I bought a set of Scat 6" rods part#2-1CR6000. Now I need a set of pistons... I found some, but I don't know if there compatible here is the Mahle part# SBC250030F05. The rods are full flaoting, but I don't know if you must have "full floating pistons" as well. I know, I'm a newb. Thanks in advance.

 

Ya need pistons with the snap ring grooves in them to hold the pin and ya need the correct pin and have them fitted to the rod and piston.

 

Pins always float in the pistons. Normal pressed pins are pressed into the rods. The piston then floats back and forth on the pin but the pin will never move on the rod.

A full floating rod/piston means the pin floats in the rod bushing instead of being pressed into it. With this sort or rod/pin combination you need the correct pistons that have retainers to keep the pin inside the piston so that it doesn't come out and damage the cylinder walls.

You can use full floating pistons on a pressed pin but can't use normal pistons on a floating pin.

Since you now have full floating rod/pins then you'll need to find the proper pistons with the retainer grooves to hold the pin in place.

There's always a depate as to what kind of retainer works best. 2 choices are a simple internal snap ring and spiral locks. I prefer the JE Piston double spiral lock style. 2 spiral locks on both sides on the pin means the only way the pin could ever get past the lock(s) is if you physically break the piston while it's in the engine. The spiral locks are a full 360* while snap rings will always have an opening at the ends.

 

The simple answer is that yes, those mahle pistons are correct for your application, assuming that you are not building a 383, for which those have the wrong compression height. What parts do you have so far?

 

I'm building a 355. I have the rods coming, stock crank, just ordered the pistons, intake, block, heads(neep porting), and a few odds and ends. I'm also looking to get some splayed caps, my buddies father has a crank grinder, mill and lathe and said he would set them up for me.

 

He has a crank grinder in his garage?

 

The vast majority of aftermarket performance pistons are already set up to run full-floating. Frankly, I can't think of one that ISN'T.

If properly installed, I can't imagine how a spiro-lock could EVER fall out accidentally. Snap-rings can have problems, but even those the failure rate has got to be one in a million if they're properly installed and the snap ring itself isn't fatigued or damaged.

 

Yeah, lucky huh, he has been a machinist for most of his career. It is an older setup, he bought it at an action when (Currys) a local machine shop went out of business. He's a perfectionist, the type of person who never cuts corners.

 

Yeah, Thats my Father. Its an old Storm Vulcan grinder. We tore it down and went through it when he bought it. He also has a kwik-Way boring bar, Brodgeport milling machine, and an older lathe. Hate to brag but he is a good machinist.