Chevy bb 496
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Chevy bb 496
Hi Guys, New to the site! I am looking for some input on a 496 Chevy bb that I am running in a 23 ft Scarab concept. Was checking static cyl pressure the other day and was in the 140 psi range on all but @ 5 cyl and 6. they were at 90 psi. The motor had stock peanut heads ( i know, what was I thinking). I pulled the old heads today to install a set of 502 rectangular heads with a rpm air gap intake. I found a bit of moisture in the cyl with low psi. The boat was running good (60mph @ 4600rpm) Found a small crack on the right side head (#6 cyl) in combustion chamber. Im thinking I should bolt on the new heads and see how it runs.... What do you guys think?
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Check the cylinder walls for scuffing. Pistons could
have some stuck rings from being overheated and partial seizure. Don't ask me how I know. Maybe why the head is cracked, too. Compression test indicates a tired engine. You should have at least 150 psi on all cylinders if healthy. You might try a different compression tester to be sure. Good luck.
have some stuck rings from being overheated and partial seizure. Don't ask me how I know. Maybe why the head is cracked, too. Compression test indicates a tired engine. You should have at least 150 psi on all cylinders if healthy. You might try a different compression tester to be sure. Good luck.
Last edited by MACDAD260; 08-20-2012 at 09:18 PM.
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Thanks for the input. Had a bit of scuffing on the cyl walls. I am pulling the motor tomorrow and going to do a quick hone/ring replacement and inspection on the bearings. Figured I would go up in cam size a bit while I'm at it. Keeping my fingers crossed!