Forced induction/N2O ring gap question please...

Getting ready to put my setup back together and was looking for some input on ring gaps. I'm running a T-trim @ around 15psi with 150 shot of nitrous on top of that at the track. What should i be shooting for on 1st and 2nd ring gaps? Engine builder gapped them to .020/.022 before shipping. Should i be shooting for something a little wider? This is in a 383 LT1, JE extreme duty pistons with a -31cc dish and speed pro rings. Any input would be greatly appreciated. Thanks.

Ken R.

I would go at least 0.0055-60"/inch of bore for both the first and second ring. So, I'd open up the top ring a bit and may just a hair on the second as well. Maybe around 0.025" for both.

Rich

Call the ring manufacturer and get their spect.
Rich is pretty much spot on but you need to make sure. I have run as much as .036 due to manufacturer recommendation.

Call the ring manufacturer and get their spect.
Rich is pretty much spot on but you need to make sure. I have run as much as .036 due to manufacturer recommendation.


Agree. The power loss form a gap that is a little too big is not large. The problem when rings are too tight is very bad.

Rich

Thanks for the info guys. I'll give JE a call and see what they think about gaps in my setup. Would too tight of a ring gap cause the land to start cracking between the 1st and 2nd rings? This is the reason i'm putting in new pistons in the 1st place. I cracked #2 and #4. Granted they were SRP's, but they were originally gapped at .020 & .022. Tops of the pistons looked good and couldn't really see any signs of detonation on the pistions or plugs and whenever i made any dyno pulls even with more timing then i ran on the street, i never did see any knock while scanning. Hard to say, but starting to wonder about my original ring gaps and if that possibly had something to do with it. Both pistons and multiple cracks all around the land between both rings with the tops of the pistons looking good. Whats your take on that? When i tell people my setup and what the rings were gapped at, all i get back is the same look that you find on a blow up doll. :eek: Thanks again.

Ken R.

Just Called JE and they recommended bore x .0060/.0063 for my app running 15psi, which would take them to about .024/.025. Their nitrous apps suggest x .0070/.0073 for 1st & 2nd rings which would take it to about .028/.029. Wondering since i'm spraying it at the track also if i should just split the difference and run around .025/.026ish or just run ring gaps for a full on nitrous application.

Ken R.

Do the BIG gap and be safe. Ya won't loose any performance.
How much hose?

Running bigger ring gaps, will that cause oil consumption?

Max would be a 150 shot but usually a 100 to a 150 depending on the day. Its a driver so it only sees spray at the track, which is only a few times a year or on the dyno for some pulls. It's just boost on the street.

Ken R.

.028-.029 is not too much for that amount of hose.
Don't do the oil ring. No there is no more oil consumption.