OKay i am trying to price out my turbo build.....I was wondering what is the difference other then YES 0.300 inches. Like why would you get a 6.0 with a different piston over a 5.7 with a normal piston.

With the two assembled next to each other would the end up the same lenth?

Is it just for less piston stress?

Jay

 

This came from Darin Morgan;

Rod Length
"Most people tend to overgeneralize this issue. It would be more accurate to compare different rod-to-stroke ratios, and from a mathematical stand-point, a couple thousandths of an inch of rod length doesn't really change things a lot in an engine. We've conducted tests for GM on NASCAR engines where we varied rod ratio from 1.48- to 1.85:1. In the test, mean piston speeds were in the 4,500-4,800 feet-per-second range, and we took painstaking measures to minimize variables. The result was zero diff-erence in average power and a zero difference in the shape of the horse-power curves. However, I'm not going to say there's absolutely nothing to rod ratio, and there are some pitfalls of going above and below a certain point. At anything below a 1.55:1 ratio, rod angularity is such that it will increase the side loading of the piston, increase piston rock, and increase skirt load. So while you can cave in skirts on a high-end engine and shorten its life, it won't change the actual power it makes. Above 1.80- or 1.85:1, you can run into an induction lag situation where there's so little piston movement at TDC that you have to advance the cam or decrease the cross-sectional area of your induction package to increase velocity. Where people get into trouble is when they get a magical rod ratio in their head and screw up the entire engine design trying to achieve it. The rod ratio is pretty simple. Take whatever stroke you have, then put the wrist pin as high as you can on the piston without getting into the oil ring. What-ever connects the two is your rod length."

Start with the CR you want to achieve using the chamber volume you have. Then get the pistons from there. Many things will be in flux until you find all the components you want. You may need to change the size of the chamber or something else to say avoid buying a Custom piece.

Be very careful what you buy depending on how you want to balance the rotating assy. Some components will not work together depending on the balance method.

 

5.7

 

yeah it does not matter, from what i read you will not see a gain

 

I went with a 6" rod for a lighter piston/rod combination.