Yuck, broken rings, burnt pistons - The 1947 - Present Chevrolet & GMC Truck Message Board Network

O'l Buck · 04-15-2002, 01:41 AM

my $20 327 is now down to bare block. I found out for sure where all the oil was going now. The moron that put the thing together forgot to stagger the ring gaps, and it has 2 pistons with burnt tops, broken and burnt ring lands, broken and missing pieces rings. Thank got it didn't hurt the cylinder walls. It's already .060 over and I'm not real crazy about boring it any more. It's been a long time since I've seen pistons in this bad of shape. Can anyone tell me what caused the burnt pistons and broken lands??? I forget what all will do this. The engine is only supposed to have less than 500 miles on the overhaul and I'd believe it. The bearings still look new and so do the pistons that arent destroyed.

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Ol' Buck: '72 Chevy 1/2T 4x4 shortbox stepside 350/350auto on '84
ralleys and 31/10.5s

Angel girl: 67 Cutlass convertible
330, 3spd stick

Greener: 90 GMC Jimmy
350/auto
Chad Stephens
Orleans,NE

no name yet: 72 442 under serious construction

Woody · 04-15-2002, 11:49 AM

Running an engine very lean on fuel will burn the piston tops. Other than that I don't know.....

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Woody
'69 Custom-10 Deluxe
Short Fleetside,Factory 350cid/TH400,A/C,PS,PB,Carpet
Coming soon 700R4, 350 Crate Engine, Pwr Disks...

O'l Buck · 04-15-2002, 12:20 PM

these things look like someone attacked them with a torch and a hammer. Just down 1 side of each piston. I've seen diesel truck engines do this with bad injectors, but never pulled a gas piston that looked like this, I was wondering if maybe it was a fault in the pistons, since it's only 2 of them and the others are perfect.

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Ol' Buck: '72 Chevy 1/2T 4x4 shortbox stepside 350/350auto on '84
ralleys and 31/10.5s

Angel girl: 67 Cutlass convertible
330, 3spd stick

Greener: 90 GMC Jimmy
350/auto
Chad Stephens
Orleans,NE

no name yet: 72 442 under serious construction

69 longhorn · 04-15-2002, 12:24 PM

Are they # 3&5,or # 4&6 ?

O'l Buck · 04-15-2002, 01:41 PM

69 Longhorn, they are #3 and #5

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Ol' Buck: '72 Chevy 1/2T 4x4 shortbox stepside 350/350auto on '84
ralleys and 31/10.5s

Angel girl: 67 Cutlass convertible
330, 3spd stick

Greener: 90 GMC Jimmy
350/auto
Chad Stephens
Orleans,NE

no name yet: 72 442 under serious construction

69 longhorn · 04-15-2002, 01:55 PM

Thats a hot spot,when they overheat(2 ex ports close together). Is there evidence of a blown head gasket?

O'l Buck · 04-15-2002, 02:00 PM

no, but the head gaskets were gone when I bought the engine, it was an auction deal and the guy had taken the heads off to investigate the oil burning problem. He said it only had less than 500 mi on the overhaul and figured the guy he had put it together broke an oil ring or something. It's bored .060, do you think maybe there is a problem with cylinder walls being too thin??

------------------
Ol' Buck: '72 Chevy 1/2T 4x4 shortbox stepside 350/350auto on '84
ralleys and 31/10.5s

Angel girl: 67 Cutlass convertible
330, 3spd stick

Greener: 90 GMC Jimmy
350/auto
Chad Stephens
Orleans,NE

no name yet: 72 442 under serious construction

69 longhorn · 04-15-2002, 02:05 PM

I would sure have it checked for cracks/warpage in the deck area,but It sounds like it blew a head gasket to me. I havent run any +060 blocks,but from what i understand,it shouldnt be a problem.Good luck....69 longhorn.

O'l Buck · 04-15-2002, 02:09 PM

I think I'll run it up to the machine shop. I hate to spend the money to put it together and have the same problem again. I wonder if it happend because the ring gaps were aligned, not staggered. 4 of the pistons had the rings aligned. Pretty sloppy overhaul if you ask me. Is it possible for the fire to flow down through the ring gaps and cut the pistons when they are not staggered??

------------------
Ol' Buck: '72 Chevy 1/2T 4x4 shortbox stepside 350/350auto on '84
ralleys and 31/10.5s

Angel girl: 67 Cutlass convertible
330, 3spd stick

Greener: 90 GMC Jimmy
350/auto
Chad Stephens
Orleans,NE

no name yet: 72 442 under serious construction

tom hand · 04-15-2002, 02:14 PM

I had a 60 over 350 that started burning oil on one cylinder for no reason. When a motor burns oil on just a couple of cylinders it will detonate just on those cylinders but it is much harder to hear. My 60 over 350 melted the head off valve which finished off the head, piston and block. I sure a lot of people will tell about their 60 over blocks that they had no problem with,but I think once you get to 60 over it's kinda like forrest's box of chocolate.

