Everything I have read says, hyper pistons are used for emissions and noise reasons. They expand less than forged pistons, thus have a better seal when cold, producing less blowby at that time. Plus, much less $$.


Darrell.

You are correct but we are talking high perf and heavy duty engines here , I am sure the guy buying an LS1/2/etc powered performance car or the guy buying the one ton truck would not mind paying an extra couple hundred dollars to get forged slugs.
One of the reasons the 5.0 fords gained the following they did was because the stock forged pistons made them easy to supercharge or spray without worrying about cracked pistons,, the newer supercharged Mustangs and Lightnings all had forged slugs.
Maybe I am not business minded enough but still seems like a dropped ball by GM to save a few pennies.

WTF is a ' NASCAR spring ' ?? The same springs used in Jr's engines?? Just wondering.

Nascar Springs:
http://www.compperformancegroupstore.../merchant.mvc?

Nascar springs are high rate high stroke springs sufficient to keep the valve train in contact at 10,000 rpm on a high lift cam and that are made of high purity spring steel that will also survive an x-hour race at 10,000 rpm without suffering fatigue that would allow the valve train to seft destruct. Also about double the cost of a typical spring.

Cam only?
 

So adding a HP3 cam only would do nothing for a stock HO except the possibility of reversion?

I run hyper piston in a blown engine with 9.5:1 static compression. The engine next to it has forged pistons. Same setup on each engine except for piston fit and ring end gaps. Producing around 700hp each by my estimation. End of season run, both engines to the pins for more time than usual, which is usually a lot anyway... 3 melted forged piston. Hyper engine is crisp and happy with no problems. This was the 5th season on the hypers, 2 seasons being roots blown. The one year we had hypers in both engines but had a failure unrelated to pistons that led to trying forged in the other engine. Forged didn't even make it one season. So why do you question GMs choice on pistons again?? If set up right hypers outperform forged. The caveat is if a setup problem occurs, the hypers crack and explode, the forged melt which is a usually a happier ending for the rotating assembly and block. The problem people have with hypers is they bolt on blowers without changing the ring end gaps. They try to do this with FI and no ability to tune the FI curve to make the engines live. It really gives hypers a bad name which to me is ill deserved. Learn how to build an engine correctly, you can run hyers all you want and make more power than with forged.

I know old thread, did anyone ever try these out and if so any issues?