ORIGINAL: RingWinger
Andy and Greg
Thanks for the great link on How Stuff Works:
I clipped this bit out:
Diesel fuel has a higher energy density than gasoline. On average, 1 gallon (3.8 L) of diesel fuel contains approximately 155x106 joules (147,000 BTU), while 1 gallon of gasoline contains 132x106 joules (125,000 BTU). This, combined with the improved efficiency of diesel engines, explains why diesel engines get better mileage than equivalent gasoline engines.
Notice the term: