Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > 911 Engine Rebuilding Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered
 
Join Date: Jul 2013
Location: Brisbane, Australia.
Posts: 2,611
JE Piston Ring Thickness

Just got the JE 10% off email... had a look at their offerings.
Trying to understand what the difference of thicker or thinner rings is?

The piston with the thinner rings, is more expensive...

Which one should I order?




__________________
Always learning.
www.aircooledporsches.com.au

See me bumble my way through my first EFI and TURBO conversion!
https://youtu.be/bpPWLH1hhgo?si=GufVhpk_80N4K4RP
Old 02-17-2024, 02:19 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered
 
Join Date: Dec 2007
Location: Just a little north of 13669/Nation's capital
Posts: 1,289
Send a message via AIM to brighton911
I had a set of 98 mm JE pistons with the thinner oil control rings and experienced high oil consumption. I had the pistons cut for the thicker rings and never looked back. Yes, the thinner rings most likely have less drag but at a cost of excess oil use.
__________________
1986 Targa Guards Red
2021 MT09 SP
Old 02-17-2024, 03:27 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered
 
Join Date: Jul 2013
Location: Brisbane, Australia.
Posts: 2,611
Quote:
Originally Posted by brighton911 View Post
I had a set of 98 mm JE pistons with the thinner oil control rings and experienced high oil consumption. I had the pistons cut for the thicker rings and never looked back. Yes, the thinner rings most likely have less drag but at a cost of excess oil use.
that's very interesting...
__________________
Always learning.
www.aircooledporsches.com.au

See me bumble my way through my first EFI and TURBO conversion!
https://youtu.be/bpPWLH1hhgo?si=GufVhpk_80N4K4RP
Old 02-17-2024, 04:03 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
It's a 914 ...
 
stownsen914's Avatar
 
Join Date: Jan 2008
Location: Ossining, NY
Posts: 4,709
A well known 911 race engine builder advised that for a normally aspirated race application to use 1 mm top, 1.2 second, and 2.8 or 3 mm oil rings. Looks like the exact specs on the right above.

The price difference is odd if the ring thicknesses are the only difference.
Old 02-17-2024, 08:42 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered
 
Join Date: Dec 2014
Posts: 13,871
Quote:
Originally Posted by mikedsilva View Post
Just got the JE 10% off email... had a look at their offerings.
Trying to understand what the difference of thicker or thinner rings is?

The piston with the thinner rings, is more expensive...

Which one should I order?



I have a set of #274048 I’m about to install, the skirts are not coated as seen in pic, maybe that’s the difference in price??
__________________
House producers wanted to end the show after season 8 to keep the enigmatic appeal of the central character and maintain the show's mystique. Ahhh The Mystique!!!
Old 02-17-2024, 09:49 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered
 
Join Date: Dec 2014
Posts: 13,871
The catalog your looking at is wrong, according to J&E the skew number on the higher price pistons are 11.5 compression and have a different dome cc. You want the lower priced ones for a 9:5:1 compression. Here’s the data sheet that came with my pistons.
__________________
House producers wanted to end the show after season 8 to keep the enigmatic appeal of the central character and maintain the show's mystique. Ahhh The Mystique!!!
Old 02-17-2024, 10:03 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered
 
Join Date: Dec 2014
Posts: 13,871
__________________
House producers wanted to end the show after season 8 to keep the enigmatic appeal of the central character and maintain the show's mystique. Ahhh The Mystique!!!
Old 02-17-2024, 10:04 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered
 
Join Date: Dec 2014
Posts: 13,871
__________________
House producers wanted to end the show after season 8 to keep the enigmatic appeal of the central character and maintain the show's mystique. Ahhh The Mystique!!!
Old 02-17-2024, 10:05 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered
 
Join Date: Jul 2013
Location: Brisbane, Australia.
Posts: 2,611
Quote:
Originally Posted by Dpmulvan View Post
The catalog your looking at is wrong, according to J&E the skew number on the higher price pistons are 11.5 compression and have a different dome cc. You want the lower priced ones for a 9:5:1 compression.

Not sure how it is wrong, as this is from the JE Piston website. Your SKU number 27048 and your data sheet show you for the thicker rings, exactly as per the JE website states.

So I changed my 'filter' on the JE website and instead of choosing 95mm bore, I selected 3.74inch bore, and a different option appeared. According to the come volume, this would give a compression ratio of 10:1 (which would be ideal for me) assuming a 1mm deck height.
What I dont understand is why they have a different option using inches for the bore instead of mm. It is a different piston altogether. Annoyingly, they do not publish the ring thicknesses to compare.

Apologies for the size of images... I use IMGUR to host them but they seem to be changing how they do things and resizing is really hit and miss...




