Reg,

Many thanks for the precise formula and the clarification about the semi-synthetic being for diesel cars. That may make a difference. And very important, as you pointed out, that diesels have double the mileage so any comparisons have to take that into account.

Just got back from our new Home Depot store. You guys living in big cities just don't know. Until HD, I had to mail order any and all metric stuff. Before HD, I had to do the same for aluminum bar stock. Before HD, I had to do the same for thin wall, aluminum tubing. Just picked up some for that muffler for the Tanaka along with some hex head bolts. So it looks like this small mining town is waking up. Wonder what's up? Price of gold? Anyway, for gearheads, and there are quite a few around here, that makes life a lot easier.

Also at HD are 10 litre jugs of Varsol. So what? At 14 dollars that comes to $1.40 per litre. So what again? Varsol has an auto-ignition temperature of 227C and compared to kerosene at 210C, that's not too far off. Just a bit more Ignition Improver and we may have another alternative fuel to try.

About rods. I've done a search for thin wall, seamless, smooth tubing. As luck would have it, Microgroup Tubing has just that as used in many instrumentation applications. Just need to find a size that, along with thin music wire as the needles, we may be able to come up with a very workable needle bearing set up for even the little .15. As we don't have high RPMs to contend with, we can make the entire rod out of brass. The extra strength will help where needed and the extra weight, where not needed, can be trimmed off. This allows the tubing to be press fit in place. The needles will ride directly on the wrist pin and the inner bore of the tubing. Full complement and full floating. The tubing, by the way, has a wall thickness of .5mm or .0196. Along with .01 needles, that still makes a fatter dog bone but I checked, there's just enough room. The tubing is available in a variety of materials, will call the company to find out which is the hardest and most suitable for this application. I'll bet they never had such a request before.

But there may be an even simpler, cheaper way to make wear at the wrist pin a thing of the past. It'll take some serious R&D to prove out but if it works,,,,