locking nuts on end of valve rods.

I had a moment whilst out on my last road run where the engine suddenly started performing weirdly, loosing power then subsequently locking up with steam pressure on both sides.

The issue was very clear once i had removed the LP side cover and the two lock nut on the end of the valve rod had worked loose and come off. stick with oil residue to the bottom of the valve chest.

The were locked on with high temp thread lock but they still wound off.

Has anyone else had a similar issue and was wondering if anyone had drilled a hole through the rod and fitted a spit pin to stop them winding fully off.

The worrying thing for me is there was no valve tick before this happened. In other words they loosened and came off pretty quick.

This thread is as much advice as it is query as I wouldn't want it happening to anyone else. Luckily I wasn't going fast and didn't bend anything.

Hi

I put the half nut on the inside. Then the lock is held with a bigger nut engagement. No problems and checked every year. No locking compound either.

I did the same. large nut on outside to give maximum lock. Think I will split pin just to be safe.

As lynn and Sonick say there is some science to the thinking as you can see from the below link. I found this a few years ago and found it a some what fascinating site but perhaps that is just too weared.
Simon
http://www.boltscience.com/pages/twonuts.htm

Now that's a useful tip. I've never given that a thought before. Makes a lot of sense.
Also alleviates the risk of stripping the thread on the thin nut.

Thanks guys

Jim

Hi Jim
If you found this A fascinating science then having a sole mate means I am no longer weared!!
Simon

Now that makes two of us Simon.
Nothing wrong with being weared.
I've made a career of it.