oversquare. if the bore is 3 the stroke may be only 1.5. this allows the high rpm.

on the desmo valves, a little more detail: the cam has an extra lobe next to the one that opens the valve. there is a lever that attaches to the top of the valve somehow and the second lobe closes the valve positively. this stops valve float.

this was used as late as the fifites on the mb f1 engines. also ducati motor cycles have them to this day, i think. it is still a good system.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.