Advice about HMG! I'm new here

alex_asgar · 05-04-2009, 12:34 AM

Hi, I'm new at this forum, so first, hello to everybody, I'm spanish so my english is not going the be the best... hope you don't mind it.
I just bought 92 7MGTE Supra, it has about 60.000 miles. I'm aware of the well-known head gasket supra problems... and I was wondering if I could get some advice about what to do first on my supra. I've read that Toyota never recognised a problem with the torque of the supra head bolts (heard they should be torqued on 72 lbls instead of the 50's factory...) and that they are very likely to have blown head gaskets. So I thought, the first I'll 'do with my car is replacing the factory HD and putting a HKS metal head gasket with ARP head bolts properly torqued. But now I see there are a lot of models of MHD, 2mm, 1.2 mm.... The supra's factory hd is 1.2, but I don't know if it would be better to put the 2.0mm hd to gain reliability.. even tough i'll loose some compression ratio. What do you think about eveything? Should I even wait and ride more miles before replacing it?
Thank you very much.

mirage83 · 05-04-2009, 02:27 AM

My personal opinion? Unless you have some reason to actually suspect a bhg all I'd do for the moment is check the torque on the headbolts. Retorque as necessary, make sure your cooling system is operating properly, stuff like that.

If and when you get a bhg (they do happen) and want to go to a metal hg, your machinist will be the one to tell you what size gasket you need to go with as it depends to a large degree on how much shaving they have to do to the block and head. BTW, mhg's take far greater precision on the decking work than normal head gaskets, so the finish has to be just right or it won't last.

I like ARP headbolts and headstuds, they're really good quality parts. But I don't myself really recommend changing them out unless you're doing the headgasket as well. I do know people who have done it replacing one bolt, torquing it then going to the next one, but the results are mixed. Some had no trouble afterwards, some suffered bhg's very shortly thereafter. The bhg's might have been totally unrelated, but I wanted you to know the whole story.

In any event, for the time being I'd just enjoy the car. 92's are relatively rare, and one with that few miles on it are even more rare. Take proper care of it and you should be fine for a lot of miles to come.

Oh, btw, your english is fine. Much better in fact than that of some who call this country home.

ddmcse · 05-04-2009, 10:38 AM

you shouldn't put a metal head gasket on without serious prep of the block and the head .
those surfaces need to better than factory

alex_asgar · 05-04-2009, 12:02 PM

Ok, I get that, I'll check the cooling system and see if it's ok. I've had the car only for a week so I guess i'll need more time to assure that. Then I'll just retorque my head bolts and enjoy... Thank you very much about everything.
mirage, thank you for the comment about my english.

IHateHacks · 05-04-2009, 12:08 PM

If you want to sleep good at night, perform a Block Test.

A Block Test detects CO (carbon monoxide) gas in the cooling system/radiator. If CO is present in the cooling system, exhaust gases are present. If exhaust gases are present, your head gasket is leaking.

05-04-2009, 12:34 AM	#1
alex_asgar Stock Join Date: May 2009 Location: Spain, Barcelona Posts: 2	Advice about HMG! I'm new here Hi, I'm new at this forum, so first, hello to everybody, I'm spanish so my english is not going the be the best... hope you don't mind it. I just bought 92 7MGTE Supra, it has about 60.000 miles. I'm aware of the well-known head gasket supra problems... and I was wondering if I could get some advice about what to do first on my supra. I've read that Toyota never recognised a problem with the torque of the supra head bolts (heard they should be torqued on 72 lbls instead of the 50's factory...) and that they are very likely to have blown head gaskets. So I thought, the first I'll 'do with my car is replacing the factory HD and putting a HKS metal head gasket with ARP head bolts properly torqued. But now I see there are a lot of models of MHD, 2mm, 1.2 mm.... The supra's factory hd is 1.2, but I don't know if it would be better to put the 2.0mm hd to gain reliability.. even tough i'll loose some compression ratio. What do you think about eveything? Should I even wait and ride more miles before replacing it? Thank you very much.

05-04-2009, 02:27 AM	#2
mirage83 12psi boost Join Date: Feb 2007 Location: Georgia Posts: 359	My personal opinion? Unless you have some reason to actually suspect a bhg all I'd do for the moment is check the torque on the headbolts. Retorque as necessary, make sure your cooling system is operating properly, stuff like that. If and when you get a bhg (they do happen) and want to go to a metal hg, your machinist will be the one to tell you what size gasket you need to go with as it depends to a large degree on how much shaving they have to do to the block and head. BTW, mhg's take far greater precision on the decking work than normal head gaskets, so the finish has to be just right or it won't last. I like ARP headbolts and headstuds, they're really good quality parts. But I don't myself really recommend changing them out unless you're doing the headgasket as well. I do know people who have done it replacing one bolt, torquing it then going to the next one, but the results are mixed. Some had no trouble afterwards, some suffered bhg's very shortly thereafter. The bhg's might have been totally unrelated, but I wanted you to know the whole story. In any event, for the time being I'd just enjoy the car. 92's are relatively rare, and one with that few miles on it are even more rare. Take proper care of it and you should be fine for a lot of miles to come. Oh, btw, your english is fine. Much better in fact than that of some who call this country home. Last edited by mirage83; 05-04-2009 at 02:37 AM.

05-04-2009, 10:38 AM	#3
ddmcse 500whp yet? Join Date: Jun 2005 Location: CT U.S.A. Posts: 966	you shouldn't put a metal head gasket on without serious prep of the block and the head . those surfaces need to better than factory __________________ 300+ RW HP Dyno run, jdm,mod turbo,3"exh,electfan,greddyboost Blown HeadGasket info My Supra KiXGaS

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05-04-2009, 12:02 PM	#4
alex_asgar Stock Join Date: May 2009 Location: Spain, Barcelona Posts: 2	Ok, I get that, I'll check the cooling system and see if it's ok. I've had the car only for a week so I guess i'll need more time to assure that. Then I'll just retorque my head bolts and enjoy... Thank you very much about everything. mirage, thank you for the comment about my english.

05-04-2009, 12:08 PM	#5
IHateHacks 20psi boost Join Date: May 2006 Location: New Haven/Hamden Posts: 793	If you want to sleep good at night, perform a Block Test. A Block Test detects CO (carbon monoxide) gas in the cooling system/radiator. If CO is present in the cooling system, exhaust gases are present. If exhaust gases are present, your head gasket is leaking.