Greg,

Yes, the entire essence of using ether was to get the stinky little b&%$ds to start. Back then, electric starters weren't available and who invented the first spring starter? With all the caveats, (justified) to never use a starter,, well that's what held us all back, it seems. My experience is that even with the far higher compression ratios in diesels, they respond well to starters with no more danger to the engine than if they were glow. The key is to have your adjusting elements as close as possible for that first start. In the case of glow conversions, that can be done on glow fuel.

In the case of diesels, that can be done with an ether based fuel. Here's how you can go about tuning your favourite diesel engine to run on all kero fuel. Get it all tuned up on your stock fuel. Then make a mix containing, say, 10% ether. If it won't start, up the ether a bit. See where the settings are and then take the ether content down progressively. At one point you're running with no ether. Small steps, no pain.

You still need an electric starter though. It should be sized for the job and above all else, with a starter, NEVER prime into the EXHAUST.

There is the issue that higher compression ratios are needed to run all kero fuel. At one point I'm going to test various ether content fuels and make notes of the compression screw position. Subjectively, it does not appear to be as much as one might think.

Injecting high ether content with some device could do the trick in competitive situations. Can't wait to see what the inventive brains come up with down the road.

Your comment about 1/2A glows with no fins at all is interesting. The old paradigm was that the smaller the engine, the hotter they run. And yet, small engines need more ether,,, or so we thought. Small engines really only needed more ether to get them going. Once going, all that heat was a good thing.

A thought has just occurred to me. While ether allowed easier starts, because of its volatility and colling effect, it was, in a way, working against itself. The more ether, the easier start but then, the cooler the engine ran, contributing to the need for more ether etc. etc. As you take away the cooling effect of the ether, the heat generated by combustion allowed the kero to ignite more easily. Well, at least, once the engine started.

Another point brought up by Stewart in the land down under, was port design. The Mills engines ran so well and started so easily because, as he illustrated, the fuel charge was fully atomized when injected into the combustion chamber, as opposed to big, fat droplets. Critical to diesel and maybe, on some designs, the ether helps the kero get vapourized more easily.

Much, much food for thought. This thing isn't over,, by a long shot.

And thanks for the patent link. MOST interesting reading. I've got that printed out for some light reading later on. Neat.