Loctite the exhaust nuts?

Am I misremebering or was there not a steel bendover lock once available from Norton?

There are lock rings with little "H" shaped projections but my understanding is that they don't work well.

The lockrings allow the nuts to undo enough to damage the threads but not enough for you to see they are loose, the worst of both worlds.

I use the bronze nuts, tighten when cold and once again when hot and never carry the big spanner as its not needed.

I use the stock lock rings. I don't think loctite or any other sealer would be advisable for exhaust nuts.

I torqued my exhaust nuts cold, then re-torqued them hot and bent over the tabs on the lock rings. No issues. Since I noticed that the lock rings could rattle, I warped them before mounting, so they fit tight to the head at two points, and tight to the exhaust nuts at two points, offset 90 degrees.

I originally ran 850 pipes and rings with collets, but changed to 750 pipes with 750 rings after cracking two left-hand exhaust pipes at the wye.

I don't know how many 750 heads have bunged up threads, but am convinced that the 750 pipes are the way to go on an 850, as these pipes allow much more thread-to-thread contact between head and nut.

To the safety wire idea...what if on 750 setup the compression washers between the exhaust nut and cylinder head compress more after the first torque. If you safety wire and call it a day and the washer compresses you still run the risk of damaged threads due to a loose header pipe flange. My experience, like others, is tighten a few times after getting the engine hot and you won't have any further issues. Always heat up the engine before trying to remove.

David

Hi Gang:
I have repaired hundreds of heads in my shop.The main culprit is the 850 head with the balance pipe,taking away 1/8" of thread with the split collar.I have been recommending for a couple of years to use norvil bronze nuts along with the 2 seperate header pipe system.They expand with the head and don't loosen off.Just use new washers,a little anti seize and retighten a few times after starting to settle and crush the new washers .
Bruce
http://www.tritonmachining.ca

If it ain't broke, take is apart and figure out why.

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Just to add to the chorus - re-tighten the bejesus out of them when hot.

Phil

ps - Hi Bruce - nice to hear you on the board!

Thanks Phil:
I read it all the time,but forget to reply my 2 cents to some of the problems.Really great,great site.Lots of guys with tons of experience with commandos.
Bruce