What kind of abuse will the GM PM rods take? I know they are rated up to 500 horsepower, what have you guys put them through? I am trying to keep my build cheap. The Scat forged I-beams are rated to 500 horsepower and 7500 rpm for comparison purposes, although they are made from different material.

I dont plan on shifting this motor much over 6500 rpm.

Here are the specs on the motor for now:

377 (std bore 383)
Probe Industries Forged Pistons (11.3:1 compression)
GM Forged PM Rods
Scat 9000 crank
Ported E-tec 200 heads
Custom Solid Cam (in the neighborhood of 259/269@.050, .599/.620 lift w/ 1.6's)

Car craft made 530 horsepower with a similar motor, but a 350 and it peaked power at 6300 rpm. I would imagine this should see no more than 6800 rpm.

Seth

 

Those pm rods are as good as the old "pink rods" but they are not rebuildable like the scats or the pinks, they have a "cracked cap" The mating portion of the rod is not machinable

 

Those are same rods as in the LT1/LT4 style engines and many guys have put over 300hp to ground on those rods reliably.

Same in the ZZ4 series motor with 355 hp and those shortblocks have been built up with numbers approaching 500hp. I wouldnt try 500 hp on those rods but its usually the bolts that fail.

Super AFR ZZ4 has 460 horse at 6500rpms or so which is pushing it in my opinion.

Check This thread out.

https://www.thirdgen.org/techbb2/sho...hreadid=263969

 

I will be running ARP rod bolts, so rod bolts wont be a factor. Thanks for the input, keep it coming.

 

The number I've seen floating around about PM rods are ~450 crank hp.

About them being rebuildable, they can be "rebuilt." However, from the factory, they are better balanced (as a set of 8). As a rod, they are also a bit more "stable" so they don't really take advantage of shot peening or really any other forms of stress relief. As far as rod bolts and re-sizing, sure. I have a set of PM's with ARPs.

 

I was under the impression the cracked cap design was not fesiable to rebuild..would you mind explaining how they are rebuilt if they become non-concentric?

 

I had always heard that PM rods were "as good as pink rods", but personally I'lll never use them again. My 37,000 mile Camaro SS (no power adder, ever) had its #5 rod disintegrate while driving down the road normally several months ago! Oil pressure was good, there was no coolant in the combustion chamber...even the bearings looked great. There was not much left of the rod, other than the ends...the rest was powder! My machinist looked at it and thinks it was poor heat treating, and the former Camaro brand manager, who I talked to recently, agreed...not common, but it happens.

 

The older PM rods couldn't be rebuilt, but i hear the new ones can. I knew once upon a time, but its seemed to leak from my brain since then. I only have a finite amount of infintesimal space.

 

They can be reconditioned..i know that for a fact, but it has slipped my mind aswell...anyone that wants EVERY possible fact for LT1/LT4 motors get this book..http://www.eshop.msn.com/search/deta...&prodId=450202
(which i have but its in michigan and im in NY)

there are guys over on camaroz28.com who are pushing over 450 RWHP on stock rods...granted they have ARP bolts/studs...