I've got a spare rocker assembly off of a mid 1954 head that I'm reconditioning.
I got a set of the reproduction rocker shafts on Ebay because the original shafts had deep grooves worn in the bottoms where they contact the rocker arms.
I used a benchtop disc sander to take the grooves out of the rocker tips where they contact the valve tips.
When I go to put the rockers on the new shafts, I could feel resistance near the center of the rockers travel.
I looked at the inside diameter of each rocker arm where it rides on the shaft and there is a round button of metal in the bottom I.D. of each rocker arm corresponding to the oiling hole in the bottom of the shaft. The button has a groove it in that matches the oiling groove around the rest of the rocker I.D.
My theory is that the metal that wore off of the shaft settled in a depression that may have been machined into the bottom I.D. of the rocker arm. The groove would have been kept open due to the ridge in the shaft where the metal didn't wear away.
Has anyone else ever seen anything like this? The button of metal was resistant to a pick that I used to try to pop it out.
