59ab ring gap placement

Karl Wolf

Karl Wolf

Well-known member
I read something about ring gap placement disseminated from Honest Charleys Speed Shop about a superior method of ring gap placement, cannot remember where I saw it... method or where to find it... Anyone? Thanks, Karl
 

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The gap placement scenarios are filled with myth. I have made records of gap locations and found after a short dyno run or drag strip runs the gap locations will change dramatically.
 
Thanks for your trouble, BillM...
So there are two different theorys on ring gap placement...
1) Put the gaps at opposite ends of the wrist pin
2) Put the gaps so that they are perpendiculiar to the crank (just a point of reference)
I used number 2 last time, works fine

Anyone else with comments or opinions?
 
I agree that JWL is 100% right. All this ring gap position stuff is a myth and bench racing by those who only care about telling the wildest story of the night. Consider: Let's say an engine has a ring gap of .025" and the clearance between the top pf the piston and the cylinder wall is .160" (that's .080" on each side). So, .0125 X .08 = .002 sq. in. That's 2 thousandths of one square inch! How much compression can escape through this tiny opening? Very, very little! What does get by the top ring has to then pressurize the empty ring land space between the top and 2nd rings before it will go past the 2nd ring gap, so it doesn't matter where that 2nd ring gap is! Or the 3rd ring gap or the 4th, for that matter! Any story about an engine not starting because all the gaps were lined up is pure baloney, utter nonsense!
Just put the gaps anywhere you feel like (they won't stay there anyway).
 
On the aircraft engines were check compressions every 100-hours or annual inspection. Many times I've had one with lower than normal compression and pressure at the crankcase vent. I always run it again for a while and recheck. 9 times out of 10 the compression is back to normal with normal pressure at the case vent. It is not unusual for top compression rings to line up and they seldom stay that way for long.

It is a modern mystery as to how many revolutions the average piston ring makes during its life time.

I always just make sure the compression ring gaps are at least near 180 degrees appart when installing assemblies. The piston may be cam ground but the bore and the rings are round so it really doesn't matter where they are clocked in relation to the cylinder

Kerby
 
The theorists who say placement is vital have said in writing that rings rotate at a steady and consistent rate, following the spiral of the honing and maintaining their relative positions...this seems to me pretty far fetched, and I am glad to hear you tested it! Another myth. Or maybe they were using a REALLY coarse hone!
 
I read "Smolies" Chevy engine assy book many years ago and always set the gaps as he suggested. Don't know if it works or not , but at least it's something.
 
No truth whatsoever about the ring orientation.Jwl is correct they are always rotating due to cylinder hone pattern. But there are times when the rings all line up and stay there,and 9 times out of 10 it is because the bore is no longer round and when the ring points reach this area they no longer are able to rotate due to the fact the points are now at the largest point in diameter and usually stay there. The ring end gaps that are suggested by the SAE engineers and not ring companies state the measurements are minimums not maximums. This min gap is to avoid ring end butting.

Ronnie
 
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