Hypereutectic pistons?
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From: South Central PA
Hypereutectic pistons?
I have a 300 I6 I am completely overhauling for my 84 F150. I came across a set of hypereutectic(?) pistons brand new, pretty cheap. Manufactured By Federal Mogul. Time to show my ignorance I guess, but what are they, just made out of a different alloy or something? This truck is going to be my daily driver, pretty much all stock. Just wondered if these are more a performance item, maybe not as durable or long lasting as going with stock or forged pistons? 
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Hypereutectic pistons?
They are in the middle as far as performance and durability. They are stronger than cast, but not as strong as forged. And I believe they are supposed to be quieter than forged. Forged pistons grow as they warm up, so you have to leave alot of clearance in the cylinder for them. This makes the engine have a knocking sound when you first start it up. Cast and the hyper's don't expand as much, so they can be run tighter in the bores.
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From: South Central PA
Hypereutectic pistons?
Thanks for the responses guys, think I'll just hold off and go with forged, buy them in a complete engine kit. I need everything else anyway. In case anyone else is interested they are .030 over, 4 days left on the auction. I think they were only $20 when I looked. I better just stick with the ol' reliables!
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Hypereutectic pistons?
>They are in the middle as far as performance and durability.
> They are stronger than cast, but not as strong as forged.
>And I believe they are supposed to be quieter than forged.
>Forged pistons grow as they warm up, so you have to leave
>alot of clearance in the cylinder for them. This makes the
>engine have a knocking sound when you first start it up.
>Cast and the hyper's don't expand as much, so they can be
>run tighter in the bores.
This is a very good explanation. If you're not supercharging or squeezing they are just as good as forged, less oil blow by on start up and possible longer engine life due to initial tighter clearances.
'93-'95 Mustang GT 5.0's as well as the 4.6 Mustang GT's run hyper pistons and except for the above mentioned mods they run fine and long.
> They are stronger than cast, but not as strong as forged.
>And I believe they are supposed to be quieter than forged.
>Forged pistons grow as they warm up, so you have to leave
>alot of clearance in the cylinder for them. This makes the
>engine have a knocking sound when you first start it up.
>Cast and the hyper's don't expand as much, so they can be
>run tighter in the bores.
This is a very good explanation. If you're not supercharging or squeezing they are just as good as forged, less oil blow by on start up and possible longer engine life due to initial tighter clearances.
'93-'95 Mustang GT 5.0's as well as the 4.6 Mustang GT's run hyper pistons and except for the above mentioned mods they run fine and long.
