Head Removal

[bigal]

Suddenly lost power and noticed tremendous imbalance in the A4 in our 37 Pearson. Checking compression indicated almost no compression in cylinders 2 and 3, leading to the diagnosis of Head Gasket failure. Proceeded to remove the Head noticing that several of the Head Nuts were very loose. The gasket did show signs of being compromised between the 2nd and 3rd cylinders. Several of the studs on the manifold side had Heli-coils inserted and the Heli-coils came out with the studs. Attempted to replace the Heli-coils, but couldn't torque the nuts without spinning the studs, so have gone to 1/2-13 studs in the block with 7/16-20 threads through the Head (which means the Head has to be drilled to clear the bigger threads). Is this going to compromise the engine, i.e. lead to water jacket failure?

[Don Moyer]

Drilling the holes in the head to 7/16" should not affect the head in any way nor should going to 1/2" threads in the block. However, if you haven't yet started your work, you might consider our 7/16" repair studs as being somewhat easier to use and a bit less invasive.

Don

[bigal]

Don - The Heli-coil tap major diameter (.460) is larger than 7/16 (.438) tap and this lead to the decision go to the 1/2-13 tap. Even the 1/2-13 threaded connection does not seem that great and I am wondering whether to use a metal loaded epoxy to seat the studs. Or should I just use the red hardening Loctite (262)?

[Don Moyer]

Either sealer should work well but if the threads end up having a bit of play in them I'd go with the epoxy. Loctite will not cure properly if your threads end up being a little loose because it only cures in the absence of air.

Don

[bigal]

I ordered the head gasket your site sells and notice that it is actually 2 gaskets. Is is recommended that 2 head gaskets be used? The head gasket we messed up noly required one (it came in a gasket kit with the Universal logo). The head gasket will have to be altered to clear the 7/16 studs.

[sastanley]

bigal...yes...you should use both gaskets. It has something to do with the thickness of the old gaskets as compared to the new gaskets.

Did you speak with Ken in parts? He is great at answering any questions you may have.

There is also lots of data on this site about the two vs. one gasket.