Roller rockers 1.6 no needle bearings affordable

pishta said

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.

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You correct in the fact the smallest needle bearing provide the best load bearing surface on the rocker shaft. Most inexpensive rockers used large caged needle bearing because their cheaper. Bronze bushed rockers, in my opinion are the best option for most engines using adjustable rocker gear. Benefits include a long lasting wear surface and low initial cost which is a better option than aluminum or roller bearings on a steel shaft.
Ever wonder why roller tips are installed on rocker arms, Doesn't take a scientist to figure out that aluminum or non heat treated metal will wear out quickly. A roller bearing will provide a long lasting wear surface. But is the roller tip effective in increasing horsepower. The answer is NO. Mopar did a study years and years and determined that roller tip would be 6 inches in diameter to effectively reduce fiction.
So what's all the hype on roller rockers and horsepower increases.
Generally aftermarket rockers provide more accurate ratios and that provides the increase in horsepower and not because of roller bearings.