NovaKeagan

I'm currently gappings rings for boost, I'm using a summit racing ring set.

It states for the top ring, the gap must be:
bore x .006 for cast pistons (0.023)
and
bore x .0085 for hypereutectic pistons (0.032)

I then looked up piston material for an L33, the internet seems to state that the 4.8/L33 flat tops are "Hypereutectic Cast Aluminum Alloy" so now I'm confused?

Should I be gapping for cast, or gapping for hypereutectic?

RB04Av

"Hypereutectic" refers to the metallurgy of the material they are cast from. "Eutectic" is the ratio of the various ingredients, that results in the lowest possible melting point for any concentrations of those constituents. "Hypereutectic" means the alloy has more of the constituent that has the higher melting point than a eutectic alloy. So, they're cast; but the alloy they are cast from, is hypereutectic in nature. In this case the material that is "more", is silicon (the "less" being aluminum).

Use the hypereutectic instruction since they're cast from an alloy having that property.

TrendSetter

If your ring gaps are too loose you might know. If your ring gaps are too tight everyone will know.