need help choosing a head gasket

supranutz · 12-10-2009, 12:45 AM

my gasket isnt blown but at 160,000 miles its never been replaced i plan to go to a bigger turbo among other things and figured id just get it out of the way now instead of later, i plan to buy an hks gasket they come in several thickneses , i plan to resurface the head as i do on any hg what thikness gasket is appropriate ????

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.

supranutz · 12-10-2009, 01:55 AM

im not really lookin to pull the motor out but i want to put a better quality gasket than a stock one what else would you recommend ???

cre · 12-10-2009, 02:01 AM

Actually, the genuine Toyota HG isn't bad at all. If you really need a metal head gasket though, I would recommend Cometic; They're the most forgiving. Forgiving or not though, you're asking for trouble if you don't get the block resurfaced. If you pull the head and there is ABSOLUTELY NO PITTING and the block is level within a couple thousandths of an inch you can try lapping it with a precision lapping plate and diamond lapping compound and hope for the best.

The only composite HG I would use myself would be the Toyota HG. Neither the HG nor the head bolts were the problem to begine with... it was just the low torque value. My HG and those of most MKIII owners seem to have lasted 15 years or more with the low factory torque holding things together.

Still, for a high power build I do recommend a metal HG, but I do not recommend cutting corners.

12-10-2009, 12:45 AM	#1
supranutz Stock Join Date: Nov 2009 Location: texas Posts: 13	need help choosing a head gasket my gasket isnt blown but at 160,000 miles its never been replaced i plan to go to a bigger turbo among other things and figured id just get it out of the way now instead of later, i plan to buy an hks gasket they come in several thickneses , i plan to resurface the head as i do on any hg what thikness gasket is appropriate ????

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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.

12-10-2009, 01:55 AM	#3
supranutz Stock Join Date: Nov 2009 Location: texas Posts: 13	im not really lookin to pull the motor out but i want to put a better quality gasket than a stock one what else would you recommend ???

12-10-2009, 02:01 AM	#4
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Actually, the genuine Toyota HG isn't bad at all. If you really need a metal head gasket though, I would recommend Cometic; They're the most forgiving. Forgiving or not though, you're asking for trouble if you don't get the block resurfaced. If you pull the head and there is ABSOLUTELY NO PITTING and the block is level within a couple thousandths of an inch you can try lapping it with a precision lapping plate and diamond lapping compound and hope for the best. The only composite HG I would use myself would be the Toyota HG. Neither the HG nor the head bolts were the problem to begine with... it was just the low torque value. My HG and those of most MKIII owners seem to have lasted 15 years or more with the low factory torque holding things together. Still, for a high power build I do recommend a metal HG, but I do not recommend cutting corners.