Resolved 1G - Another Ring end gap post.

[Anfurnyy]

Sorry for making another one of these posts but ive searched for hours now with no real answer as most peoples setups are different and require different gaps.

My setup is:
2.0L
bored .020 over.
Manley 9:1 piston w/skirt coating
Shooting for around 700+wheel and 40+psi on e85. I will also run 91 on a flex fuel setup. Not looking for big power on 91.
Looking to be driven a few days a week, weekend warrior/ Track every now and then.

My issue is using Manleys sheet for reference, for "High Boost 30+ PSI applications" they recommend bore size x .008" for both The 1st and 2nd Rings and so now my rings are setting at .027". Which after reading other peoples, seems huge.
Ive read many peoples ring gaps and this is damn near the largest ive seen outside of full flow Drag cars.

At the top of their ring gap list they also list a ""Street, Strip, Circle" Application listed at Bore x .0045". Is this for N/A cars? Is this what i should be using?

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[1990TSIAWDTALON]

Here, you can see how I set mine up. Three of these are 30-45lb boost setups. One is a stock, mild build.
Most of mine are .020"-.024" top ring and .026"-.028" 2nd ring.
They do not burn a lick of oil or use any and have the room for the rings to expand under high cylinder pressures and heat. It is just how I set mine up, it is up to you on how you want yours. The rings seat right in after a 320 grit flex honing in each bore and of course a very very thorough cleaning of those bores.
Marty

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[Anfurnyy]

Here, you can see how I set mine up. Three of these are 30-45lb boost setups. One is a stock, mild build.
Most of mine are .020"-.024" top ring and .026"-.028" 2nd ring.
They do not burn a lick of oil or use any and have the room for the rings to expand under high cylinder pressures and heat. It is just how I set mine up, it is up to you on how you want yours. The rings seat right in after a 320 grit flex honing in each bore and of course a very very thorough cleaning of those bores.
Marty

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Thanks for the reply. That helps quite a bit actually. In my opinion, I feel like my gaps are too big. At least the 1st one anyways. .027 for a second rings seems acceptable. That .024 range sounds nice but does .003 REALLY make that much of a difference when to comes to end gap? It seems that sometimes there's that much variance between cylinders

 

[Anfurnyy]

Here, you can see how I set mine up. Three of these are 30-45lb boost setups. One is a stock, mild build.
Most of mine are .020"-.024" top ring and .026"-.028" 2nd ring.
They do not burn a lick of oil or use any and have the room for the rings to expand under high cylinder pressures and heat. It is just how I set mine up, it is up to you on how you want yours. The rings seat right in after a 320 grit flex honing in each bore and of course a very very thorough cleaning of those bores.
Marty

Do you think it would be beneficial for ring flutter reasons to open up the 2nd ring to .029"? I see you have one of yours at .030".

 

[1990TSIAWDTALON]

You have to be extra careful on the ductile steel 2nd rings, they gap MUCH easier than the chrome moly top rings do. I got a little aggressive with those but I am not worried one bit. If you are really planning on a 700hp build, you need gaps that won't butt or you will score the cylinder, making it have blow by or break a ring from expansion.

 

[Anfurnyy]

You have to be extra careful on the ductile steel 2nd rings, they gap MUCH easier than the chrome moly top rings do. I got a little aggressive with those but I am not worried one bit. If you are really planning on a 700hp build, you need gaps that won't butt or you will score the cylinder, making it have blow by or break a ring from expansion.

Yeah I realized when gapping the 2nd rings the first go around that they ground much faster.

I understand that heat = expansion in the top ring I'm just worried about bad compression / blowby with the amount of gap I have now since it seems larger than most other that sound like they are around the same setup. I don't think with this amount of gap they rings will touch even with 40psi, but I also don't want awful compression and blowby.

Is it worth gapping the 2nd ring to that .029" range?

 

[1990TSIAWDTALON]

I would keep the 2nd ring bigger than the first but the final gap will be up to you. I know my gaps do not allow blow by nor do they use oil.
As an example for large gaps, here is my latest Small Block Chevy V8 build sheet. On this motor, I did not gap the rings, only checked them and recorded what they were for the rebuild.
It has even larger 2nd ring gaps and is the same as my 4g motors, no smoke, no blow by and runs fantastic.
Marty

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[DSMPT]

I also don't want awful compression and blowby.

I'm just worried about bad compression / blowby with the amount of gap I have now since it seems larger than most other that sound like they are around the same setup

1st rings are the one for sealing. 2nd rings are more for scraping oil. So even if you open up 2nd rings a little bit, you wouldn't lose compression. And yes you would probably have some amount of blow-by gas if you have .029-.030 2nd ring gap, but this is something you can't avoid on a loose/safer setup for high hp build. And having blow by is always better than building pressure in ring land between 1st and 2nd ring.
Usually no need to be worried much about that little difference on 2nd ring gap as long as 1st rings are set properly and 2nd rings have slightly wider gap than 1st ring gap.