__________________
Always learning.
www.aircooledporsches.com.au

See me bumble my way through my first EFI and TURBO conversion!
https://youtu.be/bpPWLH1hhgo?si=GufVhpk_80N4K4RP

Last edited by mikedsilva; 02-17-2024 at 02:19 PM..
Old 02-17-2024, 12:18 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Registered
 
Join Date: Dec 2014
Posts: 13,871
Mike, what I was saying is that in your original post you asked what the difference was, I told you the piston on the right with the thinner rings according to my catalog is a 11:5 compression that’s the difference. If you’re building a 3.0 95mm with 9:5:1 you want to order the pistons 274048. I’ll email you the je catalog.
__________________
House producers wanted to end the show after season 8 to keep the enigmatic appeal of the central character and maintain the show's mystique. Ahhh The Mystique!!!
Old 02-18-2024, 07:01 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Registered
 
Join Date: Jul 2013
Location: Brisbane, Australia.
Posts: 2,611
Quote:
Originally Posted by Dpmulvan View Post
Mike, what I was saying is that in your original post you asked what the difference was, I told you the piston on the right with the thinner rings according to my catalog is a 11:5 compression that’s the difference. If you’re building a 3.0 95mm with 9:5:1 you want to order the pistons 274048. I’ll email you the je catalog.
Are you saying that where they list the dome volume od 38.5cc, that this is an error?

In my later post, I found the 3rd option which does sy it has the higher compression, however they dont list anything for rings...
__________________
Always learning.
www.aircooledporsches.com.au

See me bumble my way through my first EFI and TURBO conversion!
https://youtu.be/bpPWLH1hhgo?si=GufVhpk_80N4K4RP
Old 02-18-2024, 07:04 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Registered
 
Join Date: Dec 2014
Posts: 13,871
Quote:
Originally Posted by mikedsilva View Post
Are you saying that where they list the dome volume od 38.5cc, that this is an error?

In my later post, I found the 3rd option which does sy it has the higher compression, however they dont list anything for rings...
Shoot me a valid email I’ll send you the catalog. Stop worrying about the rings, there’s only 4 stock 95mm domed pistons for a 3.0 and all are different compressions.
__________________
House producers wanted to end the show after season 8 to keep the enigmatic appeal of the central character and maintain the show's mystique. Ahhh The Mystique!!!
Old 02-18-2024, 07:41 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
 
Registered
 
targa72e's Avatar
 
Join Date: Feb 2004
Location: denver
Posts: 1,147
I recently had a similar question on two part numbers for 2.7 engine that looked the same. I emaled JE pistons and the response is below.

261663 is a standard design piston at a weight of about 404 grams

353235 is a newer version of that piston with some extra features and underhead milling making it a more desirable lighter design. 368 grams.

Cost for 261663 is 1622.18

Cost for 353235 is 2367.17

john
Old 02-18-2024, 09:12 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)
Try not, Do or Do not
 
Henry Schmidt's Avatar
 
Join Date: Apr 2004
Location: Fallbrook, Ca. 92028
Posts: 14,066
Garage
Creating a good seal in these air cooled engines is and has always been a challenge.
Ever since we started working with JE back in the early 90s (when they needed .007" clearance) ring have been an issue.
We try to avoid the shelve pistons from JE and CP and special order our pistons with Goetze ring packs. It cost more, and take longer but the results are generally positive.
The Goetze oil ring is easier to gap (many 3 piece rings recommend "don't gap" and Nikasil coating seems to prefer the one piece oil ring to control oil consumption. Material properties, coating performance and ring design are decades tested and track proven.
Not going to the track, we seen Goetze rings still performing well way into the 200K range.
__________________
Henry Schmidt
SUPERTEC PERFORMANCE
Ph: 760-728-3062
Email: supertec1@earthlink.net
Old 02-18-2024, 09:28 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #14 (permalink)
Registered
 
Join Date: Dec 2014
Posts: 13,871
I’m using a little higher RA with the JE stock rings than I would with Goetze. Hopefully that will help a little.
__________________
House producers wanted to end the show after season 8 to keep the enigmatic appeal of the central character and maintain the show's mystique. Ahhh The Mystique!!!
Old 02-23-2024, 05:32 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #15 (permalink)
Registered
 
Join Date: Jul 2013
Location: Brisbane, Australia.
Posts: 2,611
Quote:
Originally Posted by Dpmulvan View Post
Shoot me a valid email I’ll send you the catalog. Stop worrying about the rings, there’s only 4 stock 95mm domed pistons for a 3.0 and all are different compressions.
never got your catalogue, but JE sent it to me and even they said not to rely on the data on the web!
__________________
Always learning.
www.aircooledporsches.com.au

See me bumble my way through my first EFI and TURBO conversion!
https://youtu.be/bpPWLH1hhgo?si=GufVhpk_80N4K4RP

Last edited by mikedsilva; 02-23-2024 at 08:55 PM..
Old 02-23-2024, 08:50 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #16 (permalink)
Registered
 
