0-360 cylinder torque values

[Far North Texan]

I have looked on past threads, and online, and do not see the answer to my question.

I have a Lycoming 0-360 on my 6A. It has been idle for some time, and now I have finally gotten checked out and flying again. Yesterday I flew for 2 hours and then changed the oil, and noticed that below the #4 cylinder is a bit of oil. Not a measurable amount, just enough to be dirty, and it seems to be coming from the base of the cylinder. I am borrowing some cylinder wrenches and will attempt to tighten up the studs and see if maybe they are loose.

what is the torque value that I need to check for these studs?

I am obviously hoping for a simple fix here and this seems to be the first step?
thanks for any input.

[BobTurner]

Well, if they're loose you probably would have lost a cylinder by now. But to answer your question:

It's not that easy! Lycoming numbers are for lubricated threads, not sure how to get threads lubricated at this point. The nuts are torqued in a proscribed fashion. Finally, some "studs" actually are rods running thru to the other side. Make sure you put a wrench on the nut on the other (#3) side to keep it from turning.
Final torque spec is: 50 ft lbs on 1/2" nuts; 35 ft lbs on 7/16" nuts; 25 ft lbs on 3/8" nuts. If you apply that and they turn, for sure they are too loose. But since oil is probably gone from threads this is no guarantee they are tight.

Didn't previous installer put "inspector's putty" ("torque seal" - yellow or orange stuff) over nuts and cylinder base? Do any show signs of nut moving?

Since the cylinder seals with an O ring I think it is unlikely your problem, unless there was some dirt or such under the O ring at installation.

[Far North Texan]

Thanks.
I borrowed the wrenches and checked and they were all tight. So am happy about that.
The studs do not have torque seal on them.

[lr172]

Originally Posted by Far North Texan

Thanks.
I borrowed the wrenches and checked and they were all tight. So am happy about that.
The studs do not have torque seal on them.

You really shouldn't be happy yet. You need to find out why there is oil there. You can hope it is from return line connections, but you need to figure it out.

Good luck.

Larry

[Far North Texan]

I am certainly open to suggestions.
I took an oil sample but that was yesterday so of course I don't have results yet.
Will triple check that all connections are tight, clean it good, and test run it.