"cavelamb himself" wrote in message
...
John Halpenny wrote:
On Dec 20, 12:03 am, cavelamb himself wrote:
snip

But that all assumes you are going to use it direct drive - which almost
nobody does. If you use a gearbox, belt PSRU, or HiVo chain PSRU, they
will
all give you an offset of several inches, making for the same center of
gravity without the other changes, and allowing for much greater power,
because engine RPM's can be run much higher for the same prop RPM.

And what does all that do to 1) weight and 2) CG ???


1) A PSRU gives a smaller faster engine, which is usually lighter even
with the weight of the reduction gear.
2) Raising the output shaft several inches is the same as lowering the
CG, and the bulk of the engine that spoils your view, the same amount.

John halpenny



Not necessarily.

Starting with a V8 (or any other given engine) doesnt make the engine
smaller...


This only works for an engine "designer"...

Very true, and perfectly describes the difficulty of this sort of
discussion.

Peter