What are the differences between Cast pistons, forged pistons, and Hypereutectic pistons? forged is more expensive, then hypereutectic , then cast. I am pulling all my parts together and pricing item out for my 352 into a 390 bulid. chassis is done, now it is time for engine work, with all the parts needed its around 1000.00 just in parts, if I could cut piston price down it would save me around 200 dollars. Thats about the price of the intake, or the price of the cam and lifter kit.

 

Cast: Lowest cost alternative. Regular cast aluminum, not very strong, good for stock rebuilds. Many OEM's used 'em.

Hypereutectic: Same as cast, but with more silicon added. This makes a more dimensionally stable, and somewhat stronger, piston. Many OEM's use this kind in new motors today. They can fit tighter in the cylinders and are more resistant to scuffing.

Forged: Extremely strong. They are not cast, but are beat into shape with thousands of pounds of force. This creates a denser molecular structure which actually makes the material stronger. Unfortunately, they also expand more with heat than either cast or hypereutectic, and must be given a little more piston to bore clearance. This can cause them to make a little noise when cold. Go this way if you're hard on motors, or are planning on racing, using nitrous oxide, or forced induction.

Additionally, you may not have a choice when it comes to what piston to get. Some cast or hypereutectic pistons may only have a compression height of 1.750", while the forged unit, supposedly for the same application, may be 1.780"! Be sure to look at the specs before buying.

 

Thanks Kurt, you're a wealth of knowledge. Someday I would like to shake your hand, you have helped me tremedisly.

 

Yea, like the 289 Hi-po, 428 CJ, SCJ, and a few other factory Hi-po motors I can't recall at the moment. Like you said, if you're not going to blow it or NOS it, why waste the money? Hyper's are a good compromise these days.