Dome nuts: replate or replace?

That’s a lot of them! I thought they were 1/8 BSP, probably BSPT. That’s 0.383 diameter, 28 TPI. The UNF thread is close, 0.375" diameter, but 24 TPI. Anyway, if they work, they work. The threads will jam which is what you need; if 24 TPI is a precise match you should be able to screw the plugs deep enough to fall out inside the exhaust passages outboard of the valves. IMHO, could be wrong…not sure what I used decades ago.

There was a similar thread recently discussing whether the temperature sender threads in the intake are BSP or straight UNF (NF) threads.

Not sure if my eyes are picking it up or it’s just an optical but are they tapered?

. I just put 6 of them in the correct die for the EGR fittings holes, but not all the way through. Then screwed them in tight until the remainder of the BPS thread stopped them from going ng further in. Perfect.

Back to the big chrome nuts. What is the trick to torque them without scratching the chrome!?

I am thinking about wrapping the nuts with a layer of teflon tape.

Thanks.

I’d say tape and these nuts that grab the side of the nut and leave out the corner?

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Never, ever damaged then while using a proper socket.

Don’t overthink this.

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I’ve never scratched my nuts while torqueing down the head. Just use a standard socket and be careful.

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You can take a strip of nylon electrical tape and wrap it around the inside of a socket. The cam cover nuts are extremely low low torque so no worries there.

Well congratulations, John! SWMBO claims I can’t abstain for more than a few minutes. :slight_smile:

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I will not say it.
I will not say it.
I will not say it.
I will not say it.
I will not say it.
I will not say it.

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Using a 6 point socket rather than a 12 point will help prevent damage.

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Good point: I NEVER torque w/o using a 6-pointer.

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I’ve never torqued an XK cam cover dome nut in my life! Didn’t even know there’s a torque figure for them. As Wiggles says, all you need is a good fitting six point socket then you won’t damage them.

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The bling is on. More importantly, the camshafts are set (temporary bolts) on TDC like the crankshaft and the distributor drive, lobes are oiled, oil filter us in place… Start time is nigh.


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And of course now that the job is done I find at the bottom of a drawer a brand new (repro) set of dome nuts I bought years ago…

The chrome work on these repros is nowhere as nice as what my local plater did on the original dome nuts.

So I am happy and will put the others on eBay.

That seems to be some kind of unwritten law, doesn’t it? You never find something you stashed away until after you can’t find it and buy and install it’s replacement.

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Unwritten, in virtual stone.

:wink:

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Yep, had the alternator fail on my S11, ended up purchasing a new one. A week later came across the set of brushes that I had purchased, on the off chance I’ll need them, on the shelf in the garage :rage::face_with_symbols_over_mouth:

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Now if I could just find that spare flat floor ots I bought just in case I needed it. I am sure it must be around somewhere!

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My opinion is replace. Considering the exterior hasn’t survived well…

The important thing is the condition of the threads? First and foremost, each nut has to bring equal pressure on the head to seal the gasket when torqued to spec. Fouled threads will lead to uneaven clamping forces. The other problems follow quickly.