Preheater

I agree that, if you prime first, hand propping does significantly increase
the probability of the engine starting. It also does present a small
increase in the risk of galling cold bound parts and hurting the hand
propper.

If I really needed to get that engine going and had no back ups, such as at
a remote airport with no second battery, power cart, or shelter, I would
certainly do as you suggest. We've proven though that a well cared for
0-320 on the coast of Maine will start 3 -6 blades every time, all winter
long, (including below zero weather), without ever touching the prop as long
as the oil is heated with the sump heater. It didn't start any more
reluctantly last winter than in the summer.

If there is no reason to turn the prop, why risk it?

I think care and feeding of the mags and ignition system is the big
overlooked factor in cold starts. Our A&P also made an adjustment to the
primer nozzle that increases its effectiveness.

--
Roger Long