I hear ya, its a personal preferance... every person that argues this with me says " the bearing will tear up the crank" well, everyone knows that there is a pressurized oil film and that will not happen unless you have other issues, at that point your screwed anyway.... P vs. H dont matter...

I read the Lingenfelter article, and the conclusion I am drawing from it is that the P-series bearings are a little softer and more forgiving for a cast IRON crank, while the harder H-series bearings work better for a forged STEEL crank. However, the aftermarket cast cranks are made of a steel alloy, not cast iron like the factory ones. Sounds like these fall somewhere in the middle. I do recall reading somewhere that the nodular iron cranks that were used by some of the manufacturers have to be properly polished after being turned, or they will eat up the bearings due to the molecular structure.

Sure would be nice to get some weigh in from some pro's. I am more confused than ever now. Might have to give Clevite's tech line a call tomorrow.

if you go on there website you will find your answer,s.

If you were going to call anyone I would call Eagle or email them asking them. I looked at that crank on Jegs and it says it has small (.092")radiused fillets so you can use OE bearings. No need for chamfered bearings. Using the "P" would be fine if you wanted. IMO I think either one would work fine.

http://www.jegs.com/p/Eagle/Eagle-ES...55263/10002/-1

Thanks for the info, Jim. I am going to contact them today and get the scoop from them. Might also contact Clevite to get their take on the H-series bearings as well. Wish I had known that Eagle "guarantees a target bobweight +/-2% that reduces balancing time" as mentioned in the literature. It ended up costing me over $400 for the balancing job because they had to add mallory to the crank. For that money, I could have gone with a forged crank! Wonder if they would have stood behind that guarantee? ;)

Not to hijack the thread, but after reading this I'm more confused then before I read it. I'm building a 509ci with factory steel crank, dimple rods, and je pistons (550-600hp). Should I use the clevite h series or the hk? Or am I totally off base and should be looking at king bearings.

Thanks

Only difference between h and hk is ones coated... Ones not...

Tom,

Hope this helps.

Bob

I've got a Lunati forged crank and they had to add mallory to it. You needed the mallory because you didn't have enough bob weight for the piston-rings-rods your using.

Good read here. http://www.carcraft.com/howto/ccrp_0...g/viewall.html

Thanks Bob - some interesting info there! I called Eagle tech support, and the gentleman there said that the smaller fillet on the cast steel crank allows the P-series bearings to be run. He said that is what they ship with all of their kits. He said these should be fine to run on almost all NA applications. He said my power level (525 - 550 HP) would be well within the limits of the cast steel cranks, and 750 HP is where they start to strongly urge stepping up to a forged crank. He did say that I could run the H-series bearings if I wanted to without hurting the crank, but the P-series are a little softer, so if anything were to go through the bearings they would entrain the contaminants more fully and possibly cut down on wear to the crank.

I also spent some time looking at the pictures of bearing on the Clevite site, and it's kind of tough to tell if the damage to my bearings were from contaminants or oil starvation. I will need to take a much closer look at them - might take some closeups of them tomorrow to post on the site. There almost HAD to be metal going through them from the cam lobe spalling and the distributor gear wear, but I want to fully analyze this failure before I start reassembling.

Here is a link to the site => http://catalog.mahleclevite.com/bearing/