Hypereutectic??

[basement]

I've been checking out stroker kits for my 360 and Hughes offers a crank, rod and piston kit. But in their parts description the pistons are Hypereutectic. What the heck is that and would anyone recommend them?

[Chryco Psycho]

Hyper is an expensive cast piston with higher silicon content making them more brittle
why anyone would recommend them is beyond me , I just pay a few extra $$ & get forged

[moparnut]

The logic besides being cheaper is Hyper are fine for street engines,forged are heavier duty but are only needed if you run nitrous or a blower.I have used them many times but as Chryco said,prefer forged.Would I choose Hyper over forged or visa versa,it depends on what i am building/budget.Consider our cars for most of us will only be driven a few K miles a year and most of the factory high perfomance engines of the era had cast pistons and the lasted just fine under hard driving conditions.It all boils down to how much you want to spend.I personally wouldnt hesistake using cast or hypers considering how much the cars will be driven and rarely hot rodded since i need my drivers license to live

[Chryco Psycho]

Factory cast pistons are totally different breed , they had a steel liner inside them to limit expansion & a different alum alloy

[moparnut]

Thanks for the info Chryco,I have dismantled at least a dozen virgin mopar engines and never saw any sleeving.I'll have to take another look since i have a pile-o-pistons in the corner of my shop

[Chryco Psycho]

look inside the pin boss area

[moparnut]

You mean the wrist pin has a sleeve around it?if so i have seen it,i didnt know the aftermarket cast didnt have them.your a wealth of knowledge as usual

[Chryco Psycho]

that would be the steel liner

[moparnut]

Chryco,you have seen many many more engines than i have I'm sure.Have you seen cracked aftermarket or hyper pistons in an engine?

[moparnut]

That should have read cracked aftermarket cast or hypers

[Chryco Psycho]

Actually no , I have seen hyper pistons outside of an engine after cracking or exploding though , it seems to leave holes on the block 

[moparnut]

Now ya tell me

[moparnut]

Of course a buddy recently pull his new 302 out of his early bronco and had 6 cracked trw forged pistons...

[Chryco Psycho]

using a lot of nitrous
  a forged piston will crack & live sometimes , , I have seen skirts broken off etc , Hypers tend to fail on a more catastrophic basis

[moparnut]

this was only on pump gas,although i think his ex overheated to motor and fried the engine....Whatta Gal!lol