ESE's works engine tuner

[jonny quest]

Those are some high transfers Swepatrick

[Flettner]

Thanks, very nice.
Interesting, how flow restrictions, at partly opened black parts, influence engine performace before full throttle.
Maybe, would be some difficulties with jetting at partly opened throttle ( if not with EFI )

this one will run TPI mark two. Ulitamatly designed with these Gibs (black things)being controlled by the ECU.
Twist grip just tells the ECU what the rider wants. ECU tells the engine room what to do.
This cable (toothed belt) opperation is just to get the bike up and running.

[jbiplane]

A question

Recently JPX paramotor change exhaust system.
Now it become lighter, quiter...


Before it was more classical


Any idea of internals?

[katinas]

this one will run TPI mark two. Ulitamatly designed with these Gibs (black things)being controlled by the ECU.
Twist grip just tells the ECU what the rider wants. ECU tells the engine room what to do.
This cable (toothed belt) opperation is just to get the bike up and running.

Thank you, I need adjust my old thinking.

Add pic of modified crank for testing with one cylinder on NS 250 crankcase.

[SwePatrick]

Those are some high transfers Swepatrick

Yes, i know.
But this isn´t a cruiser

[Frits Overmars]

Yes, to be exact 4.574 total degree on the diam. It´s a dragracing pipe to be used with methanol, and the taper is 2.287 on the radius. I have tried milder tapering also, but it seems like the cylinder want quite big diameters on 1st and 2nd diffuser.
If i make those two a little bit smaller in diam, i loose power and the powercurve becomes very 'peaky'. The timings is 134/134/134/196
And it seems happy with 15 degree advance at peak power, this with 10.57-1 i compressionratio and 1.28 in crankhouse compressionratio.

Aha, the methanol may explain the short pipe and the small need for ignition advance because of a low EGT. But since you mentioned a Minarelli base engine, I assumed that an 98 cc version would have a short stroke and a big bore, which would not help blowdown angle.area. The 134° transfer timing won't help either, but it does lower the Helmholtz frequency quite a bit when the crankcase volume is coupled to the cylinder volume at such an early stage in the cycle. So that may explain the preference of the engine for big pipe diameters.

I based my guesswork on an assumed 39,7 mm stroke, 56 mm bore, 130°/198° port timings, 15:1 compression ratio and max.power at 12500 rpm. How far was I off?

[fpayart]

It is a shame I am sure if he could put his ego aside I am sure he could have contributed something useful but LucF was bined for repeated abuse of forum members and attempting to derail a fine technical thread by repeated trolling of other members.
If he attempt to return under a new pseudonym he will be binned again.
KB is lucky to have overseas legends such as Jan Thiel and Frits Overmars posting as well as other occasional posters such as Francis Payart and Neels van Niekerk.

Hello everyone,

Thank you Husaberg for having a thought for me.
Francis PAYART is not very diligent as a contributor to your incredible forum.
By cons, I read regularly and I appreciate a lot of your posts.

Regarding LucF, it's a shame he did not know how to moderate himself, I appreciate his work, I think he still had a lot to share.
This forum is not the place for disputes between people.

For my part, I have a lot of work, especially with a new project of a new complete bike.
We are fortunate in France to still be able to participate in specific races with two-stroke 250cc Grand Prix motorcycles.
Since last year, we participate with two prototypes equipped with Superkart FPE engine.
One from an Aprilia RS250 road chassis and the other from an Aprilia RS125 road chassis.
The experience is encouraging enough that I decide to re-design a new, more compact engine, better suited to the bike.

Some information and pictures:
http://forum.2temps.fr/viewtopic.php?f=8&t=16752
http://forum.2temps.fr/viewtopic.php?f=8&t=17577
http://www.pit-lane.biz/t875p450-tec...-fpe-superkart

[TZ350]

Finaly got the Dyno up and running again in its new home.



Ok its not a 2T but I spent a very enjoyable afternoon helping with Mikes impressive #6 Turbo EFI Bucket project.

