Zero gap or regular rings

[dallam2]

Gents; I'm freshening up my Camaro's 383 engine with new rings and bearings. I like the idea of little or no blowby with the zero gap rings but am reading some strong negative issues about them. I'm running cast pistons and a 100 horsepower setting of nitrous. Have any one of you gents used the zero gap rings and if so can you tell me if you noticed a difference in blowby etc. and how they seemed to deal with a small nitrous charge? Thanks

 

[cmonson]

I thought that the bottle and zero gaps were a no no...

 

[mrdragster1970]

.

Everyone I know has stopped using them with N2O.
We pretty much all use hellfires.

.

 

[hhott71]

Cast pistons and NOS? Not the best idea....

 

[Rich Schmidt]

The rings will long outlast your cast pistons when it comes to N2O use. I run them in my 439 bigblock. I use up to a 300 plate shot but only a few runs per year with the nitrous,mostly I bracket race it at 7500rpm on motor. I use total seal zero gap second rings. Back on my last engine I ran conventional rings and put a real lot of runs on the engine,eventually the blowby was getting pretty bad. I actually threw a vacum pump on it,and that resealed the rings a bit,but the vacum pump never pulled more then about 5" of vacum under full load. On the new engine I used the gapless rings. I have 3" of vacum even at 900rpm idle,and it goes right up to and a little beyond where the relief valve kicks in at 10" as soon as I crack the throttle. The engine went from about 145 psi which was the best the old engine would get even when fresh to 170. I like to go a skazillion runs with no maintenance on the engine,so I figured that even after these rings are worn out they will still be nearly as tight as a fresh set of conventional rings. The total seal setup is a little different then rings with a stepped end gap. Total Seal cuts a groove in the outer edge of the bottom side of the 2nd ring and gives you a ring that is basically a trimmed down oil ring rail,and you install the 2 in the same groove with the gaps staggered. The 2nd ring isnt much different then a dykes ring exceept you fill the void with a second little ring. Back when they first came out some guys with really high rpm engines had ring flutter issues,that might have been(was)related to pressure buildup behind the top ring. This seems to not be a real issue at least not with the setup they use now.

I could see this rings being combined with a vacum pump as a real good setup for an alky fueled engine where fuel wash into the oil is really hard on the engine. With near perfect ringseal and pump to pull water vaopr out of the crankcase the oil should stay a lot cleaner.

In your setup I see no downside to them except cost. I also dont see a real upside. If nothing else,you can run the gaps a little wider for nitrous and still not see a lot of blowby,and maybe the skirts will gall a little less from there being less heat making it past the rings.