[TR] Could a steel shim head gasket be the answer to blowing head gaskets

[Tony Drews]

I've seen over 225 psi on my race TR-4 motor.  Seems I had close to 
250 on at least one cylinder.  Head gaskets aren't a problem for me 
(since I quit using the shim and copper ones, anyway), although I go 
maybe 1000 (very hard) miles between rebuilds.  Liner protrusion is 
key.  You need a few thou (say 2 to 4 thou), but not too much.  You 
can adjust this to a point by making custom figure 8 gaskets out of 
proper thickness shim stock.  Can be carefully done with 
scissors.  They should be reasonably flat, although I have a thou or 
two difference between the lifter side of the block and the opposite 
side.  The stock (Payen AE-330) composite gasket handles this 
fine.  I highly recommend Payen over the slightly cheaper stuff 
available.  ALL LINERS SHOULD HAVE VERY SIMILAR PROTRUSION - any 
differences will quickly cause head gasket leaks.

You can get ARP head studs and increase the torque a bit too, but 
that's probably overkill for a street car.

I presume you're doing the water in the oil thing instead of the 
"blowing all of the water out of the radiator" deal (caused by 
combustion gases in the water passages).  Water in the oil can also 
be caused by fig 8 gaskets.  I've seen that caused by poor cleaning 
of sealing surfaces, or by uneven surfaces on the sealing 
surfaces.  Combustion gases in the water is generally caused by no 
liner protrusion, or differences in liner protrusion, or a cracked 
head, or even a cracked liner.

I don't recommend an additional gasket - you've just doubled the 
number of surfaces that can leak.

By the way, I coat the block / liners / head / head gasket (and fig 8 
gasket) with Gaskacinch - seems to help things seal without being 
overbearing.  Be careful on the fig 8 deal - I got a little on the 
surface between the liner "foot" (the protrusion below the fig 8 
gasket) and the block and then couldn't assemble (and had a heck of a 
time disassembling).

If you are totally sure that the fig 8 surfaces are good, the fig 8 
gasket has no burrs, but you have a liner that sticks up a few thou 
more than the others, it is possible to shorten it using a plate of 
glass with a sheet of sandpaper / fine emery cloth taped to 
it.  Carefully run the top surface across it in a figure 8 pattern - 
check length frequently as going to far ruins the liner.  You have to 
be VERY meticulous in this to not get the top of the liner slanted 
too.  Takes less time that you'd think.  BE ABSOLUTELY SURE this is 
necessary before doing.  Usually there's a piece of grit on a figure 
8 sealing surface instead of a liner that's too long.

One other thing - there's a slight chance that too much advance 
causing ping would cause head gasket problems.

- Tony Drews