Compression Ring End Gap

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eekvonzipper

eekvonzipper

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Does this look weird to anyone?
I took apart a motor that I thought was a stock/unmolested 273.
It was smoking and using alot of oil.
After a Freshen up on the heads it was getting around 120psi in the cyls.
I pulled the piston with the lowest 115psi, removed one of the rings and put it back in the cyl
the End-Gap was around .132 - .134!!!
I was expecting to see an .020 gap, Was I wrong?

gap.jpg
 
That's what I thought...
I was gonna check the shape of the cylinder with feeler gauges but after I saw the first gap I just stopped and turned the garage lights off.
 
Aww man...I have some cheap *** snap bore gimmicks I drop in there, at a few different levels and side to side locations then measure them with a caliper. Is it as accurate as a dial bore gauge? Heck no, but it's pretty close, for what I do. So you were going to shove the ring around and take end gap readings n different places? That outta tell you something..taper, at the least
 
Yeah, That's all I was looking for... Hone or Bore was the question.
Hopeful that I won't need a Machine Shop for any of this.
Even Our Jack-n-th-box is closed because of Staffing issues... Lol
 
That's insane... what the hell is wrong with people. Down here, a good,.Trustworthy Machine shop, is damn near non existing. There are a few left... like good alignment guys, they are fading... sadly.
 
eekvonzipper said:
Does this look weird to anyone?
I took apart a motor that I thought was a stock/unmolested 273.
It was smoking and using alot of oil.
After a Freshen up on the heads it was getting around 120psi in the cyls.
I pulled the piston with the lowest 115psi, removed one of the rings and put it back in the cyl
the End-Gap was around .132 - .134!!!
I was expecting to see an .020 gap, Was I wrong?

View attachment 1715815561
Click to expand...
That seems to be an overly large end gap, but have you checked the bore diameter? Perhaps set the ring at the bottom of the bore. There will be less wear there. The top of the bore is where the bore wear will be the greatest.
 
It appears you may not have the ring square in the cylinder. Get the ring JUST in the cylinder, flip a piston upside down and press the ring on into the cylinder a little. That will square it up and give you a correct measurement.
 
Did that Triple R...
Even if it was at a 45degree angle in there it shouldn't look like this. Should it?
 
I would expect .020 or less, maybe .025-030 for a boosted or nitrous combo.
I've seen rule-of-thumb of .0045per inch of bore. So .016.


Wow, I don't think I would be that curious....... at 3 a.m.
 
Last edited:
Stnd Bore. 3.625" One Ring was .100 the other .134 one of the lil Oil Rings .170
I think someone rebuilt this on Monkey Mountain in Potosi Missouri! What the hell???
 
eekvonzipper said:
Stnd Bore. 3.625" One Ring was .100 the other .134 one of the lil Oil Rings .170
I think someone rebuilt this on Monkey Mountain in Potosi Missouri! What the hell???
Click to expand...
I wonder if somehow they got the wrong rings? Have you got something to measure the bore with? It would be worth it to order a set of standard rings to measure those for comparison, if the bore checks out. Standard pistons and rings in an over bored block? The mystery deepens. lol
 
Hmm. There no excuse for that. Maybe a flipper, or someone impatient couldn't get the right rings local? Don't make sense, as Total Seal is a call away. Piss on Hastings
 
If that thing is standard bore.... it's just simply got the wrong rings in it. File to fit usually are too tight, but they are intended to be select fitted, maybe .015 to start. Standard rebuilder rings are a little sloppier(usually perfect for boost or nitrous.) I would expect .020-025 for a rebuilder set.
Yours are just plain wrong.
 
33IMP said:
If that thing is standard bore.... it's just simply got the wrong rings in it. File to fit usually are too tight, but they are intended to be select fitted, maybe .015 to start. Standard rebuilder rings are a little sloppily (usually perfect for boost or nitrous. I would expect .020-025 for a rebuild set.
Yours are just plain wrong.
Click to expand...

Or it's a bored block with standard stuff.
 

eekvonzipper said:
Rusty I just went out there with Calipers. It's 3.625 at the top
I got N.O.S. Rings coming this week from a Trusted Member here
Click to expand...
How bad of a ridge does it have? Do you have a way to measure the bore about half way down? Those rings you have coming may well answer some questions.
 
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