ESE's works engine tuner

[TZ350]

243325 243323

Looks like Ned has opted for an aircooled engine.

243324

For real drive out of corners use a steam engine, max torqe at min rpm.

[husaberg]

Mick just said - "maaaete,turn the fuckin things off and give it a go."
Went out and put it on pole,easily.

Afterwards he no doubt said "No Worries maate"

In all fairness with all due respect to Mick he was gifted.
But from what can understand Mick hated change.
All he wanted to do was ride what was in essence the 92 spec bike and win.

The only reason they probably managed to convince him to test it in the first place was the title was well sewn up already.

While It is hard to argue with this methodology given Micks results.

The thing is with 5x the engine size and with 6-8 times the power (185-200 odd BHP supposedly) on a bike weighing about 135kg , Even Mick didn't really need the extra stomp anyway.
These factors are not nesercarily the case with a 80 odd kg 100cc bucket on a tight go kart track with a rider lacking the demi god skills of Mick.

But binning the idea after one test season is not quite what I would call a through examination of the idea.
24-30% extra midrange is impressive result in anyones language.

If you reverse the idea around or use faster responding medium I think it has merit.
While I have no doubts similar results can be achieved with ignition or PV
What happens after these are optimised?

Is the switching of the power jet at near peak revs as Woobly has suggested achieving this result by default?
Are some of the increases due to the pipe temp, Rather than with more precise fueling?
Is the over rich mid to lower top end working here to lower pipe temps in mid range too?

If can you believe Wayne (Gardner) asertions on how HRC with its 200 full time finally staff managed to get the NSR to handle at a least passible ie “RGV like” thereby giving Mick something capeable of being refined into the weapon with Micks input it became.
I can see HRC were not as infallible as some people might think.

There are other inert substance that could provide a short term cooling effect plus other, More volatile substances that can provide a short term heating event used in tandem you could have the best of both worlds

My point is,
Anything that can add useful mid range power to a 2 stroke should not be dimissed without further investigation.

[speedpro]

243325 243323

Looks like Ned has opted for an aircooled engine.


I love it. A good later model RS125 hacked to fit a GP engine. Who said bucket racers aren't serious?

[F5 Dave]

. . .
Dave: its a 1991 CBR250RR (MC22), is fairly wide, will let you know how it handles after next weekend.
. . .
Ahh, that's why I didn't recognise it. From the side it looks very purposeful, but odd suspension set up. Wide huh? Can't fit it in the press & skinny it up a bit? Suppose it would get a bit long then:rofl: ahh I crack me up!

[wobbly]

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

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

[husaberg]

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

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

Yeah in regards to the ATAC With a power valve I was thinking along those lines for the "The new hush hush cloak and dagger even more secret than Speedpro's Rod project".

Ie the PV for the timing and the ATAC for volume.

Were you aware of the Gardner photo session story? I think it’s hilarious to think that’s what HRC had to do.

Was I on the right track with the power jet Wayne?
Or just off on a tangent?

[jasonu]

Was I on the right track with the power jet Wayne?
Or just off on a tangent?

Send him some chokky fish and he might send you an answer...

[husaberg]

Send him some chokky fish and he might send you an answer...

I keep eating yours,Sorry
I will have to develop more willpower.
Are you using our RS frame,
Now just how many Choc fish would it take to "borrow" it for a bit

[jasonu]

I keep eating yours,Sorry
I will have to develop more willpower.
Are you using our RS frame,
Now just how many Choc fish would it take to "borrow" it for a bit

What is this 'our RS frame'???

[wobbly]

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

[husaberg]

What is this 'our RS frame'???

Whoops missing the Y from your sorry.
looks like I need to employ a Font fairy as well as punctuation pixie and a spelling smurf

[Buckets4Me]

looks like I need to employ a Font fairy as well as punctuation pixie and a spelling smurf
when you find your's (HA HAHA ) can you let me know where ?

[Moooools]

243166
And there is also a pic of my nice new subframe. Aluminum, weighs 800 grams! weigh, weigh better than the original steel item which was 3.8kgs, just don't know how it will go in a crash test...:shutup:
Now if I can do something about the 4.5kg gas tank and get my new pipe on there I might be down to around 85kgs.

Sorry I know it's not as exciting as those damm sexy pipes wobbly posted up

Just went back to look at your bike. 4.5kg tank can be sorted.
1. Go to trademe and order pit bike tank
2. To to burnsco and by fiberglass cloth, epoxy resin, pva releasing agent and mold release wax.
3. Apply two release agents as per instructions, or however you like it.
4. Apply fiberglass how the Internet says to, but keep it thin, really thin.
5. Abuse the now dry fiberglass shell until it is no longer stuck to the tank.
6. Strengthen the shell from the inside until you are happy with it.
7. Comment on how ugly your handiwork is, and tell yourself it will look better next time you do it.
8. Put it on the bike.
9. Race the bike.
10. Realise that you forgot to put the pit bike tank in.
11. Put the pit bike tank in.
12. Never try and make one that looks better.
13. Work out that if you had used the same amount of time starving yourself instead, then you and your bike would look better and weigh the same amount.
14. You're welcome.

[husaberg]

wobbly;Im not allowed Chokky Fish bugger it as I have type 2,that is under control with diet and single malt.

Single Malt? well really I thought it would be forbotten

Still leaves green bananas though I guess.Bugger

Did Honda with the NSR500 H20 injection either shield/Lag the pipes.
My guess is at speed the cooling air would drag out a huge amount of temp as well which is the opposite of what it needs too.

I was thinking antilag (ala turbo rally car) but the pipe wouldn’t survive the bang I guess maybe a hot wire heater and or meths in the water injection for removing latent heat then going bang for reheat.I guess it ony needs to fire once or so to reheat the pipe?
And yes before anyone says I know meths is not a bucket legal fuel.

[Dutchee]

13. Work out that if you had used the same amount of time starving yourself instead, then you and your bike would look better and weigh the same amount.
14. You're welcome.
Lol, if he weighs 85kg I'd be shocked. He's a skinny runt. Not all bucket racers ate all the pies, some were too slow and missed out on them.
Then again, maybe he weighs more than it looks. But he ain't Buddha's size ;) lol
Oh, just got told who'd post this, he'd be around your size.

[Buckets4Me]

And yes before anyone says I know meths is not a bucket legal fuel.
but are you using it for fuel ?
it's not even passing threw the engine :facepalm:
and when they take a sample it will not show up in the tank

so where is the problem ?

[husaberg]

but are you using it for fuel ?
it's not even passing threw the engine :facepalm:
and when they take a sample it will not show up in the tank

so where is the problem ?

nice one not the place for it me thinks

[husaberg]

Lol, if he weighs 85kg I'd be shocked. .

Is 85kg a runt? I am a fat bastard at 90kg small margin for error?

[koba]

I was thinking antilag (ala turbo rally car) but the pipe wouldn’t survive the bang I guess maybe a hot wire heater and or meths in the water injection for removing latent heat then going bang for reheat.I guess it ony needs to fire once or so to reheat the pipe?


Not that I'm a pyro or anything but I reckon a blast of meths powered heat in a hard wind blast (speed of bike) would do fuck all heating.

[husaberg]

Not that I'm a pyro or anything but I reckon a blast of meths powered heat in a hard wind blast (speed of bike) would do fuck all heating.

It’s meant happen inside the pipe. The idea was to use the heat removed from evaporating the mixture might first cool the pipe and then have it burn off to raise the pipe temp at higher revs.
I believe it might even auto ignite? Could happen? Maybe in the real world it may need some ignition source.It's just a theory I might try it on someones elses bike first in case it goes bang on me.

Maybe your onto something Koba without even realising it It could happen in a second skin outside the header with a presure release valve to flash off the steam

That would be a big bang engine.

[koba]

Its ment to be Inside the pipe.

Still, wouldn't it cool rather than heat? latent heat of evaporation and all that shit (please bear in mind I'm just back from being out on the razz with the lads at a fight night, brain may be a bit funny).

[husaberg]

Still, wouldn't it cool rather than heat? latent heat of evaporation and all that shit (please bear in mind I'm just back from being out on the razz with the lads at a fight night, brain may be a bit funny).

The origional idea was to use meths as it should burn off afterwards. Hopefully then restoring the heat in the pipe unlike water re Honda's ill fated NSR500 water injection which was taking to long to reheat for top end power.It's just an idea.The theory is like, 4 pages back
Cool pipe for mid range power
Hot pipe for top end.

[Moooools]

Lol, if he weighs 85kg I'd be shocked. He's a skinny runt. Not all bucket racers ate all the pies, some were too slow and missed out on them.
Then again, maybe he weighs more than it looks. But he ain't Buddha's size ;) lol
Oh, just got told who'd post this, he'd be around your size.

I was meaning bike and rider weight combined would be the same... I don't tend to make presumptions about people's weights in my posts.:innocent:

[Henk]

I would have thought meths would give more cooling that water since it evaporates so much faster, and it doesn't burn all that hot so maybe not much gain there.

[husaberg]

I would have thought meths would give more cooling that water since it evaporates so much faster, and it doesn't burn all that hot so maybe not much gain there.

I may be reading the table backwards but meths has half the latent heat requirements for evaporation as water does and burns far better than water but yes not that much heat.

[Gigglebutton]

but are you using it for fuel ?
it's not even passing threw the engine :facepalm:
and when they take a sample it will not show up in the tank

so where is the problem ?

Passing it through toast or cooking it up on a BBQ and you may end up like Amy Winehouse. Take it easy boys. Buckets are addictive enough as the are

[Moooools]

Passing it through toast or cooking it up on a BBQ and you may end up like Amy Winehouse. Take it easy boys. Buckets are addictive enough as the are

Actually all alcohols with an odd number of carbons will just kill you. methanol means one carbon so you will end more like those Russians on a ship who decided to celebrate a successful journey with the methanol they used for cleaning...

[bucketracer]

The origional idea was to use meths as it should burn off afterwards.

No one has mentioned where the oxygen to burn the meths is coming from.

But assuming enough oxygen can be introduced to support combustion of the evaporated meths and create some heat there would be an interesting over pressure situation in the expansion chamber.

[husaberg]

No one has mentioned where the oxygen to burn the meths is coming from.

But assuming enough oxygen can be introduced to support combustion of the evaporated meths and create some heat there would be an interesting over pressure situation in the expansion chamber.
You raise some valid points but as they don't suit my hypothesis, I will ignore them! Lol:shutup:
I guess Walter Kaaden didn't have that kind of expansion in mind when he initially designed them.

Alcohol have there own oxgen but it will not burn without extra i think. I rememberYank tanks used to use smog pumps to add oxygen to clean up the emissions though or?

Well maybe to propel the meths oxygen oxygen under pressure in a soda stream bottle leading to a venturi kills two birds with one stone. Then no pump required.A industrial solenoid to control with a set up like NOS but yes the overpressure could well have
"interesting results" A real Big bang bucket engine.
Remember the antilag turbo set ups pop pop pop........BANG.They were under pressure in an unfriendly exhaust environment the turbo exhaust is much hotter and heavier walled manifold though.

That still leaves the double skinned header pipe with water introduced between the skins with water flashing to steam and released to atomosphere with a presure release valve.

[bucketracer]

Its a safe place, the world of good ideas as everything is possible with talk and nothing actually has to work.

Theory and endless talk jousting with others to prove who is smartest is great fun but probably belongs some where else, like the talk shit thread.

Mostly the people who post on the Team ESE thread talk about what they are doing, have done or are trying to do. The common thing is that they "Did" first, and then posted something about their ideas and the efforts they went to.

[TZ350]

I am going to try water injection at some point as I have already got the gear made up for it.

The plan was to get a good dyno run without and a run with water injection and then turn the injector off at the point the two graphs cross over.

At first it seemed simple to me, if I could get a power extension at the bottom, the two graphs joining together nicely with the top end revving out like before then the thing should work.

But of course a full on dyno run is not like picking your way through the twisties where you are on part throttle a lot of the time using that low end grunt. Not a lot of people apex a slow corner using full throttle.

So it’s likely that enough water to tame the fire at full throttle on the dyno is going to be way to much at quarter throttle and some moderation of the water according to engine load will be needed.

This complication with water injection makes the simpler open/closed ATAC idea Wobbly proposed look much more attractive and variable crank case volume looks interesting too.

I am going to look at all of these ideas some day but at the moment the problem is getting the carburator tucked in out of the way when using the Vtec variable inlet timing device. I think the variable timing is important as it better matches the inlet to high and low rpm.

If I am going to have good low down grunt then I need good low down carburation. So far nearly anything I do seems to add length to the inlet and that shortens the power spread by cutting back peak power and over rev.

I have ordered a 24mm pumper Kart carb, I don’t really need the pumper part but the carb is quite a bit shorter and can be bolted directly to the engine without a rubber mount saving a lot of valuable mm’s.

1st things 1st, when the variable inlet timing and carburation is sorted then I will see what can be done with the pipe for more low end.

[husaberg]

[
QUOTE=bucketracer;1130115332]Its a safe place, the world of good ideas as everything is possible with talk and nothing actually has to work.


jousting with others I was not aware I was, If so sorry?


Mostly the people who post on the Team ESE thread talk about what they are doing, have done or are trying to do.

I think you way have got the wrong end of the stick of what I am trying to accomplish with this reworking of a failed in field testing. But never the less is an extremely interesting quirk of 2 stroke tuning poential.
Water injection in trial conditions can achieve a 24-30 % increase in mid range power. What 2 stroke doesn't need thi,s if it could be done without aftecting top end power .
This has been documented by some of the leading boffins in the two stroke world.
I thought this was a 2 stroke tuning forum where ideas are shared.

In the industry that I work in, We first thoroughly brain storm an idea before it implemented. That way input from many is considered and experience is shared for the good of all.
Different opinions are then sought and considered. The idea it is then tested/refined as nes then implemented and lastly it is refined as needed again .

If someone at my work breaks protocol or tries a new idea without this process, People can die.No joke.Ultra high voltage.

Apologies to all if I have got carried away.

When I find the original photos they will have to be scanned as they were film only and notebook and get round to sorting though it all. As well as taking some new ones when the weather improves.
I will post the specs and photos notes of my original bucket along with some of the details and progress of the new engine that Wobbly is curently helping with.inatial design stage mostly nutted out and novel in its base model as far as I know.
Once all the bits are in place, (from at last count 6 different engine models), That are to be raided for the...hp bucket.
This to will be mostly shared.
The bucket in my avatar was my original 68kg bike. Which had some interesting modifications buried inside .
Personally seeing you seem to doubt my practical ability. I designed and built my first expansion chamber at 16, It was officially measured at 123db (that loud it hurt) and added 45kph to the top end.It sure was ugly though and I still have it. In the first test session I was that excited I tried it without a stinger and it spat a ring and took the top land off the piston.The impetuousness of youth.me old man sure was pissed. But he welded it back together (the Piston)anyway and repinned the rings to, he is a clever bugger.

[bucketracer]

I thought this was a 2 stroke tuning forum where ideas are shared.

Its not a talk feast, at its best its a forum where people share incites into their experience and/or work they are currently doing or to ask a genuine question.