Join Date: Dec 2014
Posts: 13,871
Quote:
Originally Posted by mikedsilva View Post
never got your catalogue, but JE sent it to me and even they said not to rely on the data on the web!
I’m sorry Mike, just checked my Mail says it was sent last Sunday 12:16 pm est. At least you got it. Let me know if I can answer any questions.
I used an 800 grit brush research hone instead of a red scotchbrite to deglaze,gives you a little higher RA around 7 to 10 with 4 quick strokes in soapy water.
__________________
House producers wanted to end the show after season 8 to keep the enigmatic appeal of the central character and maintain the show's mystique. Ahhh The Mystique!!!
Old 02-24-2024, 05:04 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #17 (permalink)
Registered
 
silver911rdb's Avatar
 
Join Date: Oct 2007
Location: Wethersfield, CT
Posts: 573
Garage
Interesting read. My 1984 911 was built with JE high compression special make pistons. They're high dome, 12.5:1 compression with 22mm rod ends. I had a fuel related issue and ended up melting a hole in one of the pistons, requiring new replacements. When ordering a new set from JE, they suggested the latest improvement would be to order them with the thinner rings. I went with their recommendation and placed the order. The engine did make more power, unfortunately it was short lived. I started to get massive blow-by with about 5 hours on the engine. I did a leak down test and the numbers were bad on all cylinders. Taking the engine apart showed that all the pistons had a large amount of carbon buildup, especially on the oil control rings. Not really having much faith in the JE piston rings, I contacted Total Seal to see what they offered. They told me that they didn't know why JE piston was recommending the narrow piston rings for the air cooled 911 engines. They designed a set of rings that they thought were going to make the pistons work in my application, although it wasn't ideal. It's been 20 hours since I installed them and I'm having a blow-by issue again. Measuring my original JE's pistons with thicker ring widths, the top and middle ring measure .056" (1.4mm) thick, the oil control ring measures .113" (2.87mm). The updated JE piston set spec's out 1mm top, 1.2mm middle, 2.8 oil control ring.
So in my experience, I don't recommend the thinner piston rings. To resolve the issue I'm thinking I should widen the ring grooves and install a new set of piston rings. I like what Henry Schmidt says about the Goetz rings. I've done a quite a few rebuilds over the years and have used their rings. I've never had an issue. I wasn't sure I could use their rings on a track car, but from the sounds of it, I could. Does anyone know if Goetz has an option for my 98mm piston in the above wider widths?
__________________
-Rich-

1984 911 Track
1985 911 Track/Autocross
Old 05-12-2024, 06:20 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #18 (permalink)
Registered
 
Join Date: Dec 2014
Posts: 13,871
Quote:
Originally Posted by silver911rdb View Post
Interesting read. My 1984 911 was built with JE high compression special make pistons. They're high dome, 12.5:1 compression with 22mm rod ends. I had a fuel related issue and ended up melting a hole in one of the pistons, requiring new replacements. When ordering a new set from JE, they suggested the latest improvement would be to order them with the thinner rings. I went with their recommendation and placed the order. The engine did make more power, unfortunately it was short lived. I started to get massive blow-by with about 5 hours on the engine. I did a leak down test and the numbers were bad on all cylinders. Taking the engine apart showed that all the pistons had a large amount of carbon buildup, especially on the oil control rings. Not really having much faith in the JE piston rings, I contacted Total Seal to see what they offered. They told me that they didn't know why JE piston was recommending the narrow piston rings for the air cooled 911 engines. They designed a set of rings that they thought were going to make the pistons work in my application, although it wasn't ideal. It's been 20 hours since I installed them and I'm having a blow-by issue again. Measuring my original JE's pistons with thicker ring widths, the top and middle ring measure .056" (1.4mm) thick, the oil control ring measures .113" (2.87mm). The updated JE piston set spec's out 1mm top, 1.2mm middle, 2.8 oil control ring.
So in my experience, I don't recommend the thinner piston rings. To resolve the issue I'm thinking I should widen the ring grooves and install a new set of piston rings. I like what Henry Schmidt says about the Goetz rings. I've done a quite a few rebuilds over the years and have used their rings. I've never had an issue. I wasn't sure I could use their rings on a track car, but from the sounds of it, I could. Does anyone know if Goetz has an option for my 98mm piston in the above wider widths?
I just installed a set of JE pistons reluctantly. Too many unanswered questions for me.
Ring gap differences, RA, differences, conflicting advice from different people.
I ended up using a slightly higher RA of around 10 to 12 hopefully to help rings seat a little better. I also split the difference on ring gap, I don’t understand why JE doesn’t take expansion of nikasil/ aluminum cylinders into consideration when advising ring gap on these motors. If I had to do it again I’d just spend the extra $$$ and go with mahle and goetze.

__________________
House producers wanted to end the show after season 8 to keep the enigmatic appeal of the central character and maintain the show's mystique. Ahhh The Mystique!!!
Old 05-14-2024, 06:29 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #19 (permalink)
Reply


 

Tags
je piston , piston ring , ring thickness


All times are GMT -8. The time now is 03:59 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.