ORIGINAL: gkamysz
The viscosity of biodiesel is low and I don't think the engine will hold up without additional lube. I don't think it's a good idea to use significantly less than 20% after crunching some numbers this morning. I was hoping we could go lower, but I know that the exhaust in my four strokes on 20% oil etherless is dry already. There is a property of lubricants called lubricity that is the ability of the lubricant to reduce friction other than it's viscosity. The problem is that there is no standard method of defining lubricity.
Andy, how much of your soybean oil was burning? Are you sure it wasn't just the ether burning? I don't remember a post with a run on straight soybean oil? Post 234 is what I'm referring to.
Greg,
That's an excellent point. I suppose I really should not have jumped to conclusions but as I see, you did try to point this out but only said that there was a lot of oil being ejected. It certainly could have been virtually ALL of the oil coming out of the exhaust.
Next step is to get some SVO, run it with the 30% ether and then take the ether out in increments to zero. That will tell the tale. Now that I have the .15 re-built with a proper, brass bushed on both ends rod, we can really beat it up with these trials. Made two so if I trash the rod, I can keep on truckin' with not too much anguish. [:@]
And about lubricity? There IS a way to test for it. That's the blown rod test.
See above. [X(]