Head Gasket--Re-torque on 5VZ-FE??

[edelm]

So I just purchased a '98 4runner with a bad head gasket. This is my first one, and I'm super excited. I have the heads off now, and I have MLS gaskets to put in.
I've done head gaskets on SOHC engines. Re-torquing is easy, you just pull the valve cover. On this DOHC engine, I'd have to take the cams off in order to re-torque, and there's a considerable amount of work that goes into removing the cams once the engine is assembled to the point that it can run for a while.
So to all you who have replaced your head gaskets, did you re-torque? If not, did it work out alright?
I purchased Fel-Pro Permatorque head gaskets, which claim they do not need to be re-torqued. Does anyone have experience with these? Do they last without ever being re-torqued?

Thanks for your help.

 

[edelm]

I've answered my own question. Here's a good description of the theory behind the head bolts.

Bolt Engineering - Torque to yield and Torque/Angle Tighten (TTY & TAT) - Mickey's RV8 Site

The head bolts are torque-to-yield. They stretch out some when you torque them down. Because of that, they should not be re-torqued, and should be replaced when you do the gasket.

With graphite gaskets, when the aluminum head expands with heat, it compresses the gasket some. The MLS gasket doesn't compress much, so the TTY bolts stretch some (maybe they just expand with heat as well??) to account for the expanding aluminum head.

I'm trying new head bolts from a cheap head gasket set by Evergreen. I figure if they are made out of the same grade metal, which they appear to be, they will yield at the same torque and apply the same force at that point. I will update this post if they ever fail on me.

 

[jlaho]

I'm doing a head gasket replacement on my 1997 4Runner and was looking at the Fel-pro Permatorque gaskets as well. How did they turn out for you, if you don't mind me asking?

 

[19963.4lsr5]

Yota Shop is where I and a few others got out headgaskets and replacement kit from.


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