ESE's works engine tuner

[TZ350]

259365

The Wobbly Piranha is finished, we are keen to try it out on the dyno, but because the ignition map will need to be changed and that takes time, its maybe next week after Te Puke.

259366

A big thanks to Wobbly for his design and kitset pipe and Darren for his work putting it together, because without his help this would not have got finished. There is no way I could have done it myself, making a good job of pipes is a real art.

[Grumph]

Salvaging grooved shafts was indeed my main thought, any increase in seal life and/or reduced friction could be a side benefit.

Currently putting sleeves on the seal rubbing areas of an X7 road resto. Pretty common fix on those things.
The crank expert in ChCh - Barry Lynch, tends to hard chrome worn areas on race motors and grind, but sleeves road stuff. Horses for courses.

[Bert]

Look good TZ. looking forward to the dyno results.

or maybe not as it likely to have far more get up and go than mine...:weep:

[sonic_v]

259365

The Wobbly Piranha is finished, we are keen to try it out on the dyno, but because the ignition map will need to be changed and that takes time, its maybe next week after Te Puke.

259366

A big thanks to Wobbly for his design and kitset pipe and Darren for his work putting it together, because without his help this would not have got finished. There is no way I could have done it myself, making a good job of pipes is a real art.

I like to create my curves within the computer before I even go to the dyno, then it is possible to run through tests very quickly. Usually with a new pipe it can be very informative to run 3 or 4 straight line curves first as this can direct you to which curves to choose.

[TZ350]

Good idea, I will do that, I will set up some straights and good guess curves first. I have a good idea where things probably should be but just moved up the scale a bit. The good thing about the IgniTech is that the ignition curve can be re programed on the fly.

[breezy]

tz350,has this exhaust been designed to increase the power spread? you said you d hoped to get to around 4k usable power. noticed the belly setion has gone, is this the way to go now? does this pipe rely heavily on the ignition set up to work to its best? could this be the end of your excellent thread in pursuit of 30+rwhp suzuki gp125...i would sincerly hope not...:clap::beer:

[wobbly]

The pipe was designed to give a wider range but at a slightly higher rpm again.
This may in fact not be possible with the transfer geometry it has, and it may need to be lengthened a little to put it back in synch with the porting.
The timings are spot on, but for sure the scavenging regime isnt a RSA copy.
The belly starts at 66% of TL, but has 3 sections of bend within it - and another at the junction of the rear cone - that is why it looks that way, I was copying the centreline shape of a pressed pipe..
Every pipe is timing critical, this design is no more or less sensitive in that it will need the retard slope moving to the right if it forces the peak power up a few rpm.

[TZ350]

tz350,has this exhaust been designed to increase the power spread? you said you d hoped to get to around 4k usable power, could this be the end of your excellent thread in pursuit of 30+rwhp suzuki gp125...i would sincerly hope not...

No, :laugh: not the end yet, there are quite a few other people contributing interesting stuff to the thread and there is a way to go yet in developing this motor, both for max power and probably more importaintly, power spread.

The pipe should (hopfully) extend the top a bit and I hope a VTEC valve will plump up the bottom, then there are the 50's, and Wob is working on one for Giggles that will hopefully be 18 or so hp so plenty to do yet.

[Farmaken]

Will we see you at Te Puke TZ ??
Be nice to see the Wobbly Piranha feasting on fourstrokes !!:cool:

[TZ350]

Will we see you at Te Puke TZ ??
Be nice to see the Wobbly Piranha feasting on fourstrokes !!:cool:

Yes I will be at Te Puke as Kel's pit crew, but if its wet he may elect to run his FXR as trying out a new bike for the first time on a very tight wet slippery track might be a bit much.

But if its dry enough it would be good to get a few laps just to settle it in before the GP at Taupo.

I am looking forward to catching up with you when we get there, probably arrive mid morning Sat.

[koba]

Yes I will be at Te Puke as Kel's pit crew, but if its wet he may elect to run his FXR as trying out a new bike for the first time on a very tight wet slippery track might be a bit much.

But if its dry enough it would be good to get a few laps just to settle it in before the GP at Taupo.

I am looking forward to catching up with you when we get there, probably arrive mid morning Sat.

Cool, it will be good to see you there :)

I think it looks like a bit of a power track as far as kart tracks go, I always feel the disadvantage when pulling out of very slow corners and onto straights.

[husaberg]

TZ now has 30 or so HP a an impressive powerspread and he has achieved it but without a Electric PJ so far.
Will the expected performance gains in over rev potential (thus powerspread) you would expect from having one be hindered by the fact his carb is rather small (24mm because of the rules)
Also would the extra heat produced in the pipe from the high speed lean of effect his bike differently being air cooled. rather than being liquid cooled.

I also keep tripping over stuff done in the 70's and 60's that suggests something along the lines of a 10-20% greater power loss mid race compared to a liquid cooled as well.
Not that it matters, his engine still makes 30 HP more than mine does at the moment.:rolleyes:

Has anyone ever ran the bike on the dyno long enough to get an idea of the performance loss you would expect from a AC bike compared to a Liquid cooled.

On the subject of bearings and seals and so forth.
Something Dave said about if worse comes to worse with his need for a suitable little end bearing he would use a crowded set up. Wobbly said something about Bultaco days and i didn't twig, What he was meaning because something i never understood with Jennings writing that the Bultaco would last better at high revs if the little end was substituted for a crowded set up. Why? Were the standard cadged ones just crap?

One other bit i can remember reading something where someone claims the MV the little 125cc and 250cc ones race bikes had an odd big end that was uncrowded with two different diameter rollers bigger ones inside and smaller ones sort of between on the outer toward the outside of the rod.
I guess it would allow smaller diameter rollers anyone have any ideas on that?

[Yow Ling]

One other bit i can remember reading something where someone claims the MV the little 125cc and 250cc ones race bikes had an odd big end that was uncrowded with two different diameter rollers bigger ones inside and smaller ones sort of between on the outer toward the outside of the rod.
I guess it would allow smaller diameter rollers anyone have any ideas on that?

I cant imagine different diameter rollers, maybe different lengths. Any roller that was just a tiny cock smaller would carry no load, and the fat ones would be just greedy,

[bucketracer]

Has anyone ever ran the bike on the dyno long enough to get an idea of the performance loss you would expect from a AC bike compared to a Liquid cooled.

We have often done 10-15-20 runs at a time when setting up the ignitions with no more of a break between them than the time it takes to slow the dyno drum and there was no real power drop but we are expecting it will show up on the track, Taupo should tell more.

