hypereutectic pistons...

[aldeswarii]

i'm really not sure what these are. the only difference i can find between them and cast iron is that they're made of some aluminum alloy or something...what are everybody's thoughts/opinions on these? does anybody have a link with some information about them? thanks

 

[71vert-pga]

The last car I saw cast iron pistons on was a chevy from the early 50s.

 

[Route666]

It's a fancy name for cast aluminium with silicon in it. They expand less than cast pistons, and so are great for OEM applications where engine life is more important than gross rpm or horsepower because the tolerances can be made tighter, and so nothing will rattle around when cold. The silicon also makes them a bit slipperier. Having said that, they won't last long in a high-rev or big power motor. Not as long as forged anyway.

 

[302 coupe]

hypereutectic pistons strength-wise are far better than cast, but not quite as good as forged. They'll take a beating, you'll need forged for NOS and forced induction applications.

You'll have a hard time finding cast iron pistons these days. I don't think ford has ever used iron pistons, especially in gas engines. I doubt they ever used them in diesels either though. Besides the weight, you'd have serious issues with detonation using an iron piston. Its a common understanding that all pistons are aluminum.

 

[RajunCajun]

one Link for ya to further confuse ya

 

[aldeswarii]

so all (or most at least) pistons today are hypereutectic?

 

[allcarfan]

so all (or most at least) pistons today are hypereutectic?

Depends on the application. I think for most performance-oriented vehicles sold today, they are forged....ie cobra, gt, vette. The 87-92 mustangs had stock forged pistons. They switched to hypers in 93.

A hyper piston can take a lot of hp. I would feel 100% safe running 500hp naturally aspirated on a hyper piston.

 

[ratio411]

I have the benefit of living near several long time Ford racers/gurus... with more money than they know what to do with too.
They have tried about every engine combo with every piston combo. The consensus is these pistons are a good advance in production engines, but any decent power level will turn them to sand when you least expect it.
Spend a couple extra bux and get forged.
Dave

 

[D.Hearne]

I've turned Silvolite Hypereutectics up to 7500 rpms in a Canfield headed 5.0, and they handled the power and rpms better than the 40 over roller block did.

 

[390Fe]

allcarfan...

Are you positive on the 87 up with Forged and not the Hypereutectics? I had an '87 5.0 (Bought new) and I'm pretty sure one of the selling points was the fact that it had Hypereutectics instead of cast or forged to go along with the roller lifters and such.

I can't swear to it though... I had to sell it before I really got to tear into the engine (insurance on a 20 year old male with a new 5.0 was SCARY high back then)

 

[allcarfan]

87-92 did, indeed have forged pistons and rods. It is one of the main reasons people really like these shortblocks. There are many stock 87-92 shortblocks that run 10 second blasts. We have a guy in our club that is on the brink of 9s with a stock bottom end.

Shane

 

[brianj5600]

We have a guy in our club that is on the brink of 9s with a stock bottom end.

Shane

Would that be a twin turbo cobra? There is a guy from Ga that split a 5.0 block with hypers. I have heard of a few people splitting 5.0s w/o hurting the stock hyper pistons.

 

[12sec67]

87-92 did, indeed have forged pistons and rods. It is one of the main reasons people really like these shortblocks. There are many stock 87-92 shortblocks that run 10 second blasts. We have a guy in our club that is on the brink of 9s with a stock bottom end.

Shane

i thought- 86-87 had forged and then went to hyper's after 88 - and on.

i have hyper's and i haven't had any problems and most of my friends have power adders on top of them also and soon i will too
a little squeeeze never hurt no one