need help choosing a head gasket

cre · 12-10-2009, 01:21 AM

You'll also need to have the block machined for any MHG. You won't know what thickness until the shop finishes machining both the head and the block. Get the amount of material they removed and add that to the thickness of the stock HG (1.37mm)... ad a bit more if you're planning on running a TON of boost.

The block and head need to be perfectly flat and EXTREMELY smooth for a MHG. The HKS stopper is the hardest as you need an RA of 10 (might have been as high as 20; the higher the number the rougher the finish)... if the shop doesn't know what this means (RUN) or don't know if their machine can do it, find another shop.

12-10-2009, 01:21 AM	#2
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	You'll also need to have the block machined for any MHG. You won't know what thickness until the shop finishes machining both the head and the block. Get the amount of material they removed and add that to the thickness of the stock HG (1.37mm)... ad a bit more if you're planning on running a TON of boost. The block and head need to be perfectly flat and EXTREMELY smooth for a MHG. The HKS stopper is the hardest as you need an RA of 10 (might have been as high as 20; the higher the number the rougher the finish)... if the shop doesn't know what this means (RUN) or don't know if their machine can do it, find another shop.