Position Of Prop In Relation To TDC.

[Geico266]

Does it make a difference? Is there a proceedure for mounting a wooden prop on the crank?

0-235 Sterba prop.

[carguy614]

Mount your prop horizontal with crank at TDC. That makes it possible to hand prop the plane if you have the need. As far as balance or indexing is concerned, it makes no difference with your application.

Hope this helps....Chris

[Geico266]

Originally Posted by carguy614

Mount your prop horizontal with crank at TDC. That makes it possible to hand prop the plane if you have the need. As far as balance or indexing is concerned, it makes no difference with your application.

Hope this helps....Chris

Thanks Chris, it really does help, and hand cranking may be needed at some point.

I have head of guys that have had a vibration in their engine prop set up that they could not get out was corrected by changing the position of the prop. Have you ever hear this? Anyone?

[rvmills]

Originally Posted by Geico266

Thanks Chris, it really does help, and hand cranking may be needed at some point.

I have head of guys that have had a vibration in their engine prop set up that they could not get out was corrected by changing the position of the prop. Have you ever hear this? Anyone?

Larry,

Kahuna has his prop clocking procedure and subsequent vibration reduction well documented here:

http://www.mstewart.net/super8/propclock/index.htm

Good read, though it is for a Hartzell CS prop on an IO-540. Not sure how closely it would apply to your application, but worth looking at.

Cheers,
Bob

[carguy614]

If my memory serves me correctly, there are specific clocking procedures for CS props on certain engines. The 200 HP with a certain counterweighted crank seems to come to mind. As for the 235, and my o-320, fixed pitch props can be indexed at any position. If you have a dynamic balance done, your balancer guy may reindex to get lower numbers with less weight. He will always use the horizontal positions first to enable hand propping.
Regards...Chris

[Geico266]

Originally Posted by rvmills

Larry,

Kahuna has his prop clocking procedure and subsequent vibration reduction well documented here:

http://www.mstewart.net/super8/propclock/index.htm

Good read, though it is for a Hartzell CS prop on an IO-540. Not sure how closely it would apply to your application, but worth looking at.

Cheers,
Bob

Originally Posted by carguy614

If my memory serves me correctly, there are specific clocking procedures for CS props on certain engines. The 200 HP with a certain counterweighted crank seems to come to mind. As for the 235, and my o-320, fixed pitch props can be indexed at any position. If you have a dynamic balance done, your balancer guy may reindex to get lower numbers with less weight. He will always use the horizontal positions first to enable hand propping.
Regards...Chris

Thanks for the info guys.

It just seems to me that "clocking the prop" is a good way to minimize vibration of the power pulses. I might be dealing with more theory than practicality on an 0-235, but what else am I gonna do in the winter?