[husaberg]

I cant imagine different diameter rollers, maybe different lengths. Any roller that was just a tiny cock smaller would carry no load, and the fat ones would be just greedy,
I should draw a picture, but the larger ones and smaller ones both carry weight

[wobbly]

The solenoid Powerjet does lean off the BSFC curve BUT, what you need to get is that all it is doing is returning the fuelling to much closer to optimum.
Its not really "leaning it out "as such,it is dumping more of the available heat energy in the fuel - into the pipe, speeding up the wave action and thus extending overev available.
I dont think this engine has reached its thermal dissipation limit yet - as evidenced by the power not going away badly under load.
You know when you get there, as I did with KT100 pipe design project I did years ago.
As soon as the pipe produces more than 18Hp at the crank, the cylinder and head cannot get rid of the heat produced, and it will fade badly after 3 laps - hitting the thermal limit wall.
Needing fuel to cool it, not make power.
Thus I worked for months locked in a dyno room in Flat Bush extending the band width, at the expense of peak power.
It worked, as I have sold 2000 of the things in well over 10 years and they have won every Nationals title in that time.
I will slope over on Saturday to Te Puke, and poke a screwdriver in the spokes as a helping hand for you,

[F5 Dave]

Husi, when we were talking of crowded rollers Jennings was dealing with bikes running at sod all revs & presumably cages were pretty so-so back then. Wobblies opinion from memory was that at decent revs the rolers would rub against each other & with load that would cause skidding. It makes sense so I never went that way.

[husaberg]

Husi, when we were talking of crowded rollers Jennings was dealing with bikes running at sod all revs & presumably cages were pretty so-so back then. Wobblies opinion from memory was that at decent revs the rollers would rub against each other & with load that would cause skidding. It makes sense so I never went that way.
Yeah i with you with the crowded VS cadged (I raced old dungers remember) and some of them had no little end bearing either.
I do however understand it is not directly the speed that is the issue rather the variation in acceleration and deceleration that is issue. (YES I KNOW IT IS RELATED TO THE SPEED) The cadged roller bearing that Jennings suggests throwing, may have been a riveted or pressed design, rather than a solid design which i believe is superior. Of course the little ends don't suffer i believe to the same extent.
I understand at least one road bike had silver plated big ends or a least the manufacturer has superseded the original part number with one i also understand some bikes (TZ)at least had titanium cadges. I guess the silver plating may be to stop the work hardening of the Ti?
I would like some one expand a bit on the pro and cons of the other materials though.
I have seen a lot of talk about four strokes big ends failing on overrun which i guess is a result of the engine reaching higher revs due, i guess the engine being revs higher on overrun through the wheel speed driving the engine than it would reach on its own accord but that is just a theory mind you.

Below is a rather crude inaccurate rendering of what i had seen attributed to some early small MV race engines. Not to scale but it will express the design i guess.


Oh yeah Wob thanks for the explanation i wouldn't have guessed the KT100 only made that little power as well. So thanks.

oh yeah i found this as well maybe i should have read it again.

[Ocean1]

Up side of having no cage is that you get more rollers in the same space, giving you less load per roller, so the bearing can take higher loads. Down side is the rollers rub together at twice the speed of that against the inner or outer, so revs are usually limited.


The main function of a cage is to keep the rollers apart, but as important is to keep them parallel to the shaft. There has to be clearance between the inner and outer elements, without a cage the rolers are free to skew slightly until the roller ends touch the outer and the roller centre bridges across the middle of the inner. Even very small deviations from parallel impose extreme loads on the bearing, across very small surface areas. In fact the skew causes side load in inverse proportion to the angle, as the roller tries to "turn" sideways, effectively becoming a wedge. There are actually sprag (uni-directional) clutches that make use of this effect, they can lock a shaft up at very high torque, not a feature you really want in a gudgeon bearing.

[husaberg]

Up side of having no cage is that you get more rollers in the same space, giving you less load per roller, so the bearing can take higher loads. Down side is the rollers rub together at twice the speed of that against the inner or outer, so revs are usually limited.


The main function of a cage is to keep the rollers apart, but as important is to keep them parallel to the shaft. There has to be clearance between the inner and outer elements, without a cage the rolers are free to skew slightly until the roller ends touch the outer and the roller centre bridges across the middle of the inner. Even very small deviations from parallel impose extreme loads on the bearing, across very small surface areas. In fact the skew causes side load in inverse proportion to the angle, as the roller tries to "turn" sideways, effectively becoming a wedge. There are actually sprag (uni-directional) clutches that make use of this effect, they can lock a shaft up at very high torque, not a feature you really want in a gudgeon bearing.
Yeah if i remeber right the Vincent had small diameter half width crowded rollers 2 sets of short rollers with a divider in the middle i guess to stop the skewing.

Yeah the starters on 50 cc chinese crf50 have the set up as you desribe. I thought it was rather clever and i said that to a mate thats a Cat mechanic he wasn't impressed he said lots of starters have them.
I couldn't find the bit where jenning said to throw out the Bultaco cadged wrist pin bearing though.

[TZ350]

Entry list for the GP
http://pacificmccracing.wordpress.com/2012/03/07/nzsbk-championship-round-5-entries/

There looks like more than 30 Moto 4's (Buckets) lining up for the GP at Taupo, and F4 is looking like the biggest field, considering the entry fee I was not expecting so many of us would bother to make the trip.

I am glad so many have, and considering the names on the list, it should be an exciting meeting as its wide open, there are several potential winners this year.

[koba]

There looks like more than 30 Moto 4's (Buckets) lining up for the GP at Taupo, and F4 is looking like the biggest field, considering the entry fee I was not expecting so many of us would bother to make the trip.

I am glad so many have, and considering the names on the list, it should be an exciting meeting as its wide open, there are several potential winners this year.

I know, I'm gutted to have to miss it due to budgetary constraints.

[Yow Ling]

I hope they have the live streaming for the Moto 4's

Maybe now is the time to start asking for it, I think Jellywrestler on KB has something to do with it, Ill call him

[richban]

I hope they have the live streaming for the Moto 4's

Maybe now is the time to start asking for it, I think Jellywrestler on KB has something to do with it, Ill call him

What would be cool would be a guest commentator that knows a bit about the riders / class. TZ?

[wobbly]

On the over run with the gas closed - there is no combustion pressure on the piston, and this combined with riders that hook down thru the gears
when doing a corner entry, the extra rpm kills the bottom end.
This in effect doubles the cyclic peak load, at TDC and BDC as well.
Bartol said that they regularly saw 16,000 on a 125 when on trailing throttle, and this was killing the cages.
So they added an injector that was rpm and TPS driven, such that over a set rpm on trailing throttle it dumped fuel/oil into the case.


Where is the live streaming - someone got a link.
BTW - several Euro sports sites have live streaming of Moto GP, practice sessions and all.

[F5 Dave]

The ESE guys need to extend their GP entries to include the F5 bikes. Surely if entered in F4 they wouldn't late entry charge you. $70 for extra class, not the full $100.

Edit, hey hold on I don't see TZ or Greenie entered in F4 either?! (Pacific club website) How can you 'do-the-deed' on these mega buckets if you're not entered?? I see Ned & Av.

[TZ350]

The ESE guys need to extend their GP entries to include the F5 bikes.

The last 4-5 months have been very busy preparing specialist CNG equipment for export to China and India, and we can't do much more than field two bikes at the GP this year. Next year we expect to have at least three F5's or possibly five of them as there is a whole bunch in the pipe line, three RG50 based and two with RS chassis and 18 rwhp Aprila 50 engines.

[F5 Dave]

But one weekend & surely your & Greens bike are ready to ride?

