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Hi, I'm crazying I have a problem whit my 29 Chevy. The engine is not running well, sometimes it runs 5 cyliners, other times it runs 4 cylinders. I'm testing sparks and they're ok. I adjusted valves (0,008"). No results. I'd like to know wich is the cylinders' compression. I see in another topic that the compression of the engine for Chevy 1931 is 70/90 psi. Is it the same thing for 29 Chevy? Thanks for help. Saluti dall'Italia, Alfredo
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Tech Advisor ChatMaster - 25,000
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Tech Advisor ChatMaster - 25,000
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The Mangy Old Mutt
"If It's Not Junk.....It's Not Treasure!"
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Thanks Yunkyard Dog. I make a test and I check. Saluti dall'Italia.
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Joined: Feb 2016
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Shade Tree Mechanic
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Hi, It's been a year and I I start writing again. I have controlled compression with test dry and all cylinders have 60 psi with cold engine. Equal values (60 psi) with hot engine. Open Throttle. What do you tell me? Saluti dall'Italia.
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Shade Tree Mechanic
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Someone can help me? I have read that the compression ratio for '29 is 5:1 My compression is 60 psi. Is it good?
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Joined: Jan 2002
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ChatMaster - 25,000
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For older models all of my material just states compression should be the same on all cylinders and does not give a number.I would say 60 pounds for that engine with all being equal is fine. Compression gauges can vary as well as engine cranking speeds and engine temperature.
If cylinders cut out at times and is not an ignition problem you could have valves sticking and not closing properly and can be caused by carbon on the stems or guides too tight if they are new.
Last edited by Chev Nut; 07/30/18 01:55 PM.
Gene Schneider
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60 psig for a used engine with unknown history is okay. The fact they are all about the same indicates that nothing major is wrong. Your problem is more likely ignition or a sticking valve or two.
How Sweet the roar of a Chevy four!
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Shade Tree Mechanic
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