Prop /crankshaft clocking

First, I have a new Lycoming YIO-360-M1B and Hartzell C2YR-1BF/F7472 prop new from Vans. Engine has Lycoming long term storage and this is the first it has been rotated. I pulled the plugs and want to rotate the crankshaft to the correct position for prop installation. Where should the little "o" be positioned that is stamped both on the crank and flywheel/ring gear? Currently I have the engine at TDC of #1 as aligned with the mark on the back side of the ring gear and the top crankcase seam (the starter is not marked on this engine) and verified by piston position with the "o" at the 7PM clock position looking at the prop face.

I always clock a two blade prop one hole counter clockwise from TDC. This way you can see the timing marks. The flywheel mark and dot on the starter will line up at #1 TDC and will be very difficult to get right with a prop blade in the way.

Your prop hub and crankshafts bolts are indexed in such way that the prop can be installed in only two ways, which is 180 degree from each other. take a look at the inside of your hub and you will see.
It will not matter which way of the 180 degree you install it. If you have excessive vibration, you might try to flip the porp 180 degrees to see if that helps. If not, then prop balancing would solve it

Hope this helps.

Bavafa said:

Your prop hub and crankshafts bolts are indexed in such way that the prop can be installed in only two ways, which is 180 degree from each other. take a look at the inside of your hub and you will see.
It will not matter which way of the 180 degree you install it. If you have excessive vibration, you might try to flip the porp 180 degrees to see if that helps. If not, then prop balancing would solve it

Hope this helps.

Click to expand...

Thanks your correct. I was over thinking this and remembering from my fixed pitch installation. Looks like the prop must stop long before TDC for clocking to be correct with only this one way to install.

Hartzell technical assistance

Call Hartzell and ask for Les Dowd. He will give you the new part numbers for the new prop pins (lugs). I did mine and it was very easy and very effective in removing vibrations. The prop is turned back 60 degrees against the rotation.

Steve