I would say that might the RS50s in RS frames might spur me into fitting my Derbi engine. . . .but I've been saying that for, shit it must be 7 years & the engine has been finished for over 1/2 that. Next year, I keep saying. RG still battles on, but at least its out there.

[TZ350]

It isn't going to happen ....

[F5 Dave]

What? - you going to the GP, or me finishing the 50?

I keep having to sticky tape the 100 back together in between the dirtbike & trying to get some time to do the 500. I'll get to the 50 sooner or later. But then the roadbike needs maintenance, or some mod I've read about on the internet, heck the Trials bike occasionally needs attn. Must start that resto project I've been collecting parts for. . .

[TZ350]

What? - you going to the GP, or me finishing the 50?


Us taking 50's to this years GP, we just can't do it ...... sorry :weep:

[Yow Ling]

Where is the live streaming - someone got a link.
BTW - several Euro sports sites have live streaming of Moto GP, practice sessions and all.

Streaming was on NZSBK website, had live video with commentary , plus live timing , and live chat all on the same screen

[richban]

we can't do much more than field two bikes at the GP this year.

So reading between the lines. We have Avalon on a 30hp rs chassis bike and Ned on pretty much the same. Well all I can say is bugger! Could be the year boys.

[ac3_snow]

... Could be the year boys.

Sure hope so, would be well deserved with all the work they have put in!!

[TZ350]

So reading between the lines. We have Avalon on a 30hp rs chassis bike and Ned on pretty much the same. Well all I can say is bugger! Could be the year boys.

Av's is only 25 rwhp and Kel is on my 30hp Beast but 30hp only leaves Kel with the same power to weight ratio as Av and Av's got the better chassis.

Dave M will be peddling Speedpro's 30hp FZR/MB100

So it looks like some real compitition this year.

[Yow Ling]

Got word back from Spyda/ Jellywrestler re commentary

"as for buckets F4 if it's there we commentate and can't see any reason the live streaming won't cover it, biggest thing we need is commentator info so will be up there earlier in the weekend to get as much as i can
yep saw nick do the deed at levels all those little bike classes have good racing too, it's somethinbg i'm focussing on more these days
cheers
spyda "

If you guys can help with a little background about the current bucket scene it would make the commentary all the better.

Personally Im over the "Bucket of Shit" mentality that comes with uninformed commentators, Spyda is up with the present and does a great job but needs good info to promote our sport.

Cheers
Yow

[richban]

Av's is only 25 rwhp and Kel is on my 30hp Beast but 30hp only leaves Kel with the same power to weight ratio as Av and Av's got the better chassis.

Dave M will be peddling Speedpro's 30hp FZR/MB100

So it looks like some real compitition this year.

Bloody Bloody Bloody. I had a feeling that team Shanny would be there, new and improved. Well my new engine is still underway. I finished the manifold today. By total fluke it is .3 mm longer than perfect. New forged piston is machined and ready. Just waiting on the crank. Needs rebalancing coz the piston is a lump. New cams new valves new everything really. Looking at reving it to 14. We will see. Bring your cement bags.:rolleyes:

[kel]

Dave M will be peddling Speedpro's 30hp FZR/MB100

Ooh didnt see that one coming.
Taupo is going to be very interesting, all going well one of us (The Daves all 3 of them, Nathanel, Avalon Rick or myself) will put the 4 strokes in their place, but it sure wont be easy with so much talent on show! I'd hate to have to call the top 10 it really could go any way.
How lucky am I to land a ride on the the beast :2thumbsup

[kel]

What would be cool would be a guest commentator that knows a bit about the riders / class. TZ?

Agreed. The ESE crew chief would be a fine choice.

[richban]

How lucky am I to land a ride on the the beast :2thumbsup

Yep I want to book a ride on that thing. Maybe on a kart track. That would be just stupid good.

[kel]

Yep I want to book a ride on that thing.

Dont know about that, I'll be looking to renew my contract:lol:

[speedpro]

1st place should sort that. Shame really :Pokey:

[marsheng]

I'm finally getting the hang of some of the tuning pieces on carbs. However this part has still eluding me. It is an OKO 30 mm. I have got the idle jet correct, a good needle with clip in the correct position and the main jet seems ok. It starts idles and runs well below 2/3 throttle but nearing full throttle, (the bike still pulling well) I get a nice thick mist at the carb mouth above 9500 through to 13000

It has an emulsion tube and from what I have read, above 2/3 throttle, the holes in the tube lean the mixture off to ensure the correct balance. My guess is there is so much fuel being drawn out that it is not really vapourising well and floating all over the place. As some of it is being drawn into the engine as droplets, the bike still runs well as the air/fuel in vapour is the correct ratio. The main jet is already quite small.

I'm asking as drilling extra holes in the emulsion tube or increasing the air bleed holes (drilling the carb out) will improve the vapourisaton of the fuel but it is one of those jobs where it is difficult to return back to original if required.

Any suggestions ?

[speedpro]

Any suggestions ?

It's fine, leave it alone. All you are seeing is the mixture that was rushing into the engine bouncing back out because the intake has closed. Most of it gets sucked back in on the next cycle

[Frits Overmars]

It's fine, leave it alone. All you are seeing is the mixture that was rushing into the engine bouncing back out because the intake has closed. Most of it gets sucked back in on the next cycle:niceone:. If you really want to know, try retarding the intake closure. And get a spare emulsion tube if you intend to alter the present one :cool:.

[Yow Ling]

Marsheng failed to mention its a 4 stroke

[marsheng]

Marsheng failed to mention its a 4 stroke

I tried this carb a year ago I could not get it to work properly. Interestingly, the guy who I bought this from, also could not get it to work. It is basically a new high performance carb. I've got a bit more knowledge now and giving it another go and have got better results but still not good enough.

http://www.marshland.co.nz/ftp/CB150/CarbInners.JPG

I stripped the unit and I noticed that the air bleed jet is very small, about 0.8 mm which would 'confirm' that the fuel is not getting enough air to correctly emulsify.

[Yow Ling]

OK Im only posting this here because this is the only thread on kb most people read

Sorry its a diesel, but it is out there so worth a look

http://www.simplicitymotorworks.com/Documents/Rotary%20Piston%20ICE%20-%20Its%20Features.pdf

has a disk valve and several departures from normal

maybe this better link

http://www.simplicitymotorworks.com/

[richban]

I stripped the unit and I noticed that the air bleed jet is very small, about 0.8 mm which would 'confirm' that the fuel is not getting enough air to correctly emulsify.

There was a thread on a pit bike site in AU that talked about fixing really crapy PWK knock offs. With my 30 and 32 I drilled it to 1mm. Manly because the castings were a bit wrong. Is this a power jet version? When I get my FCR working I could lend you my 32 it should be jetted and very close to what you need. Little rich on the bottom but hey just keep it pinned.

[wobbly]

I checked the emulsion air passage on a pile of different 2T type Keihin carbs when I converted a 4T FCR downdraft to work on a 2T.
They ranged from 1.7 to 1.9 mm - none were jets as such ,just drillings into the emulsion well below the shroud.
The tuning stuff available on FCR suggested that 2mm always worked best on a 4T as the better emulsification gave better power - even though the AFR was a little
too lean up top due to the big air jet.
On the dyno I played with the replaceable main air jet, and settled on a 150.
As with this and the low shroud, its fuel curve was spot on.

