just need some info on mhg (move thread if needed)

89supra7mgte

New Member
Sep 20, 2009
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colorado
Ok so i know i have been through this alot with my car, right now no issues. Just curious about a few things. I bought the car a year ago with po claiming bhg (MHG) no signs form my inspections. To be safe I decided to put a new composite on, engine maybe had 30 min idle time prior to my purchase on jdm 7m. Block and head were machined (backing plate also) Has arps as well. Well got 300 sissy miles on the car and 8 dyno pulls at 15 psi, bhg just cruising to the gas station. Anyways tore it down head and block still flat, cleaned up and looked like just got back from machine shop. I decided to re-install the original mhg, but this time took out the two rivets on pass side front and rear.

Today started the car up after installing safc2 (first one got stolen) let idle to op temp checked cooling system and fans and so on, all is good. brought rpm up to 1500 for a bit as well. No external leaks and no excessive pressure into expansion tank. I am going to do the same tomorrow or this weekend followed by a re torque on head at 100ft lb (didnt have moly lube and was told 30w works at 100 ft lb)

My question is, if the gasket had not properly been sealed on this install how soon would i see bhg? I would assume that if the ra was out or too much i would see problems pretty soon correct?

Experts enlighten me please thanks
 

I6Boost

New Member
Apr 14, 2010
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My Supra
89supra7mgte;1592896 said:
Ok so i know i have been through this alot with my car, right now no issues. Just curious about a few things. I bought the car a year ago with po claiming bhg (MHG) no signs form my inspections. To be safe I decided to put a new composite on, engine maybe had 30 min idle time prior to my purchase on jdm 7m. Block and head were machined (backing plate also) Has arps as well. Well got 300 sissy miles on the car and 8 dyno pulls at 15 psi, bhg just cruising to the gas station. Anyways tore it down head and block still flat, cleaned up and looked like just got back from machine shop. I decided to re-install the original mhg, but this time took out the two rivets on pass side front and rear.

Today started the car up after installing safc2 (first one got stolen) let idle to op temp checked cooling system and fans and so on, all is good. brought rpm up to 1500 for a bit as well. No external leaks and no excessive pressure into expansion tank. I am going to do the same tomorrow or this weekend followed by a re torque on head at 100ft lb (didnt have moly lube and was told 30w works at 100 ft lb)

My question is, if the gasket had not properly been sealed on this install how soon would i see bhg? I would assume that if the ra was out or too much i would see problems pretty soon correct?

Experts enlighten me please thanks

So you put that head gasket on there with the thoughts of "I wounder how long this will last"
Your gonna be doing main/rod bearings real soon.

You cant just keep putting on a new headgasket everytime it blows.

Why do you think its not sealed correctly?
You said the block is still flat, how did you check this?
&& if you would of had the RA checked your thread wouldn't exist right now.

None can tell you "when" or "if" your car will blow, there all totally different
and it depends on how you drive it.
 

89supra7mgte

New Member
Sep 20, 2009
797
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0
colorado
Very true. I am assuming the po did not torque the head properly, he had external leaks, and blown turbo. When i originally pulled it apart when i purchased it, you could see that it had been fresh out of the machine shop. He never drove it after doing the work, mainly because the turbo, blah blah blah.

Anyways I am not wondering because i know the head and block are flat, used high quality straight edge from work, snap on or some shit, with .001" feeler gauge, smallest i had everything is flat and true. Not too mention 300 easy miles on the engine, with no overheating, would it be necessary to re machine everything again?

Old gasket blew due to quality. i ran it 8 times on the dyno at 12-18psi with no issues. The gasket actually blew with no boost on engine.

So far new install is going good, two heat cycles re-torque. no coolant loss no overheat. driving style is conservative, boost when needed, not constant.

I am not asking how long it will last nor am i concerned about it, was only asking if by chance the gasket did not seal what would be the most likely time of seeing it.