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TR2/3/3A TR3/TR4 Cylinder Head Gasket SElection

GerryL

Jedi Hopeful
Offline
What recommendations would you recommend for a stock TR4 engine with 87 cylinder liners? I have heard that the head gaskets for the standard bore 86 cylinders will result with the gasket extending into the combustion chamber, resulting in shorter head gasket life. There also seems to be significant variation in prices for the copper clad gaskets. Does higher price correspond to better quality. BPNW has a cylinder gasket (Head Gasket Set Big Bore 87mm to 90mm) which is described as providing a better seal without extending into combustion chamber. This gasket is described as "made with a perforated steel core and and elastomer surface that heats very evenly for a superior seal, plus the fire rings are made from a stainless steel. No blown head gasket with this head gasket". Would this 87/89 gasket provide any real benefit to justify the significant price difference?
 
Rumor has it that Payen has stopped production of those. But the last "no name" 86mm composite gasket I got from TRF had plenty of clearance for use with 87mm liners. I expect it will work fine.

However, double-check that the liner protrusion is within spec (.003" to .0055") when you measure on either side. I fought with head gasket issues for many years until I realized that I was always measuring on the same side ... when measured on the other side there was no protrusion at all! I've now found this on two engines in a row, so I have to think it is somewhat common. (But both were fairly early TR3 engines, so maybe it's not as common on later engines.)

Although the "right" solution would be to have the block machined, I worked around the problem by adding a ring of copper wire around each cylinder, soldered to the head gasket (mostly just to hold it in place during assembly). I covered over 100,000 miles on the engine I had in my (now wrecked) TR3A and never had a head gasket problem again. When the current TR3 started leaking after just a few months, I found the same problem (to a lesser extent) and applied the same fix. It's still going some 5 years later.

 
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