I will post the specs and photos notes of my original bucket along with some of the details and progress of the new engine that Wobbly is helping with.

Now, this is keeping it real and posts about your projects will be very welcome .............

[husaberg]

Now, this is keeping it real and is very much welcome .............

The generation gap maybe us old buggers (I am 37) sure do like to talk.
I do see your point though.
I will not show Wobbly the pics of the transfers though, he threatened do do bad things to the last guy who had transfer septums that were about half as sharp as mine.
It wasn't my fault- it was err...the fashion back then?.Plus you could shave with them.Or cut my leather tie with them, remember those boys.

[bucketracer]

It wasn't my fault- it was the fashion back then.

Yes, so much that is done follows fashion, one of the great things about Buckets that I love, is that fiddlers can try out their own original ideas and fashion be dammed.

[husaberg]

Yes, so much that is done follows fashion, one of the great things about Buckets that I love, is that fiddlers can try out their own original ideas and fashion be dammed.
sorry its a long one.
Remember the mid 90's

What I found back when I was playing with the Mb100/H100 MB5 bucket was the commonality with not only the cr80 ra/rb for the ignition etc .
There is also a great deal of commonality with a lot of other honda engines got to love Honda for that.Lazy bastards they were, the designers.
One easy mod I found when playing was the xr200 clutch(I think it was could have been the cb100 in hindsight but it is a four stoke single) mod the basket is wider it i.e. std an extra 1 plates std slightly beefier hub and although the spine is different it simply presses out with the mb fitting in its place.
The tooth profile and number of teeth is the same the xr200 clutch has a wider shoulder behind the spline which needs to be slimmed down also. The xr200 hub has a beefier release bearing and alloy bearing pressure plate I seem to recall a mod to the pushrod and a spacer gasket. The plates of a EBC catalog are all steel and proper fiber and are not pulp based like the mb100/h100.used to use mobile 1 oil.2 stoke mix was A747 at 20:1. Squish was as per bell book but I never did measure the comp ratio.

Tuning wise my h100 based engine at the time up there with the fastest real legal bikes I ever encountered. The Honda xl125 bikes were the fastest then but they were all xr200 in disguise (Names withheld) was super quick and ultra trick but he even admitted it had a "thin sleeve" and interesting stroke these were pre fxr150 125cc days though.
There was a gp100 that could outrun mine but he was a far better rider (He still is too)and I suspect he was also a 125 as the ccs were ground of the barrel. My bike was pretty tame initially and one of the first mb5 100 in the south island as far as I know it was mb5 ignition ( it has an high speed retard )I had an cr80 ignition but could never find a suitable cdi unit I did try a xr200 one with the cr80 stator it worked but wouldn’t run over 6000rpm (off course it was from a four stroke with the ignition normally run at half engine speed) it had the cut down rd reed manifold complete with stuffers cut a little and the 4 petal reed block and tzr 28 mm downdraft (Trick then)it was ported to bell book spec with the transfers raise by the lift the barrel 1.6 spacer way Machine a similar amount of the top.I was To chicken to touch the transfers it was super torquey but probably needed a 34mm carb In hindsight it really needed one and it would explain why it was no flat after the additional porting work.I was going to fit an silver plated big end from the cr125 m 76ish I think. I had a box of nos 125 bits at the time. it was able to be fitted with the 125 rod same length etc but was 2mm wider and would have needed the checks of the crank machined it used to run to 12500 regularly on the std crank so I never got around to it. The engine for the most part was super reliable although the mag side bearing let go a couple of times and had the mag spin on the taper repeatedly until I lapped it on. It was 68kgs dry with a gutted cut down tank and the std oil tank as a fuel tank, BHP was estimated at 23 ish in comparison to other bikes. There was no dynos in the south island then. After I brought my first farm a was always to poor and got to fat and the bike was left neglected at my parents in a leaky shed .I rescued it last year with the hope of resurrecting it but I am probably to fat now. I put on a set of Honda 2.5x17 rims cbr250 front and a 3,5x17 front from a cbr400 on the rear. I already had a floating 300mm cast iron rs125 disk for the front with a 4 piston brembo and a rs125 mc from spares of my cr500 motard I got around to fitting a set of usd forks from some Chinese bike with nice alloy yokes the project stalled there once my son starting mx.
A mate of mine used help me with a lot of the grunt work stuff he came up with the concept of the 6 speed mb100 in the south island at least as far as I know.His bike used to run a huge plumper carb from a jet ski with a more mildly ported mb100 (Although I think the mb100s were a bit more racey spec in the porting std)
this bike would piss all over mine in acceleration, but it would bog on over run and practically high side you on corner exit it came in the sudden although I think I found a write up on how to fix this latter on in an ancient cycle article, interesting Cagiva fuel injection suffered the same problem.
I rode his bike once at a bucket meeting and beat a couple of guys who had national championships then and later f1 and f2 It was a tight track though it said more about this and the bike set up than my riding ability.
will add pics and notes later.

[Yow Ling]

Thanks for the Story,
Where is your farm? There is buckets at Levels mid August.
You wont be the biggest guy there, and at 37 you will be at least 15 years junior.
No point in letting your bike rust in the shed, otherwise sell it to me and Ill let it rust in my shed with all the classic buckets Ive collected

[wobbly]

Stoner kicks Horheys arse at Laguna, bravery and poetry in motion, a joy to watch.
I would come to Mt Welly if anyone rode a bucket like that boy - woo hoo.

[gav]

Where abouts in the South Island were you racing? Were a lot of fast MB's at Woodbourne in the early days.

[kel]

I would come to Mt Welly if anyone rode a bucket like that boy - woo hoo.

Bit hard to steer with the rear with only 16hp. See Lorenzos practice crash, traction control wasnt engaged, spat him in a milli second. Check out the photo, still has his hand on throttle!
243481

[wobbly]

Lorenzo was sore after the race - no wonder when another millisec after the pic above he did a full face belly flop on the tarmac.
Forget steering the rear,Stoner kept it pinned around the outside at full noise,amazing.

[goose8]

Bit hard to steer with the rear with only 16hp. See Lorenzos practice crash, traction control wasnt engaged, spat him in a milli second. Check out the photo, still has his hand on throttle!
243481
I've seen Nigel ride like Lorenzo did in practice a few times very similar to the photo

[husaberg]

Thanks for the Story,
Where is your farm? There is buckets at Levels mid August.
You wont be the biggest guy there, and at 37 you will be at least 15 years junior.
No point in letting your bike rust in the shed, otherwise sell it to me and Ill let it rust in my shed with all the classic buckets Ive collected

We sold our last farm for the sake of the Kidz schooling ,travel for the mrs and the stress huge mortgage etc (that comment should gain points with the Mrs. aye) about 2 years ago. The Mrs. has got the house she thought she always wanted (still not finished bloody master builder my arse) and I got a few toys. I still work full time as I always have but have scaled back my hours in actual paid work I used to Average 60 with bursts over 100 this was not including the farm mind you. I now strictly do 40 .I also sacked my old boss for a real easy job with the same money as I used to get working long hours. Ps West Coast.
Re levels the sound check for the classic at 123db was there, they might not want me back a few more houses down now to now i bet .:yes:

[Gigglebutton]

Lorenzo was sore after the race - no wonder when another millisec after the pic above he did a full face belly flop on the tarmac.
Forget steering the rear,Stoner kept it pinned around the outside at full noise,amazing.

Watched the race race last night after the girls finished with Project Runway & Britain's next best baker Grrrrrr. Fuck yeh, awesome move by Stoner. The best race so far. Hope Rossi can sort that Duke out. Next season should be good with the 1 liter motors and a bigger field

[wobbly]

Have just found out that the Suzuki VJ23 cylinder is a T port ( like the older models and also Aprilia RS250) but it has sub ports as well.
This may be an even better choice for sitting on a RG bottom end and sleeving to 50mm.
Anyone got one I can look at.

[kel]

Have just found out that the Suzuki VJ23 cylinder is a T port ( like the older models and also Aprilia RS250) but it has sub ports as well.
This may be an even better choice for sitting on a RG bottom end and sleeving to 50mm.
Anyone got one I can look at.

Ah the last of the RGV's. Recently saw one for sale in NZ at a very resonable price, dont think the owner appreciated what he had.
I have seen cylinder pictures on the net somewhere you could try http://www.rgv250.co.uk/ But why the need for so much exhaust area, the RGV already had a lot of exhaust.

[wobbly]

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

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

[F5 Dave]

Yeah a mate has one apart at the mo, he's waiting for crank, apparently this Japan quake thing has F'd things up a bit. Its def a T port, don't remember seeing aux ports, but then again we were too busy looking at the broken rod.:shutup:

I could try get a port rubbing & scan it.

[bucketracer]

I could try get a port rubbing & scan it.

A rubbing and photos would be great if you can get them ............

[wobbly]

While its apart I am more than happy to pay for freight to get it here for a days measuring.
Get your mates Email and I will give him my NZC account number so it cost him no time or money as they will do a pickup.
cheers
wob

[marsheng]

No point in letting your bike rust in the shed, otherwise sell it to me and Ill let it rust in my shed with all the classic buckets Ive collected

He has enough bikes as it is. Best you get on it yourself and come and play with us !!!.

[F5 Dave]

I'll talk to him. Bike is sitting in his kitchen waiting for parts. (bedroom already has a 256 80s GP bike & lounge an RZ500 project).

[koba]

I'll talk to him. Bike is sitting in his kitchen waiting for parts. (bedroom already has a 256 80s GP bike & lounge an RZ500 project).

It has come to my attention that some uncharitable types might label someone indulging in such habits as "an Animal".
These people are fools as it is a clear and definite sign of great taste.

[Kickaha]

(bedroom already has a 256 80s GP bike

poor bastard

[husaberg]

It has come to my attention that some uncharitable types might label someone indulging in such habits as "an Animal".
These people are fools as it is a clear and definite sign of great taste.

I have made a wee start on the old bike refurbisment.
Sorry about the mess it's the maids day off.:violin:

[koba]

I have made a wee start on the old bike refurbisment.
Sorry about the mess it's the maids day off.:violin:

Nice.
It looks short.
And Light.

[bucketracer]

I have made a wee start on the old bike refurbisment.

Looks great, love those upside down forks ................. looks like its going to be a serious bit of kit when you have finished refurbishing it.

[husaberg]

Looks great, love those upside down forks ................. this looks like serious bit of kit

$45 came with a frame and other crap, Chinese of a 3/4 bike I think, maybe Hummer?They weigh about the same as the originals to.
I will try and find some ohlins stickers to keep up with the jones.It was bloody hard to find any forks in the correct length as most are to short (PITBIKE) or to long any real bike.
The originals are 26mm and rusty with the top yoke forming part of the handle bars (All steel )and a single pinch bolt on the lower yoke only, They had to go.They Seem to damp ok and the spring rate is close to spot on.The Stem needs a little work as it solid. I have got a 4 piston Brembo to go on with the 300mm cast iron floating rotor and RS master cylinder. The swing arm is Chinese alloy and stronger than the original ,(not hard ,stock is piss weak)
Its a little short but came with a load of bits for $25 I have a small 160mm disk and plan on using a ktm 50 caliper (assuming my son doesn't mind sharing it). With adaptors to suit either an A100 or fs1e sprockets or KTM 50 (they are available in almost any size.)
Incredibly the wheels (17x2.5 and 17x3.5 both Honda fronts)$240 for both Tintin great bloke They weigh pretty much the same as the 18x1.4 original comstars.

If anybody wants some 90/90/18 17 year old slicks. Open to offers.(A bit of nugget on the sidewalls to cover the cracks and they would be like new!)

The frame will need to be hacked a bit to fit the monoshock. Probably pit bike at this stage and the frame spine has to go as any carb bigger than the tzr250 will not fit .The std frame had to be dented (Big hammer muliple hits)to fit the origion 28mm flatslide carb in. The subframe was always a bit low (It scraped on the seat pan at times) and with my extra kgs of (muscle?) it will need to be raised.
Below is scanned pic of the original oldschool (well I was fresh out of school)bucket .I think the year was 97
Note the tank . if you have seen a std MB5 one. You will know why.

Does anybody remember which bike of the 80s had a remote preload adjuster ns400? suzuki impulse?I was thinking of adapting one

[ac3_snow]

Been having a few issues with getting my bike to idle, would either not idle (not enough gas) or continue revving like mad, (enough gas and perhaps and air leak) so funnily enough turns out my bike had an air leak. Don't know that I should be admitting it on here, but I never got around to blocking the oil inlet hole in the side of the barrel.:facepalm:
243642

So with that out the way I continued the leak test and found the head gasket wasn't quite sealing at the rear of the cylinder. I already have an oring but the addition of copper gasket helped that. Then found the base gasket was also leaking at the rear of the cylinder, neither of them huge amounts but fixed them up all the same.

Made my tester with the remains of an old spark plug, an extra long valve from a bicycle tube and some arldite.
243643

By the time this was all done it was perhaps a little late too piss off the neighbors so still don't know if it will idle just yet, minor details tho. Can't wait for saturday!
243644

[F5 Dave]

I have made a wee start on the old bike refurbisment.

Yeah those forks should have juust about enough travel.

Can't see what the swingarm pivots mods are, but my old MB50 frame stiffened up considerably with teh addition of a tube run above the pivot between the plates. However don't be as stupid as I was back then, test position with the chain on using large sprockets & more importantly consider sw movement. (had to cut a slot in mine).

[F5 Dave]

<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <w:DontGrowAutofit/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]--> Well I spent some time putting the MB100 engine together a few times checking squish & chamber volumes. I had to modify a mandrel I had for holding the head as it suited watercooled heads & this is large & chunky aircooled. I’ve always got mates or local machine shops to adjust shapes with either “machine 0.2 off” instructions or anecdotal “take a little out” of the head amounts. For anything more serious I’d go there with an engine, burette & solder & we’d make a few cuts or I’d give them a template to follow that would get close to right.

When I got a lathe I always envisaged that I could do this myself, but I’ve doubted my 40’s lathe or mandrel was good enough to get straight sealing surfaces. Now my mandrel is straight this is a good start & I’ve made some cuts of the head squish area & chamber finding that the stock chamber wasn’t that straight compared to the head face or spark hole. Now they line up & the squish clearance is the same back to front & adjusted to 0.8mm.

I’ve taken the squish area back to under 8mm wide & measured compression. As I took successive cuts it came down from 15.2:1 to 14.7:1. Then I ran out of time but will snick a bit more out to aim at 14.3 so I’m not going crazy with air cooling for the moment.

MSV calcs are still pretty high like 25m/s, hard to get them lower & still retain some squish band.

The chamber height is quite tall & retains some of the std triangular shape despite being somewhat more squat than std top hat, but will do for the first runs. The next head I will cut quite some more off the sealing face & start again & later experiment with a toroidal shape. What I am having difficulty with is making curved cuts with my range of std cutting tools. I have some ground tools, but have never seen a curved cutting tool & sod knows how you’d grind one. Any lathe experts have a better idea?

