two ring piston experience?

[dwilliams]

Two ring pistons have come and gone from the drag racing world a couple of times in the last 30 years.

With the ring pack being such a high percentage of internal friction, I can see the attraction of deleting the compression ring.

Have any of you guys tried the two ring pistons? Would you care to share your experiences and opinions?

[bigjoe1]

I dont talk too much about it, but I do the 2 ring thing quite a bit. I use C P pistons, and they tell me that is is getting very popular. I only use it on what I call a maximum effort buildup. I have never seen anything negative about it. You must use a vacuum pump or a drysump, but there is so0me serious HP to be had. JOE SHERMAN RACING

[Cobra]

2-ring piston packages and compact pistons are the hot setup. Improvements in ring materials and cylinder finishing support the 2-ring design. The cylinder/piston/rings are a major source of friction in an engine, and any reduction is welcome. 2-ring piston packages should be used a lot more than they are. Auto manufacturers are spending big money to research this area for gains in fuel mileage.

[DCal]

I will defer back to Joe on the horsepower part. A large portion of 2-ring use that we saw was from the IHRA pro stock customers.they have a situation where the piston is almost out of the cylinder with those huge strokes, they were primarily interested in more piston skirt. The problem became,of course,was oil control. Oil has an octane rating of zero,so the issue is will more skirt or the additional ring be best? Many Nextel Cup pistons have only two rings and of course they have a dry sump. We feel that for drag racing use, such as Super Stock, a three ring piston is best because the modern day ring package with napier-type second rings provide a very low drag. You still can pound a flat top 350 motor into submission by letting oil into the combustion chamber. A cutomer recently went 209mph in Pro stock using a .8mm top and second ring with .135 radial walls. These rings will be available in most bore sizes. You can check with Kevin or Keith at Total Seal 800/874 2753 Please come by the CP piston booth at PRI if I have'nt been clear

[cboggs]

A cutomer recently went 209mph in Pro stock using a .8mm top and second ring with .135 radial walls. These rings will be available in most bore sizes. You can check with Kevin or Keith at Total Seal 800/874 2753

Please come by the CP piston booth at PRI if I have'nt been clear

Regarding being "clear", .. a pet peeve of mine, ..

you've invited people by your booth but signed no name, ..
and have not filled out the info in your profile.
I think it should be mandatory for the level of professionalism we maintain here
to fill out the profile so we know who everyone is.

Ok, rant over, ..

If the 209 mph run you are talking about was the runs in Richmond, ..
I was there, .. saw them as well as the record runs, .. all I can say is WOW !

I'm going to send my engine builder by your booth, . maybe I can get away
from my booth to go too, .. but we have several piston issues to discuss, ..
who should he ask for?

Cheers,

Curtis

[DCal]

CBoggs You're right,I apologize, I never intended to post except to respond to a member of this site that had a problem with one of my employees about gas porting. Failing to do even that correctly, I must admit I can't type and am far too busy to keep up. So I won't respond very often. My name is Dave Calvert and the invitation stands re:PRI. Darrin Morgan turned me on to this very informative site and I'm so pleased to find a site without backbiting and name calling and where everyone is so informed.

[Robert Kane]

Ok, but who do you work for? If your company was in that 209** mph engine, then I would like to know who I can get that type of product from. I agree with Curtis 100% about posting names and company info when making posts. Guess we share the same peeves.
Robert.

[bigjoe1]

Dcal, Or Dave Calvert is a big player at C P Pistons. They are the state of the art piston manufacturer of the industry today.Check out their web site when you have a chance. JOE SHERMAN RACING

[dwilliams]

What kind of geometry are you using on the two-ring pistons? .043 top ring, .150 spacing and a 3/16 oil ring?

[cboggs]

CBoggs You're right,I apologize, I never intended to post except to respond to a member of this site that had a problem with one of my employees about gas porting. Failing to do even that correctly, I must admit I can't type and am far too busy to keep up. So I won't respond very often. My name is Dave Calvert and the invitation stands re:PRI. Darrin Morgan turned me on to this very informative site and I'm so pleased to find a site without backbiting and name calling and where everyone is so informed.

Welcome to the forum Dave, .. we are lucky to have a person like you here,
i hope you'll share some experience regarding pistons.

Yes SpeedTalk is like nothing else on the net, ...

I have two people I want you to meet at PRI.

Curtis

[bobqzzi]

I realize that if you went with 2 rings you'd want to have a piston specifically designed for it;however, would doing a bcak to back dyno test in which you removed the second ring be valid?

Can a 2 ring piston be used without vacuum or drysump in a class where cylinder pressure is low due to rules?

[maxracesoftware]

I realize that if you went with 2 rings you'd want to have a piston specifically designed for it;however, would doing a bcak to back dyno test in which you removed the second ring be valid?

Can a 2 ring piston be used without vacuum or drysump in a class where cylinder pressure is low due to rules?

i started running 2-Ring Pistons around 1980
didn't have a Dyno back then,
but back-to-back DragStrip tests the 2-ring Pistons were just
hundredths faster,maybe as much as half a Tenth.

No Vac-Pumps back then

if you remove the 2nd Ring,
empty 2nd Groove,
its going to be an "Oiler"

from HearSay, someone told me Patterson tried
Siliconing up the 2nd Groove, and making a few Dyno tests,
i was tempted to try that, but never did .

It sure makes you wonder about a 2nd Groove GapLess ring
i sure never found any HP or TQ with GapLess Rings yet.

[bigjoe1]

If you have a 3 ring piston, you can put an under size ring in the second( like 030 or 060 smaller than the bore really is) this would fill the groove but not put any drag on the cylinder walls. I have not done it ,but I have heard of this being done before.The Napier Hook second is a very good alternative, if your pistons have three grooves. JOE SHERMAN RACING

[cmw]

This is the bottom line on 2 ring pistons, if you can control the oil with the oil control rings, keeps the compression ring from flooding, not scratching the cylinders and not transferring material back and forth from the rings and cylinders then the 3 ring piston will work. Drag of rings is a big problem with making hp. I have run .8mm compression rings with a 2mm oil control rings with the correct vacuum it will make horsepower and with using the correct hone and cross hatch can be vary taxing along with using the correct piston ring assembly oil for break-in. Then when you change ring material you start all over again. If you don't have an engine dyno it is hard to do, but it can be done. When and if you find out what makes it work, it does not pay to tell anyone how you made it work with out getting big money for your efforts.

[Mike@DiamondPistons]

I'm not a huge fan of the 2 ring piston design. In my opinion I just do not like seeing the top ring do double duty during operation. The top ring is designed to be the compression ring. With the second ring being removed from the piston, you are now asking the top ring to act as the compression ring and also as a oil control ring. If limited to land spacing due to a small compression height, I like to see the customer go to the .0415 or .8mm ring pack with a napier second ring. I have many customers switch from a two ring piston design to a conventional 3 ring design with narrow rings and pick up horsepower and go faster down the track due to ring seal and stability.

Mike Panetta