Rod Bearing Wear

[Chris Hill]

I'm not really sure if rod bearing life is a hp or a rpm issue or a combination of the two.

My gut says it's more of a rpm issue rather than a hp issue, but I still need to prove it.

[Chris "drooze" Wertman]

Originally Posted by Chris Hill

I'm not really sure if rod bearing life is a hp or a rpm issue or a combination of the two.

My gut says it's more of a rpm issue rather than a hp issue, but I still need to prove it.

LOTS of things, lots lots lots, rpm, clearances, oil system, load, etc etc.

Ive had bikes spinning 12k+ for 90% of their track time with no appreciable bearing wear. Ive had Harleys same (XR750's) and other Harleys that ate bearings like they were crank food. Machine work, finsih. bearing material on and on and on.

Im still a bit sketcy on clearances with the H bearings compared to other stuff, and I think Im seeing some side loading on my bearings which well...that a biggie for certain failure.

Not the right guy to be answering it, I guess Im agreeing in part, basically there are a ton more things than even I normally think of.

[SSDiv6]

Originally Posted by Chris Hill

I'm not really sure if rod bearing life is a hp or a rpm issue or a combination of the two.

My gut says it's more of a rpm issue rather than a hp issue, but I still need to prove it.

Chris, bearing wear and life is defined by torque, rpm and hp. As you know, they are all related to each other. Go back and refresh on Mohr's Circle.

[Jeff Lee]

Consider the ability of the rod to stay round. OEM rods, when stressed in a racing application, will distort and elongate. The bearing will decrease the clearances at the parting line, creating a scraper and wiping the oil from the rod journal. Yes, I was very happy with NHRA allowing quality, aftermarket rods.