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1G Piston ring gap

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dsmalaska

Proven Member
75
1
Dec 18, 2013
Avondale, Arizona
Alright, so I finally got my block back had it bored .020" over. I was measuring ring ago last night and it's big but not past the service limit .031". My question is can I get by with it or what should I do? Here's what I got. I'll double check the measurements later if need be.

Ring gap
Cylinder 1
1st compression ring .022"
2nd .029"
Oil rings (top) .027". (Bottom) .0265"

Cylinder 2
1st CR .025"
2nd CR .029"
Oil rings (top) .025" (bottom) .025"

Cylinder 3
1st CR .026" (.025" to small, .0265 to big, guess .026")
2nd CR .029"
Oil rings (top) .024" (bottom) .023"

Cylinder 4
1st CR .019"
2nd CR .029"
Oil ring (top) .022" (bottom) .020"
 
That's pretty flippen close to the service limit. I'm rusty on the average piston ring gaps. I'll see if I still have it written down in my log book when I did my build. I have 160 compression across. Four off from standard.
 
That's pretty flippen close to the service limit. I'm rusty on the average piston ring gaps. I'll see if I still have it written down in my log book when I did my build. I have 160 compression across. Four off from standard.
I have references for the specs on ring gap but since they're to big what do I do? New rings or? It's all brand new itm piston and rings. I do have another set of pistons with rings maybe I'll give those a shot
 
What engine is this for? 6 bolt or 7? What internals? The rings should be fine. the 2nd ring seems a little high but you'll be okay. the more hp you make the more of a gap you will need for the rings to expand. How did you take your measurements exactly?
 
It's a 6 bolt. It's just a stock rebuild so I can drive it honestly. Down the line it'll have dsmlink and hx35 with supporting mods but not for awhile. And I put the rings in the bore one at a time and pushed them down with the piston so they're flat and square in the bore and used a feeler gauge to measure gap. Each set of rings went in a different bore to get the most accurate gap measurements per each ring set.
 
Take your measurements in three different places in each cylinder and write them down. They should be the same measurement that's if the machinist did a good job. Why did you have it bored over? You can normally get away from boring it out
 
Take your measurements in three different places in each cylinder and write them down. They should be the same measurement that's if the machinist did a good job. Why did you have it bored over? You can normally get away from boring it out
It had a pretty good ridge at the top of the cylinder, and the machinist said it'd be best but that was the machinist who lied to me about prices and shit then the shop fired him and then I call to pick it up a week later and they tell me he's no longer there and the real prices of the work being done I had no choice but to pay the prices and it took 3 months to bore/hone, deck it to be clean and flat and "wash" the block. It's BS but it is what it is.
 
So these are brand new ITM rings out of the package? Measure the bore to make sure it's bored and honed correctly for your desired PTW clearance. An improperly machined bore will make your ring end gaps too loose.

I've also had new rings out of the bag be too loose on a properly machined bore, but I don't remember what pistons. I ordered rings for .040" over pistons so I had more meat to work with when I filed them down.

FWIW, I run .018" 1st and .022" 2nd. Wiseco pistons. 35 psi on a HX35. (55-60lb/min)
 
So these are brand new ITM rings out of the package? Measure the bore to make sure it's bored and honed correctly for your desired PTW clearance. An improperly machined bore will make your ring end gaps too loose.

I've also had new rings out of the bag be too loose on a properly machined bore, but I don't remember what pistons. I ordered rings for .040" over pistons so I had more meat to work with when I filed them down.

FWIW, I run .018" 1st and .022" 2nd. Wiseco pistons. 35 psi on a HX35. (55-60lb/min)

I wish i had your set up. Just me switching from the T28 to the Big16G was a huge difference. Cant imagine how the HX35 pulls
 
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