Ring end gap ?
Thread Starter
Race Director
Joined: Apr 2000
Posts: 17,650
Likes: 190
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Ring end gap ?
What would be a good top ring end gap for my 406 with moly rings and SpeedPro hyperuetectic pistons, no nitrous mainly driven on the street ?
Melting Slicks
Joined: May 2001
Posts: 2,131
Likes: 4
From: May help you? You can sure as hell try!
Re: Ring end gap ? (MotorHead)
Good rule of thumb is 0.005" per inch of bore for the top ring. You may want to go to 0.006 to 0.007 if you're running "NAWSS" :D or a blower. Go about 0.005" more on the 2nd ring than your gap on the top (this is contrary to the old recommendations that would have you gap the 2nd ring tighter than the top but take my word for it--your oil control and blow by will be better and absolutely no power loss will result).
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
Re: Ring end gap ? (MotorHead)
You had better consult Speed Pro because I know that Keith Black series of Hyperutectic pistons requires a larger end gap than forged or standard cast aluminum pistons will. Hyperutectic pistons will retain more heat than a conventional alloy of aluminum requiring larger end gaps than normal. The old saying of 0.004 for every inch of diameter may not apply in your case, K-B end gaps would be at 0.020 to 0.022 in your motor. The worst thing you can ever have happen to your rings is for the ends to butt toghether, it will quickly destroy the rings and cylinder walls, massive oil consumption and power loss will then happen.
Pro
Joined: Jun 2001
Posts: 672
Likes: 0
From: Quebec
Re: Ring end gap ? (Solid LT1)
:iagree: with all that been said.
The second ring end gap should be a little more to prevent pressure to build bethween the two ring. That pressure could lift the 1st ring causing a major blowby.
I run 0.20" on the first and 0.22" on the second. I plan on running 100 hp nitrous oxyde on my 350.
Stephan
[Modified by American Boy, 1:11 PM 4/13/2004]
The second ring end gap should be a little more to prevent pressure to build bethween the two ring. That pressure could lift the 1st ring causing a major blowby.
I run 0.20" on the first and 0.22" on the second. I plan on running 100 hp nitrous oxyde on my 350.
Stephan
[Modified by American Boy, 1:11 PM 4/13/2004]
Race Director
Joined: Mar 1999
Posts: 10,258
Likes: 1
From: Calif.
Re: Ring end gap ? (Solid LT1)
You had better consult Speed Pro because I know that Keith Black series of Hyperutectic pistons requires a larger end gap than forged or standard cast aluminum pistons will. Hyperutectic pistons will retain more heat than a conventional alloy of aluminum requiring larger end gaps than normal. The old saying of 0.004 for every inch of diameter may not apply in your case, K-B end gaps would be at 0.020 to 0.022 in your motor. The worst thing you can ever have happen to your rings is for the ends to butt toghether, it will quickly destroy the rings and cylinder walls, massive oil consumption and power loss will then happen.
:withstupid:
Yes! Yes! Yes!
Hypereutectic pistons require a wider top ring gap than regular cast of forged pistons because they run hotter. You get that top ring end gap too tight and it'll butt, lock up, and you 'll tear the top of that piston clean off and punch a rod through your block. (Ask me how I know this.)
[Modified by The Dude, 5:07 PM 4/13/2004]
