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MG MGB Technical - Exhaust manifold studs & rocker pedestal studs

I have just had some work done to my cylinder head and I am now in the process of refitting the rocker pedestal studs and exhaust manifold studs back into it.

My question is, when I refit the studs, should I use anything on the threads, loctite, high melting point grease or a drop of oil for example?
Or should I just leave them clean?

Cheers
Colyn
Colyn Firth

Partially, it depends what has been done to the head. You may be advised to run a tap through the blind holes to clean the threads up before you put the head in place. But clean is good enough.
Allan Reeling

Check the manifold stud holes - some run through into the pushrod holes - these will benefit from a drop of Loctite otherwise I always use a little threadguard / coppaslip on the manifold studs. Rocker pedestal studs just need nipping up, no special treatment.
Chris at Octarine Services

Thanks for that guys,
I will check those manifold studs Chris.

I didn't actually dismantle the rocker assembly myself and so I received the valve gear back in "kit-form".
It has been quite a few years since I rebuilt a cylinder head and so I had forgotten about the two thin shims that fit underneath two of the pedestals.
Are these standard parts on all MGB engines?

I'm told that they fit under the two central pedestals but it would be good to hear what you guys say about them.

Cheers
Colyn
Colyn Firth

Hi Colyn, sorry I forgot to give you the rocker assembly back, tis in the post (UPS) today.
The two shims go under the middle posts to put some bend on the shaft to stop it fretting. They were factory fit after 71 and retro fit when heads were stripped off in service work. As the shaft is only held in place at one end post the rocker arm motion can and does cause the shaft to oscillate and wear the shaft at an alarming rate. It is good yours had them on when your engine was rebuilt as most builders/head fitters do not put them back on or supply them if they are missing!
I should have gone to Specsavers not noticing it was missing from your head :)
Peter Burgess Tuning

Thanks Peter,
my fault for talking so much instead of letting you get on with the job.
I didn't know that about the rocker pedestal shims.

I'm really looking forward to trying the head out, will bring the car back to you as soon as I can book a spot on your dyno.

Cheers
Colyn
Colyn Firth

I usually seal the manifold threads with hylomar.

Colin
Colin Parkinson

This thread was discussed on 06/02/2020

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