Bore & Stroke

[gld]

What is the wildest combination of bore & stroke you have seen in a running model engine???????

[darryl]

I don't know about a model engine, but I think it was Honda that made a short stroke engine. It had oval pistons and revved like crazy. I thought that was kind of wild-

[Bented]

I don't know about a model engine, but I think it was Honda that made a short stroke engine. It had oval pistons and revved like crazy. I thought that was kind of wild-

Rule evasion by Honda.
FIM rules at the time limited engines to 4 combustion chambers, Honda built the NR, essentially a V-8 with 4 oval cylinders and 8 connecting rods and 8 valves per cylinder, however still considered a 4 cylinder engine by the rules.

[Paul Alciatore]

FIM?

Not all of us are motorcycle fans so I had to look it up. "Fédération Internationale de Motocyclisme (FIM; English: International Motorcycling Federation)" as per Wikipedia

https://en.wikipedia.org/wiki/F%C3%A9d%C3%A9ration_Internationale_de_Motocyclisme

Rule evasion by Honda.
FIM rules at the time limited engines to 4 combustion chambers, Honda built the NR, essentially a V-8 with 4 oval cylinders and 8 connecting rods and 8 valves per cylinder, however still considered a 4 cylinder engine by the rules.

[Bented]

The French dearly love Organizing Things

FIFA (Soccer), FIA (Formula 1 motor racing) UCI (Bicycle Racing) as examples.

[darryl]

I apologize if I sent this thread on a tangent. I am intrigued by gld's question. I was at one point going to build a 'diaphragm' engine, basically an air motor which would have had a 'bore' to stroke ratio of 4 or 5. I never did build it. I found the concept interesting though.