Mending the Achilles heel of the 7MGE

[BrianRA23]

After owning a MX83 Cressida with a 1JZ and being impressed with the build quality and and all other aspects about the car I found one in the paper for $400 with a cooked engine (in the country but licenced). I bought it for my dad as it otherwise sounded great (except for some faded paint on the roof) and I thought it was a bargain.

Anyway I am going to recondition the old engine from my conversion, but was wondering if there was a fix to the Achilles heel of the 7M, being the head gasket. I assume it is just about head gasket selection, but should I go OEM or does someone have a custom fix.

No engine conversion suggestions please.

[tooch]

From what I have read, the problem is that the stock head studs are crappy, and lose torque over time, allowing the head to lift and the gasket to blow.
So a metal head gasket with some ARP studs or similar, torqued correctly should go a long way to help prevent this.

[CrUZida]

Have a serious look at the head. If the water galleries have too much corrosion, throw the head away.

I have a feeling that the alloy used in many 7M head was sub-standard.

The best solution is mill head, deck the block, holomar(sp?) spray, ARP studs, metal head gasket. Torque properly.

Anything else and you can almost guarentee it will blow in the next 2 years.

[Norbie]

Do the above and make sure the block and cylinder head surfaces are prepared properly. It's probably overkill but you can be pretty sure you won't blow a headgasket after doing that.

[BrianRA23]

Thanks for the info, I will strip it and get it off to the machine shop as suggested.

Is there an off the shelf metal head gasket available for the 7MGE?

I have tried to locate one in the past -who sells them?

Do I need to get a copper one made?

[RONA]

Thanks for the info, I will strip it and get it off to the machine shop as suggested.

Is there an off the shelf metal head gasket available for the 7MGE?

I have tried to locate one in the past -who sells them?

Do I need to get a copper one made?

My car has a HKS 1.2mm MHG wheres Ed to tell us where he got it when we need him

[EldarO]

fixing the 7M really isnt that big of a job, just people skip a very important part.

corrosion!

the "meat" between the water galleries, oil galliers, and combustion chamber are thin to start with, however, combine this with corrosion over time, and you end up with even less material.

the key to fixing a 7M BHG properly, is to make sure all the material that should be there, is infact there.

so, get a head with minimal corrosion, then see if its in a decent state, if not, a head shop should be able to sort something out for you.

once thats done, both the head, and block need to be completely flat, and smooth.

im using a stock headgasket, on stock studs, and the engine has seen 10-11 psi, regularly, and i havent had an issue.

so, get the head checked to see if its in good enough condition to use, block and head machined flat, new headgasket, and if your paranoid, ARP headstuds.

headgaskets can be made, just go to your local (friendly) mechanic who does that sort of work, and he/she should know someone that can help you out.

Eldar.O.

[TheStitt]

Toyota have released a new stock head gasket, part number 1111542021

Both Whatthe and i have been running them with no real issues on our GTE's. He melted a piston and I warped the head before hurting the h/g.

For a GE I would just check everything deck the head, new toyota HG and just slightly over tourque the head bolts and if you really feel the need go a set or ARP's. This is all I did with my GE the first engine conversion my car saw, before the GTE. I had no issues at all the engine got flogged within an inch of its life for a year and survived.

[whatthe?]

Toyota have released a new stock head gasket, part number 1111542021

Both Whatthe and i have been running them with no real issues on our GTE's. He melted a piston and I warped the head before hurting the h/g.

For a GE I would just check everything deck the head, new toyota HG and just slightly over tourque the head bolts and if you really feel the need go a set or ARP's. This is all I did with my GE the first engine conversion my car saw, before the GTE. I had no issues at all the engine got flogged within an inch of its life for a year and survived.

And perhaps a new thermostat

j/k, I luv u

[TheStitt]

and yes as Matty pointed out get a new thermo stat its that $20 that is still causing me grief

[BigWorm]

I don't know if Stitt is refering to the same one, but I just picked up a partially disassembled 7M-GTE tonight that came with a new headgasket which was of the multi layered metal variety, and turned out to be a standard Toyota part.
It looked to be of very similar construction to my (4AGE) HKS metal head gasket. Looked the bizz.

[whatthe?]

There is no metal HG for 7M that is toyota genuine, the one we speak of is a graphite composite job. Who told you it was factory?

[BigWorm]

The Toyota sticker on the packaging. I guess there's a chance it's non genuine in a genuine packet, as it was open, I'll try to find out more.

[whatthe?]

Well, if there is I'd love to know the part number as would every other 7M owner on these forums. It would make finding a decent MHG for our engines much easier!

[BigWorm]

I didn't get a chance to sight the packaging and Toyota sticker & part no. again, but it seems the consensus is that it must just be an aftermarket jobie after all, that someone's stuck in the Toyota packaging for whatever reason.

Meh, I'm no 7M follower, I guess this is how some of these random fallacies begin.....