RE: Spitfire 1500 engines

[lmdpth@lmd.ericsson.se (LMD/T/TB Peter Thorsen)]

> Does this mean that if the bore is bigger than the stroke by a significant
> amount it will rev it's nuts off.....:-)

The longer the stroke the faster the pistonhead will move inside the
cylinder at the same rpm (It has to cover a longer distance in the same time)
The lubrication of the cylinder walls will be reduced when the piston head
moves too fast relative to the walls so a longer stroke will usually mean
that the max revolutions has to be reduced, meaning lower power than if they
were not.

In Europe the Spitfire 1300 engine delivers 75 hp at 6000 rpm while
the 1500 delivers 71 hp at 5500 rpm (but a better torque). How much of that
reduction in power is attributable to the bigger bearings I don't know.

 - Peter