It would seem logical to assume that having the pin intruding into the oil ring groove could possibly increase oil consumption. At least, as the engine a accumulated miles. I can't speak with any personal experience on this because I've never put a motor together that had the pin breaking into the oil ring groove.

 

Look at Mahle

930221525

They’re lightweight and low cost. They also have fairly small valve pockets. The small valve pocket may be part of why the rings can be up higher to give more room for the pin. I got one of my kits off eBay with a Black Friday eBay discount code in total I paid $570 in 2018 for the set. Bought some total seal gas ported rings for them. From all appearances, the 1/1/2mm ring pack that comes with them is the same as what Total Seal used before cutting the grooves.

 

That was the logic many years ago when these pistons first hit the market. Millions of pistons going trillions of cycles have proven that there's not an issue.

 

I like those 👍👍👍

 

I've built many with them too, but my issue with them is long term, not a short term problem like skirt wear. Reality is, you never see 150k+ stroker motors, ever. Meanwhile, there are tons of boosted 250k 5.3's and cam only 150k+ LS1's making numbers. The oil ring issue is a gradual one, but it's common sense to see that if it's not supported, it's going to flex. If it flexes then oil gets past it. Add lots of rpm to that and the problem is exasperated. I think the reason why nobody really gives it a thought is the skirt wear or other issues usually doom a stroker way before "that" becomes the issue.

 

I agree with this. For 50,000 mile and under engines, it's probably great. But if you're building a reasonable performance engine, and expecting 100,000+ miles with low, or no, oil consumption, it will probably make a difference. I'll also add that the longer the stroke, the faster the piston and ring wear.

 

Exactly, GM knows none of this would pass life testing in the real world, we can sit here and say I drag and drive etc etc or, but nobody is racking up 100k miles on this short piston stuff. It's hard to find that data anyway as when performance geeks get something like this they beat the snot out of it daily, but even in a daily driver world these short pistons will have issues over the long haul.

I just used some Mahle SBF aluminum 434ci pistons with a .250ish comp height that had the 1/1/2 pack and it had tons of room in it. It helps a lot that the 351w based engines are 9.500" deck though.

 

Believe it or not, there are 150,000 mile LS7s in C6 Corvettes. But only if the heads or rods don't destroy the engine first. I've seen more than one, but they are the exception rather than the rule.

 

Yeah, I've seen those too, but it's a case of good oil and a **** ton of luck. Somehow, they reached that perfect wear spot of not cracking the liners, dropping a valve, trashing a rod or breaking a piston or lifter problem. Any LS7 that made it that long deserves to be gold plated and trophy status.

 

Just how many miles are you planning to put on this mill before you either rebuid it or swap it out for something else...this 416 you already have out for a rebuilld? There are a **** ton of big block 496's running around with well over 100K miles on them without issue.
And you actually DO want oil to get into the oil distribution ring, that's how it gets spread out over the full circumference of the cylinder. Bottom outside edge of the second ring is the scraper that removes all but what's in the tiny grooves of the hone pattern, leaving just enough to lubricate the rings.
When they first came on the market, pistons with pins in the oil ring had buttons that filled that gap after the pins were installed, but they have all but quit making them. You'd think that if this really was an issue, there would be more of them rather than less???

 

Here is my 540 BBC Diamond piston with the 4.25 stroke and the 6.385 inch rod. has a little of the oil control ring open to the bottom. Here is the LS piston with 4.125-inch stroke has a little more open to the bottom - Wiseco. The Wiseco LS piston the second ring was moved down .050 to help with piston support also has special taper in thrust area.

 

Here is OEM LS7 piston (4-inch stroke) - GM really squeezed all the rings in there. Shorter rod and small piston pin.

 

For my street car stuff 100k+. I'm in So Flo, I have not put less than 35k on a a car in a year in a long time and once did 60k in a year. I don't like garage queens or weekend cars, I daily my hot rods and most of my customers do too.

I'm not arguing that you need to have some oil above the rings, obviously you do for operation sake, not sure where that argument came from, but excess is excess. I'm not saying it's catastrophy waiting to happen, but it's not ideal and if you are spending the $$$, way not make it right the first time? It's an easily mitigated factor and obviously GM went through all the trouble on each LS, especially the 454 LSX, to get around it. I think it's worth paying attention too. Oil in the chamber is bad, why not it seal as good as possible?