• Hello there guest and Welcome to The #1 Classic Mustang forum!
    To gain full access you must Register. Registration is free and it takes only a few moments to complete.
    Already a member? Login here then!

Hypereutectic Pistons

Horseplay

Horseplay

I Don't Care. Do you?
Donator
I know just enough on the subject to be dangerous. I'm seriously considering buying an engine that uses a set of hypereutectic pistons from Eagle. Final compression ratio is just a tad over 10:1. Cast crank with 5140 I-beam rods (both again from Eagle).

I'm looking to hear from those who really understand the differences (good and bad) of piston construction to give me opinion here. Or those who have/had an engine with such and can comment from that experience.

I think at about 425 h.p. all is good and no concerns but I also am pretty sure any type of power adder is going to be way to much given the current CR and piston construction. Engine has aluminum heads which should help with detonation concerns a bit.

Thoughts?
 
You'll be fine. Hyper pistons requires a little looser fit as they tend to expand. If you aren't going to be spraying them with n2o or adding a power adder, they will suit you just fine.

Bill
 
"67 Fastback" said:
You'll be fine. Hyper pistons requires a little looser fit as they tend to expand. If you aren't going to be spraying them with n2o or adding a power adder, they will suit you just fine.

Bill
Click to expand...
Bill,

That is pretty much opposite of everything I have found. I read this type of piston has LESS expansion so tighter tolerances are capable which means no cold slap noise etc. I guess a lot of new car engines use this type of piston.
 
You are good to go with your combo. They are cast pistons with a high silicon content. They actually run tighter clearances as they don't expand like forged pistons do. Many new performance cars use these, even the blown CTS-V and Ford's new Eco Boost stuff.

Edit: kinda like you just said! ;)
 
"Horseplay" said:
Bill,

That is pretty much opposite of everything I have found. I read this type of piston has LESS expansion so tighter tolerances are capable which means no cold slap noise etc. I guess a lot of new car engines use this type of piston.
Click to expand...

Correct. That makes them better than forged for a car you'd drive regularly. The tolerances are tight, like 0.006", so if you're going to bore a block for hyper pistons, measure the pistons so you know exactly how far to bore the block.

Robert
 
You must log in or register to reply here.
Back
Top