Here we have the Norvel .15 rebuilt with a custom made rod, brass bushed both ends. The crank has also been fitted with brass bushings on both ends. We now have a machine with zero slop in the system.
A prior experiment using soya oil and ether as the fuel was met with the justified criticism that perhaps it was just the ether that was burning. The clue was the heavy white smoke generated by the engine at full throttle.
So this time, I made up a mix of
6 oz of Sunflower oil straght from the fridge.
2/3rd oz of kerosene (11%)
2/3rd oz of Camp stove fuel (naptha)(11%)
25 drops of Amsoil cetane booster. (1%)
Much reading on biodiesel and SVO (straight vegetable oil) lead me to this formula. Special thanks to Kelly for the tip on using naptha in a diesel fuel.
And as you can see, it runs. Note that this time, we have MOST of the mix composed of oil as the fuel. On top of that,,,, note that we have no added oil for lubrication. As a two stroke, the Norvel requires an oil to be added to the fuel for lubrication. However, as the oil IS the fuel, it serves double duty as in burning for the go and oiling for the keep it from blowing up. Neat.
The idle is smooth and reliable and on this run was a tad higher than normal. Further tweaking got it down to 3K. Top end is down from a stock, kero/ether based fuel.
The main needle had to be turned OUT some six turns. The compression screw had to be backed off one full turn.
Starts required a high ether prime. Six or more prime bursts were needed to get a run but even then, it took a lot of coaxing to get the engine to run long enough to get hot enough for the run you see. The engine gets far hotter than with a stock, kero/ether fuel.
The sunflower oil along with the ingredients had a high viscosity compared to standard fuel. This likely accounts for the extremely rich needle setting.
Yes, lots of white smoke and we DO have oil coming out of the exhaust. But that's normal. Evidently, most of the oil IS being burned and SOME is still doing duty as lubrication.
Addendum,
As discussed on RCU, we have now come to the conclusion that not much, really, of the oil is being burned. The evidence is the gobs coming out of the exhaust. That also explains the needle setting, grossly rich. It takes that much fuel to get just enough of the kerosene and naptha to allow combustion. This experiment actually disproves the notion that the oil is burning and providing power.
