ESE's works engine tuner

[porttiming124]

Condyn , I have a stock YZ250 pack from years ago - PM me with your email.

Hello Woobly.
Could I have a copy of the yz 250 pack please?
I sent you a PM with my email
thank you

[Flettner]

what is this. ktm put one injecter to the rear now it seems

I think that is the crankcase pressure sensor? Or a sensor of some sort.

[wobbly]

The R1 reed curtain area is capable of 56Hp crank , so is close to the limit now we are making 50.8 Hp sprocket - and the reed port area is equivalent to 41.7mm dia.
But it would in reality probably support 55Hp sprocket as the possible extra air flow and thus column inertia from a big ( 42mm ) carb would simply hold the petals open longer.
The next R2 is in CAD as we speak , so the R1 NDA is probably redundant at the end of this years homologation.
But the pipe design is around 40mm too short , due to the non retarding ignition curve , to keep peak power at 13800.
PM me for the 3D model port cores at Xmas time , but send a case of Opus One first , as a gift of course.

[wobbly]

Marc Marcelet has for sale a complete TFX engine real time data analysis setup.
It is here on FarceBook - https://www.facebook.com/groups/6710...4251020988364/
This was used to analyze a Vortex KF kart engine to help Neels refine the sim correlation to dyno data.
Contact me or Vortex on here if interested.

[Frits Overmars]

I think that is the crankcase pressure sensor? Or a sensor of some sort.

You'd almost think they've given up TPI and switch to a cheaper system, maybe because TPI could not be made clean enough for the Euro 7 demands?

[husaberg]

Interestingly all the engines 125-300 all use the same size throttle body......i could understand with a carb, but atomization shouldn't be an issue?

[husaberg]

.
Yea , but exactly the same amount of effort to build a 55Hp 125 cylinder as it is to build a 45 Hp one.

I totally disagree Wayne , nowhere near the same amount of effort was expended, these were brought off the shelf as opposed to being made.
Whilst i am sure to you and some other used to the finest and best. A 55 HP 125 sounds awesome and is the only option, as there is no class to race it in its a pretty limited market to sell to as 125 racing is deceased.

A 55 hp or 110hp 250 or 200hp plus 500 sure sounds great.but 2 stroke gp racing has unfortunately died.
i have no interst in superkarts or the pointy end of other karts
A 55hp 125 will also wear twice to 4x as fast as a 45-90twin -180 four hp and cost 4 times as much to maintain, hence that already tiny market just Shrunk further
Whereas a 90 HP RGV is a bit wider market (but still a tiny market) as is, the NZ bucket market or any other 2t market.
if someone wants something better, sure as shit they can modify them or spend 20 times or as you said a great stack of cash as much for something better.


Neil was awesome enough to offer to cast some cylinders so people could have some cheap cylinders to experiment with.
the first batch will be material cost plus whatever Neils costs are plus $100.
Personally see as the 2t world is so small and is shrinking daily i would have honestly expected a bit more support from a fellow kiwi.


That said i feel pretty confident it will give more hp than a Ryger.

[Flettner]

I totally disagree Wayne , nowhere near the same amount of effort was expended, these were brought off the shelf as opposed to being made.
Whilst i am sure to you and some other used to the finest and best. A 55 HP 125 sounds awesome and is the only option, as there is no class to race it in its a pretty limited market to sell to as 125 racing is deceased.

A 55 hp or 110hp 250 or 200hp plus 500 sure sounds great.but 2 stroke gp racing has unfortunately died.
i have no interst in superkarts or the pointy end of other karts
A 55hp 125 will also wear twice to 4x as fast as a 45-90twin -180 four hp and cost 4 times as much to maintain, hence that already tiny market just Shrunk further
Whereas a 90 HP RGV is a bit wider market (but still a tiny market) as is, the NZ bucket market or any other 2t market.
if someone wants something better, sure as shit they can modify them or spend 20 times or as you said a great stack of cash as much for something better.


Neil was awesome enough to offer to cast some cylinders so people could have some cheap cylinders to experiment with.
the first batch will be material cost plus whatever Neils costs are plus $100.
Personally see as the 2t world is so small and is shrinking daily i would have honestly expected a bit more support from a fellow kiwi.


That said i feel pretty confident it will give more hp than a Ryger.

Just how things roll, I guess.

[wobbly]

Real issue as i see it is that you are already behind the 8 ball.
The RGV type engine is 50.6 stroke by 56 bore and the patterns you have are for a 54 square.
Are you going to do all the calcs required to put all the ports in the correct place , as no matter what you do with jacking the new barrel up or down
then BDC is compromised as is the blowdown STA , the most important number in any engine.

