Today it was a warm and balmy 5 degrees above on the Celsius scale. So I took off the head clamp and got busy. I wanted to find out just how much work the biodiesel was really doing and how much the kerosene was contributing. This was mostly a no oil day except for the lubrication provided by the Biodiesel fuel.

First we have a picture illustrating our first Biodiesel fuel, finally settling out all of the "soap" giving us a nice, clear, pure, Biodiesel fuel on top. This picture was taken after extracting a healthy 12 ounces by using a turkey baster. Thank god for dollar stores. Anyway, posted on YouTube, throughout the day, are runs on B80, B90 and finally, B100 Biodiesel fuel. Amsoil cetane booster was used from 1 to 2%. More actually hurt performance in all areas. All of these runs were made with NO additional oil in the mix. So far, we have had no indication of overheating, excess mechanical noise or any indication at all that the engine was in distress. In fact, the finger test revealed that the engine ran cooler than with a conventional kerosene mix. Well, it's no wonder, about 40% of the fuel oil was being expelled and carrying away a lot of heat. It WAS my hope that we'd get a dry exhaust, what with the mix being all fuel, but that was not the case.

It took a special technique to get the B100 Biodiesel fuel to fire off and keep running. On a cold engine, the compression was maxed out. On this head, I have the screw and spring length adjusted so that when the spring is squeezed as far as it will go, the contrapiston is flush with the bottom of the head. This ensures that we'll never go too far and get one piston whacking the other. A nice safety feature that all diesel engines ought to have IMO. At any rate, after finding the CP setting that allows the prime to fire off, we need a half dozen prime runs to get the engine warmed up. From there, on the last, prolonged burst, we need to catch the combustion process by cinching DOWN on the compression a tad to keep the run going and holding it there till we hear a slight sag. Then we back off a sixteenth of a turn. Then we wait for the engine to sag a bit and back off a like amount. Wait for a slight sag and back off again. This can go on for six or more times till at one point, we don't get any sag. That's our setting. Any rushing of this careful process upsets some kind of delicate balance within the dynamics of the engine. Fuel, compression ratio, heat etc. Once the setting is established, the engine will run and keep running. I've run an entire four ounces and the engine didn't miss a beat. I didn't time it but while waiting for the engine to run out of fuel, I managed to post a clip to YouTube along with commentary and waiting for the download to complete. This was done to determine if the engine would suffer in any way from having no added lubricating oil.

The needle was taken out a full four turns and this made starting a little easier. As each prime run warmed up the engine, the needle was turned in, bit by bit. This is what it took to establish where the needle should be. On B100 fuel, once adjusted, the needle valve is out only a half turn from normal. That's two and a half turns. Much more reasonable. The compression setting was a whopping full turn OUT from max. Most mixes were from 1/4 to a half turn out. Only excess Amsoil cetane booster would do this on other mixes. This makes sense as Biodiesel is supposed to have a cetane number higher than kerosene. And more typically, in this case, more cetane booster made things worse.

With this learned, I decided to try and run an SVO mix. That stands for Straight Vegetable Oil. No ether, no added oil, just 100% corn oil and 2% Amsoil cetane booster. After an hour of trying, I gave up. Using the preceding technique, I could get prolonged bursts that would pick up in RPM for about a minute but then the engine would flame out. The needle was left where it was from the B100 runs and was taken WAY out and a little bit in, with no improvement. My suspicion is that as the engine picks up speed, the pure oil's viscosity just overwhelms the carb's ability to deliver enough fuel, no matter where the needle is set. Plus, the thicker fuel is likely not to be atomizing very well.

So, what to do. Thin out the fuel mix, of course. But with what? Something Graham said came to mind. WD 40,,,,, 80 to 100% Stoddard Solvent? Well what the hell, why not. My Amsoil boosted corn oil was cut 50/50 with WD 40. To my amazement, we had a run, first try. Rough, but with a little tweaking we got a good 8K. But the sound was quite smooth. Far less of the diesel clatter that this engine provides when maxed out for power. And there was a LOT of oil coming out the exhaust.

That led me to make up a mix of 80% WD 40 and 20% cheap, supermarket corn oil. I can't remember if I added any cetane booster but this time we got a decent 9K with just a bit more tweaking. And unlike all the other runs today, I tried the throttle. To my great pleasure, we got a decent, 3.5K reliable idle and after a few minutes, transition to max was smooth and solid. No burble or bother. Neat, sweet, wonderful. Full of endorphins, I decided to make up a mix using REAL oil with 80% WD 40 and 20% Klotz castor oil. But just then, two tall, imposing gendarmes came up the dark driveway. "Good evening Sir" and from there we had a pleasant conversation about how it was 11.30 PM and some silly bylaw about a noise curfew starting at 11. Oops, my bad. My poor, suffering neighbours had had enough. I don't blame them, I was having so much fun I'd forgotten the time.

So tomorrow, if the weather holds, we'll be pursuing this new, strange brew some more. Who would have thought?