Which Permatex?
 

The IA/AI I'm working with told me to get some Permatex to seal up my engine when I put it back together. Unfortunetly he didn't tell me which kind and now I can't get in touch with him.

Aircraft Spruce lists three types, which should I use?

A) Hi-temperature sealant
B) Form-a-gasket No.1
C) Form-a-gasket No.2

Based on our discussion, it sounds like he was talking about option 'C' but I'm not sure. Suggestions?

Thanks,
Bill

Bill,
Lycoming recommends "POB No. 4 Perfect Seal" sealing compound which is available from POB Manufacturing Company, Inc., Cincinnati, Ohio. and any commercial grade of No. "00" silk thread.
They also allow the use of rtv-102 and Loctite 515 without the thread. If it were me I would use the first option.
Lycoming Service Instruction 1125B is the document that discusses this in depth.
Good Luck,
Mahlon

Bill,

I acquired a brand new spool of "approved" silk thread, so if you need some drop me a line. Would also appreciate it if you find out what the POB #4 is, as I'm about ready myself.

Dave

POB Number 4 unveiled
 

Dave,
POB number 4 is Perfect Seal "Gasket Maker Sealant Number 4" It is Perfect Seal P/N GM3H. A 4 ounce can runs $5.00 from us and is enough to last a lifetime. It is also a very good gasket dressing and also a good pipe thread sealer lubricant. You ought to be able to get it from any auto parts store that sells Perfect Seal products.
Good Luck,
Mahlon

Thanks Mahlon, I wish I had paid attention to it when I got the rest of my parts (and Silk Thread) from you guys!

However, not to steal sales away from you (although I doubt that at 5 bucks this is a big money maker?), according to POB Inc., NAPA Part # JV66B is the private label version of the POB #4.

Dave

Good info
 

I didn't split the case so the silk thread isn't needed. Just pulled the cylinders, the sump, and the accessory case. (I?m replacing the accessory case with one that will accept a fuel pump.)

I guess the question should have been what should I use on the cylinders, sump, accessory case, and accessories?

Bill