[Mgs] Stoked.. err stroked!

[Richard Gosling]

 Stroking an engine limits the useable rev range because increasing the
stroke increases the speed the piston has to travel to get from the top of
its travel to the bottom at a given rpm.  As you increase the piston speed,
the flame front of the explosion has more trouble keeping up with it, so
reduces the pressure the explosion can exert on the top of the piston.

Increasing the bore has no effect on piston speeds, allowing higher rpms to
be maintained.  The only downside is a heavier piston, which engine
designers need to allow for when considering the loads that will be carried
by the conrod and bearings.

This is why screaming F1 engines are seriously over-square.  The Ferrari
F2008 is apparently 98mm bore, 38.9mm stroke - that's right, about one and a
half inches stroke!

Richard & Sammy ('73 Black Tulip BGT)