Stewart,

Yes, that's true. I was in the bearing business for some 35 years. We saw a LOT of failures due to too much, not enough, wrong kind, wrong viscosity etc. etc. But the bearing manufacturers and the lube manufacturers sometimes disagreed with each other on certain points.

They both agreed, though, that too much or too high viscosity would cause the balls/rollers/needles to skid instead of roll. This would depend, of course on load and speed. With low load and low speed, you could lube a bearing with chicken grease. Get out of that range by any margin and you had to be careful.

There's a thing called a babbitted bearing. They called it a bearing, clearly a misnomer from the days when that sort of thing was far more common. It was, basically, a lead alloy bushing that, in some cases, was poured into place against the shaft. That gave you a perfect fit. This was actually inside a thing called a pillow block. The lead, being very soft and the steel much harder, gave you a broad, hard/soft combination. These are still in use today for large, heavy, milling equipment.

My point was, if Amsoil can claim that their product is sufficient at 1% in a gasser, why would 5 times as much, (5%) not be sufficient in a bushed rod? I guess I'll have to give them a call.

Here's a thought. Make rods with VERY hard steel bushings. Cox engines, all the way up to the .09 and maybe the .15, have a steel rod. With that against a steel crankpin, I've never seen rod wear in this area on any of my Cox engines. Even those that I mistakenly ran on Morgan's Sidewinder fuel. We have no car activity around here so I had no idea that the 25% nitro car fuel I was using had only some 12% oil. And yet, this never hurt the rod. At least at the crank end. Cox are notorious for getting sloppy at the piston and a reset tool was pretty much a must if you ran them. Still, the big end was always happy no matter what fuel you ran.

At any rate, I dug up that batch of Olivelube I made last year and will be making up some diesel mixes with it for my .15 test bed engine.

And, I'm in the process of getting some commercially made BioDiesel. Where I live, it's not possible to get it at the pump. Anyone else given a thought to trying it? There may be something missing or something that shouldn't be there in my homemade stuff. Won't know till I run the real thing.