looking good.

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TZ350

4th December 2010, 13:03

richban

6th December 2010, 11:42

.

Rich, the old one looks pretty good, no wonder it went so well at last years TRRS, I am looking forward to seeing a dyno graph from the new engine.

Things are getting very interesting in Buckets now, with std FXR's bringing a lot of new people into the sport and others building fast 2 and 4 stroke specials..........

Well its better than I thought really. My bro just pointed out that the dyno dynamics dynos are about 15% down on a dyno jet and this is common knowledge. ( news to me ) It makes sense looking at past experience on the track up against street stocks. just hanging in the slipstream on the big straights so its more like 26 at the mo. But apples to apples she has lots more in the mid. The new engine is a bit on the limit so it might make good power but also might just explode in a shower of shinny light pieces of metal. Just as long as it don't explode on the same corner at Taupo that saw me K.O ed in the gravel last year.

TZ350

6th December 2010, 19:28

richban

6th December 2010, 20:20

I am very impressed by this, I wouldn't have thought it possible to get an FXR into the mid 20's. If you wanted to share a few pictures of your work I would love to see them, I have always enjoyed 4-strokes........

I can't take much of the credit for this really. My Bro is the brains behind most of it. We sit down and bounce ideas around then try them out. Like you guys do. The engine we are creating now was hatched at last years Taupo. Its taken a year to get it together. Hope to have it on the dyno this weekend for its fist run.

F5 Dave

7th December 2010, 12:30

So as I posted some while back, my old 125 on Motomart's dyno was 24hp but 19 on a dynojet. Hope that doesn't burst the bubble.

jasonu

7th December 2010, 12:51

So as I posted some while back, my old 125 on Motomart's dyno was 24hp but 19 on a dynojet. Hope that doesn't burst the bubble.

Shit Dave I was looking forward all day to say that!!! Dam time zones.
That puts the FXR at 22HP Motomart(not 23 as that is only a tiny spike at the end of the graph) less 15%+- = 18.7 HP Dynojet which most everyone else uses as the standard which is about what I thought a good FXR might make. A stock CRF150R makes 20HP.

richban

7th December 2010, 16:35

So as I posted some while back, my old 125 on Motomart's dyno was 24hp but 19 on a dynojet. Hope that doesn't burst the bubble.

Probably just some bad tuning on your part Dave.

Buckets4Me

7th December 2010, 21:32

Probably just some bad tuning on your part Dave.

or 5 years in the back shed (under the house ?) collecting dust :p

F5 Dave

8th December 2010, 16:32

koba

8th December 2010, 17:37

richban

8th December 2010, 18:30

Nah done within a couple of weeks & no changes. Actually I'd have to look up my notes, but I think I increased power whilst doing testing on the Motomart dyno, so I last tested with 19 on the DJ & arrived with no changes & read 22 or 23

& got it up to 24 with some changes. So the diff may be less than I suggested, But you see what I mean. I had heard MM dyno was 15% optimistic by the DJ operators other comparisons.

See the thing is. If you look on line and research dyno dynamics v dyno jets all you will find is the opposite to what you are saying. All that aside I am very confident that the power the bike has is very close to what the graph is saying. It has a year of racing under its belt against fast CBR's and lots of street stocks on Manfeild and Ruapuna there is video even. You can not deny race results. The last all in race at BOB is proof enough. The bike is fast. And lets not forget with me on it the total weight is 200kg

Anyway you are not allowed to bag it, coz it might be for sale after Taupo. I need top dollar.

Buckets4Me

8th December 2010, 18:52

Anyway you are not allowed to bag it, coz it might be for sale after Taupo. I need top dollar.

I'll give you twice that :)

2 dollar and you can keep the gravel

richban

8th December 2010, 18:59

I'll give you twice that :)

2 dollar and you can keep the gravel

Might hold you to that. Could be all its worth after it bursts into flames on lap 2.

Buckets4Me

8th December 2010, 20:00

Might hold you to that. Could be all its worth after it bursts into flames on lap 2.

this is realy looking to be the best year yet

wish I could be there

TZ350

9th December 2010, 05:42

.

It is looking to be a very interesting year at the TRRS, and I will be there.......... :D

F5 Dave

9th December 2010, 09:53

See the thing is. If you look on line and research dyno dynamics v dyno jets all you will find is the opposite to what you are saying. All that aside I am very confident that the power the bike has is very close to what the graph is saying. It has a year of racing under its belt against fast CBR's and lots of street stocks on Manfeild and Ruapuna there is video even. You can not deny race results. The last all in race at BOB is proof enough. The bike is fast. And lets not forget with me on it the total weight is 200kg

Anyway you are not allowed to bag it, coz it might be for sale after Taupo. I need top dollar.

Hey I'm not saying it isn't fast. Having a flat power curve means the mean power through the gears is high compared to a peaky bike so you can go faster esp on longer ccts. My 125 was getting juiced by the RG150s at Taupo back in 06/07 but I beat them all 'cause it took them till the end of the straight to catch up again. Heck I beat a few RG150s at Taupo & Ruapuna on my 50.

Ruapuna takes quite some time to learn & those local lads sure know how to ride there well. But most of those bikes aren't fast.

Stay on at Taupo this year & I'm sure you'll do very well.

speedpro

9th December 2010, 12:15

The power spread is a big thing, but a bit less so at somewhere like Taupo. We did a through the gears run on the dyno before we got it all sorted and it never went below 25hp after the shift. The MB50 gearbox is sweet but even so it was noticeable the drop in power between gears on the kart track if I shifted a bit early. Mind you it was only making 25hp then whereas it doesn't drop below that now when shifting on the dyno.

TZ350

9th December 2010, 16:26

The power spread is a big thing.........

Some interesting FXR dyno charts.

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A mid field or better FXR thats peddled with a great deal of determination and does very well.

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NedKellys GP125 graph compaired to the FXR and you can see the FXR has nearly twice the useable power delivery and that seems to make them very hard to beat with hp alone at Mt Welly.

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A megaphone equiped FXR that runs at the sharp end of A grade at Mt Welly. A little megaphoneits just befor 8K that the owner hopes to dial out with a different length inlet trumpet.

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And Marshangs very well developed and interesting FXR special ...........

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Speedpro's MB100 green line looks like it has plenty of useable power compared to TeeZee's GP125 red line and the front running FXR, blue line.

Its obvious that some hp is needed at Mt Welly but its the whole package that's important and the FXR's seem to have it as they are very hard to beat or even keep up with when racing them there.

koba

9th December 2010, 18:15

Is it correct that the last three roadrace spectaculars have been won b FXRs?

If so I guess that would make them hard to beat at Taupo too!

speedpro

9th December 2010, 21:44

Is it correct that the last three roadrace spectaculars have been won b FXRs?

If so I guess that would make them hard to beat at Taupo too!

You're clutching at straws I think :innocent:

FXR owners afer TRRS - :cry::cry::cry::cry::cry::cry:

TZ350

9th December 2010, 21:52

Is it correct that the last three roadrace spectaculars have been won b FXRs?

If so I guess that would make them hard to beat at Taupo too!

Last years winners and race results.

F4 GP, Andrew A, FXR150 best lap 1m27.48 http://www.marktime.co.nz/rfiles/091228/RACE01.PDF

1st F4 Race (6) Darryl Cotten, Honda MB best lap 1m30.52 http://www.marktime.co.nz/rfiles/091228/RACE06.PDF

2nd F4 Race (14) Darryl Cotton, Honda MB best lap 1m27.37 http://www.marktime.co.nz/rfiles/091228/RACE14.PDF

koba

9th December 2010, 22:03

You're clutching at straws I think :innocent:

FXR owners afer TRRS - :cry::cry::cry::cry::cry::cry:

haha!

I know the last two have been won by FXR's.

BUT we will be bringing up an FXR and an MB powered bike that I'm going to ride over the FXR...

(Yeah I realise I'm not even in contention.)

F5 Dave

10th December 2010, 15:19

50bucketracer

10th December 2010, 17:10

'Sfunny, I remember when one of the Sheriffs boys won a GP at Ohakea on a 'onda 4 stroke & everyone was blown away, think it was Chris (Kris?) rather than Craig.

A 4 stroke? yer kidding! Was a 2V 125 in those days too.

But more amusing was I think the next year Morley won on a 2 stroke that he had assembled from old parts like the night before or something.:blink:

Yep for those interested in a bit of bucket GP history, it was back in 94 that Kris Shirrifs took the first 4T GP win (from Jimmy & Pete Steadman with me 4th).

But there have been 3 other 4T wins before the FXR wins at Taupo - 03, 04 & 05 at Auckland with Karl Morgan (twice) & Hayden Fitzgerald.

Morley Shirrifs won the F4 GP 3x, all on his old bitsa TF100:
In 95 from Ziffle & Speedpro
In 96 from Jasonu & Jimmy
In 98 from me & F5 Dave

Speedpro & I are 2 old gents that have never quite managed to win the F4 GP - I've been 2nd 5x & he has been 2nd 2x.

I'm sure looking forward to Taupo, though I'm well short of 29hp! Hopefully there will be more to the race than hp - last year my son qualified on pole with only 18hp.

speedpro

10th December 2010, 20:38

Morley won the GP one year after making an ignition from a box of bits at the track on the morning of the GP. Wires were twisted together with a bit of tape. He is a super talented rider. I came 2nd behind Jimmy at Taupo one year, we lapped third place. I won the last Wigram GP in front of Ziffle, again we lapped 3rd place. My bike has come 2nd one more times than me. I'd been hauled away from Ohakune in an ambo and Jimmy had blown a crank so he jumped on mine and came 2nd behind Peter Steadman I think. The Shirriff 4T that won the GP dropped a valve the next time they started it. Pete Sales had a quick 125 4T and was coming 3rd at the GP one year with me chasing. Unfortunately for him the cam chain tensioner went "ping" about 100m from the line on the last lap. I pipped him, just.

Buckets are well fast enough now to head back to Wanganui again. I talked the Shirriffs into it one year and quite a few others. We did good and there was some very red faces when the racing ended, same thing at Nelson one year.

koba

11th December 2010, 05:08

Yep for those interested in a bit of bucket GP history, it was back in 94 that Kris Shirrifs took the first 4T GP win (from Jimmy & Pete Steadman with me 4th).

But there have been 3 other 4T wins before the FXR wins at Taupo - 03, 04 & 05 at Auckland with Karl Morgan (twice) & Hayden Fitzgerald.

Morley Shirrifs won the F4 GP 3x, all on his old bitsa TF100:
In 95 from Ziffle & Speedpro
In 96 from Jasonu & Jimmy
In 98 from me & F5 Dave

Speedpro & I are 2 old gents that have never quite managed to win the F4 GP - I've been 2nd 5x & he has been 2nd 2x.

