SBM Roller Lifter Choice

yellow rose said

In my above post I noted that Mike Jones is making a lifter with a steel bushing...again IIRC. I'm sure he is using a DLC bushing or something. They are worth a look but I knew in the mid 1980's if someone wanted to, they could make a roller lifter with a bushing. A bushing is much better carrying a load than a needle unless the needles are HUGE.

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Good bushings can be made from steel, but not often made from stupidly hard tool steels. Though there are some tool and die steels that could do it ($$$$) but tougher materials make better bushings, as they can distort and flex without cracking. That distortion is what allows them to temporarily conform and spread the load over more area.

Same idea behind DLC. The diamond like coating gives massive abrasion resistance and high temperature durability, but is super thin (1-2 microns) to keep strain low enough to avoid fatigue or cracks. But it can be scratched through macro abrasion (dirt/grit), so keeping the oil clean is a must.

Bearings should do better with lowering rolling resistance, but must be larger than a comparable bearing to deal with the same load. So without increasing the lifter bore diameter, a bushed axle will always take more load before failure than a needle bearing. But at the cost of increased drag (which is moot when a bearing disintegrates).