Thread: Hypereutectic Pistons for Y-block

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For toughness, hypers are sort of "middle of the road" between cast and forged. Piston to wall clearance is tight and critical.

As far as ring thickness, I prefer the thicker rings for a low rpm street motor. I guess there would be a reduction in friction by using a 0.059" ring as opposed to a 0.078" ring, but in my opinion the thicker ring will seal better, so it's 6 of 1 and a half-dozen of the other.

The main reason I like KB hypers is for the nice, flat crown that mates up with the squish pad on a Chevy head. Even the dished ones have the crater offset to match up with the chamber and a nice flat crown for squish. You just can't get a nice, clean squish with those 4-relief, run-of-the-mill Chevy pistons. The crown just is not flat on them.

Now, I realize you are talking Y-block here and I have no idea what the chamber configuration is in that motor.