[Edit] I’ve made an attempt at a curved cutter but it isn’t what you’d call that effective. Better than nothing but not flash. Can’t remember my old lathe book saying anything about curved cutters.

[jasonu]

[Edit] I’ve made an attempt at a curved cutter but it isn’t what you’d call that effective. Better than nothing but not flash. Can’t remember my old lathe book saying anything about curved cutters.[/QUOTE]

Mate, persist with the curved cutter. I made one last century and it worked fine. There was a bit of juggleing with squish clearence and width % and comp. ratio but I got it to work.

[husaberg]

F5 Dave;1130118939]Yeah those forks should have juust about enough travel.

Can't see what the swingarm pivots mods are, but my old MB50 frame stiffened up considerably with teh addition of a tube run above the pivot between the plates. However don't be as stupid as I was back then, test position with the chain on using large sprockets & more importantly consider sw movement. (had to cut a slot in mine).

Good point re forks Dave.
I must admit I hadn't really looked at the travel but no real issue to shorten the travel up a bit. The frame as it is now is pretty much std.
The mods I alluded to are the tank in the other pic as you had a MB5 you will understand the reference.
I was planning on plating the swingarm plates as the alloy swingarm is a little thinner anyway, but a little lateral bracing sounds like a good idea too, esp. as I plan to hack around the rest a bit. I was planning on doubling up the spars a bit but I am undesidered at this stage .Although I could of course install a larger spine with the monoshock inside it with a cut out for the carb? Maybe.
Note the swingarm pivot is slogged out o the clutch side I always meant to fix that must have forgot It used to wallow a bit on fast right handers.
Plan on getting grinder out this weekend regardless.

[TZ350]

The next head I will cut quite some more off the sealing face & start again & later experiment with a toroidal shape. What I am having difficulty with is making curved cuts with my range of std cutting tools. I have some ground tools, but have never seen a curved cutting tool & sod knows how you’d grind one. Any lathe experts have a better idea?

We have often hand ground up curved cutters for shaping small combustion chambers.

Afterwards any imperfections in machining the combustion chamber are linished out later with a battery drill and port polishing stick while the head is spun in the lathe, take your time and it will work out OK.

[F5 Dave]

. . . It used to wallow a bit on fast right handers.
Plan on getting grinder out this weekend regardless.

Once I braced the frame & inserted a RM swingarm my stiffened shocks (heavier springs & oil) that had seemed ok all of a sudden were too stiff as that part of the "(un)controlled frame flex" suspension was gone.

[F5 Dave]

We have often hand ground up curved cutters for shaping small combustion chambers.

Afterwards any imperfections in machining the combustion chamber are linished out later with a battery drill and port polishing stick while the head is spun in the lathe, take your time and it will work out OK.
Cheers guys, I'll have to keep experimenting with cutters. To grind them what do you use, I mean aside from the external cut done on the bench grinder, how do you get a curved internal recess?

[koba]

Does anybody remember which bike of the 80s had a remote preload adjuster ns400? suzuki impulse?I was thinking of adapting one

NC21 did. I may have one soon, depending on how I choose to deal with my pakatu rear shock.

[TZ350]

Cheers guys, I'll have to keep experimenting with cutters.

Our lathe is quite small and our cutters are not ground to the full size, the curve is ground into 1/4 by 1/4 tungsten blank and covers about a 1/4 or at most 1/3 of one side of the combustion chamber hemisphere and has the normal top and side rake. By taking progressive cuts and joining them up a fairly good result can be achieved. I have seen Darren make a complete curve out of 1" by 1" that worked ok in his big lathe.

Other lathe tools that have proved very usefull are ones ground on the end like a soup spoon (normal top and side rake) and by locking the saddle and by carfull free hand use of the two handles on the cross slide fairly good chamber shaping is possible.

Of course CNC would be the Bee's Knee's but this is Buckets and the racing Gods expect us to have a go for ourselves using whatever cleverness and oddments we can find.

[TZ350]

Been having a few issues with getting my bike to idle, would either not idle (not enough gas) or continue revving like mad, (enough gas and perhaps and air leak) so funnily enough turns out my bike had an air leak. Don't know that I should be admitting it on here, but I never got around to blocking the oil inlet hole in the side of the barrel.:facepalm:

Buckets ...... the best place on earth I recon to learn race craft and bike prep. Thanks for the posts, its very interesting to see it all coming together.

There are some great looking home builts being developed about the place, exciting times.

[ac3_snow]

Does anybody remember which bike of the 80s had a remote preload adjuster ns400? suzuki impulse?I was thinking of adapting one

I think I have one in my garage, don't ask what its off, could be an old nsr or could even be a yamaha pretty sure it was a 250 something, send me a PM if your interested.

[husaberg]

Once I braced the frame & inserted a RM swingarm my stiffened shocks (heavier springs & oil) that had seemed ok all of a sudden were too stiff as that part of the "(un)controlled frame flex" suspension was gone.
I guess that’s the problem with these old frames designed for 100km/h and plastic tyres I suppose.
The frame will be an interim measure. Not ideal but it will do for now.
Would like a pre 95 RS frame but can wait for one to pop up.
I have attempted some mockups ( please don't mock my photo editor skills):blink: Number 2 is probably the frontrunner.
Looks kind of mk4 Seeley G50

Anybody know how wide the subframe rail are on the RS125 for the seat?

[RMS eng]

Cheers guys, I'll have to keep experimenting with cutters. To grind them what do you use, I mean aside from the external cut done on the bench grinder, how do you get a curved internal recess?

Dave, you send the head to me i have 4 different shape cutters for 100-125 heads and for RS125 heads, for a small fee.

chris 09 817 9500
RMS eng

[husaberg]

Just a small point re main bearings.
You should have the crank floating - ie spin the crank in a lathe with the rod taped down and polish the main journals so that the bearing inner race just slides on by hand.

I was just thumbing through tunning for speed 1948 edition amazingly it says exactly the same thing. I always thought Phil Irving was Clever bugger .The Vincent Black Shadow should have been a bit of a givaway though.

[RMS eng]

I was just thumbing through tunning for speed 1948 edision amazingly it says exactly the same thing I always thought Phil Irving was Clever bugger .

its been around for along time 74-75 TM125 and RM125 suzukis cranks had a floating fit on the L/H side main bearing.but after a while it damages the crank.

[wobbly]

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

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

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

[jasonu]

Dave, you send the head to me i have 4 different shape cutters for 100-125 heads and for RS125 heads, for a small fee.

chris 09 817 9500
RMS eng

Yeah probaby my cutter mentioned in a previous post!!!

[richban]

For anyone interested.

Just weighed in the rolling RS250 chassis. 1990 Honda RS250 with full fairing breaks, seat, tank, heavy NSR250 wheels everything except the engine is 64kgs. With a 125 wheel conversion and the new engine I would hope to keep it under 90. Might weigh that big fat 4.5" 18 on the rear and do a weight comparison later. I am sure with the big tyre it has, it will be heavy.

[husaberg]

its been around for along time 74-75 TM125 and RM125 suzukis cranks had a floating fit on the L/H side main bearing.but after a while it damages the crank.

1974 vs 1948 hmmm....he did (phil Irving) go on say if crankpins are to loose not to attack them with a chisel,
Party pooper. Cold chisles are sure handy for percision fit stuff.:innocent:

Following on from the water injection whimsical musings or ramblings.
Honda and pretty much everybody else it seems(4 stroke mind you) now inject air into exhaust headers to burn off unwanted hydrocarbons mainly at start up or cold.They have even stole a reed valve to prevent blow back.Simple really the blackbird has it.why can't I.Together with h20 or pos meths injection it may still work.

[jasonu]

With a 125 wheel conversion and the new engine I would hope to keep it under 90.

I would hope so too...

[richban]

I would hope so too...

Dirty 4 strokes are heavy.

[bucketracer]

The dynamic stretch for my motor is about 0.5mm and I have got pretty good at shimming the barrel so the piston just kisses the head when I want it to.


In any race engine the squish height should be set at the minimum achievable,just shy of the piston tapping the head when overeved.

In a bucket where the norm is "only" 13000 there is no reason to have any more than 0.6mm.


TeeZees piston/head photos, he was doing this close clearance thing way back, when others were championing something else ...... so its satisfying to see the concept validated by Wobbly

[bucketracer]

I really am interested in seeing what power you have, as well as what your curve looks like.

...... in almost 10 years of operating various Dyno's around the place, I have personally never seen more that 17 P.S and 14 N.M (at the rear wheel) on an air cooled disc valve two stroke, running a 24mm carb.

I have probably done over 200 runs on that type of set up. (on various engines)

Lookig forward to it Teezeetreefiddy!

"working in the industry", does not guarantee that you know very much.

243723

Air Cooled 125cc 24mm carb 28.9 PS and 17.9Nm measured at the rear wheel on a DynoJet.

243724

4,500 rpm power spread with the small crank and extra crank case volume.

The graphs are TeeZees tests of the Soft vs Hard closing rotary valve and extra crank clearance and case volume.

A person doesn't have to work in the industry to know a thing or two and be able to manage a good result with their hobbies, it just takes a bit of intelligence.

There are plenty of non industry people out there working on very clever projects.

[husaberg]

bucketracer;1130119933]Working in the industry, does not guarantee that one knows all that much.
I once worked in the porn industry. As a critic, didn't get paid though But I do know what I like.:tugger:
I did however used to get paid for sticking my hand up cows buts though.:scratch:
No points for guessing which one was my hobby.:sick:
Old Vespa Boy did have some interesting stuff to say before he started on his racist rants:
By the way, where did Thomas go?

Air Cooled 125cc 24mm carb 28.9 PS and 17.9Nm measured at the rear wheel on a DynoJet.
Awesome results, Shit must aim higher.I was aiming for 30hp so the target is 35 from a 100cc lc crankcase reed with a wide spead pv atac and h2o to go go.
I hope to have it ready for Taupo!

Anyone know the pcd of an honda Rs125 rear disk? stud to stud hole is fine.
My usual resources at Motormaster http://www.moto-master.com/productnow.php# dont list the rear for a rs125 though ps geat site if you are looking for disks to adapt.
Metal gear how some useful info but no pcd http://www.metalgear.com.au/
This one (JT) one useful for sprockets pcd centre hole dia teeth avail splines etc http://www.jtsprockets.com/40.0.html
Apologies if its already posted buried some place further back

[Yow Ling]

Anyone know the pcd of an honda Rs125 rear disk? stud to stud hole is fine.


3 bolts 95mm apart

[F5 Dave]

Thanks for the ideas on cutters guys. Koba showed us a couple of examples which has got me ridding myself of my preconceptions of what a cutter should look like. My examples which came with my ancient lathe are more scoop like. I'll form a couple of cutters & see what suits. Koba's example was fairly close in concept to Wobblys, but with more angle still. self taught on this lathe stuff so I'm a bit of a muppet.

OK I'll tone down worrying about the high MSV numbers so much. I'd ignored them on the 50 where I run 0.5mm squish & up to 14000, but assumed that 50s distort the rules a bit anyway. I'm only running an old RS ign onhte 100, but will look at prog when I get it up & running & can find some coin (dirtbike extracting play money atm.)

[TZ350]

Took the GP to Mt Welly, wonderful weather for the start of the new season.

It was nice to be presented with a second place trophy for last seasions F5. During the seasion I had been beaten by all cummers including very young neewbees and I came last in nearly every race but road every meeting, hail rain or shine and always finished, so the second overall was a triumph of consistancy over talent.

F5 is wide open for that can ride well.

Sunday was the first time on a F4 bike in a very long time about 18 months I think, but was looking forward to it.

After a bit of practice I started off the back row in the A grade pre-lims. I enjoyed the fast pace but was well out of practice and with two or three laps to go was starting to get lapped by the mid field.

So in order to go faster I slowed down and dropped back to B grade. The new bikes handling is much better than the old GP chassis. The slower pace suited me, I was able to take more time and think about the corners and how to improve on them.

There were many times I was able to ride around a corner beside different FXRs but the FXR's power delivery seems to be just right because they could always just get a wheel ahead after the apex and that was enough to hold me out.

It wasn't about corner speed just the FXR pulled better from the apex to about 25m out and that was enough. And this is where over the last month or two I have been trying to improve my engine.

The highlights of the day was seeing how fast Ac3_Snow was on his new bike, it looked good and will un doubtably be a real contender in A grade.

The other was seeing Avalon on a Team ESE bike (prepaired by Chambers) take second in the first A grade points race behind Tim. Unfortunately in the second race Av got held up in the pits and had to take her place on the grid with out the chance of warming her tires up.

At the green flag she made another cracker start and was third through the first corner but unfortunately she was unseated by the cold tires going through the infield.

Dave D was unfortunate to get caught up in the crash and was unable to rejoin quickly but there was some humor to be had when the start line showed him the Blue flag as the front runners got the jump on him around the sweeper as he was getting underway again.

As I suited up for my ride I over heard Thomas say, "we have the horse, but not the rider", well its true, I don't expect to be able to ever run better than mid pack myself and are one of those who has to claim its all about the fun, but put a good rider on a ESE bike and they go well enough. At the end of the day I was stiff and sore all over from the unacustomed effort and felt like I had played several games of rugby, I was happy but needed a cup of tea and a lye down.

Photos from Damien Tomans collection from the meeting before of Av and Tim in action.
http://www.flickr.com/photos/dty1/sets/72157626941175616/

[F5 Dave]

. . .
And with any of the race type plugs we are using approx 1mm of unthreaded plug end should be protruding into the chamber.
The old B10EGV was originally designed to be used this way by NGK, but nowdays the trick plug is a R7376-10, this plug makes more power than any other tested with around +2 Hp better than an expensive Denso equivalent, here is the test i have shown before.
. . .
Wasn't aware that they were supposed to stick out a bit.
2hp on presumably an RS is pretty good. Pretty low revs for that sort of power!!

But I would always test before shelling out the $ for flash plugs. My 50 with an NGK R series racing plug back to back test against my usual B9EGV showed zip difference & yet on Darrins gave almost an hp! His headshape was very shallow though.

My old H at least in early development dyno'd best with a std fat B8HS plug compared with a fine wire. That surprised me as I'd seen 1/2 hp on a smaller MB back in the day & assumed that with some reasonable compression fine wire was better.

Then again the H seemed to run best on RD steel reeds. Just saying testing shows up some interesting things. There may be reasons for the anomalies, but at least you know.

[koba]

There were many times I was able to ride around a corner beside different FXRs but the FXR's power delivery seemes to be just right because they could always just get a wheel ahead after the apex and that was enough to hold me out.

It wasn't about corner speed just the FXR pulled better from the apex to about 25m out and that was enough. And this is where over the last month or two I have been trying to improve my engine.


Clutch? <tenchar>

[TZ350]

Clutch? <tenchar>

Quickly burnt out ......

</tenchar>

[F5 Dave]

Now there's a lever dear to my heart:yes:

Actually its been holding me up a bit in reaquainting myself with the Trials bike. Keep grabbing it & stopping drive which at 4kph in slippery mud stops traction.

[koba]

Quickly burnt out ......


