On May 15, 4:11 pm, wrote:
On May 15, 10:02 am, Newps wrote:

The engine is not designed to turn in a specific direction. Some
accessories are, such as mags, vacuum pumps, starter, alternator. The
engine itself will happily run in the other direction, several twins do
just that.

That backward-running engine has a different camshaft, mags and
oil pump to allow it to run that way. Engines won't run backwards just
because we try to start them backwards. The intake/compression/power/
exhaust strokes MUST happen in that order, and a backward-turned
engine has them all messed up.

Dan

Forgot to mention: an alternator generates just fine when run
backwards. I did it on an inboard boat I built, because there was no
room in that tight compartment for the alternator to sit alonside the
engine in its usual spot and had to be mounted backwards in front. An
alternator generates alternating curent that is internally rectified,
and the direction of rotor rotation is irrelevant. The only
consideration is the cooling fan blade angle; installing an older fan
with straight radial blades solves the problem.
The DC generator must be turned in one direction only.

Dan