The needle bearing cages in these rockers keep failing. The last time I had problems I checked with Jesel and they admitted to some issues with the older parts that I have. From what I find, the pushrod angle was hammering the needle bearing cages against the snap rings on the rocker shafts, causing the cages to wear out the snap rings and crack the ends of the cages, leading to failure.
Before this failure(30 runs ago?) I got rid of the snap rings that hold the intake rockers in place and switched to a steel washer against the rocker body's to try and solve the problem.
I don't know if this rocker failed due to being already hurt and I missed it, or something else went wrong. Anybody else having these issues?
I don't know if I should say I am lucky or not. Crank looks perfect, all but one rod bearing looks good, mains ok, one piston damaged and others scratched, block needs to be honed. luckily no severe damage to the gear drive or oil pump shaft, cam or lifters.
I hope that really damaged piston can be salvaged, the scratches in the skirt are pretty bad.
I am thinking this might be the time to pull all the 1.55 rockers and put in the new 1.7 ratio ones that I have, and get some recommendations on a different cam to work with the 1.7 ratio.
Here is a link to the thread where I tried to fix the problem. Tig, had the same issue, and someone else said Big Chief Chevys also suffer this.


https://board.moparts.org/ubbthreads/ubbt...tml#Post1215020

looks to me that the washer galled to the rocker. I don't think 1020 steel is bearing quality. I think the washer choice and clearance caused the current issue. I have set up big chief/ big duke Jesel stuff many times and have never seen this kind of failure after literally a thousand+ passes. I'm thinking that maybe Jesel had a run of bad stuff based on yours and other experiences. I would have them rebuilt/updated by Jesel. my . Hope you get it fix up soon, sounds like a disaster has been avoided. Maybe check for evidence of coil bind or valve float.

I have seen the snap rings getting worn out as well on the intake rockers with Indy heads using Jesel rockers.
The needle bearings aren't really happy being side loaded like they are in those intake rockers, and it seems like the needles can start to eat away at the side of the cage.
I saw one snap ring worn right through and the rocker body rubbing against the stand, along with about 4 more snap rings on the verge of failing, in 250 passes.
I told the owner to lower the service interval to 200 passes.
No issues at all with the exhaust rockers on that motor.

I don't know if there was a bad batch of stuff from jesel or what, just figured I'd keep an eye on it.

Does anyone have any insight as to what timeframe this bad batch may have been produced, if that's what the problem is.

I just got back from the engine shop that does my machine work, and was told a lot of Big Chief heads running Jesel rockers had this problem, and that Jesel modified the rockers to use a roller bearing to solve the issue. So, now to look up what is available for bearings. My 1.55 rockers were made way back in 1998. I have a newer (much!) set of 1.7 ratio rockers that I am considering, just have to get a recommendation on a cam, as what I have is hard on parts from what I have been told. The current cam has some older lobe designs.
Good news on the pistons, they may be salvageable, if the bores don't need much honing to get them back in shape.
B1MAXX, the rest of the intake rockers show zero signs of trouble, but I will take a very close look at them to make sure there was no damage or start of it. Plenty of room on the springs to coil bind, Comp 947 springs in at 2.000 running .775 Gross lift and 300+ on the seat.
Fast, I have not had any exhaust rocker failures either. No side loading, much less lift.

The rockers I had the problem with were 1.7's for the 572-13 heads, bought new in 2009, and I found the problem in 2013.
I have several other customers running Jesels on 440-1 heads, and I haven't seen this problem on those motors.
They all are close to .800 lift, with about 800lbs open spring pressure(Manley 221424 or PAC 1224).

Thanks for the info guys. I believe the paperwork with my Jesel stuff is dated 2005. I scored a brand new set of 1.7s off Ebay for $900 shipped. I'll make sure to check them periodically for a while.

I would guess the needle bearing failed first, then the galling on the rocker body happened next. It doesn't look like the washer galled the rocker side a full 360 degrees around. That makes it appear the galling happened after the bearing failure and as it got loose on the shaft the pushrod and springs canted it.

After looking closer at the rocker, that seems to be the case, MD. If you can zoom in on the rocker there is a lot deeper damage on the rocker body right where the needle bearing cage broke apart.
Then trash from the bearing tore up the washer and pump.

On the motor I built that had the issue, the snap rings just wore through from having the cage rubbing against them. Then what was left fell off the shaft, then the rocker body was rubbing against the stand.
One had failed to that point in 250 passes, and 3 others were very close to being at that same point. The other 4 intakes showed some wear, but weren't on the verge of failing.
Fortunately on that motor, the remaining pieces of the worn out snap ring that came off the shaft was still laying there in the head.

I bought one new intake rocker and replaced all the snap rings for the intake rockers.

sound ok on the coil bind, how about float ? is there an x pattern on the top of the valve stem? The duke/chief combos ran 948's, lift was in the .810-.850 range. Just added info, Comp had some issues for a while few years back and have switched to spiro-locs on the shafts.....

All the lash caps look good, no marks that look odd. I have the option of going to 2.050 installed height, which would put me at about 280 on the seat with 947 springs, or 360+ with 948 springs.
I am not sure which way to go if I put that much lift in it. That would be .850 max NET lift, which I think will be a bit more than I want to work with? At 2.000 installed height I can go .800 net lift leaving .060 to coil bind.
Thanks to all that have contributed, anything that can be learned about this stuff is greatly appreciated by me!

948'S were installed right around 2.100, 330lbs seat....360lbs on the seat is too much, wouldn't go that route.

You running centered or offset lifters on the intake. I think the problem stems from side load on the rockers.

I bought the offset lifters. Definitely is a side load issue. I can think of some things that aggravate the situation; too much side slop between retaining clips for the rocker body, heavy spring pressure, any valve float or loose lash.

I wonder why the T&D don't seem to have the issue? Mine runs #310/#815 @.850" offset. 300 passes and they were used when I bought them.
Doug

I looked at the T&Ds for my B1 heads and there is a ground washer on each side of the rocker between the retaining ring and rocker. I'm sure that helps.

Probably the steel on steel (bearing to snap ring) doesn't play well? Very limited surface contact area, weak bearing cage and snap ring not designed to take the pounding I bet.

That's how I looked at it.
Not really designed to take a thrust type load.

I have had this problem with Indy rockers, I now have purchased Hughes roller rockers as I dont like all those needle rollers sitting up there just waiting to fall out. I now also run a large cone shape screen inline in the -12 single pickup from sump to pump, last time engine came out I found a 1/2" bit of valve spring lodged in it !!!