Piston ring problem - Competition Diesel.Com

Highwayman · 05-18-2015, 05:35 PM

So, rings are gapped, loaded onto Pistons, ready to put in, except for one small problem. I can't get them in the cylinder.
Once the oil ring hits the chamfer in the top of the cylinder and half out of the compressor, it pops out just enough to hang.

What gives? I've tried three different compressors, all the same result.
Try a bigger hammer? Trim the oil ring expander? Im afraid of breaking a ring, or losing too much tension.

DIESEL_POWER · 05-18-2015, 05:47 PM

Lots of lubricant and a steady hard push into the bore. Going to slow often ends with your situation.

Highwayman · 05-18-2015, 06:56 PM

IMG_0844_zps8ab3e553.jpg Photo by thatonedylankid \| Photobucket

That method produced less than satisfactory results.

stubz616 · 05-18-2015, 07:20 PM

Are you using a fixed size compressor or a
Do you have a compressor that you tighten with a 1/4" extension or Allen? Can you compress the rings into the piston by hand to flush or below the edge of the piston itself?

Highwayman · 05-18-2015, 07:37 PM

Adjustable compressor, no I can't quite get the bottom rings to get flush with it by hand

I can't quite remember if I could without the expander in it or not

madmikeismad · 05-18-2015, 07:48 PM

Quote:

Originally Posted by DIESEL_POWER

Lots of lubricant and a steady hard push into the bore. Going to slow often ends with your situation.

Oh yeah?

randal07 · 05-18-2015, 07:53 PM

So many dirty thoughts.

Highwayman · 05-18-2015, 08:08 PM

You guys are making it really difficult to be pissed off right now.

*Big Blue24* · 05-18-2015, 09:30 PM

Try installing just the oil ring without the piston and see if your oil rings are too big. You'll want the oil ring gap to be at least .010"+ and yours I'll bet are too big.

Highwayman · 05-19-2015, 04:35 PM

I gapped the rings.

I can't get the old ones back in with the expander in, either

Highwayman · 05-19-2015, 05:36 PM

Is this the wrong type compressor?

IMG_0857_zps689a0bee.jpg Photo by thatonedylankid \| Photobucket

ComnRailPwr · 05-19-2015, 07:11 PM

That's what I use, they can be finicky but work. The expanders are a pita. Just gotta make sure when you crank the compressor the base is totally flush with the piston just below the oil ring.

Highwayman · 05-19-2015, 07:14 PM

Trimmed the oil ring expander, until it would just barely fit, but it went in the cylinder. Now as soon as the middle ring hits the chamfer, it wants to twist and gets hung up. Could that chamfer be cut wrong?

ComnRailPwr · 05-19-2015, 07:16 PM

Any things possible. It shouldn't really have room to do anything besides go in the hole if the compressor is bottomed out on the block all around. My compressor will actually sit down in the chamfer to where it looks like it's in the hole.

Highwayman · 05-19-2015, 07:35 PM

Mine won't because of the part that sticks out. May try trimming that and see if it'll sit down enough to keep from twisting

Highwayman · 05-20-2015, 05:17 PM

Figured out the problem. The groove has the slightest angle on the walls. Like 5° max.
I can't pull up any information about the piston or what rings should fit.The only one that doesn't fit completely in the groove is the intermediate ring.
Piston P/N 102039
My rings are s42170.
Can anyone find what I need? The only thing I'm seeing right now is a post that says they are actually 24v pistons.

Highwayman · 05-20-2015, 05:50 PM

Maybe I couldn't find anything because that isn't a real part number. Using Weston's piston profiles, I got it narrowed down to one (measurements were all off by .2 mm), but it measured to be a 286140.

or mahle power pack piston??

Highwayman · 05-20-2015, 06:09 PM

Problem solved. Piston uses Double keystone rings. Which I think is odd. I'm an idiot as well.

05-18-2015, 05:47 PM	#2
DIESEL_POWER Name: DIESEL_POWER Title: NGM Diesel Status: Not Here Join Date: Jul 2006 Member`s Gallery Posts: 5,178	Lots of lubricant and a steady hard push into the bore. Going to slow often ends with your situation. __________________ Proverbs 3:5-6 (KJV) 5 Trust in the Lord with all thine heart; and lean not unto thine own understanding. 6 In all thy ways acknowledge him, and he shall direct thy paths.

05-18-2015, 07:20 PM	#4
stubz616 Name: stubz616 Title: Too Much Time Status: Not Here Join Date: Oct 2008 Location: Brewster, MA Member`s Gallery Posts: 1,327	Are you using a fixed size compressor or a Do you have a compressor that you tighten with a 1/4" extension or Allen? Can you compress the rings into the piston by hand to flush or below the edge of the piston itself? __________________ 95 RCLB Farrell Diesel Stage 5 13mm pump,Hamilton Springs,Retainers,Pushrods,Fluidampr,Steed Speed,S467.7/soon to be S488 atmo,Full Billet Trans,DPC 4 disk TC,BD Pressure Loc,Haley Speed 5x.022s,Diesel Pros Custom Cam,O-Ringed,.010 over HG,A1000,Hellman sump,625 Studs, 30*

05-18-2015, 09:30 PM	#9
Big Blue24 Name: Big Blue24 Title: Comp Diesel Sponsor Status: Not Here Join Date: Jan 2008 Location: Cedar City, UT Member`s Gallery Posts: 6,310	Try installing just the oil ring without the piston and see if your oil rings are too big. You'll want the oil ring gap to be at least .010"+ and yours I'll bet are too big. __________________ 95' 2wd Junker Drag Truck 1502 HP Fuel-Only 12mm P7100 Pump SXE 472 over GTX55 116mm OEM 12v Block

05-19-2015, 07:11 PM	#12
ComnRailPwr Name: ComnRailPwr Title: Too Much Time Status: Not Here Join Date: Jun 2009 Location: Stoutsville , OH Member`s Gallery Posts: 3,293	That's what I use, they can be finicky but work. The expanders are a pita. Just gotta make sure when you crank the compressor the base is totally flush with the piston just below the oil ring.

05-19-2015, 07:16 PM	#14
ComnRailPwr Name: ComnRailPwr Title: Too Much Time Status: Not Here Join Date: Jun 2009 Location: Stoutsville , OH Member`s Gallery Posts: 3,293	Any things possible. It shouldn't really have room to do anything besides go in the hole if the compressor is bottomed out on the block all around. My compressor will actually sit down in the chamfer to where it looks like it's in the hole.