Hi Guys,
On other engines I have had the top of the block machined with .030"
wide by .015" deep grooves around the bores to accept .030" soft iron
wire at 1/2 depth. This provides very good support for the steel "fire
rings" found on multi layer gaskets such as the Fel-Pro Perma-Torque
series. The gaskets have held the very high pressures found on turbo
charged engines with nitrous oxide. This would not work on a solid
gasket with relatively little crushability, but I've found it to be far
superior to thick copper gaskets. Copper is very weak at high
temperatures & tends to burn out or push out when exposed to high
combustion temperatures & pressures. The steel "fire rings" in the
composition gaskets are superior to gaskets with copper rings.
The same tehnique has also worked well on motorcycle engines.
Another way to help is to use cylinder liners that have the tops
projecting above the block deck surface as found in some other LBC engines.
My BN2 has an aluminum head with better internal support between
cylinders, & has given no trouble with standard multi layer copper faced
sandwich gaskets.
Milling the stock Hundred Four iron head with it's relatively thin deck
surfaces (around .200") is a sure way to make the sealing problems worse.
Dave Russell
BN2
David Porter wrote:
> Bob,
> Glad I'm not the only one with that problem, except mines between 3 and 4.
> The elegant way to fix it is to o-ring it, Though I wonder if there is
> really enough material there to do it. I had Mordy Dunst make me a thick
> copper gasket plus very thin steel o-rings laid on top of the gasket. It's a
> pain to get it all correctly aligned, but it gives enough extra squish
> around the bores to stop the slight leakage of compressed gases which
> eventually "burn" through. I also paint the edges of the gasket with sealant
> to stop the coolant leaks along the right side edge, where the clamping is
> the worst.
> Dave
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