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Author Topic:   crank question
charlie_two
Dirt Full Roller

Total posts: 53
posted January 05, 2002 03:46 PM
hey guys. i am new to buildin v8s. i have been buildin go kart motors but now i am racing cars and i bought a set of 6inch rods. J&E pistons. i bought an eagle crank but i found out it says it is for a 5.7 rod. will this work. what is the difference in the crank. i was plannin on gettin it balanced and was wondering if everything would work ok? thanks

charlie

Mod6M
Dirt Full Roller

Total posts: 53
posted January 05, 2002 06:36 PM
The crank dont care how long the rod is. But the pistons do.

charlie_two
Dirt Full Roller

Total posts: 53
posted January 05, 2002 06:51 PM
yea i know that but i figured it may do with how it is balanced. i got pistons for a 6 inch rod. but i have been looking at forged cranks and i was wondering why some say for 5.7 and some say for 6 inch

awkwardjeff
Dirt Freak

Total posts: 458
posted January 05, 2002 07:59 PM
The reason for different rod lengths in cranks has to due with PISTON SKIRTS....AND COUNTER WIEGHTS ON THE CRANK...... You can use a 5.7 rod crank with a 6 inch rod, no problem............

If you had a crank that was designed for a 6 inch rod.........you may or maynot knock the bottoms off the pistons with the counter weights of the crank.in a crank designed for a 6inch rod but used a 5.7 inch rod.............

It also has to due with balancing up the assembly........a 5.7 rod crank will balance up very close with a 6 inch rod and light weight piston........take out metal. If you have a heavy piston, you will be bettet off with the 6 inch rod crank......it's much cheaper to take weight out of a crank then to add heavy metal to balance......

[This message has been edited by awkwardjeff (edited January 06, 2002).]

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