Damn, 'twould be fantastic to have the power to do that!

Is the gearing as good as it can be for drive out of the important corners on the track?

Just throwing a few more ideas into the mix, I'm sure you have thought of it already anyway.

[husaberg]

Koba Is the gearing as good as it can be for drive out of the important corners on the track?
Just throwing a few more ideas into the mix, I'm sure you have thought of it already anyway
I was wondering the same thing as the gp100 is 5 speed and I am sure the top 3 ratios will be the closest in terms of spacing between the gears.
Are you geared at the track to take advantage of this.ie the top three ratios.


F5Dave Wasn't aware that they were supposed to stick out a bit.
Neither was I.
I was always was lead to believe that it could cause preignition. Obviously only an old wifes tale.
is it better to have the plug protruding more into the combustion chamber becaue it it is more in the center of where the mixture is concentrated?

Also maybe Wobbly could also enlighten us on how much power increase from the new small cranks engines power increase, would/could be atributed to the less tortorious path of the mixture past the crank.Rather than say a larger crankcase volume.

[bucketracer]

One point to remember is that the best radius on the squish corner into the bowl is no radius at all.A sharp corner with just with a rub of sandpaper to get rid of the ragged knife edge, works best.

And with any of the race type plugs we are using approx 1mm of unthreaded plug end should be protruding into the chamber.
The old B10EGV was originally designed to be used this way by NGK, but nowdays the trick plug is a R7376-10, this plug makes more power than any other tested with around +2 Hp better than an expensive Denso equivalent, here is the test i have shown before.


4 NGK Spark Plugs R7376-10 on Ebay

243822

About $13 NZ each plus shipping

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=370527257800&viewitem=&sspagename=STRK%3AMEWAX%3AIT

[TZ350]

Is the gearing as good as it can be for drive out of the important corners on the track? Just throwing a few more ideas into the mix,

All good ideas, was running a 14 on the front, 13 seemed to be, too big a jump and was running out of revs before the next corner, so may try half way by putting a couple of extra teeth on the back. The FXR's seemed like they could easily run corner to corner without changing gears, so you can see why I wan't to increase the power spread of the GP.

And clean low end carburation would be a help too. I have ordered a 24mm pumper kart carb. It is much shorter than the Keihin I am using now so I hope there is enough room so that I can use the pumper with the V Tec inlet for sharper low end carburation and keep the inlet tract length below the 135mm limit suggested by Wobbly.


I was wondering the same thing as the gp100 is 5 speed and I am sure the top 3 ratios will be the closest in terms of spacing between the gears.
Are you geared at the track to take advantage of this ie the top three ratios.

One of the reasons I am trying to develop enough power spread to only need two gears is to be able to only need 4th and 5th and drop down to 3rd for emergencies when I have truly cocked things up or been baulked in a corner.

[husaberg]

All good ideas, was running a 14 on the front, 13 seemed to be, too big a jump and was running out of revs before the next corner, so may try half way by putting a couple of extra teeth on the back. The FXR's seemed like they could easily run corner to corner without changing gears, so you can see why I wan't to increase the power spread of the GP.

Gearing guide attached nice and simple.

No doubt if anyone could be bothered a programe could be found written etc
.
As you can see the options are endless 1/10 of a tooth on the rear etc not to mention the effects on on handling squat etc
I used to spend hours on speed calulations for rev drops between gears changes to overal ratios etc etc.Should have spent more time actualy riding.
Failing that, if the fxr is still holding you could always "ram him"Just how tight is Mt Welly.

[TZ350]

Thanks for the chart.


Should have spent more time actualy riding.


Some at work have said the same thing about me........ :o


.... Just how tight is Mt Welly.

Google map "1 Tainui Rd Mt Wellington NZ"

http://maps.google.co.nz/maps?client=firefox-a&rls=org.mozilla:en-GB:official&channel=s&hl=en&biw=998&bih=545&q=1+tainui+road+mt+wellington&um=1&ie=UTF-8&hq=&hnear=0x6d0d497eca59451f:0x5760086d64db2470,1+Tain ui+Rd,+Auckland+1072&gl=nz&ei=0Y02Tqz6BITqmAXu7aTwCg&sa=X&oi=geocode_result&ct=title&resnum=1&ved=0CBwQ8gEwAA

Av was taking all 7 corners around the longer infield track in 30.2 to 30.6 sec depending on traffic ....... :sweatdrop

... I am about a 1/2 hour slower.

[husaberg]

Av was taking all 7 corners in 30.2 to 30.6 sec depending on traffic ....... :sweatdrop ... I was about a 1/2 hour slower.
In fairness to your riding I am guessing she is maybe a few KGs lighter.:yes:
What did the kt100 use to lap in or still lap in?

[TZ350]

In fairness to your riding I am guessing she is maybe a few KGs lighter.:yes:

All up, Av and her bike is 90kg lighter than me and my bike.


What did the kt100 use to lap in or still lap in?

Not sure what the Karters do but one day a Kart Girl who had come down for some practice laps let Karl Morgan out in her Kart, from memory after a bit he was doing 26 sec laps.

[Buckets4Me]

from memory after a bit he was doing 26 sec laps.

and still a second slower then her :facepalm:
I thought he was going to throw her brand new kart away trying to beat it

[F5 Dave]

Thanks to Koba who came around last night & helped me grind up a reasonable curved cutter & we found a bit of slop to take out of the cross plate doofer. Plus he's making up a better flange type holder that will facilitate skimming some off the gasket face without chatter hopefully.

Heck after he left I even cleaned away a bucket of swarf as I was feeling guilty about the mess around the area.

[wobbly]

Some bastard got in and swiped those plugs - me.

The case com being bigger works better and better as the inlet is optimized to fill that volume to the same pressure ratio, and subsequently the ducts/transfers are able to move the extra vol available into the cylinder.
This then increases the delivery ratio and ultimately the dynamic com.
I dont really see much gain from reducing the cranks effect on intake streams - Jan Thiel found 1 Hp in 50 by covering over the crank wheels as is done by all the Italian 125 kart engines.

Here is a gearing chart with rev drops I did.

It may be a better way forward to look at keeping the same powerband width, but simply moving it all up a thousand revs or more.
Then with the adjusted gearing, to achieve the same terminal speed, you will accelerate alot quicker due to torque multiplication of the extra teeth on the back.

[Bert]

some of us handle metric better.:facepalm:

I think I posted this before its been converted back from excel 2010 so I hope it works.
243871

[ac3_snow]

Had my bike on the track in the weekend :woohoo: During the first few laps on saturday morning I almost had to pinch myself, was great punting around on something I had built myself, very satisfying :D

Bike went very well, after the exhaust vibrated its self in half, huge thanks to chambers for the help mending it! Sunday was a cracker day and the start of a new season in A grade. Two finishes at the back of the pack due to very foolish mistakes. Rest of the time finished around middle of the pack, hopefully can improve on this through the season!

Gearing seemed good, most of the track was spent in third then a quick chop up to 4 and 5 as I came onto the straight. Might put the cbr250 standard front springs in for the next meeting and see how that goes. Also with any luck will have a new pipe mounted properly for the next round. But all in all very happy with the weekend only a few minor issues to work on.

[husaberg]

we found a bit of slop to take out of the cross plate doofer. ............ I was feeling guilty about the mess around the area.Abridged slightly

Slop in the cross plate doofer, I am not in the urology industry, But I hear it happens to some people later in life?


Quote Originally Posted by Bert

I think I posted this before its been converted back from excel 2010 so I hope it works.

Great work,I always did mine with a calculator I like yours sooo much better.


Originally Posted by Wobbly - Jan Thiel found 1 Hp in 50 by covering over the crank wheels as is done by all the Italian 125 kart engines.
Thanks Wobbly
I was just musing that the smaller Dia crank wheels as well as increasing the crank volume may offer a straighter less torturous path for the air fuel mixture in the disk valve gp125 engine.As it would not have to go up over and arround the crankwheel to such a great extent.

[TZ350]

243909

Start of the grandsons F5 bike.

Recycling my old GP125 rolling chassis with a CB100 engine for young Rob to ride in F5.

[Henk]

Excellent, we need more F5 bikes out there.

[bucketracer]

From Henks photos http://www.flickr.com/photos/hz13/sets/72157627345245012/

243920

Its a 4-stroke 2-stroke mating thing .............

[ac3_snow]

Start of the grandsons F5 bike.

Cool! things you have to do to get your own bike back a!



Its a 4-stroke 2-stroke mating thing .............

lol I believe that could be a superior two stroke helping to start a filthy old four :rofl:

[Henk]

lol I believe that could be a superior two stroke helping to start a filthy old four :rofl:

Much as I hate to admit it, that is a filthy oil burner being used as a rolling road to start a deisel :facepalm:

[F5 Dave]

Looks like you are trying to make a dog & a cat copulate.

You can't just put them together & expect them to make babies.


You have to get them drunk first.:love:

[Moooools]

3 stroke?

What's the capacity limit on that?

[gav]

Much as I hate to admit it, that is a filthy oil burner being used as a rolling road to start a deisel :facepalm:
Well, at least they still have their uses then. :yes:

[quallman1234]

Recycling my old GP125 rolling chassis with a CB100 engine for young Rob to ride in F5.

once he get's better just add a turbocharger ;)?

[bucketracer]

once he get's better just add a turbocharger ;)?

That is the thinking .........

[quallman1234]

That is the thinking .........

http://www.trademe.co.nz/motors/motorbikes/motorbikes/other/auction-395562071.htm

Quality workmanship.

[bucketracer]

http://www.trademe.co.nz/motors/motorbikes/motorbikes/other/auction-395562071.htm

Quality workmanship.

An industry man no doubt ............ even so, it does look fun

[husaberg]

An industry man no doubt ............ even so, it does look fun

Has to be an Industry man alright.......And a sparky to boot, I bet

bitchin bov

[bucketracer]

Old Vespa Boy did have some interesting stuff to say before he started on his racist rants:

Being someone from the industry he might have been an interesting contributor, but in the end it looks like he knew less than he believed.

[husaberg]

Being someone from the industry he could have been an interesting contributor, but in the end it looks like he knew less than he believed.

But where did Thomas go? He seems to have just disapeared from the posts for Team ESE

[bucketracer]

Like other ESE members he is busy .......... ironically he is near completing an adult apprenticeship as an electrician.

[bucketracer]

2-stroke crank mods http://vincentcrabtree.co.uk/RGV250CrankStroking.aspx

Some RS125 info http://www.bonavolta.ch/hobby/en/moto/rs125r.htm

Some practical carb setup stuff http://www.bonavolta.ch/hobby/en/moto/mainjets.htm

And some VJ23 pics...........

[koba]

That is gold.
Who cares about oilin' the turbo anyway.

[husaberg]

Some stuff I found a while back for fork conversions
Plus some materials stuff here (if you want to build say a new frame) quite a neat site http://www.engineersedge.com/manufacturing_menu.shtml

interestingly it says yellow brass (what ever that is?) is 5 times better as a thermal conductor as copper is.
I remember reading Rudge (along with others too) used to use Bronze heads pre war.
They (Rudge) had Radial 4 valves/cylinder engines 50 years before Honda.

[bucketracer]

What American F4 Bikes look like http://cgi.ebay.com/ebaymotors/Honda-HRC-RS125-Formula-4-YZ92-Engine-Very-Fast-1994-RS125-Mini-GP-F4-Racer-YZ92-Motor-_W0QQcmdZViewItemQQhashZitem45fc3b0bb4QQitemZ30058 4471476QQptZUSQ5fmotorcycles

And F5 http://cgi.ebay.com/ebaymotors/Honda-HRC-RS125-Formula-5-KX65-Engine-Very-Fast-1991-RS125-Mini-GP-F5-Racer-KX65-Motor-_W0QQcmdZViewItemQQhashZitem45fc3b3aa1QQitemZ30058 4483489QQptZUSQ5fmotorcycles

[wobbly]

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

[F5 Dave]

kewl. so the insert has been machined into a std head or is that a VHM or similar to start with? Clearly moddified to be lower height. What is the insert material? Brass? Or chromated ally? Brass rings are often used to stave off Detonation, but I've never really known why aside from hardness of the metal, but its a bit mute as the piston is what gets hottest. [edit] surely the squish area where rings are used don't get that hot compared with the rest of the head?

See what you mean about MSV calcs, but presumably only if yer got a digi ign to compensate?

[husaberg]

Whats inside your head then.


Mainly fresh air in my head, As well as being plain my head is pretty empty as well.
The reason I posted it.,Is I believe TZ is using Copper?

But here is a Toridal head 1962 style villiers Starmaker Attached A TZ350/700 head for the nostalgic yes bronze incerts I think they are refered to as detonation rings now.Is that right?
A 1930 250 rfvc head sorry could find a bronze pic but it seams every man and his dog had a bronze head in the 30s though.
Also a link to Rudgehttp://big-diesel.blogspot.com/2008/05/rudge-four-intelligent-legendary-bike.html

[TZ350]

244218

Nope, not going over to the dark side. Just digging through the bits and bobs to see if we can find enough good parts to put a Honda 100 together for young Robert.

But I do have to say, at the last Mt Welly meet, young Will's new F5 Honda did sound like a Manx, it sounded real good for a 4 stroker, exciting even.

[TZ350]

here is a Toridal head 1962 style villiers StarmakerAttached and also a link to Rudgehttp://big-diesel.blogspot.com/2008/05/rudge-four-intelligent-legendary-bike.html

Interesting that the Star Maker had a toridal head.


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

What material is the insert made from?

[husaberg]

Interesting that the Star Maker had a toridal head.


They stole it from diesels (real ones)they had trouble with it and went back to top Hat.They ditched the the twin carbs to

I am however begining to wonder weather you really need more cb100 parts?
But I will send them anyway Rob.

Did you consider the 100s/xr100/crf100 engine i have alitlle inside info on how to get a 6 speed in one. they are light by diesel standards.



Quote Originally Posted by TZ350 What material is the insert made from?

I will let Wobbly answer that one.

[husaberg]

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

Hello Wobbly
Have you done any work or seen any trial/test results done with offsetting the toroidal head to the rear?

Ie to keep it at the cooler side of the cylinder as in the Suzuki Wolf amongst others.

I realise its probably moot in a liquid cooled engine.
But I will ask anyway.
Now that would be a challange to machine. CNC or not

[wobbly]

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

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

[husaberg]

Offset chamber heads were patented by a dirty Doctor from EMC

Doctor Joe.
I hear he got a whole MZ engine early in the piece to.Or so Walter reckonded anyway.
Suzuki probably didn't need to buy it as they already had there own MZ engine to copy.Thanks to Ernst Degner.

I am 90% sure my old Suzuki Wolf had a offset plug/offset squish band .I will have a look next time I am at my old mans. The old Wolf was a good handler square trail tyres and all.But All revs no action though.

[F5 Dave]

I've seen pics of desert racers with twin plugs (std plus one added near rear) to try to reduce spark lead & stave off deto on huge 500cc bores. I think they also machined the squish with more taper on ex side to reduce MSV at that point, although you would think that might have the effect of less cooling from a parallel squish. Either way extreme measures for big bores held wide open for hours on sand.

