Dang Rocker Shafts Too Soft

Hey RRR, these are the rockers that we modded to add oiling holes to the valve tops and we checked the oil flow carefully, at least while static and priming. It was oozing out between each rocker side so the bearings are getting oil , and the sides of the bearing assemblies are tight to the shafts to help retain oil in place. And the p-rod cups look perfect and they get as high or higher loading psi-wise than the needles. Valve tips are untouched as are the main rollers, and again, that is a high pis loading. Oil used was Brad Penn 10W30 throughout this 1000 miles.

For added oiling, the one thing that might help is to open up the hole in the rocker shaft where it meets the pedestal; on these shafts, that hole is much smaller than stock and it the main restriction for oil coming into the interiro of the shaft. I called PRW about this before installation, and they said it was the way it should be, so I assumed they restricted oil flow there just to keep it from going all over the place in excess amounts.

But buckets of oil won't overcome too soft a shaft material. I had read up on needle roller bearing issues before installing these, and the possible issues with insufficient hardness or depth of hardness, on the shafts, was the one common theme for problems in shaft rocker apps. And if you look into needle bearing engineering in general, that is a constant theme in all needle bearing usage. The load concentration is very high so the matching surface has to hold up to it.

Obviously, if Harland-Sharps are lasting OK, then they know how to get the shaft surface hardness to the right level. And just as obviously, bargain basement eBay specials are a matter of luck!

Well, if anything, it was a not too expensive experiment and it may help others see one potential issue of needle bearing rockers.