Just Floor It

OK, I can tell you about anything involving a motor just about.....But I gotta few questions about Rods....

1) What are the advantages/disadvantages of steel rods/aluminum?
2) What is the deal with the rod sizes? Can someone talk about rod sizes??

Thanks

onyxxtreme

iTrader: (4)

1. Stronger materials=less chance of breaking, lighter=less weight the motor has to rotate, meaning easier/quicker revving. I would go with a forged unit, as they are considerably stronger, being that the metal is "dense"
2. The longer the stroke, the shorter the rod you need. So if you went from a stock 3.622 stroke to a 4" crank, and used your stock rods, your pistons would fly out of the block. So you need a shorter rod to make the longer stroke work.

DenzSS

You're a little off Onyx. When you go to a 4" stroke, you move the pin location on the piston, you don't go to a shorter rod. We went from the stock 6.098" rod to a 6.125" rod on my 4" stroke 408.

pekkaz

The longer the stroke the longer the rod should be in order to keep the rod angle and piston side loading acceptable. Usually piston pin is located closer to the top of the piston to make this or keeping stock length possible.

Longer rod in general makes the piston stay longer around top dead center area. This I believe favors high RPM power.

DenzSS

There are a lot of benefits to a long rod when you get into the rotating assembly's acceleration curve as well.

SSCamaro99_3

iTrader: (1)

From what I've tried to understand, don't you want to run the longest rod possible without encroaching to far up the piston skirt, to the point that it affects the rings and durability of the pistons?

DenzSS

Basically, you just want to stuff the absolutely longest rod possible into the block. There are a lot of limitations, of course.

Nytmare

You don't want an aluminum rod for the street !