Yet another repair!!!

I blew my head gasket last week. That's what I get for pushing to hard in a 104 degree heat wave. As soon as my new gasket and rings come, she will be back on the road.... Until the next problem. :lol:

A little worried about the build up on my right side. I will check and replace the vales if needed.

Nice Webber. They are problem-free.

Torontonian said:

Nice Webber. They are problem-free.

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Everyone's a comedian!

Thanks for that Info Ludwig, did you make those spacers?

Ludwig, nice idea. Do those spacers sit flush, or do they stand proud a couple of mils so the gasket conforms to them?

When I brought her back to life after sitting 30 years, I didn't replace any of the gaskets in the engine. I just figured I would wait till they gave way. It didn't take long. Now I'm giving the proper attention to it. I'm not sure if the owner before me ever looked into how to properly maintain this bike. He told me he never torqued the cylinder head the whole time he owned it. Also after some inspection I realized the the head bolt nut on the side that blew was really worn. It will need to be replaced too. It sat for 30 years and the only major issues with it were the points (now an EI) and the Carbs. I am debating on weather to install the original style head gasket I ordered or to order a copper gasket. Any suggestions? I'm a amateur mechanic and a new owner of a Norton. I try to read as much on them as I can, but some things are learned with experience. So any help is openly accepted. Thanks in advanced for the replies.

ludwig said:

Don't blame it on the weather .
It is pretty clear that the head wasn't torqued up correctly for a long time .
Just look at all the blowby in the trough bolt recesses .
You can give the gasket some extra support in these weak spots by placing alu spacers on top of the trough bolts , like this :


Can you post a closeup from the blown gasket ?

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Here is the gasket... As you can see, it blew the ring and blew out that entire missing portion... The spot on the top stuck and ripped.

Looks like a once good type flame ring, trash now. The current crop of flame rings are mere folded over foil rings and w/o the special heat set glue - so after having new current version fail and almost burn up bike jetting into fuel line, at only 10 miles on easy legal Combat commute, I could not bring myself to use the new $40 one I'd ordered from Anover. I re-used an old well used copper one, annealed beyond cherry red on propane stove till wax soft with copper coat sealer. You want the whole head surface even and flush for best chance to seal bores. Ludwig's spacers will work on the bolt recesses but not for gas jet cuts if any found. I got good service with hi temp JBWeld laid in blast grooves then razored even before full set. It stayed put-sealed 1000's of hi throttle miles plus a couple head removals but eventually did get too soft-crumblly after last 3rd removal [not head leak related reasons], so needs repeating now and then. Not a real machinist method of course but worked for me. Be sure and measure new rings gap or expect more head leaks too soon.

Sierra,

You could go to a copper head gasket if you are concerned about compression blow, the copper is probably the stongest set up, but they are also the most prone to oil leaks, especially around the pushrod tunnels.
However you can try Jim Schmidts trick of laying some dental floss around the tunnels. I have found that oil leaking in the head joint area has ceased altogether, on my 850 with the installation of a reed breather valve, a very worth while $18 ugrade, pretty much reduces or eliminates all those problematic all leaks, I have found.

Regarding the oily pot, whilst the head is off, I would renew the valve guides, but also look very carefully at the any evidence of cracks in the head around the guide bores. Or maybe rough guide bores from previous valve guide refitts?

Cheers Richard

stockie2 said:

Sierra,

You could go to a copper head gasket if you are concerned about compression blow, the copper is probably the stongest set up, but they are also the most prone to oil leaks, especially around the pushrod tunnels.
However you can try Jim Schmidts trick of laying some dental floss around the tunnels. I have found that oil leaking in the head joint area has ceased altogether, on my 850 with the installation of a reed breather valve, a very worth while $18 ugrade, pretty much reduces or eliminates all those problematic all leaks, I have found.

Regarding the oily pot, whilst the head is off, I would renew the valve guides, but also look very carefully at the any evidence of cracks in the head around the guide bores. Or maybe rough guide bores from previous valve guide refitts?

Cheers Richard

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No to worried about it blowing again... Im more worried about leakage. She has enough drips. I heard the copper leak a lot. I still have to deal with the rings so it will be a few days and I can think it over.