oil plug in the crank

[acwrench]

Haven't torn down the engine just yet (IO-320) but was talking to someone this morning and he mentioned if using a fixed pitch prop (which I intend to) I'll have to remove the aft crankshaft plug. He mentioned this is to allow the oil pressure to go somewhere if not using it for the Prop governer. Any comments on this????

acwrench

[jim_geo]

Yes, I just finished my O-360 built from a kit. I ordered for a fixed pitch but was sent a kit for C/S no big deal I have some extra parts. Of course the crank is hollow and has a rear plug with none in the front. That plug is a pain to remove, Lycoming has an S/B in which you are told to drill a 1/8" hole in the seal to relieve pressure on the front plug. Apparently the oil flow is fairly low in this area and the 1/8" hole is plenty big enough to relieve the pressure.

[acwrench]

i've been told to drill the small plug and tap it with a 1/8" npt tap to allow putting in a plug if we ever do decide to run a c/s prop. any body heard of this process?
acwrench

[Mahlon]

I don't think the plug used in the IO-320 is thick enough to tap. There are other style plugs( 1.25 od) used in other crankshafts that have the 1/8 npt hole in them but the IO-320 (1.75od plug) isn't configured that way and can't accept that 1.25 OD plug.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at you own risk."

[acwrench]

mahlon,

are the plugs for the IO 320 B1A still available? I guess the alternative is drilling the 1/8" hole.

acwrench

[Mahlon]

mahlon,

are the plugs for the IO 320 B1A still available? I guess the alternative is drilling the 1/8" hole.

acwrench

Yes, the rear crankshaft plug used for the IO-320 is the same one used for all 320's.
Good Luck,
Mahlon
“The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at you own risk.”