Modified the O-360-A1A crankshaft from a Constant Speed to a Fixed Pitch Propeller. Converstion is complete. Talked with Lycoming about stagnant oil remaining in the crank during downtime... They said it was not an issue to drill additional holes top and bottom, but not so many as to weaken the plug. I added 2 holes one top and bottom. This should help drain the oil back into the sump after engine shutdown. I forgot to get a photo before inserting the front plug. I barrowed an expansion plug installation drift (P/N 64681) from the engine shop... Free of charge!! It is a 2 piece sliding center drift, it was recommended to put a bead of proseal then seat the expansion plug with the drift, then to shape a small fillet of the proseal that squeezes out. as you can see the drift puts a nice little concave in the plug.
Service Instruction No. 1435 Engineering Aspects are FAA Approved
When changing from a constant speed to a fixed pitch propeller, it is necessary to pierce a 1/8" to 3/16" hole in (or remove) the plug behind the oil return tube, and install an expansion plug in the front of the crankshaft
Engines may be changed from constant speed to fixed pitch installations or vice versa if the serial number on the nameplate is stamped with a letter "C" to denote a model conversion and a copy of FAA Form 337 listing all parts used with part numbers included, and a description of the conversion or alteration are accomplished. Also, the proper logbook entry should be made.
