Originally Posted by
Roelof
How further the crankpin is located from the center the more force you can create on the output w/o needing more combustion power. I also believe the larger movement of the piston will make the pump to suck up the mixture a little bit better.
More torque is not only about the stroke, it is more about the height and width of the exhaust port together with how much fuel you can burn. The longer the combustion stroke is before the exhaust opens the more power it has. The same is with the barrel of a gun.
Looking at F1, more power comes from more combustions per seccond, to reach that a short stroke engine is needed due the physical speed limitations of the pistons and lubrication.
As Picco has succes with their extra long stroke engines Novarossi did not do well with their xtra long stroke Keep-on and Mito models as their current topmodel is the normal long stroke 35WC.
Longer strokes do not have to be better als also with the amount of ports. It is more about timings, dimensions and materials to make a good engine.
I believe it's be been tested a lot of times over the years, and what a long stroke gains in leverage it looses in piston surface and vise versa.
It is however possible that there is small gains in decreasing the radial burn distance as the rpm goes up.
But as you mention, there is so many more things that influence the outcome that looking at just a couple of things isn't giving the whole picture.
