Roller rockers 1.6 no needle bearings affordable

nm9stheham said

I did some reading on needle bearings and lubrication, and one of the worst applications was in oscillating motions, like the motion of rockers. Seems that the reversal of motion tends to disrupt the lubricating film around a needle. This does not happen, or happen as readily, with a sleeve bearing. You can find this in some of the online bearing application info.

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They have 'em in U-joints, same oscillating motion, but I think the reason is to have the smallest bearing available in there (so as to have more meat inn the axle) and to spread the load across the largest area. You couldnt run a floating (hydrodynamic) bearing in there as there is no pressurized oil as in a rocker arm. Roller bearings dont do that well but they include their own hardened races. I think the floating bearing in the rockers is the best for the job. Cranks live for 100s of thousands of miles on hydrodynamic wedge bearings.