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TR2/3/3A Head Gasket

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tinman58

tinman58

Jedi Knight
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I am doing an engine rebuild on my TR3. Lots of info on head gaskets. I have the 89 mm pistons and the Moss supercharger. I bought some parts already. Including the solid copper head gasket. I have read good and not so good. Any real life experience on good bad or indifferent?
The gasket I have is Moss #387-525 $169.99. or #694-515 $75.99 not really worried about the cost. But which is best.
 
The critical factor is matching the gasket to the 89mm bore.
There is never any guarantee that a replacement gasket will exactly match your block configuration.
The bonus with a copper gasket is that you can trim it to suit the bores etc....cannot be achieved satisfactoriy with a steel or composite gasket.
As a matter of interest, have you measure the combustion chamber volume to ascertain the compression ratio.
 
Tinman, IMHO you have gone too far , 89mm will NOT have sufficient sidewall strength for a blower.
You will need a broom and a basket when this grenade pops.
Mad dog
 
Mad Dog, I have about 15,000 miles on the 89mm and supercharger. Hitting 7 lbs of boost. Yea I ran it hard and was told by Guys smarter than me that it’s a bomb waiting to blow. Well I am getting a little older and maybe a little smarter, so in the future I’ll be easier on the right foot. What are your thoughts on the head gasket?
 
Just heard back from the machine shop. Apparently the crankshaft was .20 over . When I got the crank I was told it was .10 over. So that explains low oil pressure and the (noise) . So they are doing a line bore, to go .30 for main and pistons. Cam looks good and the cylinder head and valves are good. fix two broken head studs, shave the head and block.
 
Who assembled the engine?.....10 over bearings on 20 over crank, surely not.
You need to be very careful if you "shave' [deck] the block...Could end up with protruding pistons, and therefore higher compression, or pistons too close to the head.
Piston tops can be machined down to suit, or thicker head gasket.
Recommend measuring the combustion chamber volume before the head shave.
Head shave after testing a piston for protrusion.
 
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you May have to tell the machine shop that the wet liners need a constant 3 , 4 0r 5 thou protrusion
I have seen shops used to moderns - deck the block with the liners in place and it’s all “nice and level” which means there will be no clamping force on the fig 8 gaskets at the bottom of the liners.
 
Tinman, Cometic head gaskets are worth the extra $$(spelling?) ran them on the race car due to the over bore.
Custom pistons would be my next suggestion. I run Vanolia's in my 59 . If memory serves ,some 70 grams
lighter than stock ,but you need to lower your pistons to take advantage of the blower(IMHO) compression
is your enemy on this motor .A little is good, a lot is NOT.I kept the 59 down to 9.1/1 just so I could use a blower.
But it did almost 160 on the engine dyno so it never got the blower. This motor has 35K on it now but when
this girl hits 6800 , You be JAMMIN !
Mad dog
 
Opps! crank was under not over.
 
I have a funny story about smuggling a crank to Honolulu back in the days when they just
took the bags and loaded up NC.
Connected next plane in LAX, and there was a really steep baggage Shute . The suitcase simply
exploded when it hit the stop at the bottom! Had to get a bunch of tape to go on ...
Mad dog
 
I have a modified TR3 head with enlarged asymmetrical valve openings and polished ports … (Kasner style). Tried a solid copper head gasket trimmed to fit. But it still leaked. Ended up buying Racetorations premium gasket with the sealant beads. Works fantastic. Very expensive but worth it.

I tried reaching Comitec several Times in this endeavor last year but they did not respond from phone or email. Hope your experience is better.
 
It's been awhile, But engine is in and running great. Oil pressure was 90 lbs at 2500 rpm's so backed off the pressure to 70 at 2000 rpm's. Very happy with everything so far. It was almost 60 degrees here yesterday so took it out for the maiden drive. Wow sure felt good. Also happy to get the garage back to normal. So next breaking time, retorque the heads and I hope that it will be the last time of major work on the TR3.
 
I got the composite head gasket from British parts northwest. Debated about the solid copper one.
 
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