white exhaust smoke
05-19-2017, 09:33 AM
#21
whit smoke
Some people insist on hardened seats in the old heads. The problem is, unless the machine shop does an ultrasonic test (UT) on each valve seat area before they cut the heads to install the seats, they really do not know how much they can cut out to install the hardened seats without getting into the water jacket (roll the dice as it is a crap shot). Combine that with the fact the old heads were sand casted and the thickness of the casting varied greatly back in the 60s, the installation of hardened seats commonly resulted in a set of expensive boat anchors (I have a pair I will send you free for shipping costs only, learned the hard way).
ONCE AGAIN, IF your head gaskets show no sign of leakage, and you have no mechanical damage (piston, valve, etc. that contacted the cylinder wall) to indicate the cylinder wall was damaged by a foreign object, and the engine was not extremely overheated (greater than 240 deg F for more than a few minutes, I would strip that head and run that head to a GOOD shop for pressured testing and magna flux (MT) as a minimum.
I am betting on either the head gasket or the cracked head (or hardened seat cut into the water jacket) as the crankcase should have gotten water in the oil if you have a cracked cylinder.
After your though investigation, you may have to decide whether to celebrate the block is not cracked or cry that you got screwed by the Ebay trash that sold you the heads that he probably knew were leakers.
I hope it is a bad head gasket.
PS: I have a set of 60s heads without hardened seats on my 68RS that have over 123,000 miles on them including racing on the strip for 5 years that I haven't experienced any problems with, although I haven't tore it down yet. Don't mess with mother nature nor GM design.
ONCE AGAIN, IF your head gaskets show no sign of leakage, and you have no mechanical damage (piston, valve, etc. that contacted the cylinder wall) to indicate the cylinder wall was damaged by a foreign object, and the engine was not extremely overheated (greater than 240 deg F for more than a few minutes, I would strip that head and run that head to a GOOD shop for pressured testing and magna flux (MT) as a minimum.
I am betting on either the head gasket or the cracked head (or hardened seat cut into the water jacket) as the crankcase should have gotten water in the oil if you have a cracked cylinder.
After your though investigation, you may have to decide whether to celebrate the block is not cracked or cry that you got screwed by the Ebay trash that sold you the heads that he probably knew were leakers.
I hope it is a bad head gasket.
PS: I have a set of 60s heads without hardened seats on my 68RS that have over 123,000 miles on them including racing on the strip for 5 years that I haven't experienced any problems with, although I haven't tore it down yet. Don't mess with mother nature nor GM design.
