Hypereutectic vs. Forged

[Hotrod]

Can someone explain what each of these are and when is the best time to use them.

[Italian LX]

The hypereutectic pistons are a cast piece and usually lighter (for the same amount of money spent); however, they are also weaker and not good in high horsepower application especially when boost is involved.

[coupe]

"Hypereutectic" is a term used in metallurgical engineering to describe a "phase" of one of the elements in an alloy metal. It has to do with the actual molecular structure of the material being in a certain "orientation," if you will.

Hypereutectic Aluminum is a lighter, stronger castable aluminum. It is machined to much tighter tolerances than forged and doesn't expand as much, so you can set up tight from factory and it will last long but yet be very cost-effective. That's why OE is all hypereutectic now (including LS1).

Alot of people are afraid of hypereutectic pistons (ie: hypereuplastic, hypereucraptic, etc.), but it's all a bunch of heresay...like alot of the internet. I would not hesitate to put 500 hp through them on a 5.0L mustang in the least.

[joker]

[Dale McPeters]

Originally Posted by coupe

Alot of people are afraid of hypereutectic pistons (ie: hypereuplastic, hypereucraptic, etc.), but it's all a bunch of heresay...like alot of the internet. I would not hesitate to put 500 hp through them on a 5.0L mustang in the least.

Originally Posted by joker

Yes, hyper pistons are just as good as forged pistons.

So if you want to build a good engine, do it right, and do it cheaply. There is no sense in spending money on forged stuff when you could put it towards something more worthwhile, like trips to Chucky Cheese.

[QWKSNKE]

I'll agree that hyper pathetics can handle similar power that forged can but one slip of detonation in a power adder car will cause them to go.

I made 525rwhp on my oem hyper pistons 2 years ago. One bad batch of gas killed #8 piston though. In my opinion they cannot handle the pressures in a forced induction car like forged can

[1sicklx]

Originally Posted by QWKSNKE

In my opinion they cannot handle the pressures in a forced induction car like forged can

[coupe]

Originally Posted by Hotrod

...when is the best time to use them.

For a budget street/strip motor, you will be fine with hypers (like the keith-blacks). For something serious, that you intend on hard-use with a power-adder, Go ahead & put some forged in there. Forged pistons have come a long way themselves lately too.

And regarding why the performance aftermarket offers Forged (ie: DSS), it's mostly because of the bad reputation that hypereutectic gets. Hypereutectic would do just fine for the average street-strip car. Find out what kind of numbers LS1's can make with hypereutectic pistons. I believe BarryD (turbomustangs.com) has run multiple 10's with twin-turbos...on hypers. :P And at Steele too (the fox hatchback from GA).

[Italian LX]

Comparing things to what other people do can only go so far. Sure, anything can be done and some people can get away with stuff like that, but that doesn't mean you should recommend other people to go that route.

It's similar to the IRS at the drag strip senario -- there are guys out there that run 10's and lower with slicks in an IRS Cobra, but I wouldn't recommend everyone to get some track tires and beat on their suspension.

Hell, I wouldn't recommend anyone put nitrous on a 300,000 mile short block, but I'm having pretty good luck with it. :P

[joker]