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Unless I espect that he will be ready very soon, because he wrote in february Croatia, Trogir Date d’inscription: Institute of TwoStrokes Nombre de messages: MOTA n est un simulateur tres precis: Can you show us a picture of a “turbo-crank”, Howard? The first time Frits shows his idea, which I already did one month before.

But maybe the spark did not ignite the mixture anymore.

Marc Admin Nombre de messages: Page 13 sur I am almost certain that somewhere on this forum I already posted a simple exhaust concept that included the venturi calculation. Read below how it all started.

Bucket Racing Fabrication

The result was a good running Kreidler with the same performance as a good running RS with 6. That is why I thought that someone else already did the fritss in the past.

Those Firts coils gave 0,3HP more per cylinder than the Krober coils, and eliminated misfiring. By the way, has anybody had already a look at Yoshimure’s MJN carb? Now we have experienced that the opposite is true, and a lot of motocross riders would love to have their two-strokes back If I would write in French, nobody would understand. So I drilled 18 exhaust holes above the intakes. Then it varies per crank degree during each engine revolution. When designing the motor’ is a square over,ars bore vs stroke the ideal or do you think slightly over square longer stroke than bore is better?


You might get some totally new ideas that I never thought of Need I say more, Bob? So far I have only seen a cylinder at the bottom with 2 exhausts, because the porting I do not see.

Bucket Racing Fabrication

It was the design of a briljant engineer of the Technical University Fritx by the name of Wout Boer. Page 9 sur Il y a en tout 30 utilisateurs en ligne:: Maybe a pair of Lectrons? But it can be microscopic or macroscopic, and that makes a lot of difference.

If so, what would be an raw estimate of the thrust produced, let’s say on a GP machine? Tuesday, January 10, Want to build a custom expansion chamber?

What an engine will tolerate, depends for a large part on its cooling. Il y frlts en tout 30 utilisateurs en ligne:: The coil is indeed an oil-filled Bosch unit, developed for Porsche. So if non-ethanol fuel is used I think this epoxy would work great for any kind of porting projects. You will also have Frits on board with you. I do not know the answer to this question, because I never tried this! I do not expect my overkars to be fully developed in time for the cc GP-season ofand it will certainly not be allowed to make the cc four-strokes look overmads inso there is no need for secrecy anymore.

Frits Overmars Expansion Chamber aka FOS exhaust concept

And what about those engines in the 20’s. Since the exit is pointing rearward anyway, that is some help, but nothing to write home about. The best result was 17,5 HP. In a racing car 4 strocker.


So if you have a crankshaft with a 40 mm stroke and a 16 mm big end pin, the web diameter should be at least 72 mm. Makes me so sad he isn’t around anymore.

Ofcourse many people doubted if this new system would work. But according to the abovementioned I suppose I was wrong. Or is it about the fuel needing to be compressed higher, in order to release the energy?

Hi Jan overmats Bob I accept that it may be difficult to match track conditions but my thoughts were, Set the motor to bottom of the start of the power range, Start with a low ignition advance, say 14 deg Set a load and get the bike stabled. I have to admit that Frits Overmars gave me the push to do it, otherwise I would have it only in my head, as he did for about 30 years.

If I did another one I would incorporate a downslope roof for the exhaust ports, upslope for the roof of the transfer ports plus more current eg Aprilia RSA port timings with exhausts to suit. What is trapped compression ratio? I’ve always viewed multi-stage diffusers as an approximation to an exponential horn, which gives an equal proportion of energy returned per unit time.