ring gap?

[Bodo]

Hey gang

Getting ready to install the rings on to the pistons and I need ring gap information.

Stock was .010 - .020. Since I'm running Hyper pistons you're supposed to run %40 greater gap to account for the thermal expansion of the piston.

That gives some really freaking large ring gaps. Around .023"

What gaps are ya'll running?

[IH 392]

A general rule of thumb is .004" per inch of bore, the type of piston is irrelevant concerning ring gap, the cylinder and heat control ring gap, the piston just moves them up and down.

[Bodo]

Thanks for the reply.

I know that KB hypers need the extra room in the rings: http://www.kb-silvolite.com/assets/silv ... lation.pdf and http://www.kb-silvolite.com/assets/kb_installation.pdf

Wonder if the sealed power H pistons do too. Guess I'm getting on the phone tomorrow to find out.

[IH 392]

The paragraph on page two of your second link says they place the rings higher, therefore they run hotter, hence the more gap, I've probably installed 1000 Silvolite Hyperutectic pistons in Chevy 4.3 V6's for LP applications in fork lifts, and never gapped one wider than the "general rule of thumb"????, we never saw ring issues, they must have had lower ring positions???

A little reading, and from what some of the machine shops were seeing, the rings were swelling and busting the pistons, there for it was the Hyperutectic pistons were no good!, they opened the gap and the problem went away.

[Bodo]

Just got off of the phone with Federal Mogul. For their Sealed Power H pistons, Top Ring should be .004 per inch +.002 for range. 2nd Ring should be .005 per inch +.002 for range.

Seems good to me. Thanks again.

[gonridnu]

KB Hypereutectic pistons do require a larger ring gap. While it may seem large it will close up as the piston heats up. If U use the standard ring gap for other pistons on KB's you will butt the ends of the rings together and blow the top ring land off the piston.

[woodjeep]

I got the following info fro KB-Silvolite tech help when I was checking the ring gaps on my silvolite hypereutectic HC3241 pistons

"You take the top ring gap recomendations from what ever motor manual you are using and increase the top ring end gap by 40%"
Bob
tech dept

he then states that you use the factory recommended gaps for the other rings. I would call whomever pistons you are using and ask them

[herbiehind]

40% works out to about .005 per inch of bore . thanks guys .

[shawnxj]

how about forged pistons with moly rings? i should be assembling my engine in about 2 weeks