I think what you guys are up against is the problem that has always plagued bleed carbs.
Dellorto and Weber have literally hundreds of tiny variations in bleed hole geometry to match a carbs fuelling to a specific engines needs.
Luckily it has been found that the primary type on a 2T is easily nailed, just with changes in needle shape, and an adjustable idle/air and main.

[Kickaha]

maybe this better link

http://www.simplicitymotorworks.com/

150cc, yeah that should be bucket eligible

[Ocean1]

150cc, yeah that should be bucket eligible

And with that big fuckoff prop you won't be short on elbow room going into the first corner...

[dinamik2t]

I accidentally just found out that Jan Thiel is a Facebook addict: https://www.facebook.com/Jamathi :shit: :p

There are some very interesting mechanical and historical photo there! Perhaps Frits could ask him, whether I could repost some of his photos here, as many wouldn't have a facebook profile.

[Frits Overmars]

I accidentally just found out that Jan Thiel is a Facebook addict: https://www.facebook.com/Jamathi. There are some very interesting mechanical and historical photo there! Perhaps Frits could ask him, whether I could repost some of his photos here, as many wouldn't have a facebook profile.I didn't have a Facebook profile either, I just registered because of what you wrote. Now I will have to learn to find my way around it.
I must say I'm a bit sceptical. I just don't believe in 'over a thousand friends' :chase:

By the way, if you want Jan's permission for anything, you will have to ask for it yourself, dynamik. Since both of you are on Facebook, that shouldn't be a problem.

[dinamik2t]

I didn't have a Facebook profile either, I just registered because of what you wrote. Now I will have to learn to find my way around it.
I must say I'm a bit sceptical. I just don't believe in 'over a thousand friends' :chase:

By the way, if you want Jan's permission for anything, you will have to ask for it yourself, dynamik. Since both of you are on Facebook, that shouldn't be a problem.

Yes, at first I was like "what's that, a facebook profile and personal photos? is that Jan Thiel?" - it seemed a bit strange., with all the respect! :confused:
I can't and shouldn't be judgemental on anybody about personal stuff, so excuse me.

As for the permission.. I didn't mean to have you 'do my dirty work'. I feel strange about asking things in personal, either facebook messages or PMs in forum. Plus, to be honest, I have a facebook profile for 'tuning demonstration/promotion' purposes only and I cannot help feeling embassared for my work against Jan Thiel's. Yes, that might be an inferiority complex, but.. ok.
Since you think it will be ok, I will send him a message.

p.s. I know there's no real word 'dinamik', but it's what my moto is called. so, if you don't forget, use the i :D

[dinamik2t]

So, Jan Thiel gave his ok. A few pics I found interesting:

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash2/58100_163122007033936_100000084143345_499030_56350 58_n.jpg


"Jamathi cilinder 1967"
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc7/s720x720/432142_2705047274658_1511052910_31821015_203156668 1_n.jpg


Derbi ignition trigger
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/s720x720/425265_2704871750270_1511052910_31820964_125386035 9_n.jpg


Cylinder inspecting - with Giovanni Sartorato e Matteo Marini
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc7/s720x720/419655_2700427319162_1511052910_31819524_162373812 1_n.jpg


"Brno 1969, our best win! On the right is my Czech friend Olda Fiser."
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/s720x720/417117_2700019388964_1511052910_31819392_929438763 _n.jpg


"With my friend GJ Rigter at the Aprilia flowbench. The tool in my hand is for flowing the transfers. We flowed them with the piston in 4 different positions."
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/s720x720/429839_2700198193434_1511052910_31819441_137903243 6_n.jpg


"The front half of an Aprilia crankcase. The crankshaft could be fixed in various positions by a springloaded ball. We used this for flowbench testing. We could see that the conrod disturbed the flow very much, so the idea of the rear inlet RSA was born!
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc7/s720x720/429494_2685369942737_1511052910_31813005_192701034 3_n.jpg

[TZ350]

OK .... that was Te Puke, its a great tight track, lots of elevation changes and hair pin corners. The weather was fine Saturday wet Sunday, and rained all day long but great racing and times in the wet were much the same as the dry.

And Tokoroa was no fluke as Av managed :first::first::first:

Placings were:-

Race 1 Av :first: Gav-V :second: Rick :third: and Kel

Race 2 Av :first: Gav-V :second: Rick :third: and Kel

Race 3 Av :first: Gav-V :second: Kel :third: and Rick

So three 2-Strokes and Gav-V's FXR at the pointy end all day.

[marsheng]

I checked the emulsion air passage on a pile of different 2T type Keihin carbs when I converted a 4T FCR downdraft to work on a 2T.
They ranged from 1.7 to 1.9 mm - none were jets as such ,just drillings into the emulsion well below the shroud.



Thanks for the info. The original Honda carb has a similar emulsion tube and it's air jet was around 1.8 mm, so it looks like it is time to do some drilling.

[kel]

And Tokoroa was no fluke as Av managed :first::first::first:

Placings were:-

Race 3 Av :first: Gav-V :second: Kel :third: and Rick


Once again Avalon looked unstoppable.
I pulled a horsepower mugging on Rick in that last race. The beast was embarrassingly fast, clearly quicker up the straight than anything else on the track.

[Buckets4Me]

Once again Avalon looked unstoppable.
I pulled a horsepower mugging on Rick in that last race. The beast was embarrassingly fast, clearly quicker up the straight than anything else on the track.

and more likely to bite than the marshalls :shutup:

[Rick 52]

Thanks for team ESE ..Great advice on port tidying and a re designed pipe gave me 1/2 a horse and a much fatter power curve ,this kept me at the sharpe end all weekend ..now I need to stop the clutch from slipping ...
Kel a pass is a pass very clean and you still had to put the power down in tricky conditions and a tidy last lap left me nothing to get you back ,very good racing from us all I think ..

[bucketracer]

and more likely to bite than the marshalls :shutup:

Kels FXR was over the noise limit and he had to park it for the day.

[kel]

very good racing from us all I think ..
Agreed. The racing was fast, clean and a lot of fun.


and more likely to bite than the marshalls :shutup:
That was a draw, 1 each.


OK .... that was Te Puke ... So three 2-Strokes and Gav-V's FXR at the pointy end all day.
Did a quick calc and by my take with one round to go its team ESE riders 1st equal on 120, Rick 1 behind at 119.

edit: actually that should have read ESE riders equal on points, Avalon leads due to greater no. of wins. What really matters is that 2 strokes lead!

[wobbly]

Anyone got a set of dimensions for a TZ350G - crossover pipes, dont want to measure them if I can avoid it.
Want them as a sim baseline stock engine.

[bucketracer]

Great racing this weekend, sorry about the weather. This is how it looks...

