Maximum to shave off the head

[ianstaley]

Originally Posted by icey756

I already have .011 of an inch off my 7mgte head. I was wondering how much in total can be shaved off before running into problems?

I wouldn't quote me on this but I have had some experience of shaving the heads on another car that I turboed some years ago. I had a BMW 730 which was a NA carburetor model of some 3.0L. I turboed it using parts from a scraped 745 turbo. Now the 730 normally ran @ 10.5 to 1 and after shaving the head it was brought down to 8.5 to 1 which the engineers that did the job said was risky as there wasn't a lot of meat on the head. Even though the head had not blown a gasket it was warped (ally head). The result was that 3 months after the job was done it blew the HG.

So I would seriously check out the engine has it had a BHG before, if it has I would not be overly enthusiastic in using the head again as you may remove too much that can't be taken up with a thicker gasket.

I would imagine that the factory Comp ratio would be about 8 or 8.5 to 1 MAX. Hope that helps.