Ring Gap?

[my68barracuda]

I guess he doesn't really understand his product totally. I have provided a photo of a KB on the left and a Mahle forging on the right. The KB has a top ring land of .280" and the Mahle .240". The Mahle does not require any additional top ring gap unlike the KB. If its placement and not alloy type as you and KB suggest then please explain. I'm curious now. J.Rob

View attachment 1715514729

the KB 239's that I will be running have the top ring down .217 from the piston crown. The second ring is a whopping .831 down from the piston crown. So this top ring is closer to the piston crown than either of the two pistons that you mentioned.

One thing to consider on the two pistons that you show in your photo.
The KB Hyper piston is a cast aluminum piston, it will have good strength but will not have the density and strength of a forged aluminum piston. Those are two vastly different pistons from a material and a processing standpoint.

 

[moper]

Over the years I've found most tech lines are guys reading the same information that comes with the product. Could be a piston, a ring, a trailer hitch, or a lift kit.... That and "We've never heard of that before" is standard response process.

Taper and out of round will make it wear much faster. Those wear rings and pistons a lot faster (think of the parts rubbing on each other a lot more as the rings follow the non-linear path of a twisted and worn cylinder wall). I'm fairly certain (some smarter person could probably verify) but the sealing losses are worse around a ring due to worn piston ring lands and a "wrinkly" wall than than through the gap. Even a gap with "extra" built in like KBs want with hard use or nitrous.

 

[93ragtop]

I am adding these pictures.

This first picture is with the second ring, and it measures .019

This picture shows the top ring... FWIW .025 is a little loose, but my .027 would not go in.

The thicker ring is the cast, (second ring)

And here are the rings on a piston, oiled before installing.

 

[93ragtop]

I have installed all the pistons. Want to thank everyone for all your input!!
I am going to disassemble the heads next..... I feel sure I will be asking for advice again.