Oil leakage

Hello now most Norton's oil leak that normal for Brit bikes we say its not leaking its just sweating a bit of oil at lest you have oil in the engine yours anna j

I just had a look at my Dommie. Sure enough, there are slight signs of oil round those two heads. But looking a bit closer...it's come down from the rocker spindle covers! They are a bit of a compromise if I remember correctly..they are sealed with paper gaskets round the edges but not up their bolt shank. Or something like that...

The other thing is the copper gaskets are sometimes claimed to be reliable (do not blow) but not as oil tight as others. Mine is copper, and is one if the places my bike does not leak...

Dave is quite correct.  A good many owners complain of cylinder head oil leaks and blame the gasket. They are not all wrong because getting a thick copper gasket to compress and seal is not too easy on a Norton twin. In recent years I have rebuilt two 99s and a 650 and each time that I used a copper head gasket, they dripped oil near the spark plug. Changing the gasket for a composite version solved the problem.

Returning to the rocker end plates these can leak a bit if not treated to new gaskets on a rebuild but are more likely to exude black gold through the coarse threads (1/4WW) of the end plate bolts. A small  amount of sealant on each thread can help and certainly popping an annealed copper washer behind each of the heads will is a smart move.

that the solid copper gasket sealed better than the composite but ONLY if well annealed before fitting and with a tiny smear of Wellseal around the pushrod tunnels.

Don't for get that you don't need to quench copper to anneal it.  The idea is to soften it so heating is all that's required.  NOT with an Oxy-acetylene torch though!

You probably will need to clean it with Scotchbrite afterwards. This superior to steel wool as it doesn't leave rustable dust.  You still have to thoroughly clean off any residue afterwards.

... but quenching does clean it nicely. It's quite hard to get a twin head gasket to the required dull red however - I use an old Primus stove but still have to add some with a butane torch.

The problem with super heating these solid copper gaskets is they can start to vapourize easily. Then the thin bits get thinner. The vunerable thin metal spots being the bolt holes each side of the spark plug and also next to the front 5/16" studs.........and where do most people complain of cylinder head oil leaks???

I agree with Ian in that a smear of goo in areas like the pushrod tunnels can help. I use Silicone RTV  but lots of people tell me that Wellseal is also very effective.

I sometimes question the grade of Copper used in head gaskets. I have a feeling that like most metals there are differing grades available and that possibly sometimes we purchase gaskets made of a grade that just refuses to heat soften. Do we have a Metallurgist contributor on had???

Hello stop you're leaks for ever with Heldite comes in a 400ml tin with brush to apply and no need for gaskets see EBay.UK gasket compounds.  Yours Anna j 

Hello now I have tested out ever brand of gasket sealer and Stag wellseal is not the same has what we used abroad ship it came in 1liter tins and was red and much better then this new stuff in tubes and a sticky brown goo ,were as heldite looks the same but better as you can use this as the gasket and it comes in tins with a brush in the screw top witch makes application much cleaner proceess and it dose not break down or dry out even in the hostess areas .tried and tested to extremes by me as for RVT silicon it was the main cause of My friend size up of his Atlas as some one applied it too much on the crankcase joints thus blocking the oil pickup return  feed and the. Engine was starved of oil.    And over use of RVT silicon was in ever oil way..     So not good is it .      yours Anna j 

Re types of copper...as I understand it, copper is usually supplied pure (or as nearly so as makes no difference). There would be no cost or any other benefit from adding an allowing element. So it should all behave the same way.

Silicon RTV has no place in engine assembly keep it for plumbing.

Wellseal is not just effective it actually works and it works well, it's petrol proof and it doesn't harden. If I have to use a sealant this would be the one

Hello Anna, I don't think I criticised Heldite I've never used it or even heard of it untill  you mentioned it, and although I didn't mention copper yes I do know about it and all the things you can do with it.                                        Like you I've been in engineering most of my life ( 83 now ) so I've seen a lot and done quite a bit although not marine as you have .                      However you stick with your sealant and I'll stick with mine and I'm sure we'll both be happy with our results.        Incidentally I must talk to you about paint for my 1951 model 88 which has been in pieces for to many years now.