Help Identifying Mark on Crankshaft Gear

lr172 · #1 08-12-2014, 06:33 PM

I am rebuilding my O-320 and currently assembling the lower end. My gears are in good shape with the lash in spec for an overhaul. However, I had very light surface corrosion on the outside of the Crankshaft gear. Contact points have no corrosion and there is no pitting.

My problem is that the etching of the mark was apparently very light on all the gears and I cannot identify the mark on the Crankshaft gear. Does anyone have a picture of the gear to help me out. The marked gear must be indexed to the the dowel pin, so I should be able to reference a gear with visible markings.

I appreciate anyone's help in this area. If a picture is not feasible, I am happy to have someone give me a tooth count from the dowel pin

Larry

rocketbob · #2 08-12-2014, 07:18 PM

Don't worry about it now but don't put on the accessory case until after the cylinders, valves, and pushrods are in. At that point its easy to put the #1 crankpin on TDC then turn the cam so both valves are closed. This way you can time the engine without looking at the marks. Then you just pull it thru and make sure two valves aren't wide open on any cylinder.

lr172 · #3 08-12-2014, 09:11 PM

Thanks Bob. Will I be able to figure this out without knowing the valve timing? Both valves are closed for 180* on each cylinder.

aerhed · #4 08-12-2014, 09:38 PM

There is valve overlap. You'll know after you stare.

az_gila · #5 08-12-2014, 11:53 PM

Shamelessly stolen for the Internet...

It's a O-360-A1A part that replaces the 61155 part number in the parts manual per SB 475.

lr172 · #6 08-13-2014, 07:43 AM

Thanks for the replies here! Gil, picture gave me what I needed. I did some searching but couldn't find a good picture. I'll need to take some search lessons from you.

Larry