Cary:
Are you using the correct head gasket? Do NOT assume that the
motor in your car is the original, and that therefore you can order a
head gasket by model year alone.
There are two different head gaskets, and they are not
interchangeable, even though they will physically fit on either motor.
When you take your head off, look at the deck of the block. Are there
recesses machined around the top of each cylinder bore? They will be
about 0.015" deep. If so, you need the later style head gasket, and it
must be installed CORRECT SIDE UP. The gasket will fit neatly upside
down, but it will fail in short order. The later gasket will have steel
fire rings around each cylinder, which must be mated with the
corresponding grooves on the motor. When properly installed, this gasket
will have a small tab at the REAR of the motor extending from between
the head and the block.
If your engine has no grooves around the bores, then you need
the earlier head gasket which does not have the steel fire rings. Check
carefully, but I believe this gasket can be installed either side up. In
either case, using the wrong or improperly installed gasket will result
in the symptoms you describe.
My car used the later gasket, but my DPO did not know which way
to put it in. Of course he put it on upside down (tab was at the front
of the motor instead of the rear). I had one half the normal compression
on my #6 cylinder as a result. This is how I learned about the differing
head gaskets.
So check carefully during your tear down. If you have the wrong
gasket or it is installed improperly, 95% chance that is the source of
your problems.
Vance
-----Original Message-----
From: owner-6pack@autox.team.net [mailto:owner-6pack@autox.team.net] On
Behalf Of Cary Henry
Sent: June 19, 2006 10:46 AM
To: 6pack@autox.team.net
Subject: Head Gasket Troubles Revisited
As you all know, I was having some head gasket leaking issues on my
project
76 TR6. I removed the head, cleaned up all corrosion and dirt on the
block
and head with scotch brite, checked the head for warpage (found none)
and
replaced the head gasket. I torqued all of the bolts to 75 lb-ft in 15
lb-ft increments. The engine was fine for a couple of weeks, but is now
seeping coolant again at the rear of the head right at the seam between
the
block and the head. I believe the head must be warped at the rear
because I
am not burning coolant, and there doesn't appear to be any coolant in
the
oil. I will be disassembling the head and bringing it to a local
machine
shop to get it magnafluxed and checked for warpage. When I reattach the
head I plan on using permatex copper spray-a-gasket sealant on both
sides of
the head gasket. I would like to recondition the head while it is
disassembled. What parts should I replace? The valves and springs look
good, but should I replace the valve guides? Also, will a standard
overhead
valve spring compressor be able to remove the double springs on the TR6
head? Sorry about all of the questions and thanks for your help!
Cary Henry
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