Stock rods, better bolts, how much hp ?

According to internet rumor, the powdered metal rods in a 5.7L Hemi are good for 500HP while the powdered metal rods in a 6.1L / 6.4L Hemi are good for 700HP.

As always your mileage may vary. A well running engine with no detonation and a responsible driver who does't rev the engine without a load might be able to survive a much higher HP than the above numbers would suggest. For example, there are LX cars with superchargers that have well over 500-700 HP and yet they live for quite a while. Yet, many eventually succumb to ventilated block syndrom.

There seems to be some disagreement on the interwebs about resizing cracked powdered metal rods.

This article from Engine Builders suggests that cracked rods cannot be resized because of the nature of the cracked mating surface of the rods. As a result, the only option is to hone the big end over-size and use oversized rod bearings. Unfortunately these over sized bearings are only available for a few motors, the Hemi not being one of them.

Here's two articles on Rod Reconditioning:

http://www.enginebuildermag.com/Art...itioning_more_to_it_than_you_might_think.aspx

http://www.motor.com/article.asp?article_ID=1866

According to ARP installation instructions resizing the rods is mandatory. You can read the instructions here:

[ame]http://arpinstructions.com/instructions/247-6301.pdf[/ame]

I'd call ARP to confirm installation instructions, for powdered metal rods, in light of the fact that they cannot be resized.

According to several rumors on the interwebs, you don't need to resize cracked, powdered metal rods because of the positive nature of the cracked surface means that the rod cap will not move when the bots are replaced.

Also, according to the Dodge Factory Service Manual, there are clear instruction that rod bolts are to be replaced since they are torque to yield fasteners. At the same time, the directions DO NOT indicate the need to resize the big end of the rod prior to installation.

My reaction to all of this research is that the rod bolts can be replaced WITHOUT resizing the big ends. That being said, I'd still carefully inspect the rods, taking care to measure the big ends to ensure that they are not oblong. If any of the connecting rods measure significantly out of round, I'd seriously consider replacing the factory rods with a set of forged aftermarket rods.

The nice thing about aftermarket rods is that you can buy a set that will easily live in a 600-800 HP motor for a reasonable cost.

Regards,

Joe Dokes