Steve
In the old days valve jobs were simply a resurfacing of the valve and cutting
the seat. Valve jobs or decarbonizing were also very cheap. The end result is
a deeper seat and a thinner valve. Result, the head appears to have valve
recession. With our current thinking that "I only want to do this once more in
my lifetime," we replace the valves and just about everything else and insist
on addressing those deep seats. Result, like new appearance and a much bigger
repair bill. As an aside, some heads are tolerant of deep seats and some crack
like fried marbles. AH 100 heads are prone to cracks (in various places), six
cylinder heads less so. Also remember that replacement valve seats are not fool
proof (good machinists or not so good, overheating, etc) and can come lose
during use. Not often but neither is the failure rate with deep seats. Just a
few thoughts....
Aloha
Perry
In a message dated 10/02/09 13:09:48 Hawaiian Standard Time, sbyers@ec.rr.com
writes:
Mike, when I had my BJ8 head rebuilt, the machinist told me that I had
significant valve recession. He showed me my head, in which all of the
exhaust valve faces were flush with the adjacent head surfaces, and a
rebuilt head from another type of car where the valve faces were
significantly proud of the head surfaces. When I got the head back, the
valves were like the other head.
I haven't seen any Healey engine head but my own, so I don't know. Was my
machinist correct or not?
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