Well after the divorce, I am ready to start up again on project Grandad, engine needs to be done, anyway question is I could spend $320 plus shipping on forged pistons from summit, or I could get cast pistons from ebay for 85 dollars. what is the difference, or if I try to save a little money could go with hyper. if there better than cast.. Nitro would be cool for the motor, or maybe fuel injection down the road. looking around 300's in hp for the motor. OOOOOO its a 352 converted to a 390, going in a 66 F-250, street\strip use.

 

Well if your only looking for 300hp..Cast will be just fine... and fuel injection wont bother cast pistons..now Nitrol?? WTF are are you gonna that would require NITRO??

If so ..you'll need a whole different build for that Go Gas!! LOL.. and at 300hp at the strip in a truck..watch out for the VW's...

RJ

 

I think he probably means nitrous oxide. In that case, I'd go forged now so you wont have to worry about it later.

 

I'm an idiot I just looked through my past threads and have asked this question before. Pay me no more attention, Kurt answered this like 8 months ago. Here it is, I am going with forged. Here is what was written then.


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.

 

The 428CJ came with cast pistons and at 400+ horsepower from the factory. The problem was if you did a lot of max revs with them, the pistons broke at the wrist pin and those HD rods did real bad things to the rest of the motor. This is from personal experience.