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MG MGB GT V8 Factory Originals Technical - Composite head gaskets

I am about to fit new composite head gaskets to my 3.9 engine. Can anyone tell me if I need to use a sealant like wellseal or similar or should they be fitted dry?.

Thanks

Mark Rawlins

I had to go through a right old procedure when fitting one to a Scimitar GTE (Ford 3 litre).

Scrupulously clean and degrease the head and block.

Assemble dry, torque down, and run the engine *without water* until quite warm but not hot.

Leave to cool down over night, torque down again, fill with water but do *not* replace radiator cap. Run until quite warm.

Leave to cool down over night, torque down again, fit radiator cap, and away you go.

No idea whether the advisor was pulling my plonker or not, but it worked.

PaulH.
Paul Hunt

Mark

You can fit them dry. Have you also looked at the ARP stud kit from RPI? Mine isn't running yet, but it seems like a good combination.

Guido
Guido Smit

Mark,
Sorry, but I bring more questions than answers to your original post. Was your 3.9 originally equipped with the composite head gaskets? Is it true that the composite gasket is thicker and will reduce compression unless the heads are milled the extra amount?. Also, is it true that one of the standard 3.9 studs is not used when you replace the standard head gasket with a composite one?
Charles
Charles Clarke

Thanks all
I phoned RPI on monday and the gaskets are fitted dry and torqued to 70ft lb.
The engine is from a 4.0 landrover discovery and was originally fitted with composite gaskets retaining a 9.35:1 ratio. I fitted the tin gaskets making it about 10:1 for performance but have had trouble with the head gasket leaking and pressurising the cooling system. Hopefully the composite gaskets are better.
It will be interesting to see the difference.

Charles, The outer row of four bolts are not used on the later engines and in fact the heads are not even drilled for these, but the composite gaskets have the extra holes.
Mark Rawlins

The car is back on the road with no cooling problems.
I am a bit dissapointed with the drop in performance so in future I will either get the heads skimmed or go back to the tin gaskets.

Cheers
Mark Rawlins

This thread was discussed between 09/06/2001 and 22/06/2001

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