LOREN8FAN

would like any info on how to position my prop in reference to the crankshaft on a os .61 2 stroke glow. thanks

dr_wogz

My Feedback: (3)

Not sure what youre' asking..

I align my props, so they are horizontal against the compressin cycle. That way, when a dead stick, you limit the chances of crunching the prop [if it were vertical & caught the grass on a hard landing..]

jaka

Hi!
Performance wise it doesn't matter. But if you want to flip start the engine and you are righ handed ...put the prop at 10 minutes past 8...or 5 minutes past 7.

aerowoof

the above post is correct but forgot to mention that is with the pistonapproaching top dead center so that when you flip it smartly your fingers/chicken stick will clear the second blade when it starts.

LOREN8FAN

thank you for all your input. the only reason that I asked this question was that the crankshaft dead time on a typical engine is taken up by the flywheel. And on most high performance engines the flywheel is balanced directly with the crankshaft. on my cessna 150 and 172 the propeller is timed to the crankshaft so thats why I asked. thanks again. if anyone has any more info please send along.

Montague

ah, I think I know what you're asking. In short, we don't have that kind of problem.

However, if you have an engine that has a vibration problem you can sometimes reduce the vibration by installing the prop so that it is vertical with the piston at top-dead-center (TDC). If you use a slightly out of balance prop, you can put the heavy blade down when the piston is up to add more counterbalance to the engine, or put the heavy blade up for less counter balance. I've never seen an engine that needed less counter balance, but one might exist, usually it's the other way around, and a bit extra weight can help smooth out an engine. Of course, a single cylinder engine will always have some RPM ranges where it just vibrates.

LOREN8FAN

Thanks Kirk, that helps me be more ready for firing this engine.