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2 Posts
Discussion Starter #1
Well my buddy blew his head gasket. He just bought the car and had it for about 2 weeks before he started messing with the boost controller (without an aftermarket boost gauge). Coolant in the oil, coolant coming out of tail pipe.

The car is pretty stock, 1987. All that I can tell that is aftermarket is an hks fmic, hks blow off valve (vents to atomosphere), manual boost controller and a cold air intake. Appears to have a stock fuel system. Engine is supposed to be out of a 92, if that matters. He wants to slowly get the most he can out of the stock turbo and fuel system and then he wants to go with larger injectors, bigger turbo, etc.... I will be selling him a real boost gauge and a wideband so he can see what is going on, before he starts turning the boost up.

Im an ASE certified master engine machinist, work at a high performance machine shop. I have lots of experiance with Toyota, all truck/suv. I am familiar how Toyota builds their engines though I have never seen the internals of 7m-gte. I will be pulling the head at my house and doing all necessary machine work at my shop. I have a few questions before I get going on this.

1)What head gasket do you guys think I should set him up with. MLS or Stock composite with o-ring? Head studs?

2)If I do o-ring, do you guys use the .045 ss wire protruding around .015?

3)Do these engines have the cam followers (lifters) that have shims for adjusting valve clearance?

4)Should I get a gasket set from Toyota or is aftermarket ok (like fel-pro, topline, etc..) Any seals / gaskets that dont come with the gasket set I should order (like fuel injector o-rings / seals)

5)Anything else I should watch for or take care of while the head is off?

Machine work I plan on doing at the shop:
pressure test
new valve guides as needed
Re-face valves, replace ex as needed with oem toyota
5 angle seat job
valve adjust
Resurface (surface finish depending on gasket)
o-ring head (if you guys recommend o-rings)
new valve seals

I will also be replacing other items such as t-stat, hoses ,belts and what ever else it needs.

If you need any more info let me know, thanks.

Frozen Lake Driver
1,284 Posts
If you just want to fix the head gasket without actually pulling the motor i'd just go with a stock HG unless the Deck is straight enough to put a Metal Head Gasket on it which will handle a lot more boost than the stock one plus as im' sure you know you can go a thicker MHG to lower the Comp Ratio which will allow you to boost a little higher. Also i would definetely go with ARP head studs, they don't stretch like stock bolts. also when you put the studs in i'd torque them much higher than toyota torque specs maybe around 70 Ft Lbs.

The 7M engines have mechnical lifters in them with shims to adjust clearance. I've seen the HKS and Cometic MHG are the best or atleast the most used. While you have the head off i'd replace the Valve seals.

I've given ya the information i know I've only been working on this engine for about a year so i hope this info helps a bit

2 Posts
Discussion Starter #4
Also i would definetely go with ARP head studs, they don't stretch like stock bolts. also when you put the studs in i'd torque them much higher than toyota torque specs maybe around 70 Ft Lbs.
I will torque the head studs to what ever arp recommends, I know not to use the Toyota head bolt specs.

Nice to know they make the mls gaskets in different thickness. I like to be able to compensate for the material I remove from the head.

I am aware of the limitations of mls gaskets, block will for sure be checked with a straight edge and cleaned very carfully. Head will be resurfaced to a "smooth as glass" finish. I know the it will cause problems if there are any imperfections with either surface.

How much boost can a mls w/arp head studs hold (assuming the tune is on)?
Should I re-torque the head studs after it has been run? Hot or cold?

Valve seals will be replaced even if they appear to be in good condition. Dont want to do this twice due to something as simple as valve seals.

Thanks the info so far it does help. If anyone else has anything to add please do so.
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