1G Ring gaps

[Anthony Hornback]

What is a good ring gap
I have Manley 85.5 9.0/1 pistons going in
Per the Manley specs my gaps are being called out to be about .027 for no.1&2 and .05 for oil rings.
Does this sounds correct? They seem a little large to me.
Running 1650 high z and a SBR G50 if that matters
Thanks in advance

 

[1990TSIAWDTALON]

Looks correct to me. For High Boost, Supercharged or NOS use.
3.346" x .0008 = .0267"
I run gaps similar to that, although I make my 2nd ring gap just slightly bigger than my top.
60mm Turbo, 2150s, 10:1, e85 here.
Mine are closer to .024" top, .028" second.
No issues. The more cylinder pressures, heat, boost all need those rings to absolutely not butt.

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[Anthony Hornback]

Looks correct to me. For High Boost, Supercharged or NOS use.
3.346" x .0008 = .0267"
I run gaps similar to that, although I make my 2nd ring gap just slightly bigger than my top.
60mm Turbo, 2150s, 10:1, e85 here.
Mine are closer to .024" top, .028" second.
No issues.

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That’s what I came up with. It just seemed a little big. I will be runing about 28psi but it’s mainly a cruising car. Does the oil ring gap seem right? It calcs at 0.50

 

[Anfurnyy]

That’s what I came up with. It just seemed a little big. I will be runing about 28psi but it’s mainly a cruising car. Does the oil ring gap seem right? It calcs at 0.50

I believe that Manley's sheet for the oil control ring just says"minimum .015" gap" so just check the oil ring gap with them installed and see if it meets that. If it does, then you're good to go.

You should be fine with .027 on the 1st and 2nd rings like @1990TSIAWDTALON said. I believe I run .028" on both of mine

 

[Anthony Hornback]

Thanks guys I appreciate you

 

[1990TSIAWDTALON]

As @Anfurnyy said, just check the oil rings. DO NOT FILE THEM. I have never filed an oil ring. Not that you CAN'T, but they are very thin, so just check for the minimum clearance. If the minimum clearance is too tight, let us know, but I doubt they will be to snug. The top rings control the explosion, the oil rings just scrape the oil off the cylinder walls.

 

[Anfurnyy]

As @Anfurnyy said, just check the oil rings. DO NOT FILE THEM. I have never filed an oil ring. Not that you CAN'T, but they are very thin, so just check for the minimum clearance. If the minimum clearance is too tight, let us know, but I doubt they will be to snug. The top rings control the explosion, the oil rings just scrape the oil off the cylinder walls.

Surprisingly I actually did have to open up my oil rings. It was definitely tricky to get it done but I did.

 

[1990TSIAWDTALON]

Better to be safe than sorry!
I check mine but rarely even put the clearance on the build sheet for the engine. The oil rings shouldn't see the same thing as the compression rings do.

 

[DSMPT]

There is no exact number and usually the manufacturer's recommendation number is general number, it's a bit in tight side. So even if a little bit larger than that, really no need to worry.

As for the oil rings, you don't need that much. Just check the gap as is out of box and if it's below minimum, then file them to the min number or a bit more than the min if you want. If it's already more than the min out of box, usually no need to file.

Just fyi, often when the rings out of box, the 2nd ring gap is already larger than the number you calculated. In this case, leave it as is or if you want to strictly set the gap as you calculated, you would need two ring sets in different size, one with the bore size and one with one size larger.
You wouldn't have issue with larger gap on the 2nd ring than the top ring's. Actually larger is safer because it prevents to build up pressure between the top and the 2nd ring.

 

[Anthony Hornback]

There is no exact number and usually the manufacturer's recommendation number is general number, it's a bit in tight side. So even if a little bit larger than that, really no need to worry.

As for the oil rings, you don't need that much. Just check the gap as is out of box and if it's below minimum, then file them to the min number or a bit more than the min if you want. If it's already more than the min out of box, usually no need to file.

Just fyi, often when the rings out of box, the 2nd ring gap is already larger than the number you calculated. In this case, leave it as is or if you want to strictly set the gap as you calculated, you would need two ring sets in different size, one with the bore size and one with one size larger.
You wouldn't have issue with larger gap on the 2nd ring than the top ring's. Actually larger is safer because it prevents to build up pressure between the top and the 2nd ring.

The rings out of the box were almost butted together . I didn’t check the oil rings yet but I’ll definitely make sure they are atleast the minimum. Thank you

 

[DSMPT]

The rings out of the box were almost butted together . I didn’t check the oil rings yet but I’ll definitely make sure they are atleast the minimum. Thank you

I realized your piston kit is Manley. They may use different manufacturer's ring set from Wiseco/CP/JE/SuperTech. So the preset gap may be different. Good luck with your build

 

[1990TSIAWDTALON]

Word to the Wise.....the 2nd rings are usually a ductile steel, where the top rings are "generally" chrome moly. The top rings will file slower since they are harder so when you do the 2nd rings, be very careful as they will file MUCH EASIER (FASTER) so go slower on your filing.and check the gap more often as you go. It is easy to over do the 2nd rings. I just wanted to warn you so you don't over file. I have done it before and then you have to buy a single set if you goof one up.

 

[Anthony Hornback]

Word to the Wise.....the 2nd rings are usually a ductile steel, where the top rings are "generally" chrome moly. The top rings will file slower since they are harder so when you do the 2nd rings, be very careful as they will file MUCH EASIER (FASTER) so go slower on your filing.and check the gap more often as you go. It is easy to over do the 2nd rings. I just wanted to warn you so you don't over file. I have done it before and then you have to buy a single set if you goof one up.

I have a spare set just in case . That’s helpful knowledge, thank you

 

[Anfurnyy]

Word to the Wise.....the 2nd rings are usually a ductile steel, where the top rings are "generally" chrome moly. The top rings will file slower since they are harder so when you do the 2nd rings, be very careful as they will file MUCH EASIER (FASTER) so go slower on your filing.and check the gap more often as you go. It is easy to over do the 2nd rings. I just wanted to warn you so you don't over file. I have done it before and then you have to buy a single set if you goof one up.

I learned this one the hard way.

 

[1990TSIAWDTALON]

I think anyone who has spent any time building engines probably has too . I figured a WARNING was appropriate.

 

[curt-s]

Better to be safe than sorry!
I check mine but rarely even put the clearance on the build sheet for the engine. The oil rings shouldn't see the same thing as the compression rings do.

I feel stupid as hell now because I just realized after reading this thread that I didn't check my oil rings. I had 1st and 2nd opened up a bit and checked all eight but I don't know why I neglected to check both oil rings from the Manley 85.5 sets
shit.
Well, here's hoping they're at minimums because I'm only running a slightly wider PTW

 

[1990TSIAWDTALON]

90% of the time (or more), the oil rings don't need touched, just checked. You should be fine.

 

[curt-s]

90% of the time (or more), the oil rings don't need touched, just checked. You should be fine.

Gonna have to be, I'm not putting it all apart. Putting just a wee little bit of trust in their sizing of them.