Questions tagged [piston-ring]
8 questions
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What is the purpose of expander/spacer in the oil control ring?
I was reading about oil control rings in the piston ring topic. Most modern engines use a 3 piece design for oil control rings where you have top rail, bottom rail and spacer-expander (sandwiched between the former two).
My question is what is a…
Heatgunner
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Does substantially increased compression test numbers after adding oil to the cylinder necessarily imply that piston rings and/or cylinder bore is bad
SOLUTION: The tubes on the top of the motor for the PCV system were backwards. See https://invidious.fdn.fr/watch?v=07ssRI8k81E for correct configuration. Oil would pool in the air intake until you drove it up hill, and then it would start to enter…
user73135
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Piston ring wear and gap
I have few questions about rings, their wear and their gap.
What makes the worn ring "worn". Is it the ring gap that widens when ring wears down? Or is it mostly the edges of the rings that wont seal so well after they get "rounded"? What is the…
wtknow
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Piston ring gap
Does this look like too big of a gap on my old to compression piston ring?
It measures more than 0.04" (I stacked a 0.02 and a 0.021 feeler gauges together) but I could not find a specification for an acceptable range in my Haynes manual for my…
amphibient
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Which piston rings affect compression/seal?
Do only the top two piston rings, which are thicker and each sits in their own lands, affect the compression and sealing of the combustion chamber, or do the bottom three AKA "side rails" also affect it? I was under the impression that the latter…
amphibient
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Effect of engine oil on piston rings
I reassembled my pistons and put new rings in. After some trouble with leaky valves, I re-ground them, sealed them tight, and put the head back on. I was getting pretty good leakdown results (using an air compressor), somewhere between 86-92%…
amphibient
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Clipping oversize oil expander ring
I am installing new piston rings and had to go with oversize filed down to spec because the standard had gaps too big. The ends of the oversize oil expander seem like they are overlapping when placed in the groove. I know they are supposed to…
amphibient
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Cleaning piston ring grooves
My piston ring grooves had quite a bit of (oily?) gunk settlement. Is it appropriate to clean them with a dental pick? Is there risk to scratching them? My assumption is not since it is not a gasket mating surface. Also, what chemical is best to…
amphibient
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