Engine/Transmission (1998.5 - 2002) Which connecting rods do we have?

[RGutierrez]

I've been told that there are two types of connecting rods for the 5. 9 Cummins engine. I did a thread search with no luck. I would like to know which rods are in the 24 valve and which ones are the better ones and why.

 

[AFarmer]

Most 24 valves (VP) had machined rods - not for sure what the break was between machined and cracked rods.

 

[59Turbo]

I believe the common rails have the cracked rods.

 

[RAMICATOR]

i think machined rods are self explanitory, but what are cracked rods?

 

[RustyJC]

i think machined rods are self explanitory, but what are cracked rods?

From a technical resource:

The cap is separated from the rod by a fracturing process, which results in an uneven mating surface due to the grain of the metal. This ensures that upon reassembly, the cap will be perfectly positioned with respect to the rod, compared to the minor misalignments which can occur if the mating surfaces are both flat.

Rusty

 

[AFarmer]

Cracked are suppose to be stronger and also don't have the think weak spot on cap like the machined do. If you look hard enough you can find a set that has much larger rod bolts for added strength - that takes some diggin. Took me a while to find those. Cracked are also a little lighter which takes some stress off of the rotating assembly.

 

[RGutierrez]

rods

What horsepower level would you estimate the stock rods are good to with respect to reliabilty?

 

[AFarmer]

I was making over 600 just fine for a while with absolutely no problems. When the engine was torn down everything looked fine - except for the crack in the side. I don't think you'll have to worry about rod failure anytime soon.

 

[pwerwagn]

See Mundo, Just go ahead and spray it!!! Your rods are fine...



--Jeff

 

[Jetpilot]

Here is a pic of the cracked rod:



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[AFarmer]

Doug - take a picture of the bolts that are in that rod.

 

[RAMICATOR]

afarmer, rusty thanks for the info.

 

[AFarmer]

You're very welcome.

 

[RustyJC]

Ditto.



Rusty