I am getting ready to order some forged I beam rods for my car. I want to spray a 150-175 shot and want a better bottom end to take the abuse.

I am running the Speed pro forged pistons that come in the summit rebuild kit.
Eagle or scat forged I beam rods
Eagle ESP

Which one do i need to order pressed or bushed pins?

thanks
Shawn

 

I would get the floating pistons because your machine shop can adjust the wristpin clearance a little larger to give you margin for use with nitrous.

 

Instead of pressed, you want floating wrist pins. I've got a nice set of Ross forged pistons in a BBC engine with floating wrist pins.

 

bushed= floating

 

I already have the pistons. they are already at the machine shop. They came with pins in them but i don't know what kind. Can you give me a idea?

thanks
Shawn

 

If the pins can move in and out of the piston, they are floating. Press fit are exactly that press fit in.

 

when i got the pistons the pins would move in and out freely. They were not on a rod though? if they are pressed do they fit tightly in the rod or the piston or both? I must have the floating pins since they would just slide out of the hole in the piston. What do you think?

thanks
Shawn

 

Floating pistons have semi circular locks which hold the pins in the piston pressed pins don't. So if your pistons didn't come with a bag of 16 of these then you probably have pressed pin pistons.

 

All piston pins move in the piston (they must!). The pistons that have locks to hold the pins in are able to be full floated, which means also floating the pin on the rod (where they would be normally pressed).