Ahh the selective coating is interesting. I've never thought of it used that way, just all over & that didn't make much sense.

[F5 Dave]

. . .
I am sure my old Suzuki Wolf had a offset head .I will have a look next time I am at me old mans. The old Wolf was a good handler square trail tyres and all.But All revs no action though.
Just an RGV250 head & that was for clearance & best rectified for power.

[husaberg]

Just an RGV250 head & that was for clearance & best rectified for power.

Sorry Dave I was meaning the first suzuki Wolf T90 like the stinger only smaller bore http://www.suzukicycles.org/T-series/T125.shtml

[bucketracer]

Thomas and I have had a cylinder head copper sprayed in the combustion chamber and right across the underside. The copper is about 1.25mm thick and the objective is to have a thin combustion shell that readily sheds waste combustion heat to the furthermost fins.

As copper has nearly twice the thermal conductivity of aluminum we expect to see less localized heat build up in the combustion chamber and faster transfer of heat to the outer fins on the head.

The forth picture is the original head showing localized hot spots.


Well we have discovered one of the problems with using polished copper in the combustion chamber. That is, it discolors when heated and goes a very dark brown/black where as polished aluminum retains its polish and reflective properties after normal heating.


And lastly, the chamber only is coated with a clear ceramic heat reflective, that retains the high temp in the chamber as the combustion gases are expanding. Creating more gas expansion is the holy grail to pushing the piston down harder , with less wasted heat into the water - on the other side of the insert.

Same with the piston - only the chamber area is coated, if you coat the whole piston, the heat reflective surface becomes hotter than the raw piston underneath, again this will create deto in he squish band area.

Maybe the clear ceramic Wobbley talks about could be the answer to stopping the copper discoloring .........

[TZ350]

Some of the more technical Links and Posts from the last 10 pages swept up together so the good stuff is easier to find.

Mt Wellington track


Google map "1 Tainui Rd Mt Wellington NZ"
http://maps.google.co.nz/maps?client=firefox-a&rls=org.mozilla:en-GB:official&channel=s&hl=en&biw=998&bih=545&q=1+tainui+road+mt+wellington&um=1&ie=UTF-8&hq=&hnear=0x6d0d497eca59451f:0x5760086d64db2470,1+Tain ui+Rd,+Auckland+1072&gl=nz&ei=0Y02Tqz6BITqmAXu7aTwCg&sa=X&oi=geocode_result&ct=title&resnum=1&ved=0CBwQ8gEwAA


Some stuff I found a while back for fork conversions
Plus some materials stuff here (if you want to build say a new frame) quite a neat site http://www.engineersedge.com/manufacturing_menu.shtml

Fork Diameters
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130124931#post1130124931

Steering stem sizes.
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130124931#post1130124931

Steering Head Bearings.
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130124931#post1130124931



I now have sets of FXR 150 cam sprocket verniers adjusters for sale. I do an exchange with your sprockets as they need to be drilled and slotted for the verniers. The exchange set is $85.


Tuning wise my h100 based engine at the time up there with the fastest real legal bikes I ever encountered. The Honda xl125 bikes were the fastest then but they were ……….

Interesting background story of Buckets ……


My usual resources at Motormaster http://www.moto-master.com/productnow.php# Metal gear how some useful info but no pcd http://www.metalgear.com.au/ (JT) one useful for sprockets pcd centre hole dia teeth avail splines etc http://www.jtsprockets.com/40.0.html

There are several posts of useful gearing charts on page 307 ……….


WATER INJECTION By Randy Norian http://www.suzuki-rg500.com/water.htm

The link has more on water injection.


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

I guess the dyno does not tell the whole story. If your going to try this, best read every thing you can.


I was just pointing out that the idea of using water, great as it may be in theory, and on a dyno when looking for bottom end, it "works" just fine.

But in a controlled test to see if its was usefull, it failed, as the systems effect had to be reduced so much that any gain in bottom end was still offset by a loss in the top end.

As Burgess said, when the effect was useful, it took too long to reheat the pipes.
My thoughts,from the testing I did with a PV and ATAC operated separately ( instead of combined together as many MX engines have now) is that this works real well with no down sides at all,and is easy to implement.

If someone can refine the original idea - then great.


I am going to try water injection at some point as I have already got the gear made up for it.

The plan was to get a good dyno run without and a run with water injection and then turn the injector off at the point the two graphs cross over.

At first it seemed simple to me, if I could get a power extension at the bottom, the two graphs joining together nicely with the top end revving out like before then the thing should work.

But of course a full on dyno run is not like picking your way through the twisties where you are on part throttle a lot of the time using that low end grunt. Not a lot of people apex a slow corner using full throttle.


The powerjet switched with a solenoid is done just after peak power, as the engine is most efficient at peak torque, where it needs the most fuel.

But the carb doesn’t know about efficiency, only bulk flow past the main jet - and the flow keeps rising as do the revs, so the mixture goes rich over the pipe ( thus reducing the temp).

By switching off some of the orifice area ( PWM is way better) we can lean down the fuel curve into the overev and heat the pipe up way more than is possible at peak torque.

On a HRC - RS250 for example the solenoids are activated at 12200 to 12800 ( adjustable plugs in the loom) and it will rev hard to 14000.
Without the powerjets it falls dead just past peak power at 12000.


STA or Specific Time Area, (Port Time Area) is at the heart of 2-Stroke port timing design.

Click the link to read the whole post.


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


"MSV is high at 25M/Sec", forget all that old shit - here is the go with squish. In any race engine the squish height should be set at the minimum achievable,just shy of the piston tapping the head when overeved.

Wobblys view on MSV and Squish, its worth reading the whole post.


TeeZees piston/head photos, he was doing this close clearance thing way back, when others were championing something else ...... so its satisfying to see the concept validated by Wobbly


Air Cooled 125cc 24mm carb 28.9 PS and 17.9Nm measured at the rear wheel on a DynoJet. The graphs are TeeZees tests of the Soft vs Hard closing rotary valve and extra crank clearance and case volume.


The case com being bigger works better and better as the inlet is optimised to fill that volume to the same pressure ratio, and subsequently the ducts/transfers are able to move the extra vol available into the cylinder. This then increases the delivery ratio and ultimately the dynamic com. I don’t really see much gain from reducing the cranks effect on intake streams - Jan Thiel found 1 Hp in 50 by covering over the crank wheels as is done by all the Italian 125 kart engines.



Here is a gearing chart with rev drops I did.

To see the chart you need to follow the link.


2-stroke crank mods http://vincentcrabtree.co.uk/RGV250CrankStroking.aspx

Some RS125 info http://www.bonavolta.ch/hobby/en/moto/rs125r.htm

Some practical carb setup stuff http://www.bonavolta.ch/hobby/en/moto/mainjets.htm



The one piece insert is far stronger than plain aluminium in such a big bore, thus the water can be run much closer to the places its needed, in the squish area , and around the plug threads, reducing thermal hysteresis.

And lastly, the chamber only is coated with a clear ceramic heat reflective, that retains the high temp in the chamber as the combustion gases are expanding.

Creating more gas expansion is the holy grail to pushing the piston down harder , with less wasted heat into the water - on the other side of the insert.

Same with the piston - only the chamber area is coated, if you coat the whole piston, the heat reflective surface becomes hotter than the raw piston underneath, again this will create deto in he squish band area.

Other collections can be found on the decade Pages .........

[husaberg]

I will be back .......

Got any 10kg blocks of Bronze TZ?

Ps I looked through the race video way back page 130 ish.
I can see why the wide spead of power is what you are chasing.
It looks like a series of corners, conected by well, more corners.
I think what you really need is a minimoto and a 40kg psycho:lol:
or a bigger track

[Buckets4Me]

I think what you really need is a minimoto and a 40kg psycho:lol:



Jo Mead on his streat magic use to do pritty well (but he wasent 40 kg)

[F5 Dave]

heck he was more like 3 times that. But he was a psycho.

[F5 Dave]

Sorry Dave I was meaning the first suzuki Wolf T90 like the stinger only smaller bore http://www.suzukicycles.org/T-series/T125.shtml
Is that an old family snap? You're quite a handsome lad, bet the gurls came running.:innocent:

So the T90 is still in a shed? I need a headlight surround & the chrome strip for the seat of my stinger resto that I'm quietly collecting bits for

[wobbly]

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

[marsheng]

I had one of these as a kid. Very fast at the time, when it ran, kept blowing up. I it would go to 10500 RPM but I eventually just dumped it.

[husaberg]

Is that an old family snap? You're quite a handsome lad, bet the gurls came running.:innocent:

So the T90 is still in a shed? I need a headlight surround & the chrome strip for the seat of my stinger resto that I'm quietly collecting bits for

Nope its defiantly not a family snap as I am true blue feral inbred, red necked yokel. Sorry to disappoint you. The wolf is complete and off limits for raiding, but I do have a parts Stinger. I can have a look for you but it is a bit of a turd I doubt it has any decent chrome sorry.
At one time a Suzuki stinger (not mine) held the NZ speed records must have been little competition at that time as it was something like 78mph for the flying quarter I think.

I will say this though, they certainly did have real downdraft carbs.

[TZ350]

My take on the copper in the head would be to have it extend only to the edge of the bowl.

Then have the alloy bowl ceramic sprayed.
This pulls heat out of the squish, but keeps the heat in the combustion area to do some work.

Only issue is the same as bronze inserts, there is still a joint face that will dramatically slow thermal conduction between the copper and the alloy.

Speedpro suggested much the same and its what I have been using.

The joint face may be a thermal barrior but there is a lot of contact area so intuativly I expect there is still a resonable amount of thermal transmission.

The copper outer fins get hot enough, so its doing its share of shedding waste heat from the combustion chamber area and cylinder top. Certainly a whole lot more than if it was not there.

With a composit gasket between the cylinder and copper head fin, the head runs much cooler than the cylinder, without the gasket the inner head area is much the same temp as the top cylinder fins. I have spent a bit of time looking at these things with a lazer temp gun.

The copper under cylinder fins in the exhaust area run the hottest, suggesting that is heat from the exhaust duct that is not finding its way into the original alloy finned cooling system.

I would like to know more about the clear ceramic coating.

[bucketracer]

.

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

[wobbly]

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

[husaberg]

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

I must admit I could never get my head around the ceramic coating and here Wobbly cleared it up in one paragrath.If only someone could achieve the same with my spelling.

Two questions though.

1 Bronze or copper which would be better?

2 Does copper or Bronze get on better with Aluminium ?

[wobbly]

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

[Fooman]

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

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

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

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


FM

[husaberg]

.

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

Nothing to do with your post, but I was thumbing through an old Mag and came across this.
Well whats so special other than it's pretty you may ask.
Just note the updraft on the carbs.
Wobbly alluded to it earlier on and it makes a lot of sense for a disk valve engine.
Sorry it's black and white.
I always wanted to do my Wolf up to look like it (even though I don't like Suzukis that much)

[ac3_snow]

wow, twelve speeds. and a powerband about 800rpm wide!!

[F5 Dave]

800 rpm?! Luxury.

[husaberg]

wow, twelve speeds. and a powerband about 800rpm wide!!

The interview with Hugh Anderson featured earlier in the same magazine.
I am pretty sure he would be New Zealand’s most successful ever motorbike Rider.Well Maybe Ivan Maugher fans would disagree.
But With 4x world championships 2x50 and 2x125 gp, plus 19 national championships and 2x IOM wins as well.

He said as Dave remarked rather toungue in cheek, 800rpm was indeed a luxury, It was most often 500rpm and 14 speeds on the 50cc.
The 125 was a 10 speeder 135mph (217kph) and 170 pounds (77kg).

Hugh also achieved this inspite of being 5"9 and weighing 11 stone so he wasn't a wee fellow like Dave is.
He was also quite successful as a mx rideras well as a grass track and was even picked to represent England in the motor cross de nations.

A genuine nice guy too. from my limited experiences with him.

Anyway back to buckets got $1 r1 fairing and seat, will chop to suit.
Should be getting materials for frame tomorrow.
I wonder if the mrs will notice her electric bread knife is missing?

[TZ350]

The interview with Hugh Anderson featured earlier in the same magazine.

Any chance of posting the interview with Hugh.

[jasonu]

800 rpm?! Luxury.

Yeah Dave, wider than most of your bikes...

[husaberg]

Any chance of posting the interview with Hugh.

A bit out of order sorry.They go 1,4,2,5,cover,3
I do note It leaves out the BOT rides in NZ on the Mcintosh Egli vincent against the japas and dukes and the rides on the first brook henry v2 with the belt drive bevel twin as well as what he did post 89 of course.
Note the megaphone stinger on the first page of the artical before Degner defected with all the MZ know how.
Suzuiki even stole the traditional MZ colour scheme So MZ changed theres to green for Envy.
http://2strokebiker.blogspot.com/2010/01/1968-suzuki-50cc-grand-prix-roadracer.html (http://2strokebiker.blogspot.com/2010/01/1968-suzuki-50cc-grand-prix-roadracer.html
)

http://www.suzukicycles.org/history/history_04-race-1960-1967.shtml

http://www.yamahaclassictwostrokes.nl/index.php?option=com_content&task=view&id=22&Itemid=32
(http://www.yamahaclassictwostrokes.nl/index.php?option=com_content&task=view&id=22&Itemid=32)http://www.yamahaclassictwostrokes.nl/yamahaclassictwostrokes/index.php/en/works-v4/1967-1968-yamaha-125-ra31

[TZ350]

Thanks for the Hugh interview.

Very Excited, I have just found out that the Auckland Motorcycle Club will accept entry's from F4 Buckets to run with 250 Prolights and 150 Street Stocks in a combined class at Hampton Downs and Pukekohe.

Dates: Hampton Downs 16/10, Pukekohe 13/11, Hampton Downs 4/12, Pukekohe 3/4.

After that dreadfully wet meeting a while back I have unfinished business at Hampton and will be there on the 16 to chase a few of those 250 4's and 150 street strokers.

Hopefully one or two other Bucketers will come along and join in the fun.

[richban]

Thanks for the Hugh interview.

Very Excited, I have just found out that the Auckland Motorcycle Club will accept entry's from F4 Buckets to run with 250 Prolights and 150 Street Stocks in a combined class at Hampton Downs and Pukekohe.

Dates: Hampton Downs 16/10, Pukekohe 13/11, Hampton Downs 4/12, Pukekohe 3/4.

After that dreadfully wet meeting a while back I have unfinished business at Hampton and will be there on the 16 to chase a few of those 250 4's and 150 street strokers.

Hopefully one or two other Bucketers will come along and join in the fun.


Hey thats great news. I will try make one of those dates. Never ridden at HD. Might need to develop one of them 10 speed gear boxes.

Imagine one of your more peaky engines in an RS with a 10 speed box it would always me on the power. Might have to mover up to F3 then. Hummm 10 speed with a quick shifer. 1st neh neh neh neh 6th nah neh neh 10th. Maybe 8. Getting cramp just thinking about it.

[Yow Ling]

Thanks for the Hugh interview.