I'm sure looking forward to Taupo, though I'm well short of 29hp! Hopefully there will be more to the race than hp - last year my son qualified on pole with only 18hp.

Morley won the GP one year after making an ignition from a box of bits at the track on the morning of the GP. Wires were twisted together with a bit of tape. He is a super talented rider. I came 2nd behind Jimmy at Taupo one year, we lapped third place. I won the last Wigram GP in front of Ziffle, again we lapped 3rd place. My bike has come 2nd one more times than me. I'd been hauled away from Ohakune in an ambo and Jimmy had blown a crank so he jumped on mine and came 2nd behind Peter Steadman I think. The Shirriff 4T that won the GP dropped a valve the next time they started it. Pete Sales had a quick 125 4T and was coming 3rd at the GP one year with me chasing. Unfortunately for him the cam chain tensioner went "ping" about 100m from the line on the last lap. I pipped him, just.

Buckets are well fast enough now to head back to Wanganui again. I talked the Shirriffs into it one year and quite a few others. We did good and there was some very red faces when the racing ended, same thing at Nelson one year.

I love hearing these sorts of stories.

jasonu

11th December 2010, 13:12

...I'm sure looking forward to Taupo, though I'm well short of 29hp! Hopefully there will be more to the race than hp - last year my son qualified on pole with only 18hp.

Your bike will also be way short of the oppositions 90+kg's.

jasonu

11th December 2010, 13:19

I love hearing these sorts of stories.

Yeah in '96 Morley spent the whole weekend pissing about with his bike, wouldn't start, wouldn't run, leaked blah blah. They were even having trouble getting it started for the race. When the flag dropped, off he went, didn't see much of him past lap 10. I heard the next time it was run (the next years GP) it shit itself, not sure how true that is.

TZ350

11th December 2010, 15:27

Buckets4Me

11th December 2010, 17:40

TRRS winners....Taken from a Blog Post of Kobas........

2007 - Tim Fraser - FXR
2008 - Richard Ford - FXR
2009 - Andrew Adlam - FXR

I agree with Koba, the FXR 's can't be written of yet..... this year is shaping up to be very interesting indeed.

the 2 hour was won by a 2t and both rick and tim couldn't keep up with it
also I belive that the rider has set a good lap time around Taupo last year 1m 27 sec ?

I recon it could easily go to a much younger rider this year

TZ350

11th December 2010, 21:15

.

In 2007 Tim had been down the week or so before to a Taupo Ride Day with his 600 and got in some valuable practice and was running hot in the TRRS F4 practice and qualified on pole.

Tim won the first F4 race, Kieth Biddle had borrowed Buckets4me's old GP125 and he won the the second race.

I was leading the third race :bleh: until half way round on the last lap and just as I was going up the hill at the back of the track the engine started playing up with fuel starvation.

Some gunge had clogged the fuel filter :crazy: and it slowed me enough for Tim and NedKelly to get by before the Chequered Flag.

The over all points for the day went Tim :first: Keith :second: and NedKelly :second: equall and myself :third:

As there is only three places on the Podeum :second::first::second: and only three cups, I missed out as third place didn't get a cup that year ....:crybaby:

Still the :second: and :second: and :third: bikes were all Team ESE 2-Strokers.

Things have got much more competitive now and just getting to the pointy end would be an achevement.

koba

12th December 2010, 08:35

Taken from a Blog Post of Kobas........TRRS winners......

2007 - Tim Fraser - FXR
2008 - Richard Ford - FXR
2009 - Andrew Adlam - FXR

I agree with Koba, the FXR 's can't be written of yet..... this year is shaping up to be very interesting indeed.

Ah, I didn't mean to blog that, I got all confused with which buttons did what. But yeah you obviously saw it.

F5 Dave

12th December 2010, 20:44

. . .
Morley Shirrifs won the F4 GP 3x, all on his old bitsa TF100:
In 95 from Ziffle & Speedpro
In 96 from Jasonu & Jimmy
In 98 from me & F5 Dave

Speedpro & I are 2 old gents that have never quite managed to win the F4 GP - I've been 2nd 5x & he has been 2nd 2x.

. . .

Yeah I haven't ridden the F4 many times, but one of the more memorable races was Taupo that year it rained cats & dogfish. I crashed the H on the old turn 1 flat out & had to kick the bike away 3 times before I was free of it :bye:& hit the dirt still sliding fast. I got to it pulled the clutch & jumped back on & tried to take off in 6th Bwooah, change change Bwoahhh, change change & was off again, left side of bar twisted in 30degrees.

I was running old Yoko 110s, but the front was virtually bereft of tread so I figured I'd just go for it. There was quite an attrition rate but I also found a groove & was hauling in people, not that it mattered I figured. But I saw Dave ahead in the distance & the red mist came down so I passed him & gapped a little. No doubt this caused Dave to figure there was some more traction & he started hauling me back bit by bit & I was getting the feeling my luck was running fine every time the front tucked on T1.

I got taken a bit off the track by a madman Grifith on the hubcentre 100 when he passed me & promptly crashed & I think that's when Dave got close enough to pass. We only had a couple of laps to go but I figured there was no point battling for a nowhere position. Little did I know I'd been in 2nd place for a good deal of the race:facepalm:.

But the funny part of the story is when I came back to the pits someone said Gee Dave, - your bleeding! Eh? Sure enough dripping out of my leathers. Sheet!:shit:, didn't even know I was hurt! Took the leathers off which now weighed about 40kg, remember it had been raining heavily & I'd done the F5 & F4 GP. My leathers were leaking a heap of red dye. Phew!

TZ350

13th December 2010, 22:29

Finding the right Tuned Length is a bit of the Chicken and Egg thing, you don't know the exhaust temp untill you have made a pipe and dynoed it. Then you can work backwards from the hp and calculate the BMEP from which you can then get the average exhaust temp which you needed to know in the first place if you wan't to accuratly design a new pipe.

226000

Bucket with the test pipes he has made.

226001

We could have used slip joints in the mid section to try and find the correct tuned length.

But the cones need to vary in length too and we wanted to use test chambers for finding the tuned length, that more accuratly reflected what the final design should be.

F5 Dave

14th December 2010, 12:55

So are you going to attempt to dyno them as straight, & if so - how will you mount them?

bucketracer

14th December 2010, 13:01

So are you going to attempt to dyno them as straight, & if so - how will you mount them?

Fingers crossed they can be dynoed straight, the exhaust points to the side a bit, so with any luck the pipes should fit.

226093

Traditional slip joint and springs at the header and the rest just propped or tied up for the duration of the test.

TZ350

16th December 2010, 15:45

.

The rush is on for Taupo and not enough time to test Buckets chambers and make a new one for the bike so we have to get the best we can out of an old RS125 pipe which we think is too short.

226222

The pipe has been split in the mid section and varying length inserts made for it. With the insert in place the wrap around on the outside is held tightly by hose clamps.

There is also a range of header extensions to go between the header and cylinder. So there are plenty of options for finding the right tuned length and adjusting it at the header or in the mid section, whatever works best.

This is a real Bucket as it has Honda, Kawasaki, Suzuki and Yamaha as well as a few home made parts, in it.

Buddha#81

16th December 2010, 17:55

TZ350

16th December 2010, 18:39

.

Yes.......... your right....... :weep:

Buckets4Me

16th December 2010, 19:16

Thats gold, you guys have been testing and devloping all year and now ya rushing to get something going for taupo?:facepalm:

If ya had a FXR you could have won the last three GP's put it in the shed between without any need for development! :weird:

seeing as how they have built 2 new bikes and rebuilt another + keepet 2 f5 and a 4th f4 bike going I dont think they have done to bad do you ?

I bet there isn't a standard fxr as reliable and fast as my 2 smoker. 18 h/pat the rear wheel. 5 years and counting, 4 2 hours, 3 taupos , 5 years non stop racing and I have had the engine apart only once (to see how it was going)

Buckets4Me

16th December 2010, 19:26

.

Yes.......... your right....... :weep:

if you want a slow booring bike

( good if you can ride but I need the H/P )

Buddha#81

16th December 2010, 19:28

I bet there isn't a standard fxr as reliable and fast as my 2 smoker. 18 h/pat the rear wheel. 5 years and counting, 4 2 hours, 3 taupos , 5 years non stop racing and I have had the engine apart only once (to see how it was going)

My standard FXR engine is having a freshen up after 4500 race km (all at ruapuna, levels, methven, nelson and greymouth street races) thats after Sketchy owned and thrash it. Relaible....i'd say more than........faster we will never know but it wasnt as fast as the ones that won the last three taupo gp's.:bleh:

I never questioned what Team ESE has achieved this year....just thought the team might have started preparing earlier?

Buckets4Me

16th December 2010, 20:34

My standard FXR engine is having a freshen up after 4500 race km (all at ruapuna, levels, methven, nelson and greymouth street races) thats after Sketchy owned and thrash it. Relaible....i'd say more than........faster we will never know but it wasnt as fast as the ones that won the last three taupo gp's.:bleh:

I never questioned what Team ESE has achieved this year....just thought the team might have started preparing earlier?

how much earlier should they start ? ( 20th november 2008 )

there has been more than 250hours spent on each of the 2 new bikes this year + Ned kellys bike has had a compleat rebuild
the 2 f5's are still running
then zebras bike needs a tune
a couple of fxr's to run up and play with
a half dosen hours on Speedpros bike
Tz's rg50 to finish
the aprilla 50 to start

you get the point ? there just isn't enough time in the day ( or year )

they spend more time playing with bikes than working and started before getting home from the last TRRS

Buckets4Me

16th December 2010, 20:36

I never questioned what Team ESE has achieved this year....

I do often :innocent:

TZ350

16th December 2010, 21:46

Relaible....i'd say .......faster we will never know but it wasnt as fast as the ones that won the last three taupo gp's. :bleh: ....just thought the team might have started preparing earlier?

There is certainly something to be said for FXR's and with any luck they might make it 4 in a row ......... :facepalm:

We started in earnest on our new Taupo bikes last March and have been working hard on them all year, I can't believe we have run out of time .... :blink:

Looks like I will be dragging an untested bike to the TRRS, still if it all turns to custard there will be plenty of exciting Bucket racing to watch :D and people to catch up with.

richban

17th December 2010, 07:17

Looks like I will be dragging an untested bike to the TRRS, still if it all turns to custard there will be plenty of exciting Bucket racing to watch :D and people to catch up with.

Snap. motor still not in bike.

F5 Dave

17th December 2010, 14:27

Just test it changes gear properly this time huh TZ?

TZ350

17th December 2010, 15:00

Just test it changes gear properly this time huh TZ?

..................... :o

TZ350

17th December 2010, 15:19

226307226306226303226305226308226302

One week to go before Taupo and this is where I am at.

The engine vibrates real bad and I need to re-balance it.

As there is no one universally "correct" balance factor, there is only the one that works in your bike and it has to be found by trial and error.

