Gentlepersons,
I think one of the reasons for chronic head gasket
sealing problems has not been mentioned here. The
stud holes in my Spitfire are not relieved at all,
and when I last removed the head and swept the
block face with fine sandpaper (wrapped around
a machinist's straightedge) to highlight high spots,
I noticed that the immediate neighborhoods of the stud
holes were higher than the rest of the block. This is
due to plastic deformation of the metal around the stud,
and will prevent intimate contact between the bulk of the
head-block area no matter how tight the stud bolts
are.
I believe the proper cure will be either to countersink
or counterbore each stud hole to put the load
deeper in the block and remove the high spots.
I have used copper gasket sealer; the interface still leaks
oil.
Tim
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