A-65-8 Continental

[yocum137]

On the front of the case there are two crankcase plugs. Remove plug, install pressure gauge, start engine, and there you go. Just make sure you oil line does not interfere with propeller track. I ran my oil line back to firewall and tied gauge to motor mount so I could read it while standing behind
wing strut.

Ah! I was just talking with a friend who has a C-85 on his L-4 and he mentioned losing oil out of the left front plug (I didn't realize there was a right one, too). I didn't even think of attaching a pressure gauge to these. Thanks for the education.

[Ramp Rat]

7 pounds of pressure at idle? I’m going to make a WAG here but, is that pressure with cold oil and I’m assuming you’re using a straightweight oil like 100W?

Considering everyone else’s ideas, what about the seat forthe oil pressure relief valve? The seat is a machined surface in the accessory case and can become pretty beat up over the years. Just a guess.
JMHO, Steve.

[Pietdriver]

Not sure why you would be doing an oil pressure check in this fashion to begin with. What lead you to suspect an issue and try this? I'm not sure that you are getting accurate information in this fashion, 7psi is low. I would look under the hood, pull valve covers, if you have oil all over the place then you should be good to go. Those front plugs are for an oil cooler, not pressure testing. you would get low pressure from one of them but not the other, (supply and return). There is no left/right oil feed in this style of engine. I believe the airplane tip up is for releasing an air lock that is rare but can occur, typically after an oil change after a long sitting period. Anyone else, help me on this one.

[Mike Berg]

This is just a shot in the dark and you may have already solved the problem but make sure you don't have a 'sleeve' under the front plug. I bought an A65 engine once that had previously been in a Luscomb with an oil cooler (was going to put it in a Champ;/no cooler) and had the same problem. Found out there was a sleeve installed inside the chamber to force the oil to go through the cooler before going down the right side of the engine. Pulled sleeve/end of problem!! It's actually in the 65 parts book if I remember correctly. One other thing you find out on these old A65 engines is that the cam bores are getting pretty worn and lose a lot of pressure,especially at the front end. Hot and running 25-30 psi in not unusual.
Hope this helps!
Mike