120 Avalon Biddle
120 Kel Nicolson
119 Rick Ford
104 Steve Booth
83 Gavin Veltmeyer
71 Warrick Head
49 Andrew Adlam
41 Malcolm Nabbs
41 Mike Kyle
39 Carl Smith
38 Gary Cunningham
35 Rogan Chandler
34 Tim Fraser
34 John Steer
30 Ken Douglas
28 Kamil Chodor
26 Adrian Mitchell
25 Henk Zeeven
17 Ryan Firn
15 Grant Nicholson
15 Caleb Adlam
15 Ivan Smith
11 Dave Manuell
10 Brian Steffensen

See the quiet achievers like Steve Booth waiting in the background to jump when all the 2 strokes seize and Gavin gets a free holiday to Hawaii on short notice...

Given the mix of fast guys to come out at Kaitoke it could be a very dynamic last round.

The offical Pacific Club Summer Series results after Te Puke .... Strokers :first::second::third: making the FXR's the also rans.

Any of the nay sayers still unable to read the writing on the wall ........ with the Taupo GP next, things are getting interesting.

[koba]

I'm saving this spot for a post that is going to take some careful composition.

OK, now it's composted in my mind long enough I'm posting it:

I was going to write a lengthy and thoughtful post about my quick run on Avalons bike.
The length will have to come from me padding it out with worthless rambling thoughts because my short play run can be described in one word:
Outstanding!

No, I don't mean that in the way we describe Romanian plum brandy, which stands out as the most horrid liquid substance to my assault my palate; It was outstandingly good.
Most times I ride someones bucket I mentally cobble together a checklist of pros and cons. The better bikes, all the fast ones, don't really have cons. Instead they have Pros and Okays, for example Rick's old FXR had an unbelievable mid-range punch and turned in exceptionally well (for an FXR), there were no aspects of the bike that could be considered 'bad' by any means.
The ESE built GP framed bike that Avalon has been using to humble the fastest racers out there was nothing short of fantastic.
Before I snuck out after the last B-grade race Keith quietly said to me "Careful with the brake, feel it out as it's probably better than you are used to."
Shit, He wasn't kidding!
The brake wasn't all, every part that makes a bike stop, go, turn, handle and feel good was better than I've felt on any bucket before.
I only had a few laps on it but I was instantly aware the bike was much faster than me, on my second lap I realised I was riding it all wrong because I was still trying to force it around corners rather than just looking where I want to go and letting the bike do the rest. That's a cool feeling.
The bike is very fast but in the kind of way it will take a damn good rider to make the most of it. Sorted.

So the purpose of this post is to thank Avalon and Keith for letting me out on it, even when they wanted to go home! I must also congratulate all the ESE personnel for their work on creating such a gem of an engine, if I didn't know better I wouldn't have believed it was a 1970's commuter engine, it makes all the right sounds and goes like the hyper kid after he's been fed a bag of red lollies.

[F5 Dave]

I might as well save this spot for some careless compostation

[TZ350]

I am saving this spot for the post Taupo excusses I have composed ..... :laugh:

[koba]

I might as well save this spot for some careless compostation

you could put some of it in bottles and call it homebrew like I do...


I am saving this spot for a bunch of post Taupo excusses I have composed ..... :laugh:

If you show up you have to make excuses that fit reality, my excuses revolve around not showing up!

[TZ350]

EngMod2T

I am trying to decide wether to leave the bike as is for Taupo or to fit the new Wobbly pipe and maybe even the triple port cylinder. Its a bit of a hassle and a hours of dyno time to get the ignition curve and carb right.

The trick in looking at these curves is to not take the ultimate hp to seriously as EngMod thinks my combustion efficiency is much higher than it actually is. I could change that in the settings but can't be bothered because re running the simulations will take to long.

With these simulations the thing to look for is the shape of the curve and the power spread not the ultimate hp which is over stated by at least 3 hp and is at the crank and not what you would see on the dyno.

259649

Red line is the current 1ex setup with RS pipe, and the Blue line is the new Wobbly Pipe

259650

The Blue line is the current 1ex setup with Wobbly pipe, and the Red line is the 3ex (tripple ex) with Wobbly pipe.

259651

The Red line is the current 1ex setup with RS pipe, and the Blue line is 3ex (tripple ex) with Wobbly pipe.

Flat for 4,000 rpm 10-14K or a 5,000 power spread from 9-14K with over rev to 15, now thats tempting, and if we can plump up the 8 to 9 bit with an ATAC valve then thats potentialy 5.5 to 6k power spread. Guess what I will be working on over the next few months.

But what to do for Taupo, the tried and true or take a gamble ......

[Buckets4Me]

EngMod2T

I am trying to decide wether to leave the bike as is for Taupo or to fit the new Wobbly pipe and maybe even the triple port cylinder. Its a bit of a hassle and a hours of dyno time to get the ignition curve and carb right.

I recon you leave it as is and spend the time sorting the carb out :yes:
then i might be able to ride it better :yes:

[TZ350]

I recon you leave it as is and spend the time sorting the carb out

Yep you could be right, its fast enough now, better to leave it as is and save something for later, 33+ rwhp and 5.5k power spread, just in case the faster FXRs can find any more power.

[husaberg]

Anyone got a set of dimensions for a TZ350G - crossover pipes, dont want to measure them if I can avoid it.
Want them as a sim baseline stock engine.

I think Your friend Neels does i guess, his site advertising for enginemod2t uses a TZ250G as an example.

and also this guy uses the t250g as a sim example he has done if that helpshttp://www.thumpertalk.com/topic/782949-engmod2t-2-stroke-simulation-software/

Bell has the pipe dimensions for a TZ125G, TZ250D/E, TZ500G not that helps you much. As Mr Murphy helped him choose his examples, Maybe different editions offer different examples?
Mr Swarbrick will know them too, as he does T20 pipes to those std dimensions for classic racers as well.

[koba]

But what to do for Taupo, the tried and true or take a gamble ......

My vote would be tried and true for your situation, changes can cause problems that take time to iron out or only become apparent on the day, you aren't in the position where the risk is worth it.

[bucketracer]

...better to leave it as is and save something for later, 33+ rwhp and 5.5k power spread, just in case the faster FXRs can find any more power.

Maybe you could get to 33-35 rwhp, but you don't need it now, keep it like money in the bank then the FXR's will always know you can easily pull something out of the hat and stay ahead of them whatever they do.

[2T Institute]

So I suppose all this is why a GP125 is approaching Manx Norton prices on Trademe? :laugh:

Well done TZ, probably why the 'powers that be' wil never allow air cooled 125's here.

[Yow Ling]

So I suppose all this is why a GP125 is approaching Manx Norton prices on Trademe? :laugh:

Well done TZ, probably why the 'powers that be' wil never allow air cooled 125's here.

http://www.trademe.co.nz/Browse/Listing.aspx?id=452663122

didnt even get a $20 bid, now where are those nortons.

