Piston ring gap

Reply Subscribe

Thread Tools

Search this Thread

Feb 8, 2009 | 10:56 AM

djmac

Thread Starter

Senior User

Joined: Sep 2003

Posts: 236

Likes: 0

Piston ring gap

I have an 92 EFI bore 60 over. I purchased speed pro molly piston (file to fit). I got the filing down pretty good around 15 strokes got me pretty close to .016 and I got carried away on one ring. On one lower compression ring I am up to .028 but I read that some recommend that lower compression a little wider anyway. So my question is do I have to replace the ring? Do I have to buy an entire set for an 8 cylinder? Also my oil control rings are around .025 out of the box. I believe that is within spec as is?

Feb 8, 2009 | 11:50 AM

mark a.

Lead Driver

Joined: Mar 2004

Posts: 8,922

Likes: 152

I would get another ring.

Feb 8, 2009 | 02:27 PM

shortbed1

Senior User

Joined: Jan 2003

Posts: 178

Likes: 0

From: beaufort

Replace the rings on that piston you can get them individually. Go back to where you bought them. Chuck

Feb 8, 2009 | 05:33 PM

djmac

Thread Starter

Senior User

Joined: Sep 2003

Posts: 236

Likes: 0

Thanks guys, I will give Summit a call tonight.

Feb 18, 2009 | 05:52 PM

kotzy

Elder User

Joined: Apr 2004

Posts: 970

Likes: 3

The rule has been as far as I can remember been .003 to .004 per inch of cylinder, or 4 inch bore would be .012 to .016, compresion rings all the same. The scraper rails on a three piece oil ring not measurable as there is no way to support them on the spacer as they are in the ring groove. kotzy

Feb 18, 2009 | 08:04 PM

djmac

Thread Starter

Senior User

Joined: Sep 2003

Posts: 236

Likes: 0

Quote:

Originally Posted by kotzy

thank you.

Mar 4, 2009 | 11:50 AM

Barry_R

Senior User

Joined: Feb 2006

Posts: 355

Likes: 1

The big gap on a 2nd ring won't hurt a thing. We recommended going about .004-.006 larger than the top ring gap in the last Speed-Pro catalog. BTW - I wrote the last Fel-Pro performance catalog and the last four Speed-Pro catalogs...