Engine frame and suspension all affect how much you feel the vibration given off by the crank. The likely range of ballance factors that will work well with a high speed 2-Stroke seems to be in the region of 50% to 65%

Posts on balancing cranks started on Page 70.

In balancing the crankshaft there is only "Reciprocating Mass", "Counter Balance" and the "Balance Factor" which is the relationship between them.

"Counter Balance" = A "Reciprocating Mass" = B and "Balance Factor" = C

Then A = B X C

This formula gives you the Mass (weight) of the Counter Balance if you know the Reciprocating Mass and the Balance Factor you want to use.

This is not new, and Speedpro has already posted hand drawn pictures like this, showing how he did it.

Check out the quote for info on working out ballance factors and how to change them.

Rick 52

17th December 2010, 15:37

Looks like testing in the rain over the weekend will you be splashing around over the weekend?:blink:

TZ350

17th December 2010, 15:40

No, Family Xmas get together.......... are you ready for Taupo? will the RS be there?

jasonu

17th December 2010, 16:03

I must have been lucky. The KE125 bottom end with RG400 piston runs smooth as silk. I would be interested to know if the other builders with the same setup have had similar results.

Rick 52

17th December 2010, 19:12

Yep I am taking the RS for a splash around ..I hope the weather will be dry at some point over the weekend..

ac3_snow

17th December 2010, 20:12

going by metservice saturday is the best chance of dry whether.
will have to wake up in the morning and check the weather string.

koba

17th December 2010, 20:48

TZ350

18th December 2010, 06:20

Yum. I have a bit of a thing for old lathes, that one looks lovely.

It belonged to Chambers Dad and that makes it a bit special. The lathe is called "Mr Rattley", and its been very useful.

F5 Dave

18th December 2010, 09:33

V belt & tool post! Makes my Sheldon look old fashioned.

gatch

18th December 2010, 19:35

V belt & tool post! Makes my Sheldon look old fashioned.

The owner of my race bike, Chris has a wee Southbend on his bench, now that thing is neat.

TZ350

18th December 2010, 19:37

Ok got it going, I had problems with the new cylinder, it had been bored for a 0.002" interferance fit, instead of clearance on the piston.

So I got onto it and linished the piston down 0.004" to fit and with the new re-balanced motor all assembled and in the bike.

This is where I am upto now.............

226434226438

Tried each of the centre section inserts in turn.

226437

The RS chamber (red line) with a 60mm mid section insert compaired to my old 21+ hp GP125 (blue line)

226436

Power went up and the curve moved to the right as the pipe got shorter.

226435

Blue line is where I am now, 23+hp, not shabby for a hand linished piston, so I guess I got the cam and taper right.

I havent finished with the pipe yet but I think whats left of the dip in the cammel hump will be able to be pulled out by increasing the inlet duration and dialling in some ignition curve instead of the straight line I have been using for testing the pipes.

More to do but it looks like it has 23+ hp potential and a 3-3.5K wide power spread.

gatch

18th December 2010, 19:39

.

Ok this is where I am at now.............

The end of the sentence ?

Buckets4Me

19th December 2010, 08:42

The end of the sentence ?

there is still time to come up with another plan and pull it all apart AGAIN !!! :facepalm:

Last year I had 18.5 h/p
Ned Kelly had 20
TZ350 had gearbox problems and around 20 h/p
Chambers had a 22h/p 100 (that threw everyone off that got on)
Speedpro failed to get the gearbox working as well

now it look like I'm not riding
chambers is watching
Ned Kelly has 10% more H/p
and TZ may or may not have fixed the gearbox and 15% more power
Speedpros bike has been tested and is around 30 h/p

bring on Christmass I say

F5 Dave

19th December 2010, 16:26

Well that is quite impressive for a GP125. Bit scary revs for a GP crank thou.

TZ350

20th December 2010, 18:02

.

This is where I am at now with my bike....... only days to go.

226720

Testing has stoped for the day,......... slipping clutch at 11ish.

Buckets4Me

20th December 2010, 18:24

.

226720

Testing has stoped for the day,......... slipping clutch at 11ish.

Just test it changes gear properly this time huh TZ?

:woohoo::facepalm::corn::sick: :scooter: :drinkup: :shutup:

so thats 30% more H/p in a week !

TZ350

20th December 2010, 21:10

quite impressive for a GP125. Bit scary revs for a GP crank thou.

Crank:- RGV250 rod kit with silver plated big end cage and rod side play set at the little end. Double row, self alligning phenolic caged main brgs, light weight KX ignition flywheel.

koba

20th December 2010, 21:27

Hardouts! <tenchar>

bucketracer

21st December 2010, 17:40

ac3_snow

21st December 2010, 18:50

:clap::not:

I believe that in an earlier post somewhere in this thread u quoted thomas as saying that 26 was the maximum HP for an air-cooled engine.
Must be satisfying getting such good figures after all the hard work you guys have put in, well done!!

RMS eng

21st December 2010, 19:26

TeeZee's bike.......

Thomas has cured the clutch slip and they are now getting 27+hp from an aircooled 125 with a legal 24mm carb.

226841

Three Times Past.......
<object width="425" height="344">

<embed src="http://www.youtube.com/v/KcNfci9OruU?hl=en&fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></object>

Fuel Fog appears in the bellmouth of TeeZee's carb as the engine gets up on the pipe.

Can those that said three times past does not happen explain where this fuel mist in the bell mouth comes from when the engine is up on the pipe if the air mass is not moving back and forth in the inlet tract and passing the main jet at least three times like TeeZee explaind it would on a well tuned bike.

so is the MNZ ok for 125 two stroke in the GP to run 28 and 30mm carbs with 24mm spacers,as a well set up TS125 with this carb set up will make 24-26 hp and have a shit load of mid power,know a racer who wants to build one,its going to make it hard for the 4 strokes.TS125 with a normal 24mm carb would not rev much more than 11000 rpm.

richban

21st December 2010, 20:19

TeeZee's bike.......

Thomas has cured the clutch slip and they are now getting 27+hp from an aircooled 125 with a legal 24mm carb.

Now that is looking rather fecking impressive. Man you guys are killing us 4 stroke boys. I have managed to get some time off work tomorrow to take the new engine to the dyno. I will let you no what happens.

TZ350

21st December 2010, 20:57

Man you guys are killing us 4 stroke boys. I have managed to get some time off work tomorrow to take the new engine to the dyno. I will let you no what happens.

I am looking forward to seeing your dyno graph, we might be winning the dyno wars but we know it takes more than that to win races, its about the whole package........... so we are not feeling to smug.

Buckets4Me

21st December 2010, 21:02

Now that is looking rather fecking impressive. Man you guys are killing us 4 stroke boys. I have managed to get some time off work tomorrow to take the new engine to the dyno. I will let you no what happens.

all they need to do now is ride harder :innocent:
cant wait to see how your bike compares

speedpro

21st December 2010, 21:06

Now that is looking rather fecking impressive. Man you guys are killing us 4 stroke boys. I have managed to get some time off work tomorrow to take the new engine to the dyno. I will let you no what happens.

I'm picking bitter disappointment followed by a decision to go 2-stroke, eh? :innocent:

TZ350

21st December 2010, 21:19

TeeZee's bike.......

Thomas has cured the clutch slip and they are now getting 27+hp from an aircooled 125 with a legal 24mm carb.

226841

Yes we are pretty pleased, and all that copper for cooling is not looking so stuped now is it!!! ......... :laugh:

richban

21st December 2010, 21:42

I'm picking bitter disappointment followed by a decision to go 2-stroke, eh? :innocent:

Insert witty comeback here ..........

homo.

TZ350

21st December 2010, 22:37

.

Any guesses where the manufacturer measures the size of this...........

226862 Venturi Flow Tube

I think that if I use a 24mm design like this, but with a main jet setup like a Gardner carburettor instead of an injector I could push the GP to over 30hp.

226863 Gardner Carb

When I think about it a 38mm carb could be modified with one of these so the narrowest part of the 24mm venturi is where the manufacturer originally sized their old carb.

So all legal by the definitions I have seen posted lately.

That to be legal a modified carb has to be measured at the same place the manufacturer originaly did.

FXR's are great and they are the bike to beat at Mt Welly and they have brought many new people into the sport and thats very good but if you want something special you still have to make it yourself, and I imagin thats what the old style spirt of Buckets was about.

Some interesting 50cc stuff here:- http://www.elsberg-tuning.dk/monark.html

F5 Dave

22nd December 2010, 09:00

Maybe Walter Kaaden was onto something with disc valves. . .

TZ350

22nd December 2010, 11:07

24mm legal carb

After Taupo I am going to enjoy getting started on my new carb. Its going to be of the slide type and the minimum dia of the flow tube will be positioned at the same place as the manufacturer originaly sized their carb

226878 The concept
226881 The parts

226880 Press the Venturi Flow Tube back to the manufactures original measuring point

226879 Perfectly legal (by anyones standards) 40/24mm high flow carb

A legal 24mm carb, as its measured at the same point as the original manufacturer did.........

Instead of restricting carb sizes or mods and therfore stifling inventiveness, the more effective way might be to limit the HP allowed to say 20 and top placing bikes are dynoed.

speedpro

22nd December 2010, 12:05

Think you'll have it sorted by TRRS 2011??

TZ350

22nd December 2010, 12:07

Think you'll have it sorted by TRRS 2011??

Yep..........

Buckets4Me

22nd December 2010, 17:08

Think you'll have it sorted by TRRS 2011??
it's only a carb this time

not a new frame bike engine and carb

jasonu

22nd December 2010, 17:28

After Taupo I am going to enjoy getting started on my new carb. Its going to be of the slide type and the minimum dia of the flow tube will be positioned at the same place as the manufacturer originaly sized their carb

226878 The concept
226881 The parts

226880 Press the Venturi Flow Tube back to the manufactures original measuring point

226879 Perfectly legal (by anyones standards) 40/24mm high flow carb

A legal 24mm carb, as its measured at the same point as the original manufacturer did.........

Instead of restricting carb sizes or mods and therfore stifling inventiveness, the more effective way might be to limit the HP allowed to say 20 and top placing bikes are dynoed.

Looks good to me.

TZ350

23rd December 2010, 17:43

Changed the gearing to suit Taupo, geared for about 116k max. Took the cylinder of to ease any high spots and for a hand linished piston it looked real good, so no problems there.

Reassembly and final run tommorow to check all is ok and that the gearing is right. Last job to do is set the preload on the front forks and all should be good....... :D

Then its off to Taupo boxing day, camp overnight somewhere and then the mad rush in practice :scooter: to qualify well for a good place on the grid.

speedpro

23rd December 2010, 20:34

116K???

My old RG/MB was geared for 160ish and would peak out no problem.

TZ350

23rd December 2010, 21:12

My old RG/MB was geared for 160ish and would peak out no problem.