[TZ350]

Some information and pictures:
http://forum.2temps.fr/viewtopic.php?f=8&t=16752
http://forum.2temps.fr/viewtopic.php?f=8&t=17577
http://www.pit-lane.biz/t875p450-tec...-fpe-superkart

Thanks Francis, very interesting, very impressive work.

[katinas]

Francis, very interesting.

One question about RS 125 road chassis. I always be little bit skeptical about street RS 125 cast (maybe not strongest casting alloy) frame beams and swing arm, with ribbed/opened inner side. How this frame perform during the race conditions. Is some flaws with this chassis especially with more powerful engine?
Thanks

[fpayart]

The bike has been modified quite deeply, fork, 250GP wheels with real tires, brakes, but the ribbed beam remains original. For the moment the only fault that can be blamed on him is his weight.
The bike is now quite light, 117kg, should be modify the rocker arm which does not permit the mounting of an effective shock absorber.
We were at the Paul Ricard circuit, last weekend, for the first race of the season, it was the first time that the bike was rolling with its big wheels, the driver is delighted, he found a huge difference in efficiency.
We made good progress in engine and chassis settings, 240kmh at 13200 rpm, in the straight line.
Alas the LIPO battery decided to die during the race...

[Frits Overmars]

... I have a lot of work, especially with a new project of a new complete bike.
We are fortunate in France to still be able to participate in specific races with two-stroke 250cc Grand Prix motorcycles.
Since last year, we participate with two prototypes equipped with Superkart FPE engine.
One from an Aprilia RS250 road chassis and the other from an Aprilia RS125 road chassis.
The experience is encouraging enough that I decide to re-design a new, more compact engine, better suited to the bike.

Some information and pictures:
http://forum.2temps.fr/viewtopic.php?f=8&t=16752
http://forum.2temps.fr/viewtopic.php?f=8&t=17577
http://www.pit-lane.biz/t875p450-tec...-fpe-superkart

Bonjour Francis, comment ça va?
I very much like the idea of an FPE-JBB .
I noticed that the JBB-frame below is shown in its usual way but the FPE-engine is mirrored, although the lettering on the cylinders is not...

[fpayart]

Hello Frits,
Thank you, I'm fine, I'm getting old a little too fast in my opinion.
You're right, it's not a photo montage, it's a complete new engine, I wanted to get closer to the usual configuration for most motorcycles, chain left.
All the study and the drawings are finished, I'm in the manufacturing phase.
I'm sure you'll notice all kinds of interesting details

[katinas]

Hello Frits,
Thank you, I'm fine, I'm getting old a little too fast in my opinion.
You're right, it's not a photo montage, it's a complete new engine, I wanted to get closer to the usual configuration for most motorcycles, chain left.
All the study and the drawings are finished, I'm in the manufacturing phase.
I'm sure you'll notice all kinds of interesting details

Francis, this things made life much, much brighter, I am SO enjoy of your work.
Some time ago, when I look for non telescopic front end, found that this concept is the best from all non telescopic concepts ( strength/weigh, forces distribution, wheel turning). If I remember correctly, it was ATOMO project with Suzuki TL 1000 engine. But this - with 2 stroke 250cc engine - simply amazing, real dream.
Thank you again and meilleurs voeux.

[SwePatrick]

Aha, the methanol may explain the short pipe and the small need for ignition advance because of a low EGT. But since you mentioned a Minarelli base engine, I assumed that an 98 cc version would have a short stroke and a big bore, which would not help blowdown angle.area. The 134° transfer timing won't help either, but it does lower the Helmholtz frequency quite a bit when the crankcase volume is coupled to the cylinder volume at such an early stage in the cycle. So that may explain the preference of the engine for big pipe diameters.

I based my guesswork on an assumed 39,7 mm stroke, 56 mm bore, 130°/198° port timings, 15:1 compression ratio and max.power at 12500 rpm. How far was I off?

It is actually 52mm bore and 46mm stroke.
But still very 'over square' so your guess isn´t totally wrong =)
Compression is dead on 15-1 in total compression.
MOTA says power peak is at 13800rpm, but i have found that MOTA often reports higher rpm than real world.
MOTA also says 40.8 peak power on methanol.

My friend is building the pipe this weekend, so we might soon get an answer if it works =)