OEM Headgaskets

cre · 07-17-2007, 01:32 AM

Are you planning on upping the boost anytime soon? The stock HG gets a bad rap. The HG wasn't ever the main problem, nor are the OEM headbolts it was the torque specs.

I would recommend new bolts but the OEM bolts are quite beefy. If you want to go with ARP's for the additional security, go for it. The OEM HG is NOT good for more than stock boost levels, I would trust it to last up to about 10, but anything beyond that and you're begging for trouble. There are a few people who I know of that are running 10psi (and have been for a year or more) on an OEM HG torqued to ~72ft lbs.

Even with an oem HG you need to check the deck for pitting, check the deck with a machinists straight edge, have the head cut a little (the HG's rings usually leave impressions which need to be removed), and then lap both for a very good and smooth surface. You may be able to get away with less, but I wouldn't try it. At any rate at this point, if the deck is flat and you do lap the head and deck well, I would probably go with a cometic HG.

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07-17-2007, 01:32 AM	#4
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Are you planning on upping the boost anytime soon? The stock HG gets a bad rap. The HG wasn't ever the main problem, nor are the OEM headbolts it was the torque specs. I would recommend new bolts but the OEM bolts are quite beefy. If you want to go with ARP's for the additional security, go for it. The OEM HG is NOT good for more than stock boost levels, I would trust it to last up to about 10, but anything beyond that and you're begging for trouble. There are a few people who I know of that are running 10psi (and have been for a year or more) on an OEM HG torqued to ~72ft lbs. Even with an oem HG you need to check the deck for pitting, check the deck with a machinists straight edge, have the head cut a little (the HG's rings usually leave impressions which need to be removed), and then lap both for a very good and smooth surface. You may be able to get away with less, but I wouldn't try it. At any rate at this point, if the deck is flat and you do lap the head and deck well, I would probably go with a cometic HG.