> 1) Are aluminum heads less or more prone to blowing headgaskets than
> cast iron? The theory being that if they are softer they may deform
> a bit more and better match any deformations of the block. Likewise
> they may deform more easily and let gas escape more readily.
I don't think they are more prone to leaking.
> 2) What about drilling the block and head to use larger studs. I
> believe that the current studs are 3/8", would going to 7/16" help?
Not necessary.
> 3) The machining marks are still quite visible in the head. Is there a
> way to smooth it out without removing the motor and taking it to a
> machine shop?
This one confuses me. You don't need to remove the engine to take the
head to a machine shop. I do recommend you take the head to a machine
shop and have it pressure tested. That only cost $20 around here.
> 4a) There were two things that gave me pause when I retorqued the
> head. First of all, sometimes I could not get the nut tight enough
> for the torque wrench to click "in the middle" of a swing and I
> would stop, ratchet the wrench back and it would click
> immediately. Is this a case of static versus dynamic friction and
> I may have accidentally torqued that stud to a lower value?
Don't use a click type torque wrench, use the flex type.
> 4b) When I retorqued the head, I did not back off all of the tappet
> adjusters. The theory being that with 10 other studs torqued all
> of the way down, the added stress from the valvesprings would be
> negligable.
Shouldn't make a difference.
> 5) Another place where I may have gone wrong was in torquing the head
> to 55 ft-lbs roather than 50. I had had a head gasket seep on a
> previous motor, until I retorqued it a bit higher.
I don't know if this will make a difference.
> 6) Has anyone else had chronic problems with blowing head gaskets?
> What was the root cause?
No, and I run 14:1 compression ratio. However a friend of mine did, he
was using a click style torque wrench that was not calibrated recently.
When is the last time yours was calibrated?
Does the head gasket always leak in the same area? If so, where.
Larry Hoy
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