Ring thickness

[Couger1968]

I did some searching on here and can't seem to figure this out. I am looking at forged pistons and have found some with 1/16 thick and some with 5/64 thick rings. It looks like ,to me, the srp are 1/16 and the probe are 5/64. Which have a longer life. I am not as worried about which make more power. My guts say 5/64 with like a total seal would last the longest.

 

[randy merritt]

Re: Ring thickness

my understanding is you do not want to run with no ring gap with a turbo motor. mine are .22 and .22

 

[Don W.]

Re: Ring thickness

Randy, he's talking about ring -thickness- not gap.

I have standard thickness rings in my motor. Don't know exactly but they are not 1/16 so I assume they are 5/64 or close. My machinist recommended against Total Seal. Also reciently a racer friend had to tear down a relatively fresh motor because of compression and oil issues. Total Seal were used. He was of the impression that his scored cyls were caused by the Napier 2nd ring.

IMHO for long life as opposed to max performance a good set of standard width rings, of the "file to fit" variety (end gaps individually filed to fit each cylinder) would be the best choice.

 

[Couger1968]

Re: Ring thickness

Do you get choice of thickness? I thought that the piston manufacture decided what to use. I don't know much about rings ,but the total seal kept popping up. File fit are a lot cheaper anyway, so I would probably use them anyway.

 

[randy merritt]

Re: Ring thickness

Randy, he's talking about ring -thickness- not gap.

I have standard thickness rings in my motor. Don't know exactly but they are not 1/16 so I assume they are 5/64 or close. My machinist recommended against Total Seal. Also reciently a racer friend had to tear down a relatively fresh motor because of compression and oil issues. Total Seal were used. He was of the impression that his scored cyls were caused by the Napier 2nd ring.

IMHO for long life as opposed to max performance a good set of standard width rings, of the "file to fit" variety (end gaps individually filed to fit each cylinder) would be the best choice.

sorry, I was commenting on the "total seal" part of the quote. I may have misunderstood. my rings are 1/16" thick. the JE pistons came set up for that thickness rings.

 

[MoJo]

Re: Ring thickness

DO NOT use 1/16" top, 1/16" second , 3/16" oil rings. Those rings and the pistons that use them are designed for racing in quarter mile with high RPM bursts of speed and use full floating pins and Eagle rods. . They are low tension rings, have poor oil control at low RPM and will not last in a daily driver. The pistons designed to use those rings are a forged of low silicon aluminum alloy with a higher expansion rate which requires more cylinder wall clearance.

You should always use standard tension 5/64" top, 5/64" second and 3/16" oil ring sets and standard gaps. I used Speed Pro L2256F-.030" OS pistons (not turbocharged) , Speed Pro R9903-.030" OS standard tension rings. Gap checked at .018" top, .022" second, .025" oil and .0026" piston / wall skirt clearance. Those gaps are on the wide side of the standard gap of .016', .020" and .022" for higher RPM. File fitting ring gaps makes the rings progressively egg-shaped so it is best to use rings that fit your bores with the correct end gaps out of the box.

On occasions where economy is no concern, high-end engine builders who build high performance race engines may go through several sets of rings until they put a set together that fit the bores out of the box. Those engine builders bore and hone the cylinders using a block plate and fit the rings using a special fixture that positions the rings in the bores. Then they put a bright light under the fixture to see if any light can be seen between the rings and cylinder walls. .Some race engines even use two-ring pistons with a gas ported top ring. In those race engines, having less cylinder wall drag is more important than good oil control. .

 

[Couger1968]

Re: Ring thickness

The TRW and speedpro have been discontinued. The only ones I have found that are even close to reasonable have been the SRP and Probe. Can anyone tell me what the srp thickness is for sure, it looks like a 1/16? If you use rpm motors number it said std was 139630 but summit said it was a .060. I think 231315 is the number for standard. It doesn't matter to much since RPM is cheaper, but I just wanted to look at the specs. Probe P2441F looks like a 5/64,but don't have D shaped reliefs. They also look like they come standard or. 030. I was hoping to keep standard,but the tolerance on them are tighter and may not get away with it. I hate to take it to .030 right away. The SRP you can get a .020 ,but they fit looser so I might be able to use the standard size.

 

[MoJo]

Re: Ring thickness

Sped Pro pistons are still available in the Summit Catalog. The pistons you are looking for are:
Speed Pro ZL2441F std.
Forged aluminum alloy
Std. 4.00" bore
21 cc D-shaped dish (for turbocharged engines)
5/64", 5/64" , 3/16" rings
$51.90 each at Summit

I bought my Speed Pro L2256F 030 pistons at Summit 18 months ago and they are still available.

 

[Couger1968]

Re: Ring thickness

Sped Pro pistons are still available in the Summit Catalog. The pistons you are looking for are:
Speed Pro ZL2441F std.
Forged aluminum alloy
Std. 4.00" bore
21 cc D-shaped dish (for turbocharged engines)
5/64", 5/64" , 3/16" rings
$51.90 each at Summit

I bought my Speed Pro L2256F 030 pistons at Summit 18 months ago and they are still available.

I thought the same thing and after calling them a few times they come up with that they are discontinued, but they had 1 piston in stock and the computers haven't changed changed it for the sets.

 

[MoJo]

Re: Ring thickness

You are right about availability of the L2441F pistons. .

The Speed Pro L2441F dished pistons for a Chevrolet 350 V8 are designated "manufacturer's availability date unknown." Apparently Federal Mogul (Speed Pro) has determined that the market for dish pistons for a 350 V8 is not large enough to justify making them any longer. The "off the shelf" piston manufacturers such as Speed Pro are certainly not going to manufacture a forged dished piston for a 4.3L V6. The owners of 4.3L turbo engines were lucky to have the Speed Pro 350 V8 dished pistons while they lasted.

Custom piston manufacturers such as Arias, SRP, Ross, JE, Wiseco, Venoilia, etc., will make any piston you want. I had some custom Pontiac 421 V8 pistons made by Ross with 5/64", 5/64", 3/16" ring lands and their price was reasonable and they had a fast turnaround. However, those were flat tops with no valve reliefs. Dished pistons or valve reliefs cost extra. It seems that JE is always back-logged with NASCAR customers.

 

[Couger1968]

Re: Ring thickness

That is why I wondering about the SRP they look good minus the 1/16 ring $450. The probe are cheaper and have the thicker rings, but are not D shaped and are not available in all sizes. Are hypers really that bad mine held up OK I abused them some. I bought a set of eagles and would need to change the pistons to use them. My other option is to return to totally stock and return the rods. I want my truck to be as long lasting as it can.