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Checking for possible cracked 356 engine block

Postby Bill Butterworth ? Thu Jul 25, 2013 6:00 pm
Before doing a needed ring job on my 1940 356 engine want to check to see if the block is OK. Have some suspicions about the block due to the recent valve job when the exhaust valve guides were replaced. 5 of the guides had .002" interference the other 3 had .003" interference. After the valve job and starting the engine and getting it up to temperature, when the engine was turned off and was cooling down heard two cracking noises from the engine, sounded like our old house furnace when when I was a kid. Have no indication of water in the oil, but that may be due the guides sealing off a possible crack? What would be a good test if any for a cracked block?
Thanks, Bill

The best possible course of action is to go put your feet up and have a beer. 99.7% sure the noise you heard was the exhaust manifold moving relative to the block as it cooled down. When you start to have a problem with overheating, bubbles in the coolant, burnt valves, or water in the oil, then you have a problem.

And if the manifolds are getting hot enough to be noisy, be sure to verify the flap in the exhaust manifold is working properly - if it is sticking closed, this will contribute to the manifolds getting HOT and you do NOT want to be cracking 356 exhaust manifolds...they are already prone to that without invitation.

Good calm advise, will wine work?
Thanks

Yes, the heat riser valve is free and functions properly. As am unable to start engine second time after valve job, will have to remove manifolds and check for crack. Had manifolds resurfaced as part of valve job so not expecting any problems.
Thanks