Im trying to find some forged or hypereutectic pistons for my 2.8 thats going to be turboed so i need to run a lower compression. Im going to use the stock rods and crank and arp studs, anyone know ho wmany psi it will stand up to? Are there any advantages to running 3.1/3.4 heads instead of 2.8 heads, can i run a low compression with the 3.1/3.4 heads? Any help would be great.

 

You want to run lower Static Compression than 8.9:1? WTF for?

If anything I'd raise the SCR, because the old "technology" of lower SCR is should be left in the 1960s. Though running iron head will not allow as high of an SCR as running aluminium heads, yu should still be able to run between 9.5:1 and 10:1 SCR, with a good tunes, and some combustion chamber work, whihc there isn't much I can see for improvment there, due to teh exsiting iron head combustion chamber shape. It's not a great start.

Anyway Federal Mogul has some off the shelf forged 2.8L pistons, but I thing the SCR was about 11:1, but it has been a while since I looked into them, or that may have been if I used them with aluminium heads. (Aluminium heads have much smaller chambers than iron head.)

The 3.1/3.4 heads are the same as '85 and later 2.8 heads.

 

They're on e-bay all the time (hypers anyways).

 

like i said its going to be turbocharged, and i always thought you need to run a lower CR if your going to have any forced induction.

 

No, and it definately doesn't need to be lower than 8.9:1. And you will be OK with hyper pistons (stock pistons are hyper skirts IIRC) as long as you have a good tune (I saw a car with 30psi and cast pistons).

 

Stock piston are just cast. It would be far too expensive to combine a different type aluminium with the top to create a hyper skirt, and a eutectic top.

Hyper-eutectic, or even hypo-eutectic refers to the amount of silicon in the aluminum.

Most OEM pistons are around the eutectic mark. I don't remember teh exact measurmant of silicon content, it could be looked up.