At the age of 15 I had my first motorcycle all of two weeks when someone told me the knocking noise was a rod trying to escape from the lower end. (Something tells me the P.O. new about this) I was referred to a guy who was a former racer who was an engineer for the company who made the bike who would rebuild it on the side in his garage. I was full of questions, one was, what kind of sealant to use with the gaskets. His words still ring true to me today. A properly assembled engine with the proper gaskets does not need any goop. I asked my Uncle who was along time diesel mech. and he confirmed this but when on to say, that may be fine for your modern day Honda (67 CL160), but the rest of us need a little help sometime.
This has been a great post. I figured we would have as many different answers as people who respond. I have used 3m (Gorilla snot), Gasgacinch, various silicones, Permatex High Tack. The problem is what goes on must be dealt with later on disassembly. Everytime I go to use a product, I hear those words about 'Proper' assembly. I used to pass it off and say that was Honda, this is Norton or whatever.
Lately, I have taken a new approach and try to prove the factory design O.K. I dress up the cover with flat sand with 400 sand paper on a piece of steal I scrounged. I then deburr the case as necessary. Then assemble with the correct gasket, dry. I snug the screws, then torgue them incremently on an inside out crossing pattern, similar to head bolts.
So far this has worked on Norton cam cover, trans cover, Mark III primary and Harley cam cover with perfect results. The best part is disassembly is easier, I seem to have to do everything twice.
I always use a new dry gasket.
David, your post on the shims with conical seal really intrigues me. Here is what my factory manuel says Section C30 / 11 third paragraph ...Very late engines use a joint gasket between the oil pump and crankcase joint faces and where a joint washer is used at this point, under no circumstances should the conical rubber seal between the oil pump and timing cover be equiped with packing shims....
Para 13, Fit a new conical rubber oil seal part number NMT272 on the oil pump outlet stub and dispense with any shims which may been fitted between the seal and pump body at the time of dismantling. Over compression of the seal will render it unfit for further use.
It appears part of the shimming process is the paper gasket behind the oil pump, and when used with the proper seal and stub outlet, should get the proper clearances without shims.
I assume you have an older manuel as this is the newer 750 / 850 combo manuel good from 1970. It seems to me Norton has superceded the older method.
One thing I don't understand is what is the 'joint washer' they are referring to. I don't see one in the parts manuel.