[Buckets4Me]

http://www.trademe.co.nz/Browse/Listing.aspx?id=452663122

didnt even get a $20 bid, now where are those nortons.

the truth is the fuel cap is damaged and i cant get fuel into it easily i dont know if the oil pump is working and i dont want to risk damaging the bearings or piston. its 6v im sure and i dont have a 6v charger to peak it up im kind of selling it as is cause i havnt had it running. tomorow ill wip out the plug and read it to see how its been running im good at reading 2stroke plugs i can tell its state of tuneby the plug. ive kickedit overslowly tosee comp and its good and its dry too. <small class="NoWrapping"> 10:37 pm, Sun 4 Mar </small> Seller Comment: i pulled out the plug its been running fine by the looks of thr plug little bit rich maybe <small>



thats maby why it didn't get a $20 bid
it's been sitting for how long and he can read the state of tune by doing a plug chop </small>:woohoo:
<small>
</small>

[Buckets4Me]

http://www.trademe.co.nz/Browse/Listing.aspx?id=452663122

didnt even get a $20 bid, now where are those nortons.

the truth is the fuel cap is damaged and i cant get fuel into it easily i dont know if the oil pump is working and i dont want to risk damaging the bearings or piston. its 6v im sure and i dont have a 6v charger to peak it up im kind of selling it as is cause i havnt had it running. tomorow ill wip out the plug and read it to see how its been running im good at reading 2stroke plugs i can tell its state of tuneby the plug. ive kickedit overslowly tosee comp and its good and its dry too. <small class="NoWrapping"> 10:37 pm, Sun 4 Mar </small> Seller Comment: i pulled out the plug its been running fine by the looks of thr plug little bit rich maybe <small>

</small><small>

and the auction was for a $20 key
how much do you pay for a manx norton key ?</small>:laugh:<small>
</small>

[wobbly]

Neels sent me a drawing of a TZ350F pipe he measured, but I also got a drawing from Bod Haldane ( Yamaha Factory ) and there are several quite big differences.
I will just have to measure a set for myself.
Bugger.

[F5 Dave]

http://www.trademe.co.nz/Browse/Listing.aspx?id=452663122

didnt even get a $20 bid, now where are those nortons.
Well my last GP I bought in large parts for $50. Just assembled it & ran great. Sold it for $150 which recovered the two $40 knobbies I'd put on it.

What?!?:confused:


Anyway it lives on & is back to road tyres & a riding school hack. Best one he's had, & he's had it like 10 years.

[dinamik2t]

Neels sent me a drawing of a TZ350F pipe he measured, but I also got a drawing from Bod Haldane ( Yamaha Factory ) and there are several quite big differences.
I will just have to measure a set for myself.
Bugger.

From a quick google images search under "TZ350 pipe" & "TZ350 exhaust":

a) http://www.perthstreetbikes.com/forum/f64/making-rz250-350-pipes-89901/index2.html
b) http://www.tz350.net/images/dyno_and_misc/rd350%20lc_performance_exhausts_design_by_greg%20s ims_reduced.jpg ..... from here : http://www.tz350.net/lcracer_article.htm
c) http://farm5.static.flickr.com/4063/4234852671_64a6bc9533_o.jpg ........ from here : http://2stroker.createforumhosting.com/surching-exhaust-measerments-yamaha-tz-350-6-port-3g300-t3745.html

Hopefully, the c) is what you 're looking for.
edit: oh, you seek the G letter, so probably not.

[TZ350]

BMEP: and why your not going to see any 12K rpm 30 hp FXR150's in F4

For those that missed it before BMEP is an important performance yardstick

http://www.epi-eng.com/piston_engine_technology/bmep_performance_yardstick.htm

Brake Mean Effective Pressure (BMEP) is a very effective yardstick for comparing the performance of one engine to another, and for evaluating the reasonableness of performance claims or requirements.

The definition of BMEP is: the average (mean) pressure which, if imposed on the pistons uniformly from the top to the bottom of each power stroke, would produce the measured (brake) power output.

Note that BMEP is purely theoretical and has nothing to do with actual cylinder pressures. It is simply an effective comparison tool.

Brake Mean Effective Pressure (BMEP)

http://www.engineersedge.com/engine_formula_automotive.htm

4-Stroke BMEP = (HP x 13000)/(L x RPM)
2-Stroke BMEP = (HP x 6500)/(L x RPM)

L = Displacement in Liters i.e., 80 cc = .08 Liters 1 ci. = 16.39 cc

BMEP for those who missed it the first time .... and why 4-strokes are inherently limited and will eventually go the way of the dinosaurs.

BMEP for a FXR150 making 25 rwhp ... 28 crank hp at 12,000 rpm

4-Stroke BMEP = (HP x 13000)/(L x RPM)

BMEP = (28 x 13000)/(0.150 x 12,000)

BMEP = 364,000/1,800

BMEP = 202 psi for the FXR150 4 stroke.

BMEP for a GP125 making 30 rwhp ... 33 crank hp at 12,000 rpm

2-Stroke BMEP = (HP x 6500)/(L x RPM)

BMEP = (33 x 6,500)/(0.125 x 12,000)

BMEP = 214,500/1,500

BMEP = 143 psi for the GP125 2 stroke.

A BMEP of 200 to 220 psi is supposedly the upper practical limit for naturally aspirated engines and is only currently being achieved by the likes of F1 race engines.

At 202 psi for the FXR, the FXR150's do not have much more development potential left unless they are spun to 13 -14,000 rpm or more but at 12k rpm and 143 psi for the 2-stroke there is plenty of relatively easy potential left for the little Moto4 race bikes, and the writing is truly on the wall for the 4's.

And with things like direct cylinder injection making 2-strokes cleaner and inherently more powerful and cheaper than 4-strokes the 2 strokers must make a come back on the world stage at some point, its just shear economics.

http://www.allpar.com/neon/stroke.html Two-stroke engines have long been promising because of better fuel economy, fewer parts, better efficiency and a smaller engine package (about two-thirds the size and weight of conventional engines) that would allow for more design flexibility.

More on BMEP http://hpwizard.com/bmep.html and lots of other interesting formula like wind resistance.

[F5 Dave]

ok lets do some simpler math

Litre road bike now pushing 170hp x0.15 (for 150cc) = 25.5hp

Developed to world super spec easy 200hp x 0.15 = 30hp.


But realistically, no way will reach that spec with FXR parts. Just want to poo in BMEP calculations.

[bucketracer]

ok lets do some simpler math

Litre road bike now pushing 170hp x0.15 (for 150cc) = 25.5hp

Developed to world super spec easy 200hp x 0.15 = 30hp.


But realistically, no way will reach that spec with FXR parts. Just want to poo in BMEP calculations.

What rpm is the world super spec 200hp engine spinning at.

I think TeeZee pointed out the FXR would have to spin to 13-14,000 rpm to make 30 crank hp and 30 was not going to happen at 12 which looks like their mechanical safe limit.

You might need to work through the math again as BMEP gives a true apples for apples comparison and indication of development potential, hp per liter does not.

[F5 Dave]

As I said simpler math, the rpm assumption was yours. Perhaps a GSXR600 rod may help with the revs. Can't help out being a single, mind.

Heck with . . .actually why am I giving the 4 stroke guys ideas again??:shutup:

[TZ350]

Your simpler math is interesting but can be misleading unlike the BMEP rpm thing which points out where you have to goto to realisticly expect 30 crank hp from a FXR150 and its about 14,000 rpm, its not going to happen at 12K, the numbers don't lie they only revel the direction required, the realitive difficulty ahead and get you thinking about what may be required to get there.

