Is it a good idea to upgrade to Metal Head Gasket even if not blown yet?

[VegaSupra]

Hi,

I searched and read through several head gasket threads, but did not find an answer to this question specifically. I don't have my 91 Supra Turbo yet (haven't picked it up yet) but it has 68,000 original miles and I believe it still has the original head gasket.

Which of these do you recommend?

A) Leaving the original gasket in place but just retourque to tigther specs in hopes that it will hold better?

B) Get a 1.2mm HKS metal Head Gasket and replace it even if it's not blown and not causing problems but we all know if probably will? Would the head need to be machined even if the OEM HG was holding fine?

C) Wait until it blows. Then machine the head, replace with metal.

Thanks!
VegaSupra

 

[Nick M]

In the mid 90's (I think) Toyota changed their composite gaskets on everything. The 4Runner was recalled for the gasket. Toyota redid all of them, but only the 4Runner was recalled. The 7M has nothing on the 3VE. You will at least want the newer style composite and proper head torque.

 

[VegaSupra]

Hi Nick. Thanks for the reply. So if I understand you correctly, you are saying... go with option B? Replace it with a metal HG and have it torqued to the tighter specs than the original numbers?

 

[CyFi6]

The head and block BOTH need to be machined regardless of the previous gasket condition when installing an MLS type gasket, and machining the block requires complete dissasembly of the engine. If the engine is running fine, I would recommend you leave it that way (wouldn't even disrupt it by retorqueing personally). If it blows, it really depends on your goals with the engine. A stock 7mgte to a 7mgte with basic performance upgrades is perfectly fine with an OEM style gasket properly installed.

 

[IJ.]

The head and block BOTH need to be machined regardless of the previous gasket condition when installing an MLS type gasket, and machining the block requires complete dissasembly of the engine. If the engine is running fine, I would recommend you leave it that way (wouldn't even disrupt it by retorqueing personally). If it blows, it really depends on your goals with the engine. A stock 7mgte to a 7mgte with basic performance upgrades is perfectly fine with an OEM style gasket properly installed.

x2, only thing I would add is if you plan to crank some boost into it or do anything to get more power then pull the engine and prep it correctly for a MHG.

If you're happy with the stock engine output then leave it be it's gone 60K without blowing and contrary to popular belief they DON'T just blow for no reason or it'd have gone long before now.

 

[VegaSupra]

x2, only thing I would add is if you plan to crank some boost into it or do anything to get more power then pull the engine and prep it correctly for a MHG.

If you're happy with the stock engine output then leave it be it's gone 60K without blowing and contrary to popular belief they DON'T just blow for no reason or it'd have gone long before now.

The only thing I would do is let the engine breathe, meaning copy the setup I had on my previous 91T.

Downpipe
Test Pipe
Exhaust
Intake
BOV

No boost controller or anything. So I suppose I can just run it stock and see how it handles the slight bump in power from the open air flow.

Thanks for the help. If anyone else has anything thing to add, please feel free!

 

[IJ.]

Those mods alone are going to bump boost/power enough to be a danger if you drive it hard....

With any luck Fuel cut will save it, a composite HG won't take ANY detonation so be sure to use the best fuel available.

 

[VegaSupra]

Those mods alone are going to bump boost/power enough to be a danger if you drive it hard....

With any luck Fuel cut will save it, a composite HG won't take ANY detonation so be sure to use the best fuel available.

Suppose I had access to a shop that would put in a HG for me for $600 total. What I'm really wondering is would it be an intelligent thing to do in advance of HG failure?

I know this is a kinda a subjective question and a bit of a 'what if' scenario. I'm just curious if anyone thinks it's a good idea to take a proactive approach or just wait til the dern things blows. Does that do irreversible damage to the head or anything? Is there any penalty to just let the HG fail and then fix it? That's what I'm really wondering.

Again thanks everyone. Really appreciate it.

 

[Poodles]

Possibly can do damage, depends how bad it blows. If water gets in the oil, rod knock is next on the list. If the cooling system gets low enough to run the head dry, it anneals and becomes junk...

 

[IJ.]

Suppose I had access to a shop that would put in a HG for me for $600 total. What I'm really wondering is would it be an intelligent thing to do in advance of HG failure?

I know this is a kinda a subjective question and a bit of a 'what if' scenario. I'm just curious if anyone thinks it's a good idea to take a proactive approach or just wait til the dern things blows. Does that do irreversible damage to the head or anything? Is there any penalty to just let the HG fail and then fix it? That's what I'm really wondering.

Again thanks everyone. Really appreciate it.

What sort of HG?

 

[CT26smoker]

Possibly can do damage, depends how bad it blows. If water gets in the oil, rod knock is next on the list. If the cooling system gets low enough to run the head dry, it anneals and becomes junk...

Yup, my thoughts exactly, so +1.....

 

[VegaSupra]

Just found out that the original owner had the head bolts retorqued at 46,000 miles. It has 68,000 miles now and he says it's never had a problem so far. So it sounds like the bolts are holding pretty well.