has anyone broken/damaged these rod bolts that come with eagle rods? i've heard there junk and would like to hear stories of them failing.

 

they're an ARP bolt, not the best but not garbage I'd say

 

Better than stock.

 

I am not a big Eagle fan, but the rod bolts are fine unless you are building an 8,000rpm motor.

Rich

 

is it just the rpm limit or is it a hp/trq limit?

 

It has nothing to do directly with hp/torque. The stress on the bolts is primarily when the piston is slowing down approaching TDC (when it's in tension). The ARP 3/8" 8740 bolts could be a problem with very high rpm, especially with a heavy piston. But absolutely not in a typical LT1. After all, the PCM can only control the engine till 7,000. What are you building?

Rich

 

no where near 7000rpms. more like 6200 rpms. i just read in a thread that the bolts are junk.

 

You will be fine.

 

thats what i wanted to hear. is this still true with forced induction(turbo) say 10lbs on the street, 21lbs at the track?

 

Yep, a blower decreases rod bolt stress when the motor is under boost. And there will be no need to spin it to the moon.

Rich

 

Someone do the math on it, please! On how much less stress a certain amount of boost takes off the rod bolts.

 

A piston with a diameter of 4.030" has ~12.75sq.in of surface area. With 12 psi of boost the force on the piston crown is ~153lbs.

Rich

 

And to continue for Rich ...... a 3/8" diameter rod bolt has a cross sectional area of .1104 square inches ... divided into the 153 lb force reduction due to the 12 psi boost over the piston as it approaches TDC.... yields a total stress reduction of 1,385.9 psi per rod .... which .... spread over two(2) rods bolts .... gives a 693 psi tensile stress reduction ... per rod bolt.

 

What about on the exhaust stroke, which is what REALLY stresses a rod bolt anyway?! Looks like zero benefit to me.

 

3/8 rod bolts are pretty pinner, run a rod with a 7/16 cap screw for ultimate strength.