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MG MGB Technical - cylinder head removal

I have a 1979 mgb gt which I want to decoke and I would welcome any suggestions on breaking the seal of the cyl. head to block. I have removed all but 5 of the head studs, these last ones are not for turning. But despite repeated hits with a rubber mallet the head won't come free. I have also tried a few quick stabs with the starter motor, it turns over but it did not pop the head. I have now run out of ideas, any fresh ideas are welcome.
R LESTER

Hi,

Try removing the manifold studs, they penetrate into the stud galleries and may act as grub screws.

Herb
Herb Adler

Remove the spark plugs from all cylinders. Watch through cylinder number two until you can see the piston moving upwards as you turn the engine over by hand. Put some rope into the cylinder and turn the crankshaft to bring the piston upwards. The rope will lift the cylinder head free from the block.

Les
Les Bengtson

Les's Idea sounds neat, other thought is attach a bracket to the thermostat housing studs, then if you have a hoist just gentle pull up, just enough to 'crack' the seal. Mike
J.M. Doust

You dont have to remove the studs - just the nuts (11)
Art Pearse

Hi Art,

You missed the point, what I mean is to remove the studs from the head. I've had them lock onto the head studs, making it almost impossible to remove the head.

Herb
Herb Adler

Herb, I understand your point and it's a good one. I was just wondering why Mr. Lester was removing the cyl head studs, unless they came out b/c the nuts were tight on the threads.
Art Pearse

Hi Art,.
Sorry about that.
I have found that head studs sometimes come out, rather than the nuts coming off, particularly the external ones.
I wonder if the studs that didn't come out include the 4 that also hold the rocker assembly, if so then my suggestion holds a lot more water. If the manifold fasteners are truly studs my idea is wrong, but a PO may have replaced them with threaded rod, as mine were, and tightened them up, (onto the head studs). It took me quite a lot of effort to remove the head. I eventually forced those 4 studs out of the block and didn't find out what the problem was until I got the head to the bench, still with those studs firmly locked in place.

Herb
Herb Adler

You should be able to remove the remaining studs by fitting two nuts and locking them together. Then all that is required is a sharp sideways tap with a mallet to remove the head.
Iain MacKintosh

If it is the remaining head studs, that are holding the head in place, they may have rusted and become almost part of the head. Repeated applications of penetrating oil and heat should free the bond that has formed between them. Les's rope trick will work almost all of the time, unless there is rust holding everything together. Also, a lead shot filled deadblow hammer will work much better than a rubber hammer in this application. RAY
rjm RAY

Hi everyone, thanks for your many ideas, I have already tried lots of penetrating oil, leaving it overnight to soak in, and then I have tried the two nut approach but I think these particular studs are rusted in or someones put threadlok on them either way they won't undo. It looks like the old rope trick is next.

Bobbo
R LESTER

This thread was discussed between 16/02/2012 and 18/02/2012

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