Well, what are the diffeences? The machine shop guy says he has the hypereutectic pistons I want, but only in double brow style. The originals had four brows on them. Anyone know if this even matters?

Thanks!

 

the 4 notch would fit either side, the 2 notch would come in rights and lefts since the piston has a front to corospond with the front side of the rod it's fitted to. you'd have slightly more compression with a 2 instead of a 4, but not enough to really consider.

 

Ed nailed it as usual. My preference is the 2 valve relief design as it yields a nice flat piston surface in the quench area, making it slightly less prone to detonation.

The extra valve reliefs in the 4-brow design are nice places for combusting fuel & air to hide away from the chamber.

The Federal Mogul and Keith Black hypereutectic 2VR designs are universal in my experience, just make sure the machinist presses them onto the rods w/ the reliefs in the right position.

 

Alright then, thanks guys!!

 

If the machinist doesn't have enough sense to correctly press them on correctly, run as fast as you can away from his shop!!

 

Actually, he was going to give me everything unassembled...will he still press the rods if he does this? Will it be too much trouble for me? (I don't have ANY specialty tools) Should I just have him assemble the whole thing?

 

I would not recommend installing the pins yourself as the rods need to be heated to install them correctly, some guys use a torch for this but you have to be very careful not to overheat the rod and then it's also hard to get the pin correctly centered with the piston.

 

Unless they're floating pins (which they probably aren't) your machinist needs to install the pistons on the rods. If they are floating pins (which aren't reccomended for the street) then you can install them yourself.

 

ok, something real quick off the topic...I was looking for heads for this beast ( '73 vette 350 block) and was wondering if I need to note or look for something special, or will any v8 heads fit it?

 

Any SBC heads will fit, however there are some les desireable heads performance wise. I would try to pass anything from the late 70's and any swirl port heads.

 

I have a question concerning this.

I have flat tops with 4 valve reliefs. However, they have the "dot" on the face that clues the installer on which way to face the piston when installing them.

Do they do this for preventive purposes or could it be they just do it to all pistons before the reliefs are cut?

Thanks

 

They probably do it to all the pistons. That would be my guess.

 

if you have a 4 notch piston it's universal fit as far as how it sits in the hole ( other than clearing the valves), the part that isn't is the rod it's attached to. the rod can only face two ways and one of them is wrong, so the front of the piston has to corospond to the front of the rod

 

O I C

Thank you

 

kfoley>>

What's wrong with floating pins on a street eng??

 

There's nothing wrong with them on the street, they're just not normally used for street applications. They're most often used in race motors where they tear it down between races. Really unless you tear your motor apart a lot, then there's really no reason to have them in a motor. However I would use the on the street if I had them.