Why not gapless rings

Why don't alky guys use gapless piston rings. Im putting together a sbc with 20 pounds of boost on alcohol and i don't know if i shoud run hellfire ring or gapless

 

we run gapless on our hemi.

 

Supposedly in a high rpm combo like the alky guys run, they flutter and lose seal. It kind of depends on what your usage is. I personally love them, all I've run since the early 90's, but I run mostly a quick index big motor combo that seldom see's 7800. Fuel/oil dilution is almost non-existent unless you're running a gobby fat tune-up, and if you're not pulling the pan every 2-3 passes and changing pistons "and" if you're running under 8500 or so, I think you'll like them a lot.

 

They can and do work. Simple as that.
Most guys just don't see a power increase over a good designed top ring for their application. There are conflicting reports that they do not last as long as conventional rings, especially in the ultra thin packages we see today. My Carolina sources tell me that they tried them in about every format, but just can't get them to make the power as the conventional. But again, NASCAR is a very different animal.
Just as long as you are not puting them in the second ring position, you are good to go.

 

Why not run them in the second groove. I have been runnung a blown SBF with total seal second rings for over 5 years now with good success. Running 8/71 with 34lbs of boost.

 

We're new to blown alcohol and are trying a gapless second with a Napiar top in a 565" 8-71 drag boat engine. Never ran gapless before but wanted to give them a try to see if will help with possible oil dilution issues. They are expensive and ours is just a fast bracket combo. If after a season I'm not convinced they are a better choice, they won't go in after our next freshen up.

 

gapless second ring?

From what I have been told and the engineering studies I have read-a gapless second ring would be a bad preformance idea. Apparently if your second ring leaks less than your top ring the end result is fluttering the top ring. A tighter second ring results in a high pressure area between the the top and second ring and can cause the top ring to flutter. On the other hand if you are running TAFC in div 6 please run the gapless second ring, especially if I am in the other lane. Dave Germain

 

We looked at this a lot of different ways and talked to a lot of knowledgeable people as well. I am an engineer and know studies can show whatever one wants them to. Think about it.... you will always have more pressure above the top ring than below it during combustion because the void below the top ring only sees leakage through the end gap. It has to be less than what's above it. Ring flutter is a catch all that get used when someone doens't know why their engine doesn't seal as it should.
Although I'm new to blown alcohol, I'm not new to racing or building motors. I had never used gapless rings before and I wasn't easily convinced this was the way to go at first. I did a lot of research as well. If this was an all out TA effort, I would have made a different choice. And if you're in the other lane from me, I hope you brought a snorkle

 

David 519

That was funny- I needed that, Thanks, Dave Germain

 

Couldn't have said it better myself. Without going face to face with Matt Hartford, we had many disagreements between us about gapless rings. I always use to say, if they are so good, why don't the OEM's use them? I used to have Total Seal make dykes rings for the import guys when I was at JE, and we sponsored some of the baddest imports in the country. Nothing against you Matt, your a great guy, just stating my opinion.

 

Hey, Total Seal makes some of the best rings out there. They are very true, very flat, and you can run ludicrous ring to groove numbers. But the gapless second is not the way to go. Like was stated on the last few posts. Entire piston manufacturers were cutting a groove between the top two rings for extra area for the trapped gasses to go to try and help. This was not a matter of testing to make your point, but rather; "This is what is happening, how do we fix it."
Like was stated, when my NASCAR boys tell me they are running something, I will definitely try it. When they tell me that they tried it and it does not work, I usually save my money and my testing. But I tried the gapless seconds anyway, and should have just listened to them. I am such a moron!
Like Ray Akerly says; "People need to start looking at the second ring as 'the secondary oil control' ring, NOT a 'secondary compression' ring."
And if you want to get lost in NASCAR, WoO, sprints, as well as drag talk on the use of rings, head over to SpeedTalk.com and do a search. Some of the best engine builders on the planet hang over there.

 

After I replied to Dave Germain, I got to thinking about my post and actually went back to my build sheets & notes on our current motor. What Total Seal intially proposed to us was a gapless second and a Dyke top. My post to Dave was based on this discussion. Apparently, lots of TA type applications like Dyke rings. Given ours is just a fast bracket and after further research/discussion, we didn't really want to go with a Dyke top. Also, while I'm not convinced about the ring flutter issue, the guy that is helping me learn about blown alcohol is convinced it's an issue. We actually went with a TNT gapless top and a Napier 2nd. My mistake Sorry guys....

 

Like Ray Akerly says; "People need to start looking at the second ring as 'the secondary oil control' ring, NOT a 'secondary compression' ring."


Funny, my motor guys and I had the same conversation last week, the C&A taper face seconds are excellent for that. He said you want the driest chamber possible. Too bad you can't get them anymore. Good thing I have a small stash

 

You can still get taper faced second rings. Speed Pro. If I remember right, the only rings C&A had made for them was their stainless dykes and "Z" gap seconds. Everything else was just reboxed.

Speeking of Speed Talk:
http://speedtalk.com/shows/033_je_pistons.html