A gentleman that owns the business CHE in cali was kind enough to talk to me about my problem. He developed a proprietary bronze bushing alloy that would stand up to the punishment of bushed, Hemi SS rocker arms, hi hp LS rockers, Isky EZ roll bushings, etc. He uses bar stock to make parts like i would need to bush my Jesel rockers. He mentioned Jesel wasn't interested, even though he has been contacted by Jesel customers that have the same issue as me.
The problem is pressure on the bearing cage,plus a twisting load on a bearing not designed for it. The force from the pushrod is offset outside of the bearings. Just like all materials, all the parts under load compress, maybe ever so slightly, but they have to, or they shatter. Soooo, apply enough shock load, and eventually anything will deform enough to put too much load on one edge, and starts to fail. I see the bearings start to gall the shaft on the outer edge, confirming the twisting diagnosis.
He said i was on the right track using bronze washers between the rockers and the rocker bar to eliminate side loading on the offset intake needle bearing cages.
As for bushings, the special alloy with a wide threaded grove in it to allow oil to enter would work. The problem is, he is swamped with work and a short run of bushings would be quite expensive. So that takes me back to having to use the needle bearings. He did suggest i do two things. Try and fit a wider bearing on the pushrod side of the intake rocker, and groove the washer to allow oil flow to the bearings.
I really appreciate the time he took to help me out. I learned from someone that had solved my very problem exactly what is going on, and what would be needed to step up to a more durable rocker capable of taking more punishment than the rockers can handle as built.
Since a lot of guys are not having the same issues, i pont the finger at having used some brutal cam lobes, maybe not a big enough pushrod, and lifters not up to the loads i threw at them.
The changes since the majority of failures are; new inverted flank cam from Mike Jones. It has very long lash ramps to minimize shock load. EZ roll Isky bushed lifters. 7/16 minimum diameter tool steel pushrods. PAC 1228 springs which provide the same loads as the 948 comps but weigh less and have a higher frequency. Since i don't race a lot, if i can get 75 to 100 runs out of this setup, i will be somewhat OK with running the needle bearings and washer combo. I have been looking for info on this problem for some time, and really appreciate it when someone takes time away from thier swamped business to talk to me!