[crazy man]

a mate was telling me in japan they drag race fxr 150 and get 37hp at the rear wheel but thought about it , they must be useing nitro in them even though a better head with all the goodies just maybe you could with out nitro

[TZ350]

... a mate was telling me in japan they drag race fxr 150 and get 37hp at the rear wheel but thought about it , they must be useing nitro in them ...

BMEP for a FXR150 making 37 rwhp ... 40 crank hp at 14,500 rpm
4-Stroke BMEP = (HP x 13000)/(L x RPM)
BMEP = (40 x 13000)/(0.150 x 14,500)
BMEP = 520,000/2,175
BMEP = 239 psi for a FXR150 drag bike, that dosn't look impossible with a diet of meth and dash of nitro.

A better head, normally aspirated and 16,500 rpm still requires a BMEP of 210 so definatly a 37 rwhp FXR150 has to have chemical help like crazy man said or be bigger than 150cc.

See Dave, the BMEP concept is great for checking stuff out.

I posted this information about the BMEP concept in the true spirit of sharing and friendship

and the desire to depress the FXR boys before the GP at Taupo .... :D

[husaberg]

Neels sent me a drawing of a TZ350F pipe he measured, but I also got a drawing from Bod Haldane ( Yamaha Factory ) and there are several quite big differences.
I will just have to measure a set for myself.
Bugger.


Looks like i need glasses 350 aye i will have another look.

this book has it i don't have this book but someone will
http://www.tz350.net/images/booksvids/final_front_cover_on_printed_books.jpg
An extensive 350 page study of all Yamaha’s TD, TR, TA and TZ racers produced between 1959 and 1982.
125, 250, 350, 500, 700 and 750cc capacities, all models.
All changes between the models.
Over 200 b&w photos of bikes, components etc.
Portmaps and exhaust diagrams.
Full specification lists.
What each is like to own and ride.
Problems encountered with each model.
Serial number limits for every model.
How to identify each model from the others.
Plus a lot more!

http://www.tz350.net/yamaha_two_stroke_production_roadracing_motorcycle s.htm

[marsheng]

I read somewhere that the Honda 2 litre (2000S) cars have the same performance as an F1 car. What ??

Take Honda's HP as stated, scale the figure by the engine size ratios and then by the RPM ratios and you get a figure roughly what the F1 makes.

Ok Lets see, Honda says 247 hp at 8300. (2002 figures)

Volume conversion 3000/2000 * 247 = 370 hp (2002 was a 3 Litre F1 engine)
RPM conversion 18000/8300 * 370 = 804 hp ---- Not far of an F1 car in 2002. (PS BMW's did 19200 RPM)

BEMP does not lie !!

[TZ350]

I read somewhere that the Honda 2 litre (2000S) cars have the same performance as an F1 car. What ??

Take Honda's HP as stated, scale the figure by the engine size ratios and then by the RPM ratios and you get a figure roughly what the F1 makes.

Ok Lets see, Honda says 247 hp at 8300. (2002 figures)

Volume conversion 3000/2000 * 247 = 370 hp (2002 was a 3 Litre F1 engine)
RPM conversion 18000/8300 * 370 = 804 hp ---- Not far of an F1 car in 2002. (PS BMW's did 19200 RPM)

BEMP does not lie !!

Yep BMEP does not lie !!!

The 1999 S2000 is little behind the tuned FXR150's, BMEP is a great tool for compairing engines and possibilities.

259700

BMEP for the 1999 2L Honda making 237 crank hp at 8,3000 rpm

4-Stroke BMEP = (HP x 13000)/(L x RPM)

BMEP = (237 x 13000)/(2 x 8,300)

BMEP = 3,081,000/16,600

BMEP = 186 psi for the 1999 2000S Honda

259701259699

Honda S2000

Graham Bell tries out Honda's recently revised roadster.

Designed by some of the engineers behind Honda's winning F1 and CART engines, the S2000's two litre DOHC straight four (a configuration chosen for compactness) boasts such race-bred features as roller rockers, forged shallow skirt pistons, ladder frame main bearing stiffener and fibre reinforced aluminium for the cylinders. It's also smaller and lighter than Honda's regular two litre engine, and at 237bhp sets a new record for highest specific output for a normally aspirated production car engine.

Of course without some form of forced induction, getting such high power outputs from just two litres requires high revs, which in turn requires cams with high lift and long duration to provide sufficient valve opening to allow the engine to draw in large amounts of air/fuel mix. Great at high revs but crap at low revs, which is a real problem for a road car - or would be without Honda's ingenious VTEC system, which works by literally having two camshafts in one, with three cams (two mild ones sandwiching a central wild one) for each pair of valves.

http://www.pistonheads.com/doc.asp?c=120&i=5155

[Buckets4Me]

BMEP for a 2L Honda making 247 crank hp at 8,3000 rpm

4-Stroke BMEP = (HP x 13000)/(L x RPM)

BMEP = (247 x 13000)/(2 x 8,300)

BMEP = 3,211,000/16,600

BMEP = 193 psi for the 2000S Honda

Interesting, this requires more looking into.

the big question is did the JAP tuners make anymore H/P from the little 2000s ? or is that about all it can make

[Grumph]

If you're going to take 2 litre four strokes for comparison, at least take some well developed examples.
To be competitive in British touring car champs and european 2 liter, in excess of 300 bhp is needed....
This is achieved without Honda's tricky dicky cams.

Four stroke development in F4 will continue I'm sure. Injection must become more common too.
I had a set of 1098 Duc heads here a while back and there's no way in the world they could be run on carbs.
Carbs require a minimum air speed to work - with ports that big the air speed drops out of a carb's comfort zone but injection vaporises the fuel for you regardless of air speed.
Then there's the multi cylinder approach...and revs....

[husaberg]

Putting a new piston in a 50cc at the moment (okay its a scooter)... Idea's on getting the 10mm (im guessing) piston circlips in, bloody tiny little things anything bigger is piss easy. They are the open type, can't really use circlip pliers. Any hints?

At the time i answered with a wee touch of sarcasm (yes it is the lowest form of wit but you should play to your strengths.)

Anyhow i did see this today never seen it before but here it is.
http://www.accu-products.com/images/uploads/c-clipper.jpg

Product Information
Two Stroke Model - Plain Sleeve Type

Piston Pin Circlip Installation The Easier Way. The C-Clipper takes all the drudgery out of this job. No more fiddling with long nose pliers and little screwdrivers and retrieving dropped Circlips from inside the crankcase. One push and your done in less than 15 seconds a side every time.

Trust us, you will not want to do another rebuild without it.

Available for most two-stroke engines
http://www.accu-products.com/images/uploads/ps_c-clipper_t.jpg
http://www.accu-products.com/images/uploads/ps_c-clipper_d.jpg
Price: $43.50
http://www.accu-products.com/accu-products-specialties/c-clipper-circlip-installation-tool-2-stroke-model/prod_3288.html
The observant amongst you will not he has no rag stuffed down the crankcase.
Can't imagine it would be that hard to knock up one if you were so inclined of course it no doubt has a patent so you should ask for their approval first.:innocent:

OH yeah the hp calculations you guys are using f1 car engines:yawn:
Have a look at the real high HP engines like Drag cars would ya.:corn:
http://www.nhra.com/nhra101/classes.aspx

[koba]

Trust us, you will not want to do another rebuild without it.


