Piston Ring Spacers

[Alan Roehrich]

I don't suggest those without a lot of experience, control of their bore finish, and access to a dyno try to use an oil ring with less than 10# of tangential tension, and 12# might be better.

The vast majority of "do it yourself" guys are best served with a 10-12# oil ring and the 1.0MM or so compression rings with spacers, and the "gas ports" on the top ring spacer. Get the Napier cut on the 2nd ring, too.

Given a relatively "common" bore size, you shouldn't need to spend more than $650 or so, maybe a little more.

When you get into the ultra narrow compression rings and ultra light oil rings, one very minor mistake can be catastrophic. Yes, they can be made to fly, if everything is right, but if everything isn't just right, they can be very difficult to deal with.

[Ed Wright]

Alan, with a 4" bore with a Napier 2nd ring, I have not found more than 7lb oil rings needed. I can tell you 4.5lbs is too light. :-)

[Rob Petrie E395]

First off thanks for the advise. I'll save my money for something else. Right now I have the Napier seconds in it. and a 8lb oil ring. Honestly cannot remember what the top ring is without going to the shop and looking in my notes. It does not seem to be having a oil problem. And my leak down numbers are good after just 40 runs. Main reason I'm tearing it apart is because I just kind of did a cheap engine to see if I liked the class racing thing. I like it so far with just one National open, one combo race and a bunch of trips to T&T to sort the car out a little and try some stuff. So I am taking it a little further along this winter. If all goes well I will go some more either during the season or next winter. Who would you recomend I call about the top rings with the gas ports in them?

Originally Posted by Alan Roehrich

I don't suggest those without a lot of experience, control of their bore finish, and access to a dyno try to use an oil ring with less than 10# of tangential tension, and 12# might be better.

The vast majority of "do it yourself" guys are best served with a 10-12# oil ring and the 1.0MM or so compression rings with spacers, and the "gas ports" on the top ring spacer. Get the Napier cut on the 2nd ring, too.

Given a relatively "common" bore size, you shouldn't need to spend more than $650 or so, maybe a little more.

When you get into the ultra narrow compression rings and ultra light oil rings, one very minor mistake can be catastrophic. Yes, they can be made to fly, if everything is right, but if everything isn't just right, they can be very difficult to deal with.

[Alan Roehrich]

Total Seal has the spacers with the gas ports. Get them from Keith.

If you get by with less than 10#, that's great, don't get me wrong. I just don't suggest it for everyone, simply because not everyone has available to them everything it takes to make it work consistently and reliably.

If you're running Napier cut second rings and 8# tangential tension oil rings, you're not going to gain much more there.

While good leak down numbers are nice, I've seen some stuff that leaked great and ran like crap, and stuff that ran great and leaked like crap. The key is dynamic seal. How much actual blow by exists in the RPM range between peak torque and 200-400 RPM past peak HP?

If you're going to try to run the really narrow rings, you need to have the pistons built with that in mind, and the clearances set for that as well. Have Keith give your piston manufacturer the ring groove dimensions, and make sure everyone agrees on everything, such as your machinist agreeing on the clearance and the finish.

[Rob Petrie E395]

After reading your first reply. I instantly gave up on the narrow rings. I've been bracket racing since the mid 90's. But there is a world of difference between here and there. And I know that and don't have any experience in this S/SS stuff so I best leave those rings alone till I get some more. I agree on the leakdown numbers but its all I got to work with for now. Kieth has said he would give me some instructions on how the block should be bored and honed. I'd bet he would do the same with these other rings your suggesting. I got what seems to be a good machinist here. They have never done me wrong so far. If I had half a brain I would probably just call one of the places like you that do S/SS engines for a living. But I'm one of those hard headed types that has to try himself first before I write a check LOL
Thank you again for helping me.
Rob


Dave
Kieth never quoted me any prices. I was told that price by another racer. Little over a grand in a whole engine? Man I got that in my heads and I got inexpensive but good used ones from another racer that changed combos. I have been told that if I really want to go fast I need to spend 3500 or more for a new set. I'm actually thinking about doing it. I guess I love work and hate money. I will say this Stocker thing seems cooler than bracket racing so far. LOL

[Alan Roehrich]

Rob, I'm not saying you can't run the super thin rings and make it work. Keith will certainly help you as well, regardless of which set of his rings you buy. I would want to start with a clean sheet of paper to run the sub 1MM rings. You can find some power. But I'd want to start with a fresh block and pistons, done the way Keith tells you.


Dave, I'm not sure I'd spend any money on a set of pure race rings just to put them on a set of cast pistons. I seriously doubt the cast pistons are going to have the precision ring grooves necessary to make really good rings work well. The flip side of that is that if you really have more than 10-15% leakage, even on a set of stock cast pistons and rings, you have serious problems, and I doubt buying an expensive set of custom rings will solve them.

[Bill Diehl]

the hone job, precision ring groove and inboard piston are what's needed for the ultra thin rings...and if your tuneup is setup to make power, a vacuum pump and pan gauge to tune by. Now a pumps not legal and guys are going to say they did this with that but......


IMHO......

[Dave Noll]

OK i'm gonna divert my own thread. 3500.00 in a set of iron heads ??? Liberally I can see a grand in parts. A concentric valve job a 1/2" deep ? Back cutting the valves ? ...... Where's the rest going ?? Roughly 2000.00 for flow bench time ??

[Alan Roehrich]

You're not just paying the guy for what he does. You're paying him for what he's learned, and for what it costs to do business.

[Bill Diehl]

Originally Posted by Dave Noll

OK i'm gonna divert my own thread. 3500.00 in a set of iron heads ??? Liberally I can see a grand in parts. A concentric valve job a 1/2" deep ? Back cutting the valves ? ...... Where's the rest going ?? Roughly 2000.00 for flow bench time ??

I will tell you about mine...
16 dell west copper seats $480
16 .502 bronze guides $144
8 ferrea hollow stem intakes $392
8 ferrea comp + exhaust $268
16 7/16x11/16 rocker studs $450
16 rockers $460
16 adjusting screws $180
16 Pac springs $340
16 Pac retainers $308
8 Pac round locks $32
8 Pac sq locks $32


that's $3000+ in parts alone, they have a legal valve job, they are not acid ported, they hold legal volume, they flow 300+ at .502


71 Boss 351C


I will sell them for 10,000