Oversized pistons with standard rings - Competition Diesel.Com

Kaiserbailey · 01-14-2015, 01:48 PM

In the middle of a build and found out I have standard size rings for my 0.020 over pistons. The ring gap checks out fine, but I'm wondering if it is a must have to get the correct size rings for these pistons. We ordered these pistons and rings from a popular vendor on here who has offered to take them back and send us the correct rings, but we already have 4 of the 6 installed. Is it worth it to take them out and send them off for the right ones?

DISTURBED · 01-14-2015, 02:01 PM

I would put the right rings on it. What I would be concerned with is the ID of the ring and the OD of the piston not having the correct tolerance. A smaller ring in a bigger hole would cause the ring to not have enough outward force on the wall and intern not be completely round causing it not to touch all the way around. Im confused how its gapping correct.

Tate · 01-14-2015, 02:07 PM

Quote:

Originally Posted by DISTURBED

Im confused how its gapping correct.

No kidding. You should have ~.060" more gap than you would on a standard bore with those standard rings.

Kaiserbailey · 01-14-2015, 02:10 PM

We checked all rings in the holes they were going in. They were all within range specified in the manual

Kaiserbailey · 01-14-2015, 02:12 PM

I wonder if they are the right rings that came in the wrong box.

DISTURBED · 01-14-2015, 02:18 PM

Quote:

Originally Posted by Kaiserbailey

I wonder if they are the right rings that came in the wrong box.

That's never happened before

Some one put the wrong label on the right box

Kaiserbailey · 01-15-2015, 08:37 AM

Soooo........ After installing and then uninstalling 4 pistons, turns out they were the right rings in the right box with the wrong parts guy on the other end of the phone.

Called a cummins dealer local to us and found out they were the correct rings. Not very happy about this.

*Snedge* · 01-15-2015, 08:58 AM

Sorry...
I built a little cheat sheet for Tbone and he looked at the incorrect number. Hate to see you inconvenienced.

Can I ask what lead you to believe the gap was wrong in the first place?

Kaiserbailey · 01-15-2015, 09:36 AM

Quote:

Originally Posted by Snedge

Sorry...
I built a little cheat sheet for Tbone and he looked at the incorrect number. Hate to see you inconvenienced.

Can I ask what lead you to believe the gap was wrong in the first place?

The gap was correct. I had called to confirm the pistons were correct and just happened to have him check the rings as well.

*Snedge* · 01-15-2015, 10:05 AM

Quote:

Originally Posted by Kaiserbailey

The gap was correct. I had called to confirm the pistons were correct and just happened to have him check the rings as well.

Again. I'm sorry for the miscommunication. Tyler has been doing a good job for me, but honestly, I don't expect him to bat 1000 for me after a year on the phone. There is more than a lot to learn.
The good news is the parts were on the money.

Joesixpack · 01-15-2015, 11:20 AM

Let me get this straight how did you figure out you had STD rings when everything they sent you was right and the gaps checked out to boot?

Edit: In fact unless something's changed Cummins marks the boxes as to size. It's in mm so other than the conversion it's hard to screw up there.

Kaiserbailey · 01-15-2015, 12:31 PM

Quote:

Originally Posted by Joesixpack

Let me get this straight how did you figure out you had STD rings when everything they sent you was right and the gaps checked out to boot?

Edit: In fact unless something's changed Cummins marks the boxes as to size. It's in mm so other than the conversion it's hard to screw up there.

There is no indication on the box. There is "0.5" marked on the piston itself. I didn't realize what that was until I got off the phone. These pistons have been sitting for a long time waiting to be installed. That is the reason for double checking the part numbers. First engine build here, and very much a learning experience. Mumau has always provided me with excellent customer service, products, and pricing. All 6 pistons are back in the engine.

Joesixpack · 01-15-2015, 12:41 PM

Ok no problem, I'd like to think a guy can learn something from every thread on here....(trouble is there's a ****load you can't pull a damn thing from). So here it is the .5 is in metric mm which converts to a **** hair shy of .020".

DionysiosA76 · 01-21-2015, 02:43 PM

Inconvenient at the most.