 

[Anfurnyy]

1st rings are the one for sealing. 2nd rings are more for scraping oil. So even if you open up 2nd rings a little bit, you wouldn't lose compression. And yes you would probably have some amount of blow-by gas if you have .029-.030 2nd ring gap, but this is something you can't avoid on a loose/safer setup for high hp build. And having blow by is always better than building pressure in ring land between 1st and 2nd ring.
Usually no need to be worried much about that little difference on 2nd ring gap as long as 1st rings are set properly and 2nd rings have slightly wider gap than 1st ring gap.

In your experience, and/or opinion is .027" too much for a 1st gap?

I'm looking for advice since I've never done ring end gaps. Don't have any experience to fall back on.

 

[DSMPT]

It's in loose side but IMO it's not too loose. It's just like my previous setup. I had .027 for 1st and .030-.031 for 2nd. I had some amount of blow-by but I was still able to drive on streets without any issue. I had compression around 165-168 psi with Kelford 280/288.
If you already have .027 for 1st rings, just don't go more and should stick with .029-.030 for 2nd.

 

[Anfurnyy]

It's in loose side but IMO it's not too loose. It's just like my previous setup. I had .027 for 1st and .030-.031 for 2nd. I had some amount of blow-by but I was still able to drive on streets without any issue. I had compression around 165-168 psi with Kelford 280/288.
If you already have .027 for 1st rings, just don't go more and should stick with .029-.030 for 2nd.

Okay perfect! Thank you a ton. I'll re-gap the 2nd again

 

[DSMPT]

Okay perfect! Thank you a ton. I'll re-gap the 2nd again

It's actually all up to you, if you want to make the car close to street build or track build. Anyways if the car is used for both street and track, you would need to compromise on something.

 

[jakelandry]

I have assembled a handful of motors but I’m certainly no expert. I really think people overthink ring gaps. Their sole purpose is for expansion and there is no one size fits all to them. You want them as tight as you can get, but you’re chasing the .001% at that point. It’s like the type of people who will spend 3k on blower ice box heat exchangers and whatnot to pick up 40 hp when they could just swap in a cam for 500 bucks. People just spend too much time thinking about the little things. I know horsepower is not your primary focus here but the point is, we use these old 4g63’s as a hammer. We just force as much air into them as we can with a turbo and expect them to take it. We expect to get in them and be able to comfortably ride around town then boost 45 psi 10 seconds later. They can absolutely do that, but we can’t expect to do that and be efficient. You simply can’t get a ring gap that fits both just like you can’t have an intake manifold that works well from 2k to 8k. Ring gaps are a mechanically tuned part that only works right within a certain window.

All that said, I’d wager that having a proper hone hatch and well-bedded rings has a greater impact on the characteristics you’re concerned about than the ring gap. My current motor has the top gap around .028 if I recall correctly but I have yet to run it. My goals are similar to yours.

 

[Anfurnyy]

I wound up just leaving the top ring @ .027" and widening the 2nd compression ring gap to .029". Thanks for the help guys!

 

[Jk's97DSM]

There’s a lot of good info in this thread.

 

[1990TSIAWDTALON]

To add to the thread, I use a 320 grit flex hone to deglaze the cylinders and clean the bores with ATF until a white paper towel comes out completely red after. Sometimes that takes 3-6 cleanings each. You can clean with other solutions but as the final step, I would still always use ATF in the bores, oil all of your rings/wrist pins and rotate them back and forth to lube the ring lands and your rings will seat within the first couple minutes. Don't forget any bearings, apply assembly lube, even if you're not sure!
@Anfurnyy , is it ok to mark this thread as Resolved?
Marty

 

[Anfurnyy]

To add to the thread, I use a 320 grit flex hone to deglaze the cylinders and clean the bores with ATF until a white paper towel comes out completely red after. Sometimes that takes 3-6 cleanings each. You can clean with other solutions but as the final step, I would still always use ATF in the bores, oil all of your rings/wrist pins and rotate them back and forth to lube the ring lands and your rings will seat within the first couple minutes. Don't forget any bearings, apply assembly lube, even if you're not sure!
@Anfurnyy , is it ok to mark this thread as Resolved?
Marty

I cleaned the bores with brake cleaner and coffee filters, till it was clean. then went back in with a microfiber to clean anything else up left by the filters. then dressed the walls with coffee filter and ATF. Applied a little extra ATF at the top couple inches of the block and put the pistons in.

You sure can! Thanks for the help!

 

[1990TSIAWDTALON]

Thank YOU for finishing the thread. It will be very helpful to others!
Marty