Very Excited, I have just found out that the Auckland Motorcycle Club will accept entry's from F4 Buckets to run with 250 Prolights and 150 Street Stocks in a combined class at Hampton Downs and Pukekohe.

Dates: Hampton Downs 16/10, Pukekohe 13/11, Hampton Downs 4/12, Pukekohe 3/4.

After that dreadfully wet meeting a while back I have unfinished business at Hampton and will be there on the 16 to chase a few of those 250 4's and 150 street strokers.

Hopefully one or two other Bucketers will come along and join in the fun.

Wow, didnt think Id see that in my lifetime, was thinking they would have fixed Chch before they let buckets run on a full track. Now you guys will need to spend up big on sprockets

[Henk]

They ran buckets at HD and Puke last year. HD is a long lap on a bike set up for kart tracks, you certainly can't make up even the smallest power deficit with corner speed they way you can on the short tracks.

[bucketracer]

HD is a long lap on a bike set up for kart tracks, you certainly can't make up even the smallest power deficit with corner speed they way you can on the short tracks.

Bigger front sprocket?

A while back, before 250 Prolights TeeZee, Chambers and Buckets4me took an early ESE 18hp Suzuki GP125 to a couple of Puke race meetings. They buzzed around at 11,000rpm all day, I think they were doing 1:32 to start with and got down to about 1:23 but there really was no race class suitable for them then.

The Auck club and Chris C had made an effort to include them, at the time it didn't work but now with 250 Prolights and Street Stocks there is a class that F4's can run in if they want to.

[TZ350]

.
Does anyone know the midpack and front runners times for Prolights, StreetStocks around Pukekohe, Hampton Downs and Taupos new track is?

[Ned Kelly]

Thanks for the Hugh interview.

Very Excited, I have just found out that the Auckland Motorcycle Club will accept entry's from F4 Buckets to run with 250 Prolights and 150 Street Stocks in a combined class at Hampton Downs and Pukekohe.

Dates: Hampton Downs 16/10, Pukekohe 13/11, Hampton Downs 4/12, Pukekohe 3/4.

After that dreadfully wet meeting a while back I have unfinished business at Hampton and will be there on the 16 to chase a few of those 250 4's and 150 street strokers.

Hopefully one or two other Bucketers will come along and join in the fun.

This could be a good chance to run the new engine in the new RS chassis. Really stretch it legs. Really keen to run HD this year. Bugger the first round is the same weekend of the Motogp at Philip Island. Oh well.

[TZ350]

OK I had a look on My Laps and best as I can tell, typical times are ........

Prolight, Steet Stock and F4.

Pukekohe times 1:23 to 1:30 mid pack, best speed 123 down to 114 mid pack.

Hampton Downs 1:37 to 1:50 mid pack, best speed 102 down to 88 mid pack.

Taupo TRRS 1:32 to 1:48 mid pack, best speed 85 down to 73 mid pack.

I expect the speeds are kmh, and the average for a lap.

244533 NedKelly on his Team ESE bike scooting along at Taupo.

Taupo and Hampton were wet, not sure about the conditions at Puke.

[cotswold]

[QUOTE=Buckets4Me;1130129310]Found this hiding on you tube



That's just dangerous!!!!

[Buckets4Me]

Found this hiding on you tube

<iframe src="http://www.youtube.com/embed/dt_c1rgYPtQ" allowfullscreen="" frameborder="0" height="349" width="560"></iframe>




maby with a few 2 strokes it can look like this

244592244593

[Buckets4Me]

and

<iframe width="560" height="349" src="http://www.youtube.com/embed/0pqrgQ4mvQQ" frameborder="0" allowfullscreen></iframe>

[TZ350]

Found this hiding on you tube

<iframe src="http://www.youtube.com/embed/dt_c1rgYPtQ" allowfullscreen="" width="560" frameborder="0" height="349"></iframe>


Great clip of Damion and friends with their FXR150's at a Pukekohe Test Day.

Interesting speed comparison with what looks like Alistar Wilton on his TZ750, (Black & Yellow leathers on a Yellow bike).

[TZ350]

244627244628244629

Found these pictures of a Suzuki GP100 cylinder (the blue pen label is wrong).

F5 Dave talked about a 3 port GP cylinder but I had never seen one.

244637244638

All of ours are like this underneath, no big third port, ours have side ports feed from the main transfers and a gash port feed by the piston at the rear, I thought they were all like ours and that F5 had been mistaken .......

[F5 Dave]

yeah it had been a while since i had seen one I just remember they were a bit queer & thought they were like the old GTs. Boost port is biggest weakness I can see, but I think you've approached that.

[ac3_snow]

what is a better gasket sealant to use on an exhaust? I have yet to stumble across a good one.

[Gigglebutton]

what is a better gasket sealant to use on an exhaust? I have yet to stumble across a good one.

I o ringed my pipe but have use high temp silicon. Seams to work ok

[speedpro]

I'm using high temp o-ring and hi-temp red silicone.

[husaberg]

Fast Freddies 500 tripple had them on 2 cylinders as well, but I found that the combo of independent atac and PV was the shit.
Adding them to a non PV cylinder is an easy way to gain a heap of free bottom though.


I was thumbing through some old mags looking for aprilia frame pics and came across
an abridged copy of an article on the history of Cagiva.I wish I had the whole one.

But two thinks leapt out at me.
The first was that Cagiva had ran at rear facing disk valve on a modified Yamaha tz500/4 crankcase ala the modern RSA engine in 1981 .Also the 1984 rotary valve v4 YZR500 ran the same thing.
Second thing was in 1989 Cagiva ran both ATAC style chamber and a rotary power valve.
It a great shame Cagiva could never stick with and develop one idea at a time, but they sure were beautiful.

I sometimes wondered if Cagiva was in a way a defacto R&D department of Yamaha.
Esp when you hear rumours of most of the major internal parts being interchangeable.

Maybe Wobbly might be able to shed some inside information on this.

For TZ why does your gp100 clinder have 123cc cast on it first line. third fom the right?
The porting looks kind of like an MZ125 I will post a pic latter.(note the offset squish band but it was the 60s)Edit it doesnt look that close afterall but there is a port I can't quite figure out in the MZ anyway.?
Also looking though the old posts Up to pg 160 odd now the disk valve duration you had then is bloody close to the MZ125 too (1962) it ran inlet opening 140 btdc 70 atdc. He was a clever bugger that Walter Kaaden.
His rotary valve seemed to be large enough for the inlet to clear the crankwheels too.

PS for AC Snow
I used black silicone (It was all that was handy,but I am sure the proper stuff would be better but it is a bucket.)
With a std honda alloy/fibre ring gasket with a overlaping male bolted to the cylinder and female spigot joint on the header with no steps and springs for my headers the silicone used to pong a bit for a start off but didn't leak.

[diesel pig]

I agree with spreedpro it's got to be the RED Hi-temp silicone.

[Gigglebutton]

I use a silicon based lubricant on the O-rings. This is hi temp & soooo slippery

[wobbly]

Yamaha helped Cagiva out alot in the last couple of years they were competing with port and pipe design.
The Yamaha factory were just getting into using CNC ananometric flow visualizing, and were at the stage of being able to predict the performance of a cylinder layout without the need for a dyno run.
I dont know what the financial situation was but the head of Yamaha racing dept at the time whos ringlish name was Suzan spent alot of time with the Cagiva tech guys.
But then they went all Italian as usual and were spending a fortune on injection - when they had never really got the carbed bike to work to its potential.
Foggy rode it for 3 laps and pronounced it a piece of shit and walked away.

[F5 Dave]

Where the heck would GP racing have been without Yamaha? The Cagiva example is only a small footnote. They have long provided the bread & butter racers & wouldn't have been making much profit if any at all due to constant spec changes & minimal numbers compared to roadbikes. However they considered it good for the sport & presumable gets their name out there if they fill much of the grid -even if they know most people only remember who won.

The TD TZ range kept privateers running & of course the ROC & Harris 500s were viable with Yam supplied engines. This action staved off moves to allow big production F1 bikes to fill the grids which would have diluted the whole concept of GP. Some ideas keep rotating around though huh?

They also did oddball things, like specifically not hiring Schwantz as they saw it as good for the sport not to have all the gun riders on YZRs.

[jasonu]

Found this hiding on you tube

<iframe src="http://www.youtube.com/embed/dt_c1rgYPtQ" allowfullscreen="" frameborder="0" height="349" width="560"></iframe>




maby with a few 2 strokes it can look like this

244592244593

I didn't know they let old Welsh guys ride buckets...
Great footage though.

[gav]

I think the very first Cagiva 500GP bikes had square four engines based on a Suzuki. They were close to giving up, until Yamaha gave them a couple of v4 engines and helped them with development etc including letting Kenny Roberts test ride the bike and help out etc. Later they also helped by getting Eddie Lawson on board for them.

[TZ350]

For TZ why does your gp100 clinder have 123cc cast on it first line. third fom the right?

Eeeek :Oops: I could swear when I looked it said 99 .......... oh well :laugh:

[TZ350]

Cagiva had ran at rear facing disk valve on a modified Yamaha tz500/4 crankcase ala the modern RSA engine in 1981

244738

Is this it? Can you post the the mag article?

[TZ350]

244739

We use silicon grease on the cylinder head o ring. (2-stroke)

244741

Best crankcase jointing compound known to man, we got this from Haldanes when it was still a Yamaha shop.

244740

The Red Hi-temp silicone Goop that we use for inlet manifolds and sealing the exhaust manifold and chamber slip joint. I expect Repco and most parts shops would stock it.

[husaberg]

244738

Is this it? Can you post the the mag article?

Here it is I wish I had the Autocourse full story

Ps where it you get the pics?
I had a little look on google as I had never seen or herd of it but came up empty.

[husaberg]

Where the heck would GP racing have been without Yamaha? The Cagiva example is only a small footnote. They have long provided the bread & butter racers & wouldn't have been making much profit if any at all due to constant spec changes & minimal numbers compared to roadbikes. However they considered it good for the sport & presumable gets their name out there if they fill much of the grid -even if they know most people only remember who won.

The TD TZ range kept privateers running & of course the ROC & Harris 500s were viable with Yam supplied engines. This action staved off moves to allow big production F1 bikes to fill the grids which would have diluted the whole concept of GP. Some ideas keep rotating around though huh?

They also did oddball things, like specifically not hiring Schwantz as they saw it as good for the sport not to have all the gun riders on YZRs.

Geeze Dave I wasn't slagging Yamaha. But I supose they did the GP thing to sell bikes to like YDS,DS,RD,LC,RZ,TZR,YSR etc.
I am sure the GP programe helped the mx programe a little bit too.
Honda also helped keep the racing closer by not hiring a top second rider most of the time.
I think the cagiva of the era are still prettier than the Yamahas of the era.ESP this one it still is ugly.Went all right though.

Heres a pick of Kevins injuries he definatly got away with it better than Wayne but imagine what he could have done with a Honda or a Yamaha Always exciting to watch.When asked why he would keep the hammer down and fall of while having a massive lead , He said, for Me winning wasn't enough,
I wanted to annihilate them!.only on the track once off it different dude

[gav]

Yeah #71 Gasket maker is available ex Repco, as is the Three Bond 1215, most of the workshops use the Three Bond, but its not cheap.

[speedpro]

Hi-Temp Red dissolves in petrol. It turns to a very soft jelly and expands.. I use Yamaha Bond or similar, or a Loctite product depending on the application if petrol is involved. The modern pump gas is particularly bad given the % of Tolulene/Tolulol.

[husaberg]

I'm using high temp o-ring and hi-temp red silicone.


Hi-Temp Red dissolves in petrol. It turns to a very soft jelly and expands.. I use Yamaha Bond or similar, or a Loctite product depending on the application if petrol is involved. The modern pump gas is particularly bad given the % of Tolulene/Tolulol.
?
For engines the dealership I was at we used Hylomar stuff for the engines.
Not exhausts though.
I think it was the official Honda recomended product.That was almost two decades ago though mind you.
From memory the reasoning was it didn't set into bits to block oilways etc.EG honda single cam covers etc.
Honda had enough top end problems as it was at the time without extra oilway blockages.
The people that distributed Hylomar may have had the best girly pic calenders though, sometimes that could sway the buying decisions of the foreman.

We used to use a lot of rubber grease for something weird on the engines too but I can't remember what for.
It sure used to smell nice though.mmmmmm.......

[speedpro]

Just something I spotted for Rob to muse over

http://www.mbe-motorsports.com/catalog/product_info.php/cPath/16/products_id/337

[koba]

Some good old clips of Mamola, mostly on Cagiva GP bikes:

http://www.youtube.com/watch?v=90Woms8gb6o
http://www.youtube.com/watch?v=XaQGI8GSVJM&feature=related
http://www.youtube.com/watch?v=BtD_U187zv0&feature=related
http://www.youtube.com/watch?v=hsTt50DgpFI&feature=related

[F5 Dave]

Geeze Dave I wasn't slagging Yamaha. . . .
I didn't think you were, I was just pointing out that they were in many instances a company loyal to racing rather than on profit & ego alone. Just be lucky I didn't start the counter rave about the big H which are a bunch of Kunts & I would never buy or ride a Honda.


Well apart from the MB, or the RS.

Or if it was an interesting model or convenient,

or I forgot. But apart from that I am unrepentant in my boycott.:2guns:

[F5 Dave]

Some good old clips of Mamola, mostly on Cagiva GP bikes:

http://www.youtube.com/watch?v=90Woms8gb6o
http://www.youtube.com/watch?v=XaQGI8GSVJM&feature=related
http://www.youtube.com/watch?v=BtD_U187zv0&feature=related
http://www.youtube.com/watch?v=hsTt50DgpFI&feature=related
Italian bike, Pirrelli tyres; a match made in heaven, or rather by somone who's arrival appeared imminent.


good clips.

[husaberg]

I didn't think you were, I was just pointing out that they were in many instances a company loyal to racing rather than on profit & ego alone. Just be lucky I didn't start the counter rave about the big H which are a bunch of Kunts & I would never buy or ride a Honda.


Well apart from the MB, or the RS.

Or if it was an interesting model or convenient,

or I forgot. But apart from that I am unrepentant in my boycott.:2guns:

Just as well no Honda rant then .I note you never offered your opinion on the styling bit.?
The engines being available was I believe thanks to Kenny and they were for a start.At least ment to be works spec other than the ignitions and electronics,and the 180 degree cranks so they were to be admired for the gesture.
But
The yzr500 motor was at the time 50,000 pounds.and they ROC and Harris had to buy a minimun of six.From memory the nz dollar was about 3 to the pound at the time.
The cranks were 6000 pounds for a pair, The cylinders were 7500 pound for a pair so they weren't excatly giving them away?

Shame the supermoto is a Honda I guess:shifty:

[wobbly]

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

[F5 Dave]

I got lazy getting an engine ready about 15 years ago & o-ringed the head by the chamber, but didn't have time to mill a square groove for the outer barrel so just used a smear of Loctite Red RTV & it coped great & have done ever since in a few engines as it is fine for water jackets & easy to machine a round groove, not so much the rounded corners of a square one.

