Help me help out my buddy here.
Thread Starter
Team Owner
Joined: May 2002
Posts: 24,337
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Help me help out my buddy here.
This poor guy has rebuilt his motor twice now, and not making any progress. His dad is actually doing the work, he's an old school diesel mechanic.
Both times, it's broken the ring lands or rings on 3 of the pistons, on the same cylinders. I try to give him advise based on the info he gives me, but he's not as knowlegable as me.
Think it could be out of round cylinders? Taper on the cylinders? Warped block? Warped deck surface allowing coolant into those cylinders every time? Maybe his dad is just a numbskull?
Any other ideas? It's a sweet ride, we used to go cruising in college, but as of late, it's just sitting under a canopy near Angel's Camp.
The last time he had it running it had crazy blowby, would cover the underside of the hood with oil droplets. Not sure if it was steam also or not, but I told him to tear it down after I saw that, and that was one rebuild ago and we're in the same shoes.
Both times, it's broken the ring lands or rings on 3 of the pistons, on the same cylinders. I try to give him advise based on the info he gives me, but he's not as knowlegable as me.
Think it could be out of round cylinders? Taper on the cylinders? Warped block? Warped deck surface allowing coolant into those cylinders every time? Maybe his dad is just a numbskull?
Any other ideas? It's a sweet ride, we used to go cruising in college, but as of late, it's just sitting under a canopy near Angel's Camp.
The last time he had it running it had crazy blowby, would cover the underside of the hood with oil droplets. Not sure if it was steam also or not, but I told him to tear it down after I saw that, and that was one rebuild ago and we're in the same shoes.
Thread Starter
Team Owner
Joined: May 2002
Posts: 24,337
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Ring gap was my suspicion the first time they tore it down, but he insists that wasn't the problem.
This is a 347 cube '57 Pontiac with matching numbers btw.
How he was able to factor out ring gap I have no idea.
This is a 347 cube '57 Pontiac with matching numbers btw.
How he was able to factor out ring gap I have no idea.
Team Owner
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From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
Originally Posted by CentralCoaster
This poor guy has rebuilt his motor twice now, and not making any progress. it's just sitting under a canopy near Angel's Camp.
Team Owner
Joined: Sep 2003
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From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
Originally Posted by CentralCoaster
Arnold.
You familiar with the area? I love it up there. Not much flat ground to do wrenching on though.
You familiar with the area? I love it up there. Not much flat ground to do wrenching on though.
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Team Owner
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From: Cincinnati, Oh USA
Is there a ridge at the top of the cylinders? Ask him what the ring gap was measured at before he installed the rings. Did he use the original pistons? What is the measured piston to cylinder gap? What is the clearance between the rings and the piston ring slot? Did he rod the oil hole in the connecting rods? Did the engine run at the opening temperature of the thermostat? or did it overheat?
Last edited by jfb; Jan 11, 2005 at 08:45 AM.
Burning Brakes
Joined: Jun 2002
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From: Redding CA
Originally Posted by JrRifleCoach
NEAR Angels Camp? Like where near Angels Camp?
Le Mans Master
Joined: May 2004
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From: Hellinois
Finalist 2020 C4 of the Year - Modified
Originally Posted by rick lambert
Hope he used a ridge reamer! if he didn't-the ridge will break em forever.
This would be my guess too, especially if it's the top ring he's breaking. Not likely ring gap in an old Poncho unless the rings are oversize for the bore. Have him check and be sure the ring lands are uniform all the way around the piston. Take an old ring piece and use it as a feeler gauge to look for tight spots. Did they clean the lands out good? Carbon will build up in there. Also, make sure he's using a top quality ring compressor when installing them. The old band style compressors are practically useless.
Racer
Joined: Mar 2004
Posts: 311
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From: Oakley Ca
With his dad being an ol diesel mechanic, I'm sure the block was prepped right and rings insalled correctly. That said, I'd look at the compression ratio and detonation. In '57 the gas was a lot better than it is now with 100 plus octane ethyl being available at every station. High compression ratios were very common. Detonation can do bad things to pistons and rings, even rods. Ask me how I know? I'm tone deaf and can't hear the ping, so I've had the experience with todays lousy gas. Used to street race a new 57 Super Chief when I was a kid. Nothing then would touch it.
Thread Starter
Team Owner
Joined: May 2002
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Thanks for the pointers guys, I'll see if I can't enlighten them a bit. I have a feeling they'll be holding off on work awhile with all the snow. He does have it parked in a canvas garage, not a tarp.
I wish I could get some time to run up there and help him out with it. His dad wants to say hell with it and drop a SBC in there. Sacrelige!
I wish I could get some time to run up there and help him out with it. His dad wants to say hell with it and drop a SBC in there. Sacrelige!