Re: Re:head gasket

["Walter Sherwin" <wsherwin@home.com>]

Before tearing things apart,  it would be useful to run around all of the
head bolts with a torque wrench (in sequence) and see if clamp load has been
lost anyplace.  I've had ugly similar experiences in a combo that used ARP
studs (non-shanked bodies) together with Fel Pro blue "Permatorque" head
gaskets.  A lot of issues conspired to produce the failure in that
particular case, but the first clue was low cold torque on various cylinder
fasteners during the pre-teardown inspection.  In my case, the solution was
to step back to bolts instead of studs (slightly more elastic), and change
gasket manufacturers (to something more compliant).

Low cold post mortem torque is usually a sign of either:    1)inadequate
initial fastener preload, or   2)inadequate fastener stretch/elasticity, or
3)your AL cylinder heads have been grossly overheated and then cooled at
some point.  The fact that the Permatorque gasket itself is not compliant
just tends to amplify the effects of the above.

For the next rebuild,  maybe also consider a cold retorque after the engine
has been moderately loaded for the first time.  Of course you might also
want to re-examine your spark advance CAL figures too.  Good Luck!

Walt.



> > (which goes away later), and has been using water.  I sure hope it's not
a
> > cracked block or head!  My question is this . . . what can I do to
prevent
> > this in the future!  I am using edelbrock aluminum heads, have arp bolts
> > torqued to 75ftlb, using felpro gasket for aluminum heads and run a 160
> > thermostat which maintains 159.4F in the summer.  I do lean on it good
at
> > least once a day though.


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