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Old March 21st, 2014, 05:05 AM
Vern Vern is offline
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Default Re: Blown head gasket vs. cracked block

Quote:
Originally Posted by GMCDAC View Post
Hi Vern, a lot of mechanics claim that if a fresh head or heads are installed on a worn short block that it can cause the rings and possibly bearings to fail due to the increase in compression because of better sealing valves. I don't buy that, done it many times on race and street vehicles.

Just replacing a head gasket wouldn't change the compression and MIGHT solve your problem. Done that a lot of times too but it was usually obvious coolant was getting in a cylinder or leaking on the outside. It is definitely possible that the head gasket won't help. Just depends more about how much time you have to mess with it, not super expensive to try it.

Oh yeah, had to hit "edit"! I have no idea why you were told that the drive shaft needs machining while doing this work!!???

DAC
What you say pretty much covers what I heard. The idea was that you shouldn't fix "the top (head)" without fixing "the bottom (piston rings, bearings, crankshaft)". The guy I talked to was a racer. I just have to think about the trade off of putting money into an I6 vs the cost of buying and possibly rebuilding a V6. Might be worth the time to try the gasket fix and see what happens.

"driveshaft" was a typo for "crank shaft". The thought being that you should replace the bearings on the pistons, but not on an old crankshaft.
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