01-14-2015, 01:48 PM	#1
Kaiserbailey Name: Kaiserbailey Title: Mirrors Flipped Out Status: Not Here Join Date: Feb 2010 Location: TEXAS Member`s Gallery Posts: 705	Oversized pistons with standard rings In the middle of a build and found out I have standard size rings for my 0.020 over pistons. The ring gap checks out fine, but I'm wondering if it is a must have to get the correct size rings for these pistons. We ordered these pistons and rings from a popular vendor on here who has offered to take them back and send us the correct rings, but we already have 4 of the 6 installed. Is it worth it to take them out and send them off for the right ones? __________________ Bill Bailey '05 Dodge 2500 4x4 QCSB 48RE 3.73 FlashScan V2 waiting on 03-05 support

01-14-2015, 02:01 PM	#2
DISTURBED Name: DISTURBED Title: YEA WE RIDE THE SHORT BUS Status: Not Here Join Date: Nov 2007 Location: Winchester, Va Member`s Gallery Posts: 6,417	I would put the right rings on it. What I would be concerned with is the ID of the ring and the OD of the piston not having the correct tolerance. A smaller ring in a bigger hole would cause the ring to not have enough outward force on the wall and intern not be completely round causing it not to touch all the way around. Im confused how its gapping correct. __________________ Thanks, Jeremy 01 CTD Retired sled puller, dedicated "Twin Turbo" tow rig 96 CTD "TOO" Disturbed 3.0 - Built by Disturbed Diesel Performance 96 CTD "The Sickness" 2.6/2.8- Built by Disturbed Diesel Performance Last edited by DISTURBED; 01-14-2015 at 02:03 PM.

01-14-2015, 02:10 PM	#4
Kaiserbailey Name: Kaiserbailey Title: Mirrors Flipped Out Status: Not Here Join Date: Feb 2010 Location: TEXAS Member`s Gallery Posts: 705	We checked all rings in the holes they were going in. They were all within range specified in the manual __________________ Bill Bailey '05 Dodge 2500 4x4 QCSB 48RE 3.73 FlashScan V2 waiting on 03-05 support

01-14-2015, 02:12 PM	#5
Kaiserbailey Name: Kaiserbailey Title: Mirrors Flipped Out Status: Not Here Join Date: Feb 2010 Location: TEXAS Member`s Gallery Posts: 705	I wonder if they are the right rings that came in the wrong box. __________________ Bill Bailey '05 Dodge 2500 4x4 QCSB 48RE 3.73 FlashScan V2 waiting on 03-05 support

01-15-2015, 08:37 AM	#7
Kaiserbailey Name: Kaiserbailey Title: Mirrors Flipped Out Status: Not Here Join Date: Feb 2010 Location: TEXAS Member`s Gallery Posts: 705	Soooo........ After installing and then uninstalling 4 pistons, turns out they were the right rings in the right box with the wrong parts guy on the other end of the phone. Called a cummins dealer local to us and found out they were the correct rings. Not very happy about this. __________________ Bill Bailey '05 Dodge 2500 4x4 QCSB 48RE 3.73 FlashScan V2 waiting on 03-05 support

01-15-2015, 08:58 AM	#8
Snedge Name: Snedge Title: Comp Diesel Sponsor Status: Not Here Join Date: Sep 2006 Location: Western Pa. Member`s Gallery Posts: 18,860	Sorry... I built a little cheat sheet for Tbone and he looked at the incorrect number. Hate to see you inconvenienced. Can I ask what lead you to believe the gap was wrong in the first place?

01-15-2015, 11:20 AM	#11
Joesixpack Name: Joesixpack Title: Pull'n it. Status: Not Here Join Date: Apr 2008 Member`s Gallery Posts: 4,118	Let me get this straight how did you figure out you had STD rings when everything they sent you was right and the gaps checked out to boot? Edit: In fact unless something's changed Cummins marks the boxes as to size. It's in mm so other than the conversion it's hard to screw up there. __________________ Basically stock if I would have built it at the factory..... Last edited by Joesixpack; 01-15-2015 at 11:24 AM.

01-15-2015, 12:41 PM	#13
Joesixpack Name: Joesixpack Title: Pull'n it. Status: Not Here Join Date: Apr 2008 Member`s Gallery Posts: 4,118	Ok no problem, I'd like to think a guy can learn something from every thread on here....(trouble is there's a **load you can't pull a damn thing from). So here it is the .5 is in metric mm which converts to a ** hair shy of .020". __________________ Basically stock if I would have built it at the factory.....

01-21-2015, 02:43 PM	#14
DionysiosA76 Name: DionysiosA76 Title: CumDizle Status: Not Here Join Date: Oct 2011 Location: Big Rapids, MI Member`s Gallery Posts: 296	Inconvenient at the most. __________________ 07 5.9L G56 Valair, E.D., Dan's Diesel Performance, S&S Diesel 12.79 @ 109.60mph 2.01 60ft.