That looks like one of those TV infomercials where they make a simple task like vacuuming seem such a chore you MUST try this new product that will make life sooo much easier.

[twotempi]

I think this is correct but others may know otherwise

With patent law you can copy one for your own use BUT not permitted to reproduce for resale.

How you deal with making one for a mate is another matter................ ??

[richban]

Four stroke development in F4 will continue I'm sure. Injection must become more common too.


Yep watching Moto3 with interest. If we could only make 200ph per litre. We might be able to keep up with the jones.

TZ you should go for broke. Tune that thing to the max. I here they run really good lean and hot. I will be bolting my engine in at the track at this stage.

[TZ350]

TZ you should go for broke. Tune that thing to the max. I here they run really good lean and hot.

Hot and bothered, year right ... :bleh: ...... only two weeks to go, I am looking forward to catching up, see you there.

[richban]

Hot and bothered, year right ... :bleh: ...... only two weeks to go, I am looking forward to catching up, see you there.


Yeah seems like we did this only a few month's ago.

[husaberg]

I think this is correct but others may know otherwise

With patent law you can copy one for your own use BUT not permitted to reproduce for resale.

How you deal with making one for a mate is another matter................ ??


with patent law no no no no you can't. I think.
A guy did that in the south island with a rotary cowshed he lost. He had copied a plan and the novel method of locating the platform on Bearing's rather than pedestal rollers or a round track with wheels it had kind of like a ball race only with Nylon balls located in a concrete groove cast into the platform the original designer was from Murchison and he did the legal challenge thing.
The shed was i think a self build in the Waitaki basin or there about's i think.(Having said that it was used in a commercial sense so who knows)
Rotary cowsheds like most great farming ideas was invented here in good old NZ. (The old Dutch are a bit behind on those such things):bye:

Although i don't see a patent number or copyright any where there in the add.

That looks like one of those TV infomercials where they make a simple task like vacuuming seem such a chore you MUST try this new product that will make life sooo much easier.

And yeah with you Koba that's why i said to stuff a rag in the case. But then again i don't have sausage fingers or 10mm gudgeon's either.
ps the misses say's vacuuming is hard work. i will have take her word for it. Just like the whole Baby birth labour thing is so painful stuff. How would I know:violin:

Having said that my articles I post er.....oh..... they are credited at least to the publisher and in most case the author i guess.:innocent:

[kel]

TZ you should go for broke. Tune that thing to the max.

Do it chief, Wobbly pipe and all! We should insist Wob orders another run of these shirts and brings them to Taupo.
"YOU'RE BEHIND ME COS I'VE GOT A WOBBLYPIPE - I had 50 of these T shirts to give to World and National Championship winners , sorry all gone"
:Punk:

Rich, make sure you leave the pin in that hand grenade this time

[speedpro]

I will be bolting my engine in at the track at this stage.

I'm thinking one "before" and one "after".

You should check if Dzus do engine bolts, could be useful.

Some sort of explosion containment system could be a good idea so you don't get any more . . . . "popular" :whistle:

[richban]

Some sort of explosion containment system could be a good idea so you don't get any more . . . . "popular" :whistle:

Dude I am super popular. Got invited to a Tupperware party the other day. Good stuff I tell yah. I am sorry about causing you pain with the oil spill. My wallet is suffering as well.

[speedpro]

Shit happens. I'm nearly over it.

[husaberg]

Dude I am super popular. Got invited to a Tupperware party the other day. Good stuff I tell yah. I am sorry about causing you pain with the oil spill. My wallet is suffering as well.


Reading between the lines rather than the results
Was there an engine incontinence incident.
From what i understand it is common oversea's as far back as the mid 90's for un house trained 4 stokes to be made to Wear "Diapers" (IE belly catch tanks)
Shame yo hear though, again as well Rich.
is the carb and new piston ok?

Oh yeah how many engines does Rich have to disembowel before he is classified as a serial killer, or is in Euthanasia:shit:

[F5 Dave]

Do you not venture far out of this thread?? Try looking at his Autopsy thread.

[breezy]

One thing I completely disagree with in the piston seizure write up is that air leaks cause a lean condition.
This is utter bollocks, any engine with a case leak will run richer, the bigger the leak the richer it will run.
Caused by the fact that the case "pump" no longer works and the fuel air mixture isnt being transferred thru the ducts.
If the engine is then leaned up to "fix" the incorrect mixture - then it seizes.

wobbly, are there any benifits in being able to control air into the crankcase, with this richening phenomenon.

[Holeshot]

Please help me find detailed information about the effects of wristpin offset

[mr bucketracer]

all these year later and i still see this floating around lol

[marsheng]

Busy rebuilding a T250. I'm battling for tuning info on these. I'm making it std to start with but wanted to know what are the next steps. An upgrade from the 2 transfer ports would be good. Any later models with more ports that are interchangeable would be good.

Maybe a slot in the cylinder to create a boost port could be an option.

Lastly any recommendations on which other older 2 stroke forums are worth looking at. I've looked at dozens but not very informative. Lots of individuals have posting of mods.

PS My motors were 1st 3rd and 4th in the BOB and I can't remember if I worked on 2nd or not. What pity we had no North Islanders there. Scaredy cats !!!

Cheers Wallace

[Michael Moore]

Wallace, I think X6/T20/T250s often get filled with Yamaha rods/bearings/pistons, so you might look there. I think with the TD3 they went to square b/s from the 56/50 of the earlier bikes.

cheers,
Michael

[Grumph]

Wallace, I think X6/T20/T250s often get filled with Yamaha rods/bearings/pistons, so you might look there. I think with the TD3 they went to square b/s from the 56/50 of the earlier bikes.

cheers,
Michael

Yes, TD3 is 54X54 - I've already told him that Mike Sinclair won a NZ250 title with TD3 barrels on his T20....
The one he's working on should be left pretty stock IMO. Owner is a social racer....

[gearhonest]

I think Uniflow was suggesting that at very high rpm - the engine (https://gearhonest.com/2-stroke-vs-4-stroke-dirt-bike/) was running harmonically.. all in 'continuous flow'..

[Roflhat]

Bit of a bump for this old thread but!

I'm building a GP100 to take to Bonneville, only going for production records so no big changes. Basically the bike has to appear standard and have the standard venturi size. Other than that you can get away with changing internal parts. Currently I've got a sort of expansion chamber welded into the standard exhaust, barrel ported, rotary valve cut to gp125 spec, standard carb bellmouthed instead of the standard shape. Got a thin spacer under the barrel, barrel skimmed and o ringed.

Went from 9.6rwhp to around 13.6, have done a couple mods since but would love to get more out of it
https://iili.io/7XD8js.md.jpg (https://freeimage.host/i/7XD8js)
https://iili.io/7XDvun.md.jpg (https://freeimage.host/i/7XDvun)