At some point my MGB (18V672 block) underwent a head transplant. The
one on it has no air injection ports, or bosses for same. The casting
number is 12H1326. The valves are dual spring but otherwise a mixed
bag--one has a rectangular groove (with a clip on the keepers), the
rest have circular grooves and no clip. All of the valves have an
upside-down plastic cup (shroud?) on the stem just above the guides,
rather than the O-ring seals. I believe the combustion chamber to be the
"pre-1970" shape, but it does not appear to be the earliest shape.
Any clues to the year of production?
The point is that the valves are pretty loose in the guides and I
observe some pitting on the seats (which are inserts). As long as
it's off, probably should fix it. The local machine shops of which I
am aware know small-block Chevys, but from previous experience I am
antsy about consigning it to their care. Alternatives?
--Apple Hydraulic will rebuild for no-lead, but for $375, which seems
excessive.
--British Parts NW sells a head w/stainless valves outright for $365.
Are stainless valves really an advantage?
--Is it safe to assume that valves/seats in newly-rebuilt heads these
days are OK for no-lead? Is this really a problem?
A. B. Bonds
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