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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.
You also run E85. My E85 car has .020" gaps and run 9s on low boost. My pump gas car has .032" gaps and runs 9s on low boost. Both setups have been 20+ PSI and never broken a piston.
There are likely ~1000 members on this forum that have broken a ring land over the years from not having enough ring gap.
You can't rely on the tune alone. There will always be unknown factors like failing fuel pump, failing hobbs switch, meth kit running empty, clogged injector, failed wideband, etc that will cause an unpredictable lean situation.
The % of horsepower being given up to make big power on pump gas is worth not dealing with unknown variables causing ring butting.
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.
I don't even believe 30 to 40 thou gap would cost 30hp.
I'm not runnig E85 on all my builds over the years. I ran cast pistons on my grand nationals, DSM, SBF, SBC,LS etc...all with factory or hyper pistons around .005 X bore or less. I've gotten the gaps too tight on occasion and paid for it as well. But never did I think "hey! lets double the suggested power adder ring gaps just because!" And I will say my first LS ran .0035ish because thats what the internet told me to do. And it did smoke pretty good out the breathers during a pass.
I get your points loud and clear, I do... My point is who's to say what is actually lost power wise? Have you tested it? And who's so say what minimum/maximum gap is needed? There is a point where it just becomes excessive and pointless. I've seen back to back dyno's with loose vs tight gaps changing Crank HP by 3-4%. And we aren't talking .010 x bore retardo gaps. So how do we know what we are giving up on an LS? If it's 3% on say a 350hp 5.3 thats 10 hp. Sure nothing stellar, but that may be 30+hp depending on boost levels. Nothing to sneeze at IMO. My point is... why give that up *IF* its not necessary. Where is the cutoff point where gap is excessive. Has anyone ever butt a ring at .028 on pump gas....025...024? If not... Why go .035? I'd just like to see some real world testing VS "bigger is better" And "everyone else will know if you go too tight, only you'll know if you go to loose"
I've never seen any back to back tests or dynos ever where someone has changed only ring gaps. It would be a very long winded dyno test to do, but would be interesting if there are any links to it ?
I'm not runnig E85 on all my builds over the years. I ran cast pistons on my grand nationals, DSM, SBF, SBC,LS etc...all with factory or hyper pistons around .005 X bore or less. I've gotten the gaps too tight on occasion and paid for it as well. But never did I think "hey! lets double the suggested power adder ring gaps just because!" And I will say my first LS ran .0035ish because thats what the internet told me to do. And it did smoke pretty good out the breathers during a pass.
I get your points loud and clear, I do... My point is who's to say what is actually lost power wise? Have you tested it? And who's so say what minimum/maximum gap is needed? There is a point where it just becomes excessive and pointless. I've seen back to back dyno's with loose vs tight gaps changing Crank HP by 3-4%. And we aren't talking .010 x bore retardo gaps. So how do we know what we are giving up on an LS? If it's 3% on say a 350hp 5.3 thats 10 hp. Sure nothing stellar, but that may be 30+hp depending on boost levels. Nothing to sneeze at IMO. My point is... why give that up *IF* its not necessary. Where is the cutoff point where gap is excessive. Has anyone ever butt a ring at .028 on pump gas....025...024? If not... Why go .035? I'd just like to see some real world testing VS "bigger is better" And "everyone else will know if you go too tight, only you'll know if you go to loose"
I'd gladly give up 30 of my 900+ Horsepower to know that I won't be breaking a ring land. The ring gaps + water/meth are the reasons my last engine survived 3 years and 1500+ passes on 93 octane at 24-28 PSI and still looked like new when I opened it up.
Sounds like its begging to be on Engine Masters or Richard H. youtube....
EM only seem to want to do $40 tests....
Whilst a ring gap test may not cost a lot of money as such...it would take a hell of a lot of time doing back to back strip downs and slowly opening up the gaps at what, 2, 3, 4, 5 thou at a time ? top ring only ? 2nd ring ? stages ? together ?
as the test would have to be on the same engine, same bores, same rings etc.
Whilst a ring gap test may not cost a lot of money as such...it would take a hell of a lot of time doing back to back strip downs and slowly opening up the gaps at what, 2, 3, 4, 5 thou at a time ? top ring only ? 2nd ring ? stages ? together ?
as the test would have to be on the same engine, same bores, same rings etc.
