problem with gm zz427
Thread Starter
Racer
Joined: Nov 2007
Posts: 350
Likes: 0
From: coon rapids mn
dad is still going to deal with gm, we have all winter to come up with a plan. it is embarrassing to start his car with all the smoke it makes at start up and with the side pipes it get everyones attention!
Burning Brakes
Joined: Sep 2008
Posts: 753
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i googled " zz502 problem " and in the Chevelle forum there are at least 3 threads about various issues with the GMPP BB crates.
Aside of the oil consumption issue (low tension rings, no plate hone) , there are also bolt-nuts randomly not torqued, random cylinder bores not honed, piston rings upside-down... all kind of things forgotten while making the engine. Are they drinking beer while making the engine?
Scary !!!!
I was almost there to buy a ZZ454... good that I read these things in time
Aside of the oil consumption issue (low tension rings, no plate hone) , there are also bolt-nuts randomly not torqued, random cylinder bores not honed, piston rings upside-down... all kind of things forgotten while making the engine. Are they drinking beer while making the engine?
Scary !!!!
I was almost there to buy a ZZ454... good that I read these things in time
Last edited by elle88; Nov 13, 2010 at 02:58 AM.
Thread Starter
Racer
Joined: Nov 2007
Posts: 350
Likes: 0
From: coon rapids mn
my old man has been talking to gm this week and it sounds like they are going to make it right! we will know more later this week but it sounds like they will pay for him to take it to the shop of his choice to perform the repairs!but we still have to pull it! ugh!
Pro
Joined: Apr 2009
Posts: 650
Likes: 1
Hey that's great news!
Imagine working to pull the motor all along knowing that you would have to fit the bill of the machine shop yourself. At least you know that your work will be justified and worth it! I would find the best machine shop in a reasonable area. You will end up with a much better in motor in the long run. Congrats and good luck!
Imagine working to pull the motor all along knowing that you would have to fit the bill of the machine shop yourself. At least you know that your work will be justified and worth it! I would find the best machine shop in a reasonable area. You will end up with a much better in motor in the long run. Congrats and good luck!
Burning Brakes
Joined: Sep 2009
Posts: 1,124
Likes: 140
From: Western New York
I'm 60 years old and have spent my whole life in Tonawanda, New York, home of the Tonawanda engine plant. I know they don't make the crate engines, but I know (knew) many guys who've worked at the engine plant on the line, and the majority of them don't even know how to change a spark plug and could care less about how the pieces go into an engine. Only concern is how much they make an hour. I'm sure it's the same at the crate motor plant. If buying a replacement engine, go with a reputable machine shop's recommendation and do your research first!
Duane
Duane
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Le Mans Master
Joined: Dec 2006
Posts: 5,557
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From: Oquirrh Mountains
St. Jude Donor '09
Thread Starter
Racer
Joined: Nov 2007
Posts: 350
Likes: 0
From: coon rapids mn
they did not find any tell tale signs but his theory is bore was a little to big and pistons where to small causing the piston to rock causing the rings not to seal. i don't have all the tech numbers in front of me right now but could get them if wanted. gm sent a rep to look over every thing at the shop too.
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
Congrats! Nice numbers.....did you guys change anything else in the engine to boost power or just a basic bore/hone/piston job?
Basically you guys did what GM should have done in the first place and bored the freakin cylinders right, then honed them with a torque plate. Sloppy sloppy work on GMs part and this is a fairly common occurrance on their crate motors..... I won't ever buy one.... or atleast not a new one....maybe an old used 502 and rebuild it myself using local machinists so I can over see the work.
Basically you guys did what GM should have done in the first place and bored the freakin cylinders right, then honed them with a torque plate. Sloppy sloppy work on GMs part and this is a fairly common occurrance on their crate motors..... I won't ever buy one.... or atleast not a new one....maybe an old used 502 and rebuild it myself using local machinists so I can over see the work.
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
It has the same cam/heads/intake as the ZZ502 only less 75 cubic inches....yet yours is making within 12hp of the 502 so.....pretty damn good I'd say.....