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72 GMC Sierra SWB almost finished---- 84 Softail
Olive Branch MS

O'l Buck · 04-15-2002, 02:18 PM

it could very well be detonation, the guy used the motor in a 70 c-30 dually to haul tractors and farm equipment around delivering and picking them up from his shop. He said it ran great and pulled good, but it burned a Qt of oil every 50 miles from the day it left the shop. He said he only ran it a couple weeks like that and then pulled it out. I wish he hadn't waited so long.

------------------
Ol' Buck: '72 Chevy 1/2T 4x4 shortbox stepside 350/350auto on '84
ralleys and 31/10.5s

Angel girl: 67 Cutlass convertible
330, 3spd stick

Greener: 90 GMC Jimmy
350/auto
Chad Stephens
Orleans,NE

no name yet: 72 442 under serious construction

Longhorn Man · 04-15-2002, 04:34 PM

I think tom hand is right

Quote:

it's kinda like forrest's box of chocolate

I have seen an 80 over 350 on the street as a daily driver.
Guy had bigger balls than I do, that's for d@mn sure.

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'69 G.M.C. 350/350. Trying to clean up the left over damage from the Dope-Smokin-Old-Man
I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it.
FINALLY got the HORNIAC...a '70 one ton Longhorn with a Pontiac 350/350 and lots of 'personality'. Check out The Longhorn Webite.
If you need a pic posted, E-mail me at longhornmail@yahoo.com
Andy, in Columbus Ohio

04-15-2002, 01:41 AM	#1
O'l Buck Recovering Truck Driver Join Date: Mar 2002 Location: Orleans, NE USA Posts: 1,883	Yuck, broken rings, burnt pistons my $20 327 is now down to bare block. I found out for sure where all the oil was going now. The moron that put the thing together forgot to stagger the ring gaps, and it has 2 pistons with burnt tops, broken and burnt ring lands, broken and missing pieces rings. Thank got it didn't hurt the cylinder walls. It's already .060 over and I'm not real crazy about boring it any more. It's been a long time since I've seen pistons in this bad of shape. Can anyone tell me what caused the burnt pistons and broken lands??? I forget what all will do this. The engine is only supposed to have less than 500 miles on the overhaul and I'd believe it. The bearings still look new and so do the pistons that arent destroyed. ------------------ Ol' Buck: '72 Chevy 1/2T 4x4 shortbox stepside 350/350auto on '84 ralleys and 31/10.5s Angel girl: 67 Cutlass convertible 330, 3spd stick Greener: 90 GMC Jimmy 350/auto Chad Stephens Orleans,NE no name yet: 72 442 under serious construction __________________ 67 K-20 350, SM465, Eaton rear, 4.56 no spin option 00 Dodge 2500 4x4, 24V cummins, 5 speed Chad South Central Nebraska

04-15-2002, 12:24 PM	#4
69 longhorn Registered User Join Date: Aug 2001 Location: rock island,il,usa Posts: 5,382	Are they # 3&5,or # 4&6 ? __________________ http://community.webshots.com/user/hotrodhorn

04-15-2002, 01:55 PM	#6
69 longhorn Registered User Join Date: Aug 2001 Location: rock island,il,usa Posts: 5,382	Thats a hot spot,when they overheat(2 ex ports close together). Is there evidence of a blown head gasket? __________________ http://community.webshots.com/user/hotrodhorn

04-15-2002, 02:00 PM	#7
O'l Buck Recovering Truck Driver Join Date: Mar 2002 Location: Orleans, NE USA Posts: 1,883	no, but the head gaskets were gone when I bought the engine, it was an auction deal and the guy had taken the heads off to investigate the oil burning problem. He said it only had less than 500 mi on the overhaul and figured the guy he had put it together broke an oil ring or something. It's bored .060, do you think maybe there is a problem with cylinder walls being too thin?? ------------------ Ol' Buck: '72 Chevy 1/2T 4x4 shortbox stepside 350/350auto on '84 ralleys and 31/10.5s Angel girl: 67 Cutlass convertible 330, 3spd stick Greener: 90 GMC Jimmy 350/auto Chad Stephens Orleans,NE no name yet: 72 442 under serious construction __________________ 67 K-20 350, SM465, Eaton rear, 4.56 no spin option 00 Dodge 2500 4x4, 24V cummins, 5 speed Chad South Central Nebraska

04-15-2002, 02:05 PM	#8
69 longhorn Registered User Join Date: Aug 2001 Location: rock island,il,usa Posts: 5,382	I would sure have it checked for cracks/warpage in the deck area,but It sounds like it blew a head gasket to me. I havent run any +060 blocks,but from what i understand,it shouldnt be a problem.Good luck....69 longhorn. __________________ http://community.webshots.com/user/hotrodhorn

04-15-2002, 11:49 AM	#2
Woody Registered User Join Date: Feb 2000 Location: Georgetown, KY, USA Posts: 631	Running an engine very lean on fuel will burn the piston tops. Other than that I don't know..... ------------------ Woody '69 Custom-10 Deluxe Short Fleetside,Factory 350cid/TH400,A/C,PS,PB,Carpet Coming soon 700R4, 350 Crate Engine, Pwr Disks...