Thus as this old Aprilia technology needs some pretty serious work to get it somewhere near right for an RGV application, I thought you might as well go ahead and update it to the later
spec as all the drawings are available on line.
And now we have TeeZee wanting something for a 110cc bucket and Neil wants 60 odd square - none of which are even close to what you have.

Maybe not as supportive as you would have expected , sorry , but realistic imho.

[Flettner]

Im no expert on twostroke development, far from it but what I do (and like) is the challange of manufactering cylinders, vairable rotary valve covers, fuel injection systems etc. Most times these parts will be not up to 'modern' spec, just how I see it.
Although I do 'look, listen and learn' my next lot of cylinders will be further up the spec range.

My first loop scavenge cylinder patterns, the 360, were designed and built 15 years ago, more intetested in just being able to cast my own at home. All they had to be was better than an F9 cylinder, I think they are.

I muddle along, I know my place.

We appreciate your free knowledge Wobbly and we do listen and learn.

[Muhr]

The next R2 is in CAD as we speak , so the R1 NDA is probably redundant at the end of this years homologation.
But the pipe design is around 40mm too short , due to the non retarding ignition curve , to keep peak power at 13800.
PM me for the 3D model port cores at Xmas time , but send a case of Opus One first , as a gift of course.

Real issue as i see it is that you are already behind the 8 ball.
The RGV type engine is 50.6 stroke by 56 bore and the patterns you have are for a 54 square.
Are you going to do all the calcs required to put all the ports in the correct place , as no matter what you do with jacking the new barrel up or down
then BDC is compromised as is the blowdown STA , the most important number in any engine.

Thus as this old Aprilia technology needs some pretty serious work to get it somewhere near right for an RGV application, I thought you might as well go ahead and update it to the later
spec as all the drawings are available on line.
And now we have TeeZee wanting something for a 110cc bucket and Neil wants 60 odd square - none of which are even close to what you have.

Maybe not as supportive as you would have expected , sorry , but realistic imho.

Is not that the case regardless of which cylinder they choose? TM does not look easier to change the bore and stroke.
What did you mean by 40mm to short pipe, is this the next one (r2) you are referring to?

[wobbly]

Muhr - The reference to the pipe length was that Ken asked about fitting a big ( 42mm ) carb and a proper ignition to the R1 for use in a road racing scenario.
If a modern ignition is fitted to the TM engine then all the development work done on the R1 pipe is out the window as its TL from the piston is around 760.
Whereas the 125 race pipes when fitted with a retarding ignition are around TL = 800 ( Aprilia - Honda A kit ) - simply due to the fact that with retard in the ignition the pipe average temp rises dramatically
with rpm , thus needing a 40mm longer pipe to keep peak Hp in the correct place.
The Aprilia made peak power at 13,000 and was not reved much to 14500 - The R1 makes peak power at 13800 and is reved to 14800 all day in karts , too high for any reliability when used
on a normal road racing circuit.

[husaberg]

There are aftermarket 54mm cranks made for the RGV but they are a little spendy for most

RG250 vs RGv250 crank.
The RG250 was the earlier case reed parallel twin with a 54mm stroke.
credit goes to Vincent crabtree for all the grunt work

The crank center needs modifying from 2 main bearings to 1 so machining down with a nice wide roller bearing from a TZ350.
The other dimensions are identical.

https://www.kiwibiker.co.nz/forums/s...post1131048706

https://www.kiwibiker.co.nz/forums/s...post1130586696

Pretty sure the RGV gearbox would be a bit iffy with 90 HP let alone 110hp

[jato]

Gearbox could be driven by a pair of straight-cut primary drive gears with a higher ratio - easier life for the gearbox and clutch plus no more side loading. relatively easy(ish) to build too so long as there is enough room for the bigger crank gear

[Muhr]

Muhr - The reference to the pipe length was that Ken asked about fitting a big ( 42mm ) carb and a proper ignition to the R1 for use in a road racing scenario.
If a modern ignition is fitted to the TM engine then all the development work done on the R1 pipe is out the window as its TL from the piston is around 760.
Whereas the 125 race pipes when fitted with a retarding ignition are around TL = 800 ( Aprilia - Honda A kit ) - simply due to the fact that with retard in the ignition the pipe average temp rises dramatically
with rpm , thus needing a 40mm longer pipe to keep peak Hp in the correct place.
The Aprilia made peak power at 13,000 and was not reved much to 14500 - The R1 makes peak power at 13800 and is reved to 14800 all day in karts , too high for any reliability when used
on a normal road racing circuit.

OK I understand!

I had imagined that the RSA was at 780 and 202 degrees. so average temp about 575m / s