Have you watched RoadKill? They've spent more time doing stupider stuff
I'll look it up and post it. There are several out there if you google search. None on an LS i'm aware of tho.
Who says you have to "give up" anything... that's the point! There is a point where it's just excessive and senseless to do. I'm not claiming I know that point, but finding out could be beneficial to the community. Just as we have proven you don't need big money fasteners, head gaskets, and you can rev the engine past 7k without it exploding instantly. I seriously doubt .009 x bore or greater would ever be "necessary" to prevent ring butt. Especially on a 1/4 mile or street car.
This one is total seal vs open gap. There is an engine masters one out there if I recall. I'll keep looking.
Who says you have to "give up" anything... that's the point! There is a point where it's just excessive and senseless to do. I'm not claiming I know that point, but finding out could be beneficial to the community. Just as we have proven you don't need big money fasteners, head gaskets, and you can rev the engine past 7k without it exploding instantly. I seriously doubt .009 x bore or greater would ever be "necessary" to prevent ring butt. Especially on a 1/4 mile or street car.
This one is total seal vs open gap. There is an engine masters one out there if I recall. I'll keep looking.
If you calculate the area of the opening of the ring gap, but only the part exposed between the piston to wall clearance, and then increase it by 50% from say .022" to 0.33", you get a meager fraction of a percent of total bore area in increase.
In ideal situations, .006-.007 times the bore size will give you an idea gap for pump gas. But if your setup is prone to detonation, overheating, etc, .009 will definitely keep it from butting rings while you figure it out. Unnecessary? Sure, but it beats the alternative.
The same exact principle could be said in relation to losing a little power to run soft timing under heavy boost for reliability, or running more octane than is needed for a given setup at the track.
I guess the same could be said about owning a fire extinguisher that you doubt you'll ever have to use, but definitely want it just in case.
No lie, I just put an extinguisher in my car JIC. Because it was cheap enough that if I never have to use it oh well, and if I do I'll be REALLY happy I have it.....just like piston gap
Got my new Proform Piston Ring Filer. Dial indicator, heavy weight anodized platform, cutting/grinder wheels and charger. It is a battery operated tool and does not have to be plugged in. Dial indicator. Battery Charger. Two grinding wheels. How you set the the ring up(Using a broken ring for display only). You square the end of the ring against the wheel, then tighten the ring clamp, turn the face of the dial indicator to zero. Then you turn on the motor and then gently push the black handled lever forward while watching the dial indicator to determine how much you want removed.
I'll look it up and post it. There are several out there if you google search. None on an LS i'm aware of tho.
Who says you have to "give up" anything... that's the point! There is a point where it's just excessive and senseless to do. I'm not claiming I know that point, but finding out could be beneficial to the community. Just as we have proven you don't need big money fasteners, head gaskets, and you can rev the engine past 7k without it exploding instantly. I seriously doubt .009 x bore or greater would ever be "necessary" to prevent ring butt. Especially on a 1/4 mile or street car.
This one is total seal vs open gap. There is an engine masters one out there if I recall. I'll keep looking.
I'd have liked to see them go back to the original rings after all testing to re-confirm the baseline.
But it still doesnt offer any real info to new rings, back to back, of exact same type, with only the gap opening up ( or closing ) by say 10 though either way of what someone might recommend as the "correct" gap.
Prob the most important part is getting the end square-once in the bore I put a white rag in there to help view the gap. Yea, my hand crank one seems like something from the 1800's, lol. Although I did a set with a hand file once.
Prob the most important part is getting the end square-once in the bore I put a white rag in there to help view the gap. Yea, my hand crank one seems like something from the 1800's, lol. Although I did a set with a hand file once.
I've done plenty with a hand file, and it is good. Although the likes of the Total Seal gapless with the stainless top ring, it can be a bit harder to file. And with a lack of patience....power assistance beckoned.
Of course on the much weaker 2nd ring...material disappears much much faster lol. And the powerfile is a handy tool all round anyway
No big deal, I'm content knowing they'll never butt, for negligible downside.
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