[jasonu]

I got lazy getting an engine ready about 15 years ago & o-ringed the head by the chamber, but didn't have time to mill a square groove for the outer barrel so just used a smear of Loctite Red RTV & it coped great & have done ever since in a few engines as it is fine for water jackets & easy to machine a round groove, not so much the rounded corners of a square one.

That is all I have ever done too. Never let me down.

[TZ350]

My brand new 24mm pumper carb has finaly turned up. Its about 30mm shorter than the Keihin. Now the inlet tract will be closer to the 135mm that Wobbly suggested.

The pumpers adjustable jets look fun to play with too, and there are other dinky toys, like the pop off gauge for setting the needle seat pressure, which is a bit like adjusting the float height in a conventional carb.

I am looking forward to seeing if I can make this fit and tuck in out of the way any better than the current gravel scoop does.

[husaberg]

My brand new 24mm pumper carb has finaly turned up. Its about 30mm shorter than the Keihin. Now the inlet tract will be closer to the 135mm that Wobbly suggested.

The pumpers adjustable jets look fun to play with too, and there are other dinky toys, like the pop off gauge for setting the needle seat pressure, which is a bit like adjusting the float height in a conventional carb.

I am looking forward to seeing if I can make this fit and tuck in out of the way any better than the current gravel scoop does.

I was mulling over my original hideously over complicated idea to retard the disk valve timing for more top end power. The set up withith a jackshaft and a reverse rotation disk with bob weights is obviously over the top .
But with a clever shaped blade with angled cut outs with a kind of rgv power valve up and down motion you could achieve the timing changes ie retard disk timing for more top end without hurting mid range with out either much more additional complication or the additional width of the V TEC just a thought?
Either that with the right shape you could maybe try the 24/7 idea again (Probably not ideal with the pumper carb though) if the blade was shaped to reduce the duration to a level to with the engine would start and run with a taper shaped for duration at full lift.

Lastly with an air cooled single cylinder such as TZ's I asume it is better to just have a simple lapped on head with a simple lipped recess spigot seal for better heat transfer?
But I wonder if the copper to alloy head to cylinder joint could be hurting some possible aditional heat transfer.probably moot

[F5 Dave]

I was mulling over my original retarded idea to hideously over complicated the disk valve timing for more top end power. .
. . .
Here fixed that for you.:laugh:

[wobbly]

TZ - you will have to run pretty low popoff, and high finger height, to get sufficient fuel into your 100cc making 30 Hp.
And I would reverse jet it from the start - 2 turns on the bottom, 1/2 turn on the top - and play from there.
You will soon get a feel for how much pump pressure to run with those settings.

[husaberg]

Here fixed that for you.:laugh:

I laughed so hard I nearly wet myself :rolleyes:
I guess like most geniuses, Your humor will only be truely appreciated after your gone.
:psst:The supermoto ride is still available Dave.

[TZ350]

TZ - you will have to run pretty low popoff, and high finger height, to get sufficient fuel into your 100cc making 30 Hp.
And I would reverse jet it from the start - 2 turns on the bottom, 1/2 turn on the top - and play from there.
You will soon get a feel for how much pump pressure to run with those settings.

Thanks for the advice, I expect to be able to try it on the dyno next week. I don't want to do anything before the next race meeting on Sunday.

I have a pop off gauge and some spare springs, it is set for 9lb now, what do you suggest?

Also I called into a cart shop today to look at their air box's, they had some neat ones with adjustable air inlets and different volumes, what do I need to look for.

[Buckets4Me]

Also I called into a cart shop today to look at their air box's, they had some neat ones with adjustable air inlets and different volumes, what do I need to look for.

A winning lotto ticket

[ac3_snow]

I spotted a pair of dellorto 22mm cabrs :psst: and I'm considering getting them and boring one out to 24mm.

Has any one done this before? I know that to do it I want to off set the hole so the bottom stays where it is and I take the material off the top/sides. Could this be done, carefully, with a drill press or would a lathe or something else be required?

[wobbly]

Easy to do in a lathe even simply by putting a spacer shim under 1 jaw ( opposite the bowl ) to get the eccentric offset needed.
Have done plenty like this - just use the fatest boring bar that will fit to reduce chatter at the tip,for a good finish.
Leave at least 0.5mm down each side to prevent leaks around the slide.

[TZ350]

........ a spacer shim under 1 jaw ( opposite the bowl ) to get the eccentric offset needed.......Leave at least 0.5mm down each side to prevent leaks around the slide.

Some carbs like the OKO are strong enough to hold in the lathe but the common die cast ones are pretty soft and easily crushed by the lathe jaws.

When we were machining old 22mm GP100 carbs out to 24mm we made up a split clamping ring.

244924

The hole in the center was bored offset by putting a shim under one jaw, just like Wobbly suggested.

244927

The lathe cuts more out of the carb at the thick side of the ring.

244925

The split in the ring allows the jaws to clamp up the ring onto the carb. With a split clamp ring the carb can be held very firmly in the lathe without damage.

A carb that is bored out until there is only a minimal amount left on the sides to seal the slide flows more air than a standard carb because there is less disruption to air flow around the slide area.

Of course one would strip the carb down before spinning it up in the lathe.

[husaberg]

I spotted a pair of dellorto 22mm cabrs :psst: and I'm considering getting them and boring one out to 24mm.

Has any one done this before? I know that to do it I want to off set the hole so the bottom stays where it is and I take the material off the top/sides. Could this be done, carefully, with a drill press or would a lathe or something else be required?

I once put the slide in back to front in a early dellotto flat slide.Funny now not so funny at the time I kicked for hours.
ps Snow I have sent the package up yesterday I hope the bag is large enough.Sing out if you want a carb I have a 28mm rg250 or 500 one lurking arround.

A while back there was a set of three MVX250 carbs on trademe $60 or $80. I am pretty sure they are 24mm flat slide downdraft keihins.

Tz I should have your stuff sorted this weekend.

[F5 Dave]

And Dellorto carbs are pretty miserable. + getting jets isn't that easy

must get around to putting a keihin on my Trials bike.

[Moooools]

Sorry to hijack thread with smelly four stroke jibber jabber, but you two stroke fanatics wouldn't happen to know of a 30ish mm carb with a really significant (60degree) downdraft angle would you?
I was thinking Rgv 250 vj21 or something similar.
Anyone got info or even a carb to sell me?

[koba]

Sorry to hijack thread with smelly four stroke jibber jabber, but you two stroke fanatics wouldn't happen to know of a 30ish mm carb with a really significant (60degree) downdraft angle would you?
I was thinking Rgv 250 vj21 or something similar.
Anyone got info or even a carb to sell me?

VT250?
Or is that what it's for?

[Moooools]

:laugh: that is indeed what it is for. But that is a valid option...

Was looking to get away from a cv carb. I have a cbr250 carb wh ich should work, but still a cv.

[koba]

:laugh: that is indeed what it is for. But that is a valid option...

Was looking to get away from a cv carb. I have a cbr250 carb wh ich should work, but still a cv.

Get it running on the standard one first.

[husaberg]

Sorry to hijack thread with smelly four stroke jibber jabber, but you two stroke fanatics wouldn't happen to know of a 30ish mm carb with a really significant (60degree) downdraft angle would you?
I was thinking Rgv 250 vj21 or something similar.
Anyone got info or even a carb to sell me?

My tractor (TEA ferguson petrol) has a old solex or maybe zenith of around 30mm with a 90 degree downdraft.It shouldn't even need rejetting as its 28hp
60 degrees, The only ones I have seen that would be past 45 degrees is an amal GP or TT 1 5/32 or ss dellotto look at a Aermacchi or Manx Norton 40m or similar

There are plenty of cv downdrafts 45 degress off fzr400 or similar. The 3ln 250 is 28mm I think.The cbr250r are 30mm odd.
The crf150r has the fCR around 30mm. Have a look at the Sudco site they might be cheaper than you think,with the US economy and dollar.

The nsr250 have one of a similar size depending on model. the rgvs are 32 or 34mm TZR250 the first one is 28mm downdraft.
I hope that helps, but you honestly would probably find it far less frustrating to stick with a 4 stroke carb.
A hyosung has a 28mm ish downdraft much similar to a fzr250 and some old Yamaha twins cruiser types had some pretty big angle downdrafts of similar size to what you want some have acelerator pump and all.

[Moooools]

I don't have one. But yes that does make sense.
I figured if I couldn't find one a non cv carb would be much easier to set up.


Right. Back to two strokes.

How about that burning oil aye?

[koba]

I don't have one. But yes that does make sense.
I figured if I couldn't find one a non cv carb would be much easier to set up.


Right. Back to two strokes.

How about that burning oil aye?

Hit Ivan up if you want a VT 250 carb, I gave him a whole bike a while ago and he was meant to give me the carbs back when he had stripped it down.

[quallman1234]

Will anything come of this?

http://twostrokemotocross.com/2009/06/two-strokes-strike-back/

[kel]

Cagiva had ran at rear facing disk valve on a modified Yamaha tz500/4 crankcase ala the modern RSA engine in 1981 .Also the 1984 rotary valve v4 YZR500 ran the same thing.

MZ used this design in the 60's, attached image is a horizontal single with rear disk induction complete with down draft carb.
244967

[F5 Dave]

you can just imagine that thing smashing through your roof in the 40s & being the last thing you see before blowing you to smithereens:shit:

[Gigglebutton]

Sorry to hijack thread with smelly four stroke jibber jabber, but you two stroke fanatics wouldn't happen to know of a 30ish mm carb with a really significant (60degree) downdraft angle would you?
I was thinking Rgv 250 vj21 or something similar.
Anyone got info or even a carb to sell me?

I have a pair of 32mm Keihin flat slides off an NSR. They have a shed load of plumbing and electrix attached

[husaberg]

MZ used this design in the 60's, attached image is a horizontal single with rear disk induction complete with down draft carb.
244967

Now thats a Radial finned Head.
I was looking at what I initally though was a distributor, but it is a float chamber for the carb to the right.on the MZ engine.
Interestingly esp the finning looks like the forward cylinder of the DKW Three below. The AJS Porcupine had spiked fins hense the name.
If you were to start from scratch with a decent 6 speed box the lay down engine could be interesting afterall the Aermachi ,experimental laydown Norton and supermono Duke vertical engines were renowned for there handling.not so sure about the 90 degree drive on the MZ top mount rotary valve though.thrown in an couple of pics of horozontal engines as well.Sorry about they are all diesels.


For Moooools if his heart is set on the 2 stroke carb http://www.trademe.co.nz/a.aspx?id=400725760
RGV 250 VJ22A MIKUNI CARBS FLAT SLIDE $100245016

[koba]

I sure as hell wouldn't pay a hundie bucks for 32's.
They are junk to most people, bucket racers probably being the one exception.

[F5 Dave]

hmm, bit odd, VJ22s should be 34s with solenoid doofers. VJ21s should be 32s.

[Moooools]

That's what I was thinking.

[bucketracer]

...... VJ22s should be 34s with solenoid doofers........

TeeZee has me working on a carb setup that has a lot of pipes and probably had a solenoid doofer originally.

We would like to know more about the air solenoids function.

And if anyone has got a carb air solenoid? please PM me or TZ350, we want to try one on our carb and see what the dyno tells us.

[husaberg]

TeeZee has me working on a carb setup that has a lot of pipes and probably had a solenoid doofer originally.

We would like to know more about the air solenoids function.

And if anyone has got a carb air solenoid? please PM me or TZ350, we want to try one on our carb and see what the dyno tells us.

His other bits seem reasonably price $50 FOR A FRAME AN'T BAD.

As for the RGV carbs. I thought the imports were all 32mm regardless.Well according to this some were 30?http://www.rgv250.co.uk/japmodels.htm
http://homepage.mac.com/rg500delta/deltaphasetwo/rgv_airbleed/rgv_airbleed.html

But i know piss all about RGV or suzukis.Well about anything really.
I was going to use one on my bucket for the air plumbing.
Its what Wobbly suggested to me.
Anyone ever tried boring the 32mm ones as the 34mm are getting a bit rare, not that they were ever that common.

I was looking for something and came across this I also knew there was an Amal (Don't get too excited dave iits a M not a N) ) RN a GP2 and a TT carb I never wondered what the RN stood for.
Its remote needle.
No idea how they work other than thay were ment to be a little aburpt with the fuel metering down low .

Before anyone starts on the these are old british crap etc.
I have seen flow figures for the old racing carbs these were beatifully made and were superior to all the jap ones up until at least the flat slides and probably still are now.
The thing is I wonder how much actual distuption the needle actually causes.
It can't be that much can it?
Are they any other motorbike needle less carbs other than the pumper ones?

Maybe Wobbly can help I believe the KR3 had some different carbs?

[wobbly]

The air solenoids on the RGV/RS250 type Keihin carbs are there for emmission and air fuel correction at part throttle settings.
One feeds air into the primary circuit to lean off the mixture at just off idle conditions and the second one feeds air into the emulsion tube to lean off the mixture at higher rpm/part throttle.
The switching points are set by the ECU depending upon rpm and TPS position.
The F3 race kits blocked these off, and used a different jet setup for high perf usage.

The KR3 had special carbs on a few bikes, as they had nightmares trying to get the Keihins off RS125 Honda to work running around the wrong way.They used a pump around system to keep the fuel level at a constant height.
I finally figured out what was happening when building the BSL.
The floats were being pulled down under hard braking - flooding the bowls.So I had CNC bowls made up with floats from TMX carbs running on rods, instead of pivoting.

[explode64]

Just a note on the RGV carbs, the VJ21 used 32mm round carbs, the VJ22 Jap spec used 32x28 oval carbs (often called 30mm) and the OZ and UK spec VJ22 had the 34mm. The 32mm cant be that bad for a 125 cylinder. 125cc KZ2 kart engines make 45hp with 30mm Carbs, but if any one has a pair of 34mm RGV carbs I could be interested :shifty:

[bucketracer]

Thanks Guys for the pictures and info, very helpful .........

[ac3_snow]

Good day at Mt Welly today, weather was beautiful! Had the new rs125 pipe on and a new head which reduced the squish area down to 1mm. When I was fitting the head this morning I noticed the markings on the top of the piston, my thoughts where the carbon build up after one days racing would suggest rich mixture. However I think I was making things up and had no idea what I was thinking about as you can see the results after today in the next picture. Whoops!
245139245140

[husaberg]

The air solenoids on the RGV/RS250 type Keihin carbs are there for emmission and air fuel correction at part throttle settings.
One feeds air into the primary circuit to lean off the mixture at just off idle conditions and the second one feeds air into the emulsion tube to lean off the mixture at higher rpm/part throttle.
The switching points are set by the ECU depending upon rpm and TPS position.
The F3 race kits blocked these off, and used a different jet setup for high perf usage.

The KR3 had special carbs on a few bikes, as they had nightmares trying to get the Keihins off RS125 Honda to work running around the wrong way.They used a pump around system to keep the fuel level at a constant height.
I finally figured out what was happening when building the BSL.
The floats were being pulled down under hard braking - flooding the bowls.So I had CNC bowls made up with floats from TMX carbs running on rods, instead of pivoting.

