Ring Gap

[turbodave231]

How much ring gap are you guys running on 1st and 2nd compression rings per inch of cylinder bore? .005 or .006?

Getting ready to file fit a set for a 4.000 inch bore.

Thanks for the help.

Dave

 

[Russ Merritt]

I went .018-.020 top ring, and .022-.024 on the second. .020 over 3.8 and JE pistons.

 

[Lee Thompson]

4.015 bore with Total Seal top ring----.026 top ring ---.022 second
Used Total Seal quick seat and after 30 min. run time, a leak down test showed showed 3 cyl. 1 percent leakage---the other 3--0

I guess it would depend on what brand ring you are using.

 

[ChrisCairns]

SpeedPro is now recommending that the second ring have a slightly larger gap than number one. The reason is so that pressure can't build up between the rings and lift the top ring off of the piston.

 

[Reginald West]

I will agree with Russ 18 to 20 on the top ring and 22 to 24 on the second ring with J&E pistons.


REG

 

[bruce]

Originally posted by turbodave231
How much ring gap are you guys running on 1st and 2nd compression rings per inch of cylinder bore? .005 or .006?
Getting ready to file fit a set for a 4.000 inch bore.

.004-.005 per inch of cylinder bore.

.018 would be a split of that.
Slightly more on the second ring.

Even on most big motors at high boost only use .005.
ie 466 CID diesel at 60 PSI at 6K RPM.

 

[9SECVSIX]

Resently checked a set of Speed Pro 3.830" bore rings, out of the box the top rings went .021" and the second measured .024"
I guess this confirms they want more gap on the second ring, not something I,ve been accustom to.

 

[Bad as L]

Here's somthing to think about....I have 2000 Ford lightning that I work on and race. Last year I went thru the engine and did everything nice.....I bought a file to fit set of moly rings, the best I could find and then at the last moment I decided to try the Total Seal gapless top ring.

Long story short....the truck used oil from day one, at first it was really bad, a quart to 100 miles and as the miles accumulated it started to drop. I immediatly blamed the Total Seal ring. The weird thing was.....there was no blowby past the breathers. At 4000 miles the oil consumption was starting to slow down and was using a quart every 800 to 1000 miles at this point I had had enough and decided to pull the motor again.

What I found was a poorly made second ring. The taper faced second ring had spots on its face that wasn't even touching the cylinder wall....one ring was broken in the way it should look. Several had light and dark spots all around and one ring had an inch and half long dark spot on it that had never touched the cylinder wall. One more thing.....the Total Seal was doing a perfect job.....it just couldn't deal with being clobbered with so much oil from below.

I showed this to and engine builder/ engine mentor friend of mine and he smiled and said "You didn't light check your rings did ya "?

Meaning I didn't put a light to them before assembly and check for this problem. Live and learn
Sorry this was so long but thought it might be relevant
Dale

 

[KendallF]

Dale,

That's a good tip. I will check mine from now on...thanks!

 

[Chuck Leeper]

Ring gap info

There's a good article in a past issue of CHP about the above subject. [about 91 era, I think] The article is called "Widening the gap". It was written by Terry O'Donnell.
It goes on to say that the "old" school" end gaps are not enuf to minimize the problems w/ gas buildup and ring flutter.
The new theory was developed w/ alot of testing by NASCAR teams...
I have that gap info incorporated in the rings in my engine. Seems to work well w/ not alot of blowby. The article gives specific info by the type of engine application, IE: blown, N2O,street, etc.
You can call Speed Pro at 248-354-8949 and discuss the technology. I spoke to Barry Robotnick before I assembled my engine.

back under my rock...

 

[turbodave231]

Dale and Chuck,

Thanks for the input. I'm calling speedpro on monday and I will light check the rings before I assemble the motor. Getting very close. Mocking up valve train and checking valve clearances today.

Dave