What's the largest ring gap you've ran?
 

I bought a ring grinder machine (hand crank version) and have Total Seal Advanced Profile Rings (file to fit). I watched some videos to get some quick reference, then went into the shop to do some fitting.

1. Marked the top ring for the hole it would go into
2. Pushed it just into the cylinder, used my old piston with the rings removed to push the new ring into the bore about 1 inch. These rings were set up for my 3.80 and are a custom set. The end gap was *maybe* .001 as delivered. Good job!
3. Took the ring out, positioned it on the grinder, spun it about 9 times, deburred it, trial fit it in the cylinder. Crap, didn't do jack.
4. Went back out to the grinder, spun it another 9 times. Deburr and trial fit. Dang it. Looked like nothing is being taken off.
5. Took the ring back out, this time I used a sharpie to just blacken the very end so I could see if I was removing material while it was still on the grinder. Aha... Now I was grinding and not stopping till I could see the sharpie mark start to diminish.
6. Trial fit it another few times, getting closer and closer. But apparently the last time, I stayed at it too long.

Using the Total Seal guide, for 15 to 30 PSI, gap should be bore size (3.800) times .007 so .27 rounding up. Last one just barely (sarcasm) missed that by ending up at .035....Phock...
So, with that lesson, on the remaining ones, I started grinding , then checking in my more frequent stops. Got them....

Next, the 2nd rings are a softer metal so the grinding is that much more 'dangerous' in terms of grinding/checking. Welp,, managed to mangle the first one of those too. Another 'amazing' show of ineptitude ending and a cavernous .035 again.

So them being custom rings, I won't be getting the engine together over this holiday. I'll have to order a single set or two (In case I butcher more) on Tuesday.

I usually run a large .032-.035" top ring on pump gas setups. Never had an issue. Made over 800 at the wheels on a 5.3 that way without so much as a mist of oil out of the valve covers.

Thanks for that. Last week, I was overhearing a couple of race engine machinists saying they'd talked with Total Seal product developers and they'd mentioned almost the same thing, regarding a gap that large and not having any appreciable blowby effect. Hence, this topic. I wanted to see if there were any supporting experiences from you gents.

I had a 6.0 with rusted cyls, I honed the piss out of them, and used a non file to fit (you still ck them) and some were prob well into the .030's, lol. So what the heck, I ran them all summer with 12-14lbs boost, never a problem. You really need to sneak up on grinding, I use a marker to also ck the end is square, prob grind and ck several times a ring. You could split the 2 rings on diff pistons so you dont have them on the same piston, but do the right thing and get new ones. If I had known I would be doing this crap for over 50 years I would have bought one of those expensive grinders, lol.

Lol.. I hear you. When I was at the machinists, I noticed he had one of those on his table. I'm tempted.....

This is why I’m not doing my rings as I’m worried I would mess them up in general as that’s something I would rather not take a chance with and have someone else do for me.

Had the same thing happen. I ground my bottom ring with the softer metal Too much and was in the .035 range. Slapped it together and it was fine. Compression check if all cylinders were with in a few psi of each other. Best advice I got when doing my motor was “you never see threads about running too large of a ring gap, but always see them when you run too small of a ring gap” aka broke piston lol good luck!

^^^^ truth!

i put the 2nd rings at .032 on the blue truck. after you butt a ring and tear off a piston crown you realize that bigger is better when it comes to our brand of boosting stuff

Thanks everyone !

This topic kinda irks me. Because you can do it without the engine noticeably running poorly its a good idea? Or it's necessary?

.032 on a 3.78" bore is nutty. .007 X bore is plenty, and then some. Generally huge gaps aren't going to save the motor, the tune will.

