7mgte head gasket

**30psi 4agte** · 20-09-2006, 08:48 PM

.
it is the design of the 7m that causes the probs not the fact that the engine isnt warmed up.

**petespipes** · 20-09-2006, 09:01 PM

Hylomar?

I thought it was a given to resurface a head before tensioning,regardless of proposed gasket.

Anyway,toyotacressida site has a book on this sublect.

Or,there are many engines without head gasket issues.

But tell that to the guy making 690rwkw with a 7m [frommemory,purple ma70]

**cambelt** · 20-09-2006, 09:04 PM

What a load of rubbish its the design of the 7m that causes BHG , its the design of the head torque and older gasket technology , with the block and prepped to JZ specs with a MLS gasket they are as relliable as a JZ engine , and means just about never blow head gaskets again
Dave

**30psi 4agte** · 20-09-2006, 09:31 PM

ahh ha ha ha I think you are taking my post the wrong way.

You say that its a load of rubbish that it is the design of the 7m that causes BHG but it is the design of the way the engine is torqued

Either way it is a design prob .

Anyway thats not what i was getting at. I am talking about the 7m being prone to probs with the std gasket on engines running over factory boost .

A std head gasket was not designed to cope with that amount of boost and neither were the head bolts designed to cope .
Thats not to say it cant be done as there are plenty of people doing this -- just to state that a steel gasket would be better suited in this application as they are designed to cope in this environtment.

**RyleyMA61** · 20-09-2006, 09:40 PM

one of the most important things when replacing the headgasket is replacing the bolts with aftermarket ones or aftermarket studs.

i'm onto my 4th headgasket, the one just blown was a HKS metal one- it blew due to the same old head bolts and dust between the head and gasket (!!!)

i also recommend a small running in procedure between retorquing of the headbolts.

i had mine fixed (standard headgasket with new bolts, torqued to 76ft/lbs) and for 500kms i was to drive with no boost, then have the bolts retoruqed. then another 500kms with only very minor boost, then another retorque.

a year on (lastest longer than my metal one, which was done by previous owner) and it hasn't missed a beat- never upped the boost past 6 however.... however i am told that i should be able to do 12psi safely, on the standard gasket, with the supporting mods.

but also make sure the block and head are dead smooth, like everyone is saying...

good luck!

**Stomps** · 21-09-2006, 10:53 AM

yeah good point.. forgot to mention.. NEVER USE THE SAME HEAD BOLTS AGAIN.. some people say its ok and they have done it blah blah etc.. but why risk all that bullshit again for the price of a head stud kit.. i mean its $250 ish.. just buy some ARP studs, get a MHG and FFS do it right..

When i had my steel gasket done first time i used all the right stuff, block/head machined, TRD sealent used with HKS MHG, ARP head studs, when i picked it up from my mechanic (Who builds rail dragsters for a living, so i assume he knows his shit) he told me drive for 1000k's off ANY boost what so ever, then come back, check the head torque etc.. We did that head up to way over the recomended factory torque and a bit more then ARP specified.. Got info off some bloke in the US with 500odd rwkw from his 7m. Never had issues with the gasket again for over a year of not exactly conservative driving..

Moral is.. if you dont have the money to do it right at the moment, save and then do it right.. put in another factory gasket now and you will end up with another BHG down the line..

Stomps

**TheStitt** · 22-09-2006, 06:51 AM

Steve

I always let my engine warm up.

I will add I'm using ARP head bolts to.

Cambelt what brand of H/G are you saying to use??

Also Stomps what Brand was your gasket??

Stitt

**Stomps** · 22-09-2006, 12:54 PM

first time HKS on my old motor

second time (current motor) cometic.. had a minor issue, coz one of the clips that holds the gasket together was on the mating surface (block and head) had to remove the clip then it worked fine... its copped a punishment for over a year now and no issues...

Stomps

**HKS_TRD** · 22-09-2006, 01:34 PM

Interesing discussion.

One point though, the standard Toyota finish on the block deck is fine for a MHG when the motor was built, but after a long unknown history and possibly some BHGs in the past the block deck is no longer smooth and so no longer the factory finish.

I've been running a HKS MHG (The bead type with ARB bolts) and no problems at 360RWKW so far. Though the stopper HKS or Greddy head gasket are superior again