Diameter Chevrolet 216 pistons?

[Mike K]

One good aspect of the old domed cast pistons is the upper ring grooves usually don' t wear ( widen ) , unlike the softer Al. alloy pistons which often have worn top ring grooves that require machining and spacers fitted ( expensive) . George Russell did a set of Ford pistons 85hp for me years ago, machined the grooves and supplied spacers for the top ring groove.

Down side is the domed chev pistons can be weak around the crown area and they have been known to fracture , the crown flies off . I think this tends to occur if you are a harsh driver eg constant high revs .


In the 50's there were a few after market manufacturers of the Chev 216 pistons ( and valves , springs, and other engine parts ) . I bought a set of Al. domed pistons ( when the US postal service had sea mail ) , weighed them and they are 25% lighter than the cast iron ones. I believe POLSON here in Aust. made 216 pistons ?

I sandblasted the original C8 cast standard pistons with a fine abrasive , I think its called 'peening' . Had no issues with it so far.