Zero reason for excessive gaps or super tight gaps. Just going by word of mouth and Richard Holdner is ridiculous! I've never butt a ring at 25+lbs, with the occasional oops to 30+. Thats with .022 gap on small bore stuff. The typical crushing of the ring lands out of the piston is almost always a result of detonation and/or too much cyl pressure too early in the rpm band. Big gaps aren't going to save you from that. Unless you've pulled the top off a piston, you likely didn't have a gap issue! Not saying it doesn't happen, but it's not teh common issue I see form most turbo setups munching pistons.

well when it happens to you (not that I'm wishing it upon you, I respect the heck out of you) and the logs dont show you why, you will reach for just about anything that is close to making sense.

also in my case it's a 4.00 bore.

really the spirit of the thread is guys are asking if "ooops 2 rings are at .035" will that open the gates to hell?" and the answer is of course, no

I briefly thought about just using the over gapped rings but decided to just order another complete set AND the electric ring gap filer (Proforms $3xx iteration. Total Seal wants over $6xx for theirs) Both the rings and the filer should be here on Thursday, but for sure Friday.
On another topic, there was a facebook thread about the LS9 Head gaskets for the 5.3. Since my prior engine had the LS9's but ended up being compromised, I ordered custom Cometics for the 3.800 bores. The difference in attendant gasket material is really noticeable.
LS9
https://cimg8.ibsrv.net/gimg/ls1tech...3d904779e3.jpg

Cometic...
https://cimg1.ibsrv.net/gimg/ls1tech...078608588d.jpg

In your second picture does the raised up valley areas make a difference? Is it supposed to make a better seal or cooling effect? Also off topic but how many people have done a junkyard 5.3 boosted and never touched the rings and had it last? My build won’t be a track build just 500-600rwhp with a blower.

I've seen videos on youtube where guys have done that. Just put a cam, turbo(s) and a tune with E85 and run freakin' high 7 second 1/4 miles in their lightweight Mustangs. Whom knows if they're being truthful. I would be reluctant to do that if for no other reason, If I blew the engine on the track and vomited all the oil on the track the other guys would tar and feather me, lol....

Likewise. And i'm not saying bad things dont happen. So you nipped the top ring land off? I've heard of several doing this on pump gas, even with relatively large gaps. I've done it myself with a 200 shot on a 5.3. (race gas) On tear down we found it was gapped at .016 however... I also run .022 on my non-intercooled 5.3 at 19lbs. (to be fair thats on e60 with water/meth tho)

Then we have guys like Stock48 run .019 on 4" bore motors all through drag week running mid to low 8's without a hiccup. Still makes me think it's a heat issue in individual cylinders, or just the tune in general. Makes no sense some get away with it and some don't. I just can't see .009 X bore as necessary on anything... 1/4 mile cars and most street cars aren't balls to the wall for more than a few seconds. Land speed record cars that are balls out for minutes dont' gap the rings at .009" x bore. Top fuel cars don't either. I get they don't use powdered metal cast pistons and expansion rates are different, but still. It just seems like bandwagon BS for the most part IMO. Much like "NEEDING" ARP hardware. I suppose to much is better than to little, sure. But why not approximately the "correct amount" if you are already in there?

Well mine will be 93pump and meth injection. But I agree and always wondered how many are telling the truth.

Definitely heat related. More gap, more heat before they butt. If you're on straight pump gas it's wise to add some ring gap cushion.

You'd never be able to tell any difference between say 30-40 thou....but you's sure as fuck know a difference if you did 20 thou instead of 30 thou.

People obsess about ring gaps as if 2-3 thou one way or another would make an actual difference.

Maybe in Formula 1 or something it might....in the real world, a little loose wont hurt anything a single bit.

Exactly. People obsess about 20 or 30hp from ring gap....that's like 1 psi difference. Same for spark plugs. If you run a slightly colder plug it's not really a big deal, but when you run too hot of a plug bad stuff happens quick.

As always with me, two steps forward, one step back...:bang:
I got one half of the engine assembled , put the RPC head on, Cometic gasket, studs etc, got that all torqued down. Then put on the rocker stands and the rockers. Torqued them to 24ftlbs... then I heard popping

Thought it was perhaps a pushrod centering... Nope... the RPC heads cant use stock rocker stands, as-is. Those little tabs apparently have to be cut off
.Broke that rocker stand in two and snapped off the tabs

https://cimg8.ibsrv.net/gimg/ls1tech...5445b26ea1.jpg