[chickenbot]

between Hypereutectic Pistons and Forged Pistons and what is stock?

 

[chickenbot]

http://www.citymotorsupply.com/performance.pdf page 4

 

[ReverendDexter]

Hypereutectic pistons are cast pistons with a high nickel content, which makes them stronger than "regular" cast pistons, but not as strong as forged. They're lighter than forged pistons, however.

Stock for '86?-'92 is forged, stock for '93 and up is hypereutectic, outside of the '03 and '04 Cobras.

 

[chickenbot]

which would you go with?

 

[ReverendDexter]

which would you go with?

Forged for 99% of applications. Being that you have a '90, it came stock with forged (assuming you have the stock shortblock).

The only time I'd go hypereutectic is for a *really* high rpm N/A motor, where I'd want the pistons to be absolutely as light as possible. Hypereutectic pistons also don't have as much shrink/swell due to heat, so you might chose to go with them for a relatively stock powered motor where tight clearances are important.

For the record, though, I'm not an engine builder, so you'd definitely want to discuss this with someone else before you went and built a motor.

 

[chickenbot]

i do but its cracked.. what do you think would be salvageable?

 

[e3sean]

ya hypertunic pistons are more suseptable to cracking under the smallest amount of detonation which is why they say not to use them with nitrous and boost where detonation happend much more oftan. i am sure they are lighter then fordged steel but i doubt they are lighter then my fordged aluminum pistons.

 

[ReverendDexter]

ya hypertunic pistons are more suseptable to cracking under the smallest amount of detonation which is why they say not to use them with nitrous and boost where detonation happend much more oftan. i am sure they are lighter then fordged steel but i doubt they are lighter then my fordged aluminum pistons.

I thought hypereutectic pistons were aluminum? And according to wikipedia I was wrong - it's not the nickel content, it's the silicon content. Not sure where I got the nickel thing from...

 

[baine21225]

I thought hypereutectic pistons were aluminum? And according to wikipedia I was wrong - it's not the nickel content, it's the silicon content. Not sure where I got the nickel thing from...

maybe you're thinking the makeup of stainless

 

[e3sean]

i just did a little reading...

Hypereutectic piston - Wikipedia, the free encyclopedia

that is some pretty good info and i think will enlighten you as it did me.

 

[chickenbot]

so the question is still which to go for?

 

[93lxvert]

I just built a 302 for my 93 lx with 10:1 comp. and used summit hyper pistons. I used them for several reasons, one i wasn't planning on running a ton of power, also they didn't break my bank acount, and they have better heat characteristics than forged or cast. hyper pistons are simply cast pistons with a 14-17% silicon content for stregnth and heat durability. Pretty much the piston acts much like fiberglass when heated where forged pistons act like clay if you will. Forged pistons absorb detonation etc.. instead of bouncing it around and that's why hyper pistons are not recomended for engines with power adders. They can handle a tremendous amount of power, but if an engine part fails, or detonation occurs the piston is more suseptable to catostrophic failure insted of absorbing detonation or a valve for instance, the piston will bounce it around because of its "fiberglass" characturistics. Hyper piston excel over forged in the fact that they handle heat very well and because of this they are cut to a much closer bore-piston tolerance and can also be held, technically, to a much closer valve to piston clearance as well. As far as weight they all vary. I know summit hyper pistons and keith black hyper piston are different in weight where KB pistons are lighter. Hyper pistons do well in alot of areas and as far as power most good hyperuectic pistons will rate at 1.5-2HP per cubic inch. Like someone said earlier if you are running a moderately moddified engine even in the 4-500hp range with no power adders (nitrous, superchargers) hyperuectic piston take advantage over others because of their superb heat resistance, limited exspansion when heated which results in a cooler cylinder, and a decrease in compression loss over forged as well as safer piston to valve clearances, however I would recommend forged for applications that would include poweradders simply because forged pistons are proven whereas hyper's are new to the market and forged pistons provide a safety net in case of detonation or a dropped valve because of their absorbing properties. I use hyperuectics in N/A app's and forged in poweradder classes. Hope this helps!

 

[baine21225]

I'd go with forged

 

[e3sean]

so the question is still which to go for?

fordged aluminum

 

[93lxvert]

If you're on a budget hypereuectic work fine for mild/moderate builds