Originally Posted by AGABE
Some Short Block Suppliers Are Quoting Cast Aluminum Pistons. Are They Any Good ??
There are millions of motors running around out there using cast pistons. For a stock rebuild or a lightly warmed over build where a motor won't be subjected to excessive rpm's or power adders, they will do an admirable job. Be careful about the compression height though, you want to replace the pistons with pistons using the same compression height as stock in order to prevent having an excessive piston deck height that might eliminate squish and contribute to detonation (spark knock).
Hypereutectic pistons are also cast, but are manufactured with an excess of silicon to toughen them up a little for use in a street or street/strip motor. Pay close attention to piston to wall clearance and ring end gap.
Forged pistons are the ultimate in strength, but are also expensive compared to cast or hypereutectic. They might be used in a street, street/strip or strip only competition motor. Pay close attention to piston to wall clearance and ring end gap.