160ish.... on the new Taupo track????

We have run a GPS data logger around the track and it looks like the fastest bit is going up the back, the front straight is not as fast.

TZ350

23rd December 2010, 21:56

More on carburettors.

"Usually the atomisers on carburettors intended for two-stroke engines are manufactured in two types: with either long or short upper parts (figure 23). The atomisers with longer upper parts cause a weakening of the mixture at low speeds and du ring acceleration from low speed; on the other hand, atomisers with shorter upper parts produce extra enrichment. Carburettors for racing motor cycles use atomisers with short upper parts."

The rest can be read here:- http://www.mypage.tsn.cc/rdd/TT/contents/CARB/dellorto/dellorto_3_6.html

bucketracer

24th December 2010, 08:50

I hear there are moves afoot at MNZ to bring out a regulation class standard carb for F4 2Strokes, here is a draft drawing of it...............

226948

F5 Dave

24th December 2010, 08:50

Must be when we ran the long old track that they were hitting 160!

Well I've packed the 50 in the van. Too bad I won't get to ride it this year, or even see it.:shutup:

Have a good run guys & make sure there are 2 strokes in the top 3 places!

50bucketracer

24th December 2010, 11:25

jasonu

24th December 2010, 12:21

I hear there are moves afoot at MNZ to bring out a regulation class standard carb for F4 2Strokes, here is a draft drawing of it...............

226948

Looks good to me.

wobbly

24th December 2010, 14:14

Bestest idea ive seen for ages, the 2 strokes would still smoke the 4 strokes, only part thats a worry is the "regulating needle" thing - too much to play with.

In the interest of real world science here I would say that 27 RWHp from a 125 is nothing to jump up and down about.
Water cooled 125s with 30mm carb in ICC karts make 44RWHP ie around 50 crank at 13000,running a straight line ignition on unleaded.
If someones got enough folding I would soon knock up and guarantee an aircooled with 24mm carb that makes an easy 38crank = 32RWHp,as this only represents a bmep of 11.3 bar or 164psi - so the carb isnt the limiting factor at all,in fact it would help the spread.

TZ350

24th December 2010, 14:59

Very Tempting........

jasonu

24th December 2010, 15:01

Bestest idea ive seen for ages, the 2 strokes would still smoke the 4 strokes, only part thats a worry is the "regulating needle" thing - too much to play with.

If someones got enough folding I would soon knock up and guarantee an aircooled with 24mm carb that makes an easy 38crank = 32RWHp,as this only represents a bmep of 11.3 bar or 164psi - so the carb isnt the limiting factor at all,in fact it would help the spread.

Enough folding = ???$'s

richban

24th December 2010, 15:29

If someones got enough folding I would soon knock up and guarantee an aircooled with 24mm carb that makes an easy 38crank = 32RWHp,as this only represents a bmep of 11.3 bar or 164psi - so the carb isnt the limiting factor at all,in fact it would help the spread.

Dude not fair. At the risk of being beaten up buy Kev, I want one. Maybe you should bring that RS250 monster you have built and I can ride it in the 3 hour.

bucketracer

24th December 2010, 18:54

Buckets4me and I have been playing on the dyno with his RG50. Baseline was 11.6hp DIN and after fitting a different ignition and new clutch and 26 runs later we finished with 14,0 RWHP DIN.......... :D ... BucketGP here we come.

TZ350

25th December 2010, 07:56

I hear there are moves afoot at MNZ to bring out a regulation class standard carb for F4 2Strokes, here is a draft drawing of it...............

226948

I am afraid this one is banned, to clever, all those ajustable jets and air mixtures and so on, but its greatest sin is having no venturi, and without a venturi the tec people couldn't figure out what size it was?...........

226996

I guess we will have to make do with what we have got. I found these pictures of someones efforts to improve the air flow through a round slide carb, they look like a good idea to me.

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And the best carb chart I have seen yet.........

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TZ350

25th December 2010, 11:01

Sleeving carbs, It looks like others are doing it too.........

"The Splitstream Velocity Insert Tube is a Venturi which is installed in the back of the 2009 CRF 450 Throttle Body, reducing the stock 50mm throttle body diameter for increased power across the power curve particularly in the bottom to midrange of the engine.The boost in torque " http://mainmoto.com.au/sscat/cat/SplitstreamVelocityInsertTube

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F5 Dave

26th December 2010, 21:42

Kickaha

28th December 2010, 17:06

So how did your stinky two strokes go at Taupo?

F5 Dave

28th December 2010, 18:07

Who's riding your 50 if you're not?
Well sorry to do that to you my old friend. But I figured if I couldn't ride it this year; someone small light & fast should.

It's a hard thing being an old guy in a young man's sport. I imagine worse to have been beat by a little girl though:innocent:.

I guess the only revenge would be to lend her your bike next year?:blink:

Actually we need a better showing from the 50s. C'mon guys!

F5 Dave

28th December 2010, 18:08

So how did your stinky two strokes go at Taupo?
Mine went fine thanks.:woohoo:

Big ups to Andrew in the F4. Proves a good rider in dreadful conditions can take it.

50bucketracer

28th December 2010, 18:20

Well sorry to do that to you my old friend. But I figured if I couldn't ride it this year; someone small light & fast should.

It's a hard thing being an old guy in a young man's sport. I imagine worse to have been beat by a little girl though:innocent:.

I guess the only revenge would be to lend her your bike next year?:blink:

Actually we need a better showing from the 50s. C'mon guys!

I could be rude & say that Avalon did better on your bike than you would have done :innocent:

Actually I think that the bikes were very closely matched & it was probably only her lighter weight & more aerodynamic form that allowed her to slowly pull away.

I'm unlikely to lend mine to her next year because I want to beat you. If for some reason I couldn't ride then Nathanael would be first reserve & I can't see anybody beating him (in the dry at least).

Yes we do need more F5 bikes next year; a very sad turnout this time around. Although 3 14hp 50s is a good showing from that perspective at least.

50bucketracer

28th December 2010, 18:25

Mine went fine thanks.:woohoo:

Big ups to Andrew in the F4. Proves a good rider in dreadful conditions can take it.

Yep I have to admit that the 4-strokes took out this year's GP in fine style. It may have been a different story in the dry as I could keep with Andrew yesterday. But our 2-strokes would not run properly in the wet, dying on closed throttle & often taking many seconds to get going again. I don't know how Nathanael managed 3rd & 4th today on his with it running so bad, but I couldn't ride mine & came nowhere.

Any way, congrats to Andrew & the other FXR jetskis.

F5 Dave

28th December 2010, 19:47

I could be rude & say that Avalon did better on your bike than you would have done :innocent:
. . .
Well why not, I was:yes:
Def intend to be there next year.

Maybe I need to start building up a bike for my boy. I've got a bit of time though; he's just about nailed forward motion on the push trike. Steering, not so much. . .

But big congrats to Avalon.

F5 Dave

28th December 2010, 19:50

So aside from cruddy conditions what were the placings?

& what were the bikes matched up like on monday? Predictions if it were dry?

Kickaha

28th December 2010, 20:35

Predictions if it were dry?

FXRs for the win :woohoo:

But our 2-strokes would not run properly in the wet, dying on closed throttle & often taking many seconds to get going again..

Perhaps you need someone who knows what they're doing to tune them for you :whistle:

Buckets4Me

28th December 2010, 21:08

Perhaps you need someone who knows what they're doing to tune them for you :whistle:

they spent tuesday in the dry talking shit

bunch of old farts

Yow Ling

28th December 2010, 21:27

http://www.mylaps.com/results/showrun.jsp?id=1767079

TZ350

28th December 2010, 22:34

what were the placings?

Top 5 in the F4 GP, I think it was, 4-Stroke 4-Stroke 2_Stroke 4-Stroke 2-Stroke (Rick was peddling his new 2_Stroker)

http://www.mylaps.com/results/showrun.jsp?id=1767079

Wet or dry it would be hard to beat Andrew, Gavin or Rich on their FXR's.

Predictions if it were dry?

Nathanael D did very well on his miss behaving 2-stroker for a 3 & 4th in the F4 races, someone who can ride well on a badly behaved 2-Stroker in the wet has to have talent and could be one of the 2_Stroke riders to threaten the fast FXR's next year........

& what were the bikes matched up like on monday?

Speedpros bike looked good, but my bike gave lots of trouble with it not coming back onto the power after rolling off for a corner, I think the problem was the wind blowing across the bellmouth of the naked side draft carb and upsetting the mixture.

On the rear moments on dry Monday when it worked well it drove a treat and could realy hook up. Not sure how it compaires to the top FXR's as they didn't wait around for me........

......spent tuesday in the dry talking shit......

That pretty much sumes up wet Tuesday. Still a great time though, catching up with old friends and meeting new people that I had only talked with over the net previously. All in all great people and a great time.

F5 GP, Avalon 1st, Dave D 2nd and myself 3rd. Avalon didn't ride in the F4 GP, she couldn't get it started, it looks like her Team ESE bike had swallowed some water and rubbish thrown up off the track by the back tire during the first race.

TZ350

29th December 2010, 09:06

For those that wan't to experement with different carbs for their bike........ all sizes of copy cat Keihin flat slides, 24-28-32-34

http://www.alexwarehouse.com/OKO-carburettor-kit-24mm-26mm-28mm-30mm_p331.html

Cheap enough to modify or play with and I wouldn't turn my nose up at the Chinese one's for experimenting with but as they are made from die cast they will be soft (as are most other carbs) and need to be held by a split ring if you want to turn them.

The OKO's are much easier to turn and are strong enough to be held directly by the lathes chuck jaws. OKO's are bored straight through by the factory and benifit from having a slight taper machined into the discharge side.

TZ350

29th December 2010, 09:45

.

Chambers Being BrollyDolly for Avalon

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Yep..... racing in the wet.

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Team ESE's NedKelly making a splash and going realy well on the wet track.
http://www.youtube.com/watch?v=ycn2Ab2cUyc

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Bugger me days!!!! one of our riders shrunk in the rain..........

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Henk's photos (http://www.flickr.com/photos/hz13/5300728241/in/set-72157625568417857/)at http://www.flickr.com/photos/hz13/5300728241/in/set-72157625568417857/

TZ350

30th December 2010, 15:11

.

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A comparison of a Honda RS125 (Blue) with TeeZee's (Red) and Speedpros (Green)

jasonu

30th December 2010, 15:23

.

227447

A comparison of a Honda RS125 (Blue) with TeeZee's (Red) and Speedpros (Green)

We had a 89RS and as standard it made 37hp on No.1 Cycles dynojet. A std 2001 RS125 makes 39-40hp. Even with a JHA A-kit they only make 45hp
Is the (what year?) RS you have graphed a standard engine? If it is I think your dyno is a little generous.

TZ350

30th December 2010, 19:34

A std 2001 RS125 makes 39-40hp.