04-15-2002, 12:20 PM	#3
O'l Buck Recovering Truck Driver Join Date: Mar 2002 Location: Orleans, NE USA Posts: 1,883	these things look like someone attacked them with a torch and a hammer. Just down 1 side of each piston. I've seen diesel truck engines do this with bad injectors, but never pulled a gas piston that looked like this, I was wondering if maybe it was a fault in the pistons, since it's only 2 of them and the others are perfect. ------------------ Ol' Buck: '72 Chevy 1/2T 4x4 shortbox stepside 350/350auto on '84 ralleys and 31/10.5s Angel girl: 67 Cutlass convertible 330, 3spd stick Greener: 90 GMC Jimmy 350/auto Chad Stephens Orleans,NE no name yet: 72 442 under serious construction __________________ 67 K-20 350, SM465, Eaton rear, 4.56 no spin option 00 Dodge 2500 4x4, 24V cummins, 5 speed Chad South Central Nebraska

04-15-2002, 01:41 PM	#5
O'l Buck Recovering Truck Driver Join Date: Mar 2002 Location: Orleans, NE USA Posts: 1,883	69 Longhorn, they are #3 and #5 ------------------ Ol' Buck: '72 Chevy 1/2T 4x4 shortbox stepside 350/350auto on '84 ralleys and 31/10.5s Angel girl: 67 Cutlass convertible 330, 3spd stick Greener: 90 GMC Jimmy 350/auto Chad Stephens Orleans,NE no name yet: 72 442 under serious construction __________________ 67 K-20 350, SM465, Eaton rear, 4.56 no spin option 00 Dodge 2500 4x4, 24V cummins, 5 speed Chad South Central Nebraska

04-15-2002, 02:09 PM	#9
O'l Buck Recovering Truck Driver Join Date: Mar 2002 Location: Orleans, NE USA Posts: 1,883	I think I'll run it up to the machine shop. I hate to spend the money to put it together and have the same problem again. I wonder if it happend because the ring gaps were aligned, not staggered. 4 of the pistons had the rings aligned. Pretty sloppy overhaul if you ask me. Is it possible for the fire to flow down through the ring gaps and cut the pistons when they are not staggered?? ------------------ Ol' Buck: '72 Chevy 1/2T 4x4 shortbox stepside 350/350auto on '84 ralleys and 31/10.5s Angel girl: 67 Cutlass convertible 330, 3spd stick Greener: 90 GMC Jimmy 350/auto Chad Stephens Orleans,NE no name yet: 72 442 under serious construction __________________ 67 K-20 350, SM465, Eaton rear, 4.56 no spin option 00 Dodge 2500 4x4, 24V cummins, 5 speed Chad South Central Nebraska

04-15-2002, 02:14 PM	#10
tom hand CCRider Join Date: Feb 2000 Location: Olive Branch,MS,USA Posts: 2,232	I had a 60 over 350 that started burning oil on one cylinder for no reason. When a motor burns oil on just a couple of cylinders it will detonate just on those cylinders but it is much harder to hear. My 60 over 350 melted the head off valve which finished off the head, piston and block. I sure a lot of people will tell about their 60 over blocks that they had no problem with,but I think once you get to 60 over it's kinda like forrest's box of chocolate. ------------------ 72 GMC Sierra SWB almost finished---- 84 Softail Olive Branch MS __________________ 72 GMC Sierra SWB almost finished---- 84 Softail Olive Branch MS

04-15-2002, 02:18 PM	#11
O'l Buck Recovering Truck Driver Join Date: Mar 2002 Location: Orleans, NE USA Posts: 1,883	it could very well be detonation, the guy used the motor in a 70 c-30 dually to haul tractors and farm equipment around delivering and picking them up from his shop. He said it ran great and pulled good, but it burned a Qt of oil every 50 miles from the day it left the shop. He said he only ran it a couple weeks like that and then pulled it out. I wish he hadn't waited so long. ------------------ Ol' Buck: '72 Chevy 1/2T 4x4 shortbox stepside 350/350auto on '84 ralleys and 31/10.5s Angel girl: 67 Cutlass convertible 330, 3spd stick Greener: 90 GMC Jimmy 350/auto Chad Stephens Orleans,NE no name yet: 72 442 under serious construction __________________ 67 K-20 350, SM465, Eaton rear, 4.56 no spin option 00 Dodge 2500 4x4, 24V cummins, 5 speed Chad South Central Nebraska



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