UL head gasket repair

[ldfly112]

just blew a front head gasket on my 1937 UL any sugestion on what head gasket is best copper / teflon ? and what gasket sealer i should use

[T. Cotten]

The tradition before I was born, Idfly,...

Was 'composite' gaskets ("Felpro asbestos") for aluminum heads, and whatever the OEM might have supplied as copper for cast iron heads. But the composites worked great on cast iron, too... If everything else is in order.

Gaskets don't blow themselves; Did it overheat?

Whether they were flat or not to begin with, you will want to "deck check" the cylinder and head for 'flatness' anyway. (I use humongous stones for both inspection, and correction.)

....Cotten
PS: If it needs a sealer, why bother with a gasket?

[Steve Slocombe]

I would stay away from the teflon gaskets and the copper ones are widely available. I usually wipe the new gaskets over with grease or oil to help them seat, and recall Harley advice to use aluminum paint as a sealer. My best tip is to run the engine for a few minutes after fitting new gaskets and torquing down the heads, then go over the head bolts by hand with a 9/16 wrench when still hot.

[dukekleman]

It's true IDFLY,
Gaskets fail for a reason. First question is, What type of gasket was in the engine when it failed?
Second, How long was that particular gasket in service prior to the failure?
Both questions are relevant because fact is, there are commonly 3-5 items related to the leed up of the failure.
Surface flatness, head and cylinder, are just as critical as surface finish, head and cylinder. Through out gasket history changes, the Moco, like other manufacturers learned that certain types of gaskets require certain surface finishes to seal/operate effectively. This is why you have seen them advertise a coating on the gasket to address a surface finish that was incorrect for the type of gasket being used. The surface finish for a copper head gasket is very different, much finer RA, than surface finish for composite gasket. Annealing a copper head gasket and possibly coating the gasket because the surface finishes are incorrect, may be necessary for success. I would highly recommend you check the surfaces, although it's labor intensive, and also check other things as well, remember, one thing most likely did not cause this issue alone, rather an accumulation of things. Be sure to check, fastener integrity, upper motor mount alignment, fuel quality, fuel ratio, ignition timing, oil quality, carburetor integrity, etc...the list goes on. Please be sure and follow Steve's advice, torque and re-torque the gasket. It critical for gasket sealing longevity!!!