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What are the running characteristics of broken piston rings?
Is there a noticeable symptom that indicates a broken piston ring?
What is it? Generally, which ring is prone to break, top, middle, or oil control ring? |
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01-29-2004, 10:28 AM
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drag racing the short bus
Join Date: May 2002
Location: Location, Location...
Posts: 21,983
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I was just dicussing stuff like this with Tyson at TRE this morning. It seems to me a leak down might divulge issues like broken rings, but even that isn't definitive.
Loss of oil perhaps? Smoking on decel? Is anything like that occurring?
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The Terror of Tiny Town |
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01-29-2004, 10:31 AM
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Bandwidth AbUser
Join Date: Nov 2001
Location: SoCal
Posts: 29,522
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Great question, movin. I'd be interested in the answer. You might also want to post this on the 911 Engine Rebuilding forum.
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Jim R. |
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01-29-2004, 11:28 AM
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Location: Peoples Republic of Long Beach, NY
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only guessing,
top piston land gets worn. so I figure the top ring is more likely to break.
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Ronin LB '77 911s 2.7 PMO E 8.5 SSI Monty MSD JPI w x6 |
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01-29-2004, 11:58 AM
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Location: So. Calif.
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Off the top of my head, a low compression test reading might be an indication and/or increased blowby.
Sherwood |
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01-29-2004, 12:21 PM
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I think it's the sound of your credit card number being typed in at Pelican, the UPS man ringing your doorbell and lots of shouting.
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2022 BMW 530i 2021 MB GLA250 2020 BMW R1250GS |
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01-29-2004, 12:27 PM
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I had detonated /overheated the top ring, piston lay, and 2nd piston ring on my #1 and the top ring on #2 cylinders on a '73 2.7 motor before.
It smoked REALLY REALLY bad.... On acceleration more than decelleration. Good luck.
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Nick '85 Carrera |
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01-29-2004, 12:38 PM
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Senior Member
Join Date: Nov 2000
Location: Great NorthWest
Posts: 3,944
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An oily spark plug.
Pull your plugs and have a look. It is a good indicator of this problem.
John
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'78 Targa in Minerva Blue |
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01-29-2004, 02:02 PM
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1.367m later
Join Date: Feb 2002
Location: small farm town Iowa..........at last
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I just had this happen to the corvair. Biggest clue was excessive oil consumption. Increased crankcase pressure, and NO compression in #6. Complete disassembly revealed both compression rings were broken and managed to scar the cylinder wall pretty good.
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non velox ad propitiare, verisimile non oblivisci If it's not The Original Automotive Innovations and Restoration, then it's just hot AIR. |
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01-29-2004, 02:50 PM
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Yeah, it's using oil (500mi/qt), but like others smokes a little at start-up then settles down, smokes a little on acceleration, and accumulates a light brown film on the valence around the exhaust pipe after about 1000mi. I don't really see hardly any smoke and looking at the plugs there's no indication anything is wrong, it's like the oil is being spit out of the exhaust ports. If I drive it hard the oil consumption goes up (400mi/qt). Could oil be sucked down the exhaust guides? If so then during positive pressure the oil is blown back up into the cam towers, and during evacuation/low pressure it's being sucked into the exhaust ports?
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01-29-2004, 05:51 PM
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Only Porsche
Only bike
Porsche
