Cylinder Studs

[ajg1722]

Hello,

Has anyone had any success removing stubborn CC cylinder head studs?
I've been applying heat and brute force but so far no luck.

Andrew

[David Morris]

Hi ajg1722,

I am from a Javelin background, but I guess heat ( and I am meaning LOTS of heat, ideally from a gas torch ) will be needed, along with lots of release agent. Also, always grip the stud right down at it's base with a good quality stud extractor. I am sure someone in the Bradford/Pre-war community can advise?

All the best,

David

[Keith Clements]

Yes heat the block not the stud. Aly expands more than steel . Rusts and other oxides break down and release their grip so lots of heat but preferably in an oven.

[David Morris]

Hi ajg1722,

Sorry Keith, I don't agree with you. If the CC studs are anything like those my WW2 Stationary engine, the studs will be steel, and also the cylinder will be cast iron. No aluminium anywhere. What is needed is some heat differential, so I suggest spot heating the cylinder around the stud base, to expand the stud hole Hopefully the stud itself will not expand so much,particularily if the heat being applied comes from a gas torch, which would be a rapid transfer of heat. Thus allowing the release agent to do it job? Putting the whole assembly in the oven just won't do the same job, as well as risking matrimonal discord?

All the best,

David

[Keith Clements]

In that case you can use a freeze spray to cool the stud.

[ajg1722]

Thank you gentlemen for your replies.

Firstly I can confirm that Bradford cylinders are cast iron with steel studs.

And all attempts at heating have been to no avail - giving it what-for with the oxy-acetylene with a No. 20 tip. My theory at the moment is that the studs go right through to the water jacket and they are firmly corroded in place. So my next step is to seal off the water jackets and let some rust removing solution (I'm using CRC Evapo-Rust) do its job for a few days. I was going to do this anyway as there is a lot of crud in the water jackets.

If this doesn't work, then it's back to heating. But I'm concerned how hot I should get it. If a bolt is firmly rusted in place, then you need to get it up to red-heat (700-800°) to convert the tough and bulky red ferrous oxide to ferric oxide, a soft black powder. But that's a LOT of heat. and am unsure what mischief this may cause, especially to the tensile strength of the studs which I hope to reuse.

I remain open to any suggestions...
Andrew

[David Morris]

Hi ajg1722,

I am running out of ideas here! Now, you havn't told us why you need to extraxt the studs? I expect they might be badly corroded, snapped off or perhaps you need to re-face the cylinder surface? Or again you might be wanting to do a rebore?

My thoughts in asking, is that is there any way you can reuse the studs as they are, as your assumption about them being corroded where they sit in the water jacket is probably spot-on! I hear what you are saying about your CRC Evapo-Rust, but persomally I have doubts that this will free the studs?

Anyway, always keen to help and all the best,

Take care, David

[Tony Fearn]

I wouldn't re-use the studs, I'd source new ones. It might be more useful to use new cylinder head nuts as well. Usually used ones are not completely parallel down the sides, and don't grip the studs as well as new ones.
Tony.