Neat trick I have often thought of doing something similar with a ballcock float vave for a farm through.The bloody cattle bend and break the arm.
Was he running some sort of home made lectrons on the first mondas?
The bit above confuses me a bit with the Keihins I guess its a typo.
The Chart to the left above plus the links seems to suggest that one of the air bleeds works up top as well, is it crap?I am guessing it was an emissions thing.I was hoping to be able to modify one for a lean over rev solinoid can they still be made to work for that?
What did you think of the remote needle Pretty trick or what. not bad for the 60 years ago.
would be interested to see how much airflow the needle costs.

With the RGV carbs the RGV website seems to sugest all (WET ClUTCH RGV250 VJ22 HAD 32mm or 30mm carbs) surely the official website would get this right.check the link http://www.rgv250.co.uk/japmodels.htm

Shit Snow Its your shout tonight Thats a hole in one.(golf rules may apply) Sorry to hear. .Re carbs there is some 28mm mikuni flatslide downdrafts for A kr250 $55 for a pair on tradme now similar to tzr250 ones by the look of them.

One a other note I was wracking my brain when someone suggested a down rotary valve engine to think of the engine that was reed and rotary Valve.
Answer is the Kawasiki KR250a/b. If I remember right Aaron Slight won the proddy 250 title on one in about 85. Probably his first national title.Here it is, its a little oddball.
Note the timming spec in the bottom right of the first attachment.Also the gaskets in the 5th attachment at the base of the cylinder I see a wee problem there and i think it still ran acording to the blog

[Pumba]

Good day at Mt Welly today, weather was beautiful! Had the new rs125 pipe on and a new head which reduced the squish area down to 1mm. When I was fitting the head this morning I noticed the markings on the top of the piston, my thoughts where the carbon build up after one days racing would suggest rich mixture. However I think I was making things up and had no idea what I was thinking about as you can see the results after today in the next picture. Whoops!
245139245140

That will buff out:confused:

[bucketracer]

....... as you can see the results after today in the next picture. Whoops!
245139245140

Bummer, now you will have to clean out the big end (or better yet, strip the motor and replace it). As the alloy sprays straight down into the rods oiling slots and jams the rollers making them skid. If its not already to late, the bigend will need to be carefully cleaned out or your next problem will be a blown bigend.

[F5 Dave]

. . . .
The bit above confuses me a bit with the Keihins I guess its a typo.
. . .
Sounds like you did get it? He's saying that the RS Keihins face forward, when you brake the floats on a lever are forced to rotate about their pivot. Closed, at least for a little while. Except if you mount them facing the other way forcing them open. Ha! Beginners mistake. I'm sure I would have thought of that.:confused: (. . . Well after someone explained that it was happening).

Yeah some old Miks had pole dancer slide floats. Maybe they weren't such a silly idea.

There seem to be a few dif RGV carbs about. I have some 32s but seem to be fitted out with air bleed tubes. Perhaps there was a jap VJ21 version as well as a Jap VJ22 & with diff years 4 or 5 or 6 versions. I've thought about fitting a tiny pilot jet in the emu tube bleed to alter the fueling curve if it needs it.

[husaberg]

Sounds like you did get it? He's saying that the RS Keihins face forward, when you brake the floats on a lever are forced to rotate about their pivot. Closed, at least for a little while. Except if you mount them facing the other way forcing them open. Ha! Beginners mistake. I'm sure I would have thought of that.:confused: (. . . Well after someone explained that it was happening).

Yeah some old Miks had pole dancer slide floats. Maybe they weren't such a silly idea.

There seem to be a few dif RGV carbs about. I have some 32s but seem to be fitted out with air bleed tubes. Perhaps there was a jap VJ21 version as well as a Jap VJ22 & with diff years 4 or 5 or 6 versions. I've thought about fitting a tiny pilot jet in the emu tube bleed to alter the fueling curve if it needs it.


Sorry Dave the bit I didn't get was at the top of the post the Keihins on the Rgvs bit I was wondering If the VJ23s had them or it was a typo.Never seen a vj23 in the flesh or indeed seen much about them at all, other than a deresticting article in PB I tried looking for a port map and came up blank on the net.I had seen the old pole floats somewhere to but never in a million years would have figured that out.

[wobbly]

Ask Sinclair in Ch Ch if you really want the carb info details.
In all blurb on the KR3 it always says they had Keihin carbs - but as the pic shows they sure arent on that bike - though Mike did say to me they all used Keihin jets and parts.
The solenoid main air corrector could be used to lean off the mixture over the top of the pipe, but this is nowhere as effective as turning off the fuel to the powerjet - I dont think those Keihins had solenoids on the powerjets though.
An overev air corrector would have to have some air being fed in all the time - to do "normal" correction, but then open up to let a heap more air in over the top to lean off the fuel curve.

That hole in piston pic - have you diagnosed what the issue is,always means too much advance for the com used,or too hot plug, or both - if run with crap fuel.
1mm squish means the squish is doing nothing - wouldnt help either, if the com was increased at the same time.

[husaberg]

Ask Sinclair in Ch Ch if you really want the carb info details.
In all blurb on the KR3 it always says they had Keihin carbs - but as the pic shows they sure arent on that bike - though Mike did say to me they all used Keihin jets and parts.

Bugger didn't think to look at the pic Lazy I guess. But I asked about the carbs as I can remember seeing some press blurb mentioning it had "Roberts Carbs". I was just curious what they would be. It intrigued me because in the article it said something of a mix of Keihin/Mikuni and the author said kind of like a lectron and kenny agreed So that threw we even more and I understood Mike was a bit of a lectron guru amonst other things of course.
The other KR Engine the rotary reed Kawaski KR250 is not what I expected every see anything similar anyone?
has Mike moved back here or just on holiday?


I have attached a bit of the puff piece I was wondering about Its not very clear sorry. I guess Kenny could have been just hyping it up a bit for the press

The clutch in the pic of the Roberts 3 you posted.
Is it a diaphragm clutch? Were they common on GP500s? Sorry about the thousand questions Wayne.

[TZ350]

Bummer, now you will have to clean out the big end (or better yet, strip the motor and replace it). As the alloy sprays straight down into the rods oiling slots and jams the rollers making them skid. If its not already to late, the bigend will need to be carefully cleaned out or your next problem will be a blown bigend.

Speedpro tells me he has had succes with engine clean and the garden hose, by wiggling the crank you can feel the dirt, engine clean followed by a bit of an aggressive flush out and then I guess CRC to get rid of the water.

But however you do it, the bigend and mains need to be cleaned out.

[wobbly]

The carbs in the pic were made by Roberts team, but I didnt know about the Lectron setup - no main jet,but all fueling done on the needle??
The clutch in the pic is a AP carbon /carbon diaphram setup, costs 4500GBP ie over 12,000NZD at the time.They ended up being dumped as we could never get consistent launches with the carbon plates.
The inertia was very low as the basket was titanuim/magnesium and in a back to back test with two BSLs at Sepang, the AP bike would pull a bike length every gearchange off the corner coming onto the pit straight.
Mike retired after Biaggi left Yamaha at the begining of the M1 project,and has been doing nothing but play with his sailboarding ever since.

[ac3_snow]

That hole in piston pic - have you diagnosed what the issue is,always means too much advance for the com used,or too hot plug, or both - if run with crap fuel.
1mm squish means the squish is doing nothing - wouldnt help either, if the com was increased at the same time.

Most people tell me it is running too lean, but it did definitely have too hot a plug (B6es). As far as timing goes I have no idea as to how to figure out what is right and not, will have to do a bit of research once mid-semester break starts next week, see if I can figure out weather I was close or miles out. Before it all fell to bits I did fell like it was lacking in the top end.
1mm is an improvement on the 1.7mm gap it had before! with $70 to get it skimmed it will be a little while before I correct it any more, think a new piston is my priority at the moment!


p.s. I was riding a (pretty stock) FXR yesterday, went a whole lot faster (30.73 seconds) than I have on my own bike yet. Will have to change that quick smart.

[husaberg]

The carbs in the pic were made by Roberts team, but I didnt know about the Lectron setup - no main jet,but all fueling done on the needle??
The clutch in the pic is a AP carbon /carbon diaphram setup, costs 4500GBP ie over 12,000NZD at the time.They ended up being dumped as we could never get consistent launches with the carbon plates.
The inertia was very low as the basket was titanuim/magnesium and in a back to back test with two BSLs at Sepang, the AP bike would pull a bike length every gearchange off the corner coming onto the pit straight.
Mike retired after Biaggi left Yamaha at the begining of the M1 project,and has been doing nothing but play with his sailboarding ever since.

Thanks Wayne.
That seems like a sad waste of talent and experiance, Any Ideas how his arm can be twisted into sharing a few stories or ideas.

I guess he wouldn't want to manage a one rider f4 team with a overweight rider of limited talent (Hmm..ok no talent) I guess. Worth a crack.

Re the clutch I used to lighten the hub by scalloping a half round cutout perhaps 8 or 10 mm deep but 15-20mm widen the bits between the tabs. I always felt I probably achieved more for looks and to make me feel better. I guess the hub on the 500s is Huge compared to the MB100. Would what I used to do actually make a measurable difference.

I don't recall much of anything in the thread about silencers any tips here I will post what I used to do.
I do of course understand this is your trade and you may want to keep most of this to yourself a bit.


Although I once had some alloy welded and rolled and spent like 2 days trying to get it looking ok.
The best easy source of thin wall like 1.2mm Aluminum tubing I could ever find. Its irrigation tube, mainly used one market gardens now not real farms. Ask around if your have rural mates, but cheap as by the meter at Mico's comes in 75 and 100mm. For the packing I used to just buy the fibreglass packing wool string not cloth at the car mufler shop.I do know someone who uses fibreglass cloth from inside of the shell of ovens
But $10-15 will do all the mufflers you are likely to ever use in a lifetime of racing.

If you want to get real trick the rotary guys use stainless steel turnings from a machine shop lasts forever even with a pp20b.More for the 4 smoke here though.
For the baffle I just used to spend a few minutes with the drill and a bit of exhaust tubing. This was as per the bell book for a straight through design. the end caps were steel disks welded to the baffle pipe and a flat piece welded around the disk parallel to the alloy sleve a four flat rivets and all done I used to spring mount the pipe to the stinger.I also used to sand bend a pipe to curve the exit for that gp bike look, But use really dry sand .I learned that bit the hard way.

[wobbly]

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

[kel]

p.s. I was riding a (pretty stock) FXR yesterday, went a whole lot faster (30.73 seconds) than I have on my own bike yet. Will have to change that quick smart.

Buying my FXR would be the quickest solution, I need the money for an RS chassis.

[F5 Dave]

S'funny I've used that silent sport stuff for a while, but get reductions in sound by switching to Daytona matting. Both in my 50 & the 500. Oh & in the dirty bike as well.

A well made reversal end cap can pull a bit of sound out as well. I also made an extension muffler to fit on the end of my existing one for a track that needed real quiet. It was a reversal followed by a short perforated section slightly bigger than the previous with another type of packing. It was quite effective & back to back on the dyno made zero difference. Only issue was it did stress the welds after a while so I swap it out with a reversal if not needed.

Don't underestimate making the thing solid as opposed to flimsy & ally doesn't 'ring' as much as steel.

[TZ350]

It was a good day at Mt Welly last Sunday, cool, no rain and great racing.

245495

I enjoyed getting out on my bike, it sure handles much better than the old GP frame and found I could turn it on much earlier in the corners than I could with the GP. Looking forward to getting my hand back in and being able to string the corners together instead of the quick dash down the straight and then wondering where I should be on the track to make the most of the corner.

245496

Great to have my Grandson out there in F5.

245497 245494

Grandson Rob and his friend Will out on the track.

[ajturbo]

It was a good day at Mt Welly last Sunday, cool, no rain and great racing.

245495

I enjoyed getting out on my bike, it sure handles much better than the old GP frame and found I could turn it on much earlier in the corners than I could with the GP. Looking forward to getting my hand back in and being able to string the corners together instead of the quick dash down the straight and then wondering where I should be on the track to make the most of the corner.

245496

Great to have my Grandson out there in F5.

245497 245494

Grandson Rob and his friend Will out on the track.



I was working....:violin:

[TZ350]

I have heard talk from JC of Buckets being limited to 20hp, I guess this is a Mt Wellington safety thing as it would make no sense to limit Buckets when they run on the bigger tracks with 250’s and Street Stocks.

The exciting thing is, if you stop aiming for max hp with a Stroker its possible to make a 2-stroke tractor that can launch harder than an FXR out of the corners and have enough over rev to carry it corner to corner.

In my experiments on the dyno I have seen graphs where the torque curve is massive low down and slowly tapers of in such a way that the power curve is long and flat.

It might with some development be possible to have 20hp at 5-6,000 and hold it in a flat line all the way through to 12,000 rpm. FXR’s don't do that, they start off low and build up.

Instead of killing them off, a 20hp limit might actually re-vitalise strokers and make them much more competitive at Mt Welly than they are now.

[ajturbo]

I have heard talk recenty from JC of Buckets being limited to 20hp, I guess this is a Mt Wellington safety thing as it would make no sense to limit Buckets when they run on the bigger tracks with 250’s and Street Stocks.

The exciting thing is, if you stop aiming for max hp with a Stroker its possible to make a 2-stroke tractor that can launch harder than an FXR out of the corners and have enough over rev to carry it corner to corner.

In my experiments on the dyno I have seen graphs where the torque curve is massive low down and slowly tapering of in such a way that the power curve is long and flat.

It might very well be possible to have 20hp at 6,000 and hold 29hp in a flat line all the way through to 12,000 rpm. FXR’s aren’t able to do that, they start off low and build up.

Instead of killing them off, a 20hp limit might actually make the strokers more competitive at Mt Welly than they are now.


I don't mean to rude or anything.. but build it and prove this point...

i am not in any favour of HP limits... that is against all principles of racing ???

but then again i have not raced for 2 years so why listen to me?:no:

[husaberg]

The only packing that works properly and wont get blown out easily is called SilentSport muffler packing.Its easily the best and can be bought from MotoWorks in ChCh.
The other issue tested is power.Anything but a densely packed muffler will loose power,and making the core ID the same as the OD of the stinger seemed to be the best setup as well.

Any luck with Mike. I wouldn’t think I would be able to keep a job open for him for much longer.You could tell him the pays crap but so is the rider.

Call me a tight wad (sorry couldn't resist.)

But this special trick (read super expensive packing) how does it gain much over the run of the mill $15 for a couple o kg stuff.
It looks the same.
Is ithe trick stuff more heat resistant resin in the fibreglass? pic from website and garage floor.
Or have I googled the wrong stuff.

That’s a Great tip re the tubing same size as stinger. I will try it. Of course for less noise we could always double skin the muffler with pos fiberglass between layers.

Interestingly I packed as much as was physically possible into the bucket one time and it was super quiet but seemingly flat as power wise. Maybe Psychosomatic
Effect? I.E my perception was clouded by some preconceived notion of more noise equal more power.