Hi Doc
After John Staigers comments I guess I need to reply.
The MLS gaskets you have are really pretty good and should have stood up to
the boost levels you have subjected them to, providing that surface finish,
flatness, and waviness are within acceptable limits.
The unit load in the bore area should be sort of OK if you have good clamp
load on all fasteners (studs)
UNLESS
You have experienced pre ignition or detonation.
If the gasket cylinder sealing area is nibbled away and/or looks like a
blowtorch hit it, you have preignition and there is virtually no gasket that
will survive.
The music wire is a crutch, and the very best seal is a high pressure gas
filled metallic"O" ring on the edge of the bore. (usually inconnel X750
material). This can now be done without machining the block or head.
Cometic and others make gaskets (spacers) that seal fluid passages and have
a larger bore to accommodate the O ring. (Helicoflex)
If in fact you have a blown gasket in the combustion sealing area, you need
to resurface the heads and block to make sure flatness and waviness are
good. The machine shop needs to use early specifications of 4.6L Ford in
all three parameters.
You should also look at clamp load. With 4 7/16" fasteners for each bore
I feel that you are marginal. 1/2" studs that provide more clamp load for
equal torque values work well with the small block Ford. Watch the exhaust
side fasteners though for loss of clamp load. If you overcome the column
strength of the boss in the head, with high heat in the port area you can
loose load with aluminum heads. My 2.3 L engines have seen that problem in
the past till I updated to the latest head with crossflow cooling and water
all around the exhaust port.
I hope some of this helps.
Rick
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