Ring gaps. . .

Post by **maxracesoftware** » Wed Feb 18, 2004 8:25 pm

what about a gapless 2nd ring

speedtalk · Post by **speedtalk** » Wed Feb 18, 2004 10:02 pm

cstraub wrote:. . .is everybody opening up the second?

Yes! IMO, the pressure that gets past the top ring needs an easy exit.

learner · Post by **learner** » Wed Feb 18, 2004 10:48 pm

i agree, open it up. A tigher gap may show less static leakage but is worse when running

Post by **maxracesoftware** » Wed Feb 18, 2004 11:04 pm

wouldn't the 2nd groove gapless ring be better ???

learner · Post by **learner** » Wed Feb 18, 2004 11:25 pm

No, the gases that get by the 1st ring have no place to go. They build up and will lift the 1st ring. Increasing the 2nd ring gap relieves the pressure.

Post by **maxracesoftware** » Thu Feb 19, 2004 4:12 am

No, the gases that get by the 1st ring have no place to go. They build up and will lift the 1st ring. Increasing the 2nd ring gap relieves the pressure.
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i agree...i just wanted to see what other opinions were ??

but "must be more" to their(Gapless) HP Losses than that explanation

when the gases do Lift the top ring off the bottom groove , still the gases should have no place else to go if 2nd groove gapless ring is now working.
engine shouldn't loose hardly any HP or increase in Blowby under load

and if the 2nd groove Gapless ring is now doing all the work
it shouldn't have more ring friction than the top ring would have had when doing all the work

"Yet" , in the dyno tests i've done and watched other engine builders use my dyno, "both" the new Top or 2nd Gapless Ring designs "LOOSE" HP
in full-load, acceleration dyno tests

the great mystery to me about the Gapless rings ,
is for some reason they seem to LOOSE more down the DragStrip than what the dyno tests show

the dyno shows should loose 1/2 tenth ET , but its closer to 1.0 Tenth ET
at the track

theres an increase in Blowby meter SCFM under full load acceleration tests , but again the Blowby doesn't explain the larger ET loss

could it be total combination , along with some oil contamination lowering octane ...these dyno tests range from 11.5:1 CR to 15.3:1 CR

Any other possible explanation or ideas on why Gapless doesn't work

speedtalk · Post by **speedtalk** » Thu Feb 19, 2004 8:29 am

maxracesoftware wrote:theres an increase in Blowby meter SCFM under full load acceleration tests

Are you saying compared to standard gap ring?

Post by **maxracesoftware** » Thu Feb 19, 2004 10:12 pm

Are you saying compared to standard gap ring?
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the Gapless rings have more Blowby than a conventional compression ring such as SpeedPro file-fitted

SW · Post by SW » Fri Feb 20, 2004 3:22 pm

We had found the same thing. The biggest gains we have found in rings was going to the total seal coated rings, not the gapless ones. By cutting our own ring grooves and holding very tight tolerences, the coated ring combo made really good improvements in ring seal as well as power.
shawn

bsfc9 · Post by **bsfc9** » Fri Feb 20, 2004 8:56 pm

can anyone tell us a little more about the coating on the total seal ring mentioned by SW?

SW · Post by SW » Fri Feb 20, 2004 9:28 pm

Total Seal calls it a PVD coating. We call it horsepower,lol. The high end rings that they sell are diamond lapped to a very smooth finish and coated to keep them from sticking when you run very tight clearance. They also have a huge selection of axial and radial thickness to choose from.The tech guy there, i can't remeber his name right now, does a good job of picking something for you based on your application if you call them, and if you have a way to measure bore finish, he can get you some more power with some other types of coatings that they have.Just don't plan on them being cheap, though.
Shawn

Shaun Tiede · Post by **Shaun Tiede** » Sat Mar 13, 2004 6:40 pm

I understand the gapless second ring is not the right choice. What feedback do any of you have on the gapless top ring and how it effects power?

bsfc9 · Post by **bsfc9** » Sun Mar 14, 2004 7:09 pm

how critical is the size of the top ring gap? i have heard discussions in which it has been proposed top ring gap is not as critical as most people think. now it is obivious that it cannot be too small, but the difference between say .018" and .027 in a 4.155 bore show negligable difference. these ideas were put forth for discussion at a seminar by a large ring manufacturer i attended awhile back. any thoughts?

Racer7088 · Post by **Racer7088** » Wed Jun 30, 2004 2:31 am

This may sound ridiculous but we have basically screwed up and run like .035 on the top of a late model type engine that made right at 615 hp and then on the next freshen ran them back around .018 and made 614 hp with everything else the same both with like .010 more on the second so I don't worry so much about the top either as long as what these guys say doesn't happen and you lift the top ring by too little second ring gap.

I've heard of even doubling second ring gap! One decent engine I did was like this also by accident and it ran great with no problems at .018 and .035.

I've also seen people have all sorts of weird situations with the gapless rings and then take them out and everythings fine.

Post by **maxracesoftware** » Sat Jul 03, 2004 3:52 pm

you need some blowby at the 2nd ring for the 1st Top ring to work

you need some blowby at the 2nd ring for the oil rings to work as they rely on a pressure differential to scavenge oil out of the oil ring groove back thru oil holes in piston skirt , then oil pan

on a Chevy 355 SBC with ; (ran 7.50's at 181 mph in 1400 lbs Dragster)
13.7:1 CR , Pontiac/Brodix 23 deg, 719 HP / 483 TQ
.043" top ring down .120" gapped at .018"

playing around on the Dyno with ring end-gaps from .016 to .018 top
i found the top ring just touches at .016-.017" on this particular engine

i file fit only one side of the ring..using the other side to "square-up" the otherside i'm gapping ...and leaving one side unfiled with its darker coating will showup if a ring has too little gap , when the dark coating shows evidence of ring butting. At .018 to .019 top rings didn't butt at .120" down with exhaust temps in 1200 to 1300 deg range

This is what i was doing many years ago to see how tight i could run the ring gaps , but now with Nitrous being so popular , many Racers have brought engines to Dyno test with top ring gaps as wide as .027"+ with 2nd rings about the same..and with good hone jobs , have as little as 3 to 4 CFM blowby, and usually no more than 6-8 SCFM Blowby with bad rod ratios.

.027 to .035 like Erik (Racer 7088) mentioned is a lot more ring gap than i thought would ever work ?

http://www.maxracesoftware.com/Blowby_Meter_1.jpg

http://www.maxracesoftware.com/Blowby_3.jpg

Don Terrill’s Speed-Talk

Ring gaps. . .

Re: Ring gaps. . .

Ring Gaps