winter ops - turning over the engine by hand?

[flyboy1963]

Mostly for all you guys who store outside in below freezing climates; is it good, bad, or neither to go out and turn the prop by hand between flights?
The old standard is to pull it thru a dozen blades, which allegedly puts some oil on things inside, but I don't know the internal oiling system of a Lyc as well as a small-block chevy.
Does this really help?...or only as a pre-start ritual? I can't imagine it causes detrimental wear, as it would be the same as the first few seconds of operation anyway.
any engine gurus have an opinion?

[Mel]

Turning the engine only wipes oil off the cylinders and cam lobes.
The first few seconds of starting doesn't leave the bare cylinder walls exposed for weeks after wiping off the oil.

[bfilarsky]

Originally Posted by Mel

If you can't fly it, don't touch it!
Turning the engine only wipes oil off the cylinders and cam lobes.

Ditto. I'm no expert, but everything I've heard is that its either detrimental or at best neutral. The practice of turning the prop through before starting comes from radials, where you're looking for a hydraulic lock.

[rv9av8tr]

Mel is right, all the old wisdom is leave it alone until it's time to run it.
Fuel Inj engines, when primed, dump fuel behind the intake valve so they are ready to immediately draw fuel into the cylinders.

Carbs with 4 cylinder hand primer should work the same as FI.

Carbs with an accelerator pump but no primer, pump the throttle a couple times then pull the prop through at least 4 blades. That precharges the cylinders with fuel so when you crank, you'll get all cylinders firing to get a good roll over and start. Worked like a champ on my Long-EZ.

[jsharkey]

Also in my opinion some kind of preheat before starting is needed in temperatures below freezing. I have a Reiff system with cylinder bands and a sump heater. It works great.

Jim Sharkey
RV-6

[rv9av8tr]

Actually, according to Lyc, preheating isn't required until 10 Deg F, except for the O-320 H series and O-360 E series, which is 20 Deg F.

Here is a good reference to cold weather engine operation:
http://www.lexingtonflyingclub.org/L...Operations.pdf

According to Premier Aircraft Engines, oil pan strip heaters should only be used 2 hrs prior to flight, otherwise the warm moist conditions created by the heater if left on all the time, will destroy the engine.

[zav6a]

Anybody have opinion on using fogging oil like is used in marine applications for winterizing?

[Sam Buchanan]

Originally Posted by rv9av8tr

Actually, according to Lyc, preheating isn't required until 10 Deg F, except for the O-320 H series and O-360 E series, which is 20 Deg F.

Here is a good reference to cold weather engine operation:
http://www.lexingtonflyingclub.org/L...Operations.pdf

According to Premier Aircraft Engines, oil pan strip heaters should only be used 2 hrs prior to flight, otherwise the warm moist conditions created by the heater if left on all the time, will destroy the engine.

I've been using a Reif sump heater for ten years. The heater runs 24/7 from November to April and no engine damage has occurred. Lots of info on this subject in the archives so I won't elaborate any further in this thread.

[jsharkey]

All I was saying is that it sure starts easier, develops oil pressure and warms to operating temeprature sooner with preheat than without

Regular operation is probably a more significant factor in avoiding corrosion damage.

Jim Sharkey

[flyboy1963]

Okay, I can see some rationale for that.
Back to the oil pump thing, does anyone know if you are pumping oil to beneficial areas?...which would of course, inhibit corrosioin etc.
Or do need 10+ psi before it moves through the passages to the bearings etc.?