This one is also a Dynjet, was your hp displayed in DIN or SAE.

Even with a JHA A-kit they only make 45hp Is the (what year?) RS you have graphed a standard engine? If it is I think your dyno is a little generous.

It wasn't our bike, and I don't know a lot about the various models and years but think it's 2008 or 09, one of the last anyway, and well sorted. There were also two kit cylinders with pipes and ignition combos tried on the day.

2008 spec from http://www.fatbaq.com/mainpage.phtml?topic=05_rs125_specs

MAX POWER [44/12250] (ps/RPM) ......PS is the same as DIN and both are a little more generous than SAE

The 44 will probably be at the crank, so 44 - 42.9 = 1.1hp loss in the gearbox, I would have expected more losses.

So if the difference is not between displaying your results in SAE and ours in DIN/PS then maybe your right.

I have no idea how a DynoJet with Winpep6 software could be calibrated, but if there is a way I would love to know.

wobbly

30th December 2010, 20:20

Here is a very accurate RWHp dyno setup showing a very well tuned "stock" late model RS125 in green against a genuine A kit Honda - red with the PV held up and blue with the PV operational.
The difference between crank ( ie simulator or driven directly ) and a RWHp dyno setup is always between 10 and 12%, closer to 12 % id using say a Dynojet 168 with load control and 10% if its just a roller.

TZ350

30th December 2010, 20:52

Here is a very accurate RWHp dyno setup showing a very well tuned "stock" late model RS125 in green........

Thanks for the graph, it looks like our dyno might be under reading :innocent:

or more likely the RS we tested was not as good as we thought :pinch: .......

TZ350

31st December 2010, 10:12

For those interested in F5 and RG50's

R/H Crankcase Oil Seal p/n 09283-28013 $10 (or was 2 years ago)
L/H Crankcase Oil Seal p/n 09283-18004 $5
Gear Change??Oil Seal p/n 09285-12006 $7

Rod kits from later RG/RMX/SMX/TS/GT/RV/MT50 have oiling slots.

ConRod p/n 12161-04710
B/E Brg p/n 09263-16034
L/E Brg p/n 09263-12023
Pin p/n 12211-04711
Washer p/n 09160-16021

Wiseco Piston 826M04100 (std bore) Fits JR50 78-2004 and Kawa KDX50 03-04

The RG50 has only 3 thick clutch plates, 4 thiner TS/TF/GP100 or 125 and a steel will fit for a much better clutch.

Clutch cover gasket p/n 11482-13710 $22
Cly base gasket p/n 11241-04710 $14

If anyone wants to sell any RG50 engine parts or general junk, please PM me..........

jasonu

31st December 2010, 13:24

This one is also a Dynjet, was your hp displayed in DIN or SAE.

It wasn't our bike, and I don't know a lot about the various models and years but think it's 2008 or 09, one of the last anyway, and well sorted. There were also two kit cylinders with pipes and ignition combos tried on the day.

2008 spec from http://www.fatbaq.com/mainpage.phtml?topic=05_rs125_specs

MAX POWER [44/12250] (ps/RPM) ......PS is the same as DIN and both are a little more generous than SAE

The 44 will probably be at the crank, so 44 - 42.9 = 1.1hp loss in the gearbox, I would have expected more losses.

So if the difference is not between displaying your results in SAE and ours in DIN/PS then maybe your right.

I have no idea how a DynoJet with Winpep6 software could be calibrated, but if there is a way I would love to know.

I didn't realise your RS was a late model (Avalons I assume) as your graph said 'old motor' and I assumed old motor ie pre 95. So your HP figures do make sense. Our figures are SAE so slightly less than DIN.
With all the different quotes from different dynos around the country it is hard to know who has what and who has the most.

TZ350

31st December 2010, 16:34

Yes, we are just learning about this dyno, being a Dynojet I guess the makers just expect average Joe blow to load a bike, rev it up and after pressing a few buttons print out a graph.

And at the mo we are pretty much their target market but would like to know a bit more about the system/software so we can feel more confident about the results.

227524

Thomas and Bucket checking out the dyno software...........

TZ350

1st January 2011, 22:46

A Team ESE bike and enough information to make a copy of this GP125 engine.......

Video clip of Taupo RRS F4/Buckets, first practice on day one. 27-12-2010 Taken from my bike #54

How it went on the track.......<object width="480" height="385">

<embed src="http://www.youtube.com/v/ycn2Ab2cUyc?fs=1&hl=en_GB" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></object>

Details of how the engine was built…….

The engine........GP125, Ned's manages 23rwhp after these simple changes.............

The vids of it on the dyno can be seen here……

Running up NedKellys RS/GP125 on the dyno
This has port duration’s of, inlet 225, transfers 132, exhaust 202 degrees and an RM copy chamber...........

The Dyno graph……..

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TZ350

2nd January 2011, 09:14

226307226306226303226305226308226302

One week to go before Taupo and this is where I am at.

The engine vibrates real bad and I need to re-balance it.

As there is no one universally "correct" balance factor, there is only the one that works in your bike and it has to be found by trial and error.

Engine frame and suspension all affect how much you feel the vibration given off by the crank. The likely range of ballance factors that will work well with a high speed 2-Stroke seems to be in the region of 50% to 65%

The re-balancing sortof worked Ok and the vibration off pipe was greatly reduced and on the power 9K+ rpm it felt smoother.

At the moment the ballance factor is 48%, originaly it was about 70% and became about 36% after I plugged the original ballance holes with alloy plugs.

I would like to try 55%-60% and to get that, I will have to put a plug of Mallory metal or Tungsten in the flywheel opposite the bigend pin.

Bren_chch

2nd January 2011, 09:32

How it went on the track...

oh fuck that looked good fun!!!!!! :yes:

TZ350

2nd January 2011, 10:02

oh fuck that looked good fun!!!!!! :yes:

Hi Bren, That was NedKelly on his Team ESE Bike, how is your RG/KE100 project going?

Have you had any decent outings to find its leggs and how it compairs to the FXR150's and CBR's down your way.

............ :D .............

TZ350

2nd January 2011, 10:28

In the interest of real world science here I would say that 27 RWHp from a 125 is nothing to jump up and down about.
Water cooled 125s with 30mm carb in ICC karts make 44RWHP ie around 50 crank at 13000,running a straight line ignition on unleaded.
If someones got enough folding I would soon knock up and guarantee an aircooled with 24mm carb that makes an easy 38crank = 32RWHp

I had a chat with Wobbly (by PM's) and what he outlined was certainly impressive. Anyone who has a good chassis and some $$$ for motor work and Wobblys time should talk with him as he could certainly design them something special, and it would be very very impressive........

jasonu

2nd January 2011, 11:08

I had a chat with Wobbly (by PM's) and what he outlined was certainly impressive. Anyone who has a good chassis and some $$$

Some $$$ = ???

k14

2nd January 2011, 14:03

Thanks for the graph, it looks like our dyno might be under reading :innocent:

or more likely the RS we tested was not as good as we thought :pinch: .......
I put my 2001 RS125 on the dyno at Ashburton (dynojet) and that had 41.9hp. That was probably the quickest in the country at the time, no one was running aftermarket kits on them and my engine was standard. However running aftermarket expansion chamber, total loss and a few other mods.

koba

3rd January 2011, 10:30

How it went on the track.......

It was Waaay fast. Very impressive, makes me want more power and an RS frame.

If I win lotto Mr Wobbly can expect a blank cheque.

F5 Dave

3rd January 2011, 17:36

Ned Kelly

3rd January 2011, 19:08

Was a good clip, didn't make up for not being able to race, but it helped. Bike had the legs on a few things, but with that much power I'd have expected it to be sucking up & spitting out things a bit quicker. I'd have said the KV had more legs. But it is hard to say from a vid clip.

Bren you have to get your shit in one sock & make it up to Taupo.

It was the very first practice of the first day. I was finding my lines again. It had been a year since I was last at Taupo. Progressed as the day went on but the the weather turned wet. All dry practice counted for not alot.

Bren_chch

3rd January 2011, 20:43

Bren you have to get your shit in one sock & make it up to Taupo.

yes master... yes! I have just the bike sitting... covered in ermmm stuff, you know what its like!

Its something i want to do, but it seems totally not possible when it comes time to organise! besides - every year i just get fatter and fatter, i'll need 40hp to compete by the time i make it! I'm not as fat as kickaha though!

Hmmmmm maybe I need to start planning it now! :facepalm:

Kickaha

3rd January 2011, 20:51

I'm not as fat as kickaha though!

:crybaby: Bren is always mean to me, someone make him stop

Buddha#81

3rd January 2011, 21:12

:crybaby: Bren is always mean to me, someone make him stop

Ummmmmm stop Bren......there ya go Kick, I tried

TZ350

3rd January 2011, 21:42

.

Something for those who want to have a go at welding up their own pipes.......

By Glen Morgan THE PRACTICALITIES OF PUTTING A BEND IN A CHAMBER:- http://www.ozebook.com/compendium/morgan/pipes8.htm

richban

4th January 2011, 08:52

i just get fatter and fatter, i'll need 40hp to compete by the time i make it! I'm not as fat as kickaha though!

Just bring one of your fat old FXRs they seem unbeatable at Taupo. he he he

Sorry boys I just had to.

TZ350

4th January 2011, 09:14

.....old FXRs they seem unbeatable at Taupo. he he he.......

Ohoooo so true............ :facepalm: ............ but then there is next year....... :D

Kickaha

4th January 2011, 09:32

but then there is next year....... :D

When the FXRs will triumph again :whistle:

bucketracer

4th January 2011, 09:38

When the FXRs will triumph again :whistle:

Or maybe not........ :p

speedpro

4th January 2011, 10:00

I'm not even going to pretend to be able to win next year. I'm gonna ride my FZR/MB and build the RS/MB with a fast motor for some small light fast person. Well, that's the plan that's been festering while I paint stuff here at home.

Kickaha

4th January 2011, 10:03

Or maybe not........ :p

:yawn: Yeah like we haven't heard that before

TZ350

4th January 2011, 10:39

:yawn: Yeah like we haven't heard that before

Ohoooo so true again......... but does anyone want to take bets that the 2-Strokers won't ever get their shit together........ :laugh:

Kickaha

4th January 2011, 10:42

Ohoooo so true again......... but does anyone want to take bets that the 2-Strokers won't ever get their shit together and religate the 4-Stroke Huff-and-Puffers to also rans........ :laugh:

Are we talking in the next decade or what?:msn-wink:

TZ350

4th January 2011, 10:49

Are we talking in the next decade or what?:msn-wink:

Time is on our side.......... I think .... hope .....

But one thing is for sure, that whatever is at the front will be a clever piece of kit that someone is riding the wheels off............

Buckets4Me

4th January 2011, 17:40

Are we talking in the next decade or what?:msn-wink:

about the same time you manage to make it up is my guess :facepalm:

TZ350

4th January 2011, 21:21

There is any amount of information on Port-Time-Area for Inlet, Transfer and Exhaust, but precious little information on Blowdown-Time-Area that I can find.

As the need for more Blowdown-Time-Area increases with increased HP and/or RPM.

It’s not enough to work out the Port-Time-Area for the Transfers and Exhaust, the Blowdown-Time-Area also has to be considered but I have not found much information on it.

I find its very easy to get transfers that fit the bill and an exhaust big enough to do the business but there is not enough blowdown to do the job. HP and RPM are just as closely tied to blowdown as it is to the other ports.

So if someone has sized the transfers and exhaust properly using the charts in Jennings book and are not getting the power expected the problem could be in the Blowdown-Time-Area. The Blowdown-Time-Area requirement is not specifically talked about by Jennings or displayed on his graph.

The ways to increase blowdown are:-

(1) To raise the exhaust port (increased time) and/or widen (increased Area) out to 70-75% of the bore width.

(2) Reduce the height of the transfers for more blowdown time. Keeping the transfers low (reduced transfer time) and wide (increased transfer area) to get back to the required Transfer, Exhaust, Blowdown, Time-Area relationships.

But how to make sure that there is enough Blowdown-Time-Area for the HP and RPM. In the past I have transposed between the lines on Jennings graph for the exhaust and transfer ports and guestimated it, but now use this Porting Calculator.

227886

Planning the Port-Time-Area for the Transfers and Exhaust,

227885

Checking the Blowdown-Time-Area.

This handy (and cheep) Porting Calculator from:- http://www.porting-programs.com/ is based on Blairs and Jennings work. And not only does it work out the Transfer and Exhaust time area requirements, it also gives the Mean Area of Blowdown required for the planned Power and RPM.

By using the Porting Calculator I was able to see that my 27 rwhp engine.

227892

with its big as exhaust that’s opening 80 ATDC (200 duration) and widened out to 75% of the bore width, and with the transfers set lowish opening at 114 ATDC (132 duration) and wide as possible. Has pretty much run out of options for increasing the Blowdown-Time-Area for more HP at 12K rpm.

So for more power the next step will be digging side exhaust ports for whatever extra mean blowdown area I can get from there.

speedpro

5th January 2011, 09:41

Small mistake with the specified carb size, or did you get the rules changed?

TZ350

5th January 2011, 14:11

Small mistake with the specified carb size, or did you get the rules changed?

Eeeek.....what....where..........:o

Oh......Ok.... if your looking on the screen shot, then that is the porting calculators suggestion for the carb size required......:sweatdrop

kel

5th January 2011, 16:43

But how to make sure that there is enough Blowdown-Time-Area for the HP and RPM.

Blow down area, so what is the answer?
My current port timing allows for the following calculated time areas
Exhaust .015543, transfer .008304, blow-down .0007708. (All measurements in sec-mm^2/cm^3) As you stated TZ Jennings suggests port time areas while he doesn’t state blow-down time area requirement.
Blair subscribe to calculated areas based on BMEP, his example 125GP racer calls for an exhaust time area of .0162 and a blow down requirement of .00113 at 11500 rpm.
So while my exhaust and transfer time areas would seem pretty close to optimum I don’t seem to have anywhere near enough blow-down. As you state TZ options to increase blow-down include – 1. Raise or widen the exhaust, but neither would seem reasonable considering my current porting (Im at 72%) 2. Drop the transfer timing, which will surely make the thing to peaky 3. Exhaust boost ports, the cylinder studs won’t allow for this one either. So Im at a bit of a loss.
From the screen shot the software you’re using seems to state the required blow-down vs where you’re currently at? Do you have the necessary numbers to append blow-down area requirements on to a copy of Jennings angle time-area graph?

speedpro

5th January 2011, 21:34

It's a bitch. Something else that meeds to be considered is the port entry angles which affect area values by the cosine of the angle, plus the port duct taper and radius.
It does seem that you cannot get the desired exhaust time/area without some extra exhaust ports. You also can't get the seperation between the exhaust and transfer ports timing wise, whilst maintaining acceptable transfer time/area, without very wide transfers which may cause short-circuiting as they approach the exhaust port/s. The blowdown time is critical and generally has been overlooked in the past. It makes sense though, if the motor is revving higher there is less time for cylinder pressure to drop once the exhaust opens before the transfers open so the motor will need a bigger exhaust port or lower transfers to create more time or area for blowdown to happen.
Then you can design a pipe taking into account what port timing and time/areas you ended up with.

wobbly

6th January 2011, 09:07

What you guys need to understand is that we ( you) are trying to emulate GP cylinder power numbers with shit porting derived from road bikes.
Having a single Ex port will limit power capability - end of story.
And trying to get the big bmep numbers means that the only way is to make the ports higher and wider.
Having 205/138 numbers is la la land, sure it will go - but it will never work properly with even the cleverest pipe design on the planet.
Blowdown is the single most important number in the spec sheet.
The other thing that seems to be overlooked by many is that Hp=T*rpm.
An engine with a 50mm stroke "should" be peaking at 13000,and be running on to 14000.
But when you have to use very high exhaust timing this tends to shut down the power over the top.Also anything but a square bore/stroke ratio makes it doubly hard to get the port areas needed.
To show what can be done, here are the STA figures for the 38 crank 125 with tripple Exhausts and as much transfer width as can be crammed in.
As its a big bore at 56mm the Ex area is low but this is of lesser importance than the blowdown.
Notice the relatively low bmep needed to achieve the power at 13000, with very normal timings of 194/132.

TZ350

6th January 2011, 11:38

Blowdown is the single most important number in the spec sheet.

Confirmation of what we were starting to figure out for ourselves........... thanks.

Having 205/138 numbers is la la land, sure it will go - but it will never work properly with even the cleverest pipe design on the planet.

Glad I heard this before I started hacking into my next barrel........

The other thing that seems to be overlooked by many is that Hp=T*rpm.

An engine with a 50mm stroke "should" be peaking at 13000,and be running on to 14000.

A GP125 Turning 13-14,000RPM should be interesting........ frigtening, but in a good sort of way .... :D

kel

6th January 2011, 11:38

What you guys need to understand is that we ( you) are trying to emulate GP cylinder power numbers with shit porting derived from road bikes.
Having a single Ex port will limit power capability - end of story.

Yes GP motor BMEP figures based on Blairs work with single exhaust port 54mm square motors.
I currently have exhaust port set at 194 degrees, problem is in the sizing of the crap transfers and the lack of room for the aux exhaust ports. Your calculation sheet illustrates perfectly the need for auxillary exhaust ports to achieve required blow-down. Damn thats going to be expensive to add to the KE.
I'm not looking to produce anything like 38hp but I may have to re-think things if thats where its going. Hopefully your calcs for 13000 rpm are based on the DT rod and bearings as thats exactly what ended up in my motor! (not allowed to use YZ rods and bearings people)
Cheers for your input Wobbly.

wobbly

6th January 2011, 12:57

The DT125 setup using a TZ125 piston i havnt transferred to a 100cc sleeved down watercooled yet, as I wont have the parts here for a day or so, but with the smaller piston, reving to 13000+ wont be a problem at all.
NoMates RG150 sleeved down uses a very light kart piston and could go much higher in rpm and power, but 4 years ago his 28RWHp was more than enough for a couple of easy champ wins limited to just 12500.
Now we have the MB100 finally approaching the potential numbers I did back then as well,then 35 crank or around 30RWHp @13000+ will soon be the required benchmark.
But even these numbers can easily be beaten with good workmanship and good basic layout of the ports/pipe/head/ignition - sorry, but a single Exhaust just aint no good at this level of performance.
Tripple or a properly designed T port are the only way.

F5 Dave

6th January 2011, 13:47

There have been people who have made T ports but I'm not sure they ever ran them for long. Unsupported bridged sleeve would surely seize. I sub ex ported my MB 13 years back, but it got killed a bit by a welder. One side looked good, the other not so much as it broke through the vertical barrel stud hole, Damn asymetrical layout! Was nicely curved, but had to put a dowel in the way which encroaches the tunnel a bit.

By coincidence I only just o-ringed it today trying to resurrect it (& yes the groove will be a sight better than the CPI barrels).

bucketracer

6th January 2011, 13:58

TeeZees motor as it is now, thats 27 RWHP and 3.5K power spread.

227997

In the interest of real world science here I would say that 27 RWHp from a 125 is nothing to jump up and down about.

With all this talk about big HP numbers we are forgetting what TeeZee has achieved with his old GP125 ...........

Hands up anyone else with an F4 Aircooled 125 2-Stroke thats making 27 RWHP or 26 or even 25, any takers at 24???

It's just all talk untill its done.

TZ350

6th January 2011, 14:32

.

The smile says it all...............

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Look at the power spread

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I make it at least 5K wide, no wonder these things are hard to beat.........

TZ350

6th January 2011, 14:39

.

Ok....... this is where I am at now.

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This barrel was one I have used before and it had been ported to Ex opening 81 ATDC 72%, Trans 112 ATDC

I am now trying to see if I can cut side ports into it, just to see if it can be done to a GP barrel............

F5 Dave

6th January 2011, 15:07

I tried to take a pic but the crumby one at work isn't much chop so I adjusted the brightness a bit. Can't see the o-ring (or the porosity).

The rubbish in the barrel is swarf. The pic makes the ports look rounded but they are quite a bit more square. The real damage when welding into the barrel is evident in the ex port where you can see the ally coming away. I'm pretty sure this will seize as there isn't any ally left over the bridges, but on the other hand it is considerably wider than a T port, so maybe it won't. I have another barrel to start again, this one was headed for the bin 13 yrs ago.

wobbly

6th January 2011, 16:05

Well the talk about "big numbers" may very well be just that, but the proof is in the pudding, and the RG100 and MB100 are very close to what was predicted.
Here is concrete proof - the Sim for my 485 TSS engine, the dyno graph, and the comparo that there is around 10 to 12% difference.

TZ350

6th January 2011, 17:14

Here is concrete proof - the Sim for my 485 TSS engine, the dyno graph, and the comparo that there is around 10 to 12% difference.

Thank you for bringing Science to the party, I am looking forward to seeing where this goes .........

RMS eng

6th January 2011, 17:57

TeeZees motor as it is now, thats 27 RWHP and 3.5K power spread.

227997

With all this talk about big HP numbers we are forgetting what TeeZee has achieved with his old GP125 ...........

Hands up anyone else with an F4 Aircooled 125 2-Stroke thats making 27 RWHP or 26 or even 25, any takers at 24???

It's just all talk untill its done.

all this dyno talk is one thing but these big HP two strokes need to do some thing on the track,all the talking is being done by 24hp 100kg 4 strokes,and the best lap at the GP 2 years ago was by a 20hp derbi 80 and still think it is Dave D will know.

kel

6th January 2011, 19:06

.

The smile says it all...............

Look at the power spread

Damn it I new he had more power, shame about the brakes :innocent:

Rick 52

6th January 2011, 19:38

Damn it I new he had more power, shame about the brakes :innocent:

Hhahah you might have to explain !! Your handle bar hooked my leathers that's why we hit the grass !!
Not that this is a problem ! The extra power is just in the carb and pipe and lots of time playing with settings ...The carb is from a XR500 and the header from a DR250
the can is the old can cut shorter with the inside cut out and a perforated steel tube with packing around the outside...

50bucketracer

6th January 2011, 23:04

all this dyno talk is one thing but these big HP two strokes need to do some thing on the track,all the talking is being done by 24hp 100kg 4 strokes,and the best lap at the GP 2 years ago was by a 20hp derbi 80 and still think it is Dave D will know.

The Derbis never got the chance to show their worth in 2010 with neither running properly in the wet. But Nathanael did qualify fastest in 2009 on his then 18hp Derbi 80, with a 1m26.25, which was nearly 3 sec faster than anybody else, until the piston broke... Maybe 3rd time lucky in 2011! His had 20hp for 2010 & mine a little more. Nobody came close to that lap time this year with F4 official timing only in the wet. Wonder if we can find a bit more for next year... have to beat those pesky diesels!

bucketracer

7th January 2011, 06:46

all this dyno talk is one thing but these big HP two strokes need to do some thing on the track.....

By his own efforts TeeZee has managed 27RWHP, I don't think any one else in F4 125 2T has managed that, and not a single.... whow.... great..... look at that.......all I hear is your moaning...........

TZ350

7th January 2011, 10:02

RMS eng is quite right, these big hp 2-strokes are yet to prove themselves.

But it is only time before someone with more riding ability than myself builds one as its simple enough.

All of my work is done with simple hand tools and some skill that anyone can apply.........

228054 228052 228053

I find the two most usefull tools are the long die grinder tips and the white piece of plastic pipe for checking the heights of the ports.

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Using the drill press for opening up and flatining the angle of the rear transfers........... crude but effective

There is no cheque book racing here, the bits are all from the 70s and 80's except the secondhand rod kits that I salvaged from an old RGV250 crank.

228057

A good view of the side ports in a Racing 50.

These Metrakit Pro Race barrels in different capacitys can be brought off the shelf for Aprilias, now that would be Cheque Book racing and I suspect a little outside the spirit of the Bucket racing rules............. nice though

F5 Dave

7th January 2011, 10:53

. . .
A good view of the side ports in a Racing 50.

These Metrakit Pro Race barrels in different capacitys can be brought of the shelf for Aprilias, now that would be Cheque Book racing and I suspect a little outside the spirit of the Bucket racing rules.............

They are out of the rules let alone the spirit.

They (metrakit race) are made for racing so easily fall into the competition parts category.

"Engines must be derived from non-competition motorcycles.
Motocross, Road Racing, Enduro and Go Kart motors and transmission parts are not permitted."

Clearly they would be deemed Road Racing.

I think the road going parts are a grey area, but race is race.

richban

7th January 2011, 11:05

Nobody came close to that lap time this year with F4 official timing only in the wet. Wonder if we can find a bit more for next year... have to beat those pesky diesels!

You are living in the past. All you guys talk like you were going to win with your big HP and fancy light bikes. The fact is, Andrew won on a modified commuter bike with crap suspension and he just out rode everyone on the day. Your comments annoy me.

TZ350

7th January 2011, 12:12

All you guys talk like you were going to win with your big HP and fancy light bikes.

We sure hoped so........... but then that would have been to easy.

The fact is, Andrew won on a modified commuter bike with crap suspension and he just out rode everyone on the day.

At Taupo, I think it was Andrew A who told me, "for $$$ and Time you can get HP but to have a Fast Bike you have to Ride the Wheels of It".

Some of us have HP, Andrew has a very fast bike........ all credit to him and the others at the pointy end.

F5 Dave

7th January 2011, 13:48

You are living in the past. All you guys talk like you were going to win with your big HP and fancy light bikes. The fact is, Andrew won on a modified commuter bike with crap suspension and he just out rode everyone on the day. Your comments annoy me.
um. . . Dave's point, was his son's bike wasn't a big horsepower bike. 18hp & that was only last GP. But wet is wet & dry is dry. And you can't argue with twice in a row results from Andrew.

And like since when as smack talk not been a part of racing?:shutup:

TZ350

7th January 2011, 15:38

.

OK.... I am now holding my hand up for the prize awarded to the most heavily ported GP125 cylinder..........

228067

After this I am going to talk to the man at Wobbly-Pipes about a decent chamber design to replace the old RS one I have been using and for some advice on where to go from here.

I have a lot of confidence in the development and simulation software he uses and what he can do with it ...........

Buckets4Me

7th January 2011, 17:38

all this dyno talk is one thing but these big HP two strokes need to do some thing on the track,all the talking is being done by 24hp 100kg 4 strokes,and the best lap at the GP 2 years ago was by a 20hp derbi 80 and still think it is Dave D will know.

well stop the blody rain then will you :angry:

old guys dont like rain :violin:

none of the big HP bikes ran this year (they say it's because they didn't have wets. I think it was because the didn't want to get wet):facepalm:

bring on next year

do you rember #52 (new bike and not very finished yet) 228085wait till we get him to build a motor with 42% more HP :blink::scooter:

TZ350

7th January 2011, 19:25

kel

7th January 2011, 20:35

Very nice work, but what about the other side?

TZ350

7th January 2011, 21:18

Very nice work, but what about the other side?

Both sides have been done...........

richban

8th January 2011, 00:15

well stop the blody rain then will you :angry:

old guys dont like rain :violin:

none of the big HP bikes ran this year (they say it's because they didn't have wets. I think it was because the didn't want to get wet):facepalm:

bring on next year

do you rember #52 (new bike and not very finished yet) 228085wait till we get him to build a motor with 42% more HP :blink::scooter:

One excuses after another. Face it, the 2 strokes got smashed. And what ever happened to no mates. He promised he was going to take the 2010 title.

1st 2nd 3rd FXR 4 stroke. Now go run to wobbly with all your hard earned cash and we will see you next year.

Buckets4Me

8th January 2011, 05:37

And what ever happened to no mates. He promised he was going to take the 2010 title.

wich year ? :woohoo:

1st 2nd 3rd FXR 4 stroke. Now go run to wobbly with all your hard earned cash and we will see you next year.

sounds like sour grapes to me ?
you broken your bike again ? or did the spade slip

chear up this is bucket racing shit talk and lots of fun (not all of us can ride or like getting wet):violin:

TZ350

8th January 2011, 06:56

Face it, the 2 strokes got smashed. 1st 2nd 3rd FXR 4 stroke..........we will see you next year.

1st 2nd 3rd FXR 4 stroke, I wasn't expecting it, but it looks like, when faced with skilled 4-stroke riders a 2-strokes HP advantage even on a long track is not as much of an asset as one would have thought........... bugger.

So us 2-strokers will have to draw on all the resources available and keep sharing what we find out and how we are going about making our mods in the hope someone will get enough shit together to make it interesting for the 4-stroke boys next year........... :D

Kendog

8th January 2011, 07:54

Kickaha

8th January 2011, 08:19

it's the quality of the rider, and Wellington has the best riders.

Yeah that's what we've always thought when they come down for BOB :whistle:

Kendog

8th January 2011, 08:28

Yeah that's what we've always thought when they come down for BOB :whistle:
True that :facepalm:

TZ350

8th January 2011, 09:59

So like you say, it's not so much 2 vs 4 or how much HP, it's the quality of the rider, and Wellington has the best riders.

Well they have been kicking our arses for a while now............ :blink:

But there are plans afoot, RMS eng, Kel and Rick52 are all good riders and working on building up fast 2-strokers........ things could change

RMS eng

8th January 2011, 10:04

1st 2nd 3rd FXR 4 stroke, I wasn't expecting it, but it looks like, when faced with skilled 4-stroke riders a 2-strokes HP advantage even on a long track is not as much of an asset as one would have thought........... bugger.

So us 2-strokers will have to draw on all the resources available and keep sharing what we find out and how we are going about making our mods in the hope someone will get enough shit together to make it interesting for the 4-stroke boys next year........... :D

Hi TZ ,a while back you put up a RG50 dyno sheet with 14 HP,good going for a RG50,did you have the STD inlet like my one reed,piston port,have put up a dyno sheet for my bike with STD inlet and about 150 deg on inlet ports and could be 24mm or 28mm carb ? was done in 1996.would still be a good kart track motor but needs 2-3 hp for a big track,also put up photos of some suzuki 100cc-125cc works bikes fom 1978.mybe how the GP100-125 got their name,but as you can see they are light years ahead of the road bikes.were made in 100cc and 125 and raced in the indonesian GP,also yamaha made a TZ100-125 for the same race.note on the GP100 motor mag is on top of the clutch cover.PS could you put up the dyno sheet for your 14hp RG50,thanks,what do you charge per hour for the dyno.

richban

8th January 2011, 11:02

wich year ? :woohoo:

sounds like sour grapes to me ?
you broken your bike again ? or did the spade slip

chear up this is bucket racing shit talk and lots of fun (not all of us can ride or like getting wet):violin:

To true I think its that time of the month. I am now officially chipper. I have never wanted a 2 stoke more after watching Andrew on his RS. I wish I could fit on one of them. Maybe an RS250 would be the go. Man them things are fast and cool. Lotto here I come.

TZ350

8th January 2011, 13:22

Hi RMS eng

Thanks for the photos, in the first photo what do you think that is on top of the cylinder where the carb usually is?

228257

Yes I think our GP's were roadbikes styled after the 60's racing machines.

The 50 has the original (heavily modified) reed piston port layout, 160 duration I think. Not much has been left untouched in the cylinder, head or cases. Chamber and engine layout/design came from a friend in Holland, and it makes its power about 13-14,000 rpm. I completely burnt out a clutch at Mt Welly last time I rode it there.

I am sorry but we can't afford to run the dyno commercially as its too disruptive to the workshop and office during the day and I am limited in the amount of hobby time I can spend after hours at work.

TeeZee

TZ350

8th January 2011, 13:37

.

Sure its a 4-Stroke, but a serious bit of kit, well worth a look and for the money it's a steal......

http://www.motorbikeparts.co.nz/product_details.php?category_id=10&sub_category_id=21&product_id=719

Kickaha

8th January 2011, 14:01

.Sure its a 4-Stroke

Is that like of those things that keeps winning the GP ahead of the smelly two strokes?:innocent:

RMS eng

8th January 2011, 14:39

TZ350

8th January 2011, 16:02

Hi TZ
i would say that is the water pump.

Of course.......... :facepalm:

Check out Team ESE's NedKelly going around Dave D at Taupo.........

228297

Buckets4Me

8th January 2011, 16:09

I have never wanted a 2 stoke more after watching Andrew on his RS. I wish I could fit on one of them. Maybe an RS250 would be the go. Man them things are fast and cool. Lotto here I come.

try an fzr250 frame 1989+ delta frame ?

I want to win lotto so if I fall off AGAIN I dont have to go back to work and explain to the boss whats happened :angry: and why I'm not coming back for 3 months AGAIN!(would be the 4th time)
also an rs250 frame would be cool but early 1990 250's seem like the next best thing tzr250?fzr250 228304228305228307

ac3_snow

8th January 2011, 20:39

.
228091228092

These side exhaust ports are hard work, now if there was a way to bring them straight out the side between the fins then I could put more of them in for even more blowdown time area.............. :scratch:

Hi TZ, Im guessing thats your auxiliary exhaust port, the small one off to the side and above the transfer port, seems to be a rather large bridge between that and the main exhaust port, I'm surprised that theres enough meat in the cylinder?
Is this something new you have come up with post Taupo? Also I'm assuming that because of the limited access between the fins you weren't able to weld in extra material and just worked with what the room available from factory?
And what would stop your from simply having auxiliary exhaust ports that just exited immediatly out the side of the cylinder? :whistle:

TZ350

8th January 2011, 21:09

Yes your right about the auxiliary exhaust ports, and the studs make it hard too. I have been tempted to wack some holes through the side of the cylinder to see what happens.

I remember some go kart guy talking about it, the rules for his McCulloch class was "no modification of the exhaust port" well he didn't modify it, he just added a whole bunch more with a big hand drill.

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I vaguly remember he claimed it worked when it was up on the pipe. Sounds to easy to be true, good rule bending idea though.

And apon mature reflection and good advice I won't be doing it...........

228384

They sure take porting seriously...........

228383

And look at that, big head, twin carbs and a rotary valve conversion...........

228385

And WTF a 4 valve twin cam head conversion...........

TZ350

8th January 2011, 22:23

.

Interesting read about the future of 2-strokes and direct fuel injection ........

http://www.dirt-bike-tips-and-pics.com/future-of-two-strokes.html

The Ski Doo 600 E-tec

228386

http://www.google.co.nz/images?client=firefox-a&rls=org.mozilla:en-GB:official&channel=s&hl=en&q=Ski+Doo+600+E-tec&um=1&ie=UTF-8&source=univ&ei=WjooTdmZCdCrca7cuZMB&sa=X&oi=image_result_group&ct=title&resnum=1&ved=0CCQQsAQwAA&biw=1024&bih=574

228387

TZ350

8th January 2011, 23:15

Hmmm it is one mans opinion but I am starting to see why F5Dave has a negative thing about Honda.........

"It was about that time, it seems, when one of the four-stroke monks had an epiphany: "Instead of spending more money on exotic engines," he might have said, "which hasn't been getting us anywhere, why don't we just buy the AMA and FIM and make our own rules? For instance, we could require that all two-stroke riders wear their helmets backward - if they can't find the first turn, we have to win!" And that is - sort of - what happened.
Honda also likes to be seen as an 'engineering company'. I must point out that trying to force a particular technology (that is not working!) on a naive public by denying options, rewriting race rules, etc. is not any sort of 'engineering'. "

And it goes on............

"For the manufacturers, the 'best bike' is the one that gets you to part with the most money. As E.F. Schumacher told us, "...in economics, the only measure of 'good' is profit. I tell people that in engineering, goodness is efficiency. The two are opposites: profit leads to more and more; efficiency to less and less."For you and me, 'best bike' must mean something else."

http://www.dirt-bike-tips-and-pics.com/future-of-two-strokes.html ........... 27th Jan

Now this warms my heart........

"This little 105-cc wonder rips 30.5 hp @ 12,000 rpm. The 105 is more of an enduro motor. The JMC pulled the MotoVerde dyno from 3000 rpm to 13,500 rpm. I cannot point to another engine that makes almost 300 hp/liter and has such a wide powerband."

http://www.dirt-bike-tips-and-pics.com/future-of-two-strokes.html ........... 23rd Feb

A 100cc water cooled Bucket with 30+hp and a wide power spread .... its got to be possible and Speedpro is nearly there..

Even more interesting............

"The huge improvement from stock might suggest radical changes. In fact, he made only minor alterations - but the right ones! After testing several vendor pipes, he went with one made by DEP. He replaced the standard 28-mm carb (same as the 85 SX) with a 30-mm Mikuni. He cleaned up the ports and set the squish clearance. But 'the secret' was adopting a CRD programmable ignition module; then spending hours finding the right curve. Ignition timing has been largely ignored by tuners. These programmable units are a rather new option and the dyno time required is expensive because any curve only fits a specific engine configuration. Change the pipe (to one with a longer convergent-cone, for example) and the ignition curve has to be gone over. But what Balaguer's results show is that two-stroke engines are much more sensitive to ignition timing than we ever guessed in the old days -"

http://www.dirt-bike-tips-and-pics.com/future-of-two-strokes.html ........... 10th March

Speedpro get yourself an Ignitech ..... Wobbly sells them .........

jasonu

9th January 2011, 07:30

http://www.dirt-bike-tips-and-pics.com/future-of-two-strokes.html
Took an hour to get through but a really good read. Thanks

Bert

9th January 2011, 09:44

......
And what would stop your from simply having auxiliary exhaust ports that just exited immediatly out the side of the cylinder? :whistle:

looks ugly.... but there is some interesting engineering:
http://picasaweb.google.com/xyger.com/StudieMalossi136XygerRennsport#

I like the reed block modification

TZ350

9th January 2011, 10:35

looks ugly.... but there is some interesting engineering:
http://picasaweb.google.com/xyger.com/StudieMalossi136XygerRennsport#

I like the reed block modification

Hi Bert thanks for the link, interesting pictures.........

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bucketracer

9th January 2011, 21:19

.

Face it, the 2 strokes got smashed.

Team ESE the Myth Busters ...........

228470

Through their own efforts they have pretty much Busted the Myth that a rider can win races with just Raw 2-Stoke HP

........... still a bit of its nice to have though.

TZ350

10th January 2011, 15:38

.

One of the smartest Port Mapping ideas I have seen in a very long time.

Chambers pushed a length of PVC pipe into a cylinder then poured some PVC primer in through the ports.

228507

And the primer neatly marked out the port windows and the lines were etched so deeply that they couldn't be wiped off.

Chambers was easily able to measure them and recons that when he cuts the new port window shapes he will transfer them to the new liner by gently sandblasting them.

Now thats dam smart thinking, I am very impressed by Chambers idea. ..............

ajturbo

10th January 2011, 15:42

One excuses after another. Face it, the 2 strokes got smashed. .

Your ALL lucky i wasn't there this year.... the might GT lives... but for lack of time and money, it didn't happen......

but now like Dave last... i have ALL YEAR to get it ready...so watch out.. i "may" even sport a new frame..!!!!!!

so stop patting yourself on the back..... be very worried about my come-back... be VERY WORRIED i say

ajturbo

10th January 2011, 15:44

F5 Dave

10th January 2011, 16:35

Or just use a spray can & let it dry a bit.

Obviously with the making the sleeve thing (assuming you're taking the RGV125 barrel down to 100) the transfers move backward in the barrel which can dick you around a bit.

TZ350

10th January 2011, 17:05

.

Chambers had a lets just try and see moment..... clever though.

228514 228513 228515

I think his plan is to re-sleeve an air cooled GP125 cylinder with a alloy sleeve and then plate it.

Bert

10th January 2011, 20:28

.

Chambers had a lets just try and see moment..... clever though.

I think his plan is to re-sleeve an air cooled GP125 cylinder with a alloy sleeve and then plate it.

Nice plan.
Scary $$$ for plating though? or is it ??? Watching this development with interest.

So what grade alloy would you be using to do this?

And when are you going to be making a RGV100 conversion kit for a GP bottom end:msn-wink:?
longer conrod, plated sleeve, spacer block for barrel, shiny new piston and away you go...

speedpro

10th January 2011, 20:30

They'll probably do it themselves, smoko, Wednesday arvo.

F5 Dave

11th January 2011, 08:23

Yeah I looked at that some time back. I had some 2011 free machining ally, but when I looked into it it is not suitable for welding. Which makes me think I should have chosen 6060 or 6261 which anodise well, so are probably suitable for plating. I guess. It's the Silicon or copper content that make them unsuitable for plating so if they don't weld or anodise well they probably won't plate well.

4042 is apparently the go, but not so common in NZ.

TZ350

11th January 2011, 08:24

So what grade alloy would you be using to do this?

And when are you going to be making a RGV100 conversion kit for a GP bottom end:msn-wink:?
longer conrod, plated sleeve, spacer block for barrel, shiny new piston and away you go...

There is a grade of alloy that suits plating best but I have forgotten what it is, When I find out again I will post all the details.

I allready use a longer rod to get some space for my under barrel finning and for the better range of pistons that can be had with 16mm little end pins.

Definatly looking at a spacer plate like your pic with the RGV cylinder and all sorts of options but the GP might have to remain air cooled as it looks like a reed valve inlet may be the way to go.

Is that a pic in your post one of your projects?

TZ350

11th January 2011, 09:06

.

As carbs are becoming a thing for us...............

An interesting book by Eric Gorr. http://books.google.com/books?id=4MealMAQSeIC&pg=PA93&lpg=PA93&dq=keihin+pwk+tps&source=bl&ots=15w7jKNuhB&sig=Xal7OIeprLKF9U1pOPKP4RlnGB0&hl=en&sa=X&oi=book_result&resnum=6&ct=result

F5 Dave

11th January 2011, 11:12

Yeah it's a good book, go buy it, he's a decent guy.

Incidentally he gave me the learn on plating in response to a question some while back (some of which I refered to in above) as he used to work at a plating company.

wobbly

11th January 2011, 12:01

Both Fletchers and Ulrich do heavy wall alloy tube in 6000 series.
This plates just fine according to Grant at the platers down South

Bert

11th January 2011, 14:02

I all ready use a longer rod to get some space for my under barrel finning and for the better range of pistons that can be had with 16mm little end pins.

Definatly looking at a spacer plate like your pic with the RGV cylinder and all sorts of options but the GP might have to remain air cooled as it looks like a reed valve inlet may be the way to go.

Is that a pic in your post one of your projects?

nothing better than a gaping great big reed block to scare the natives off, I'm looking forward to finishing off my thing. just dropped my barrel and head off to the Dave Griffiths to sort out o'rings and a couple of other bits....

As for the photo, nope just a continuation from the series I posted up a while back.

I like the idea of alloy sleeve and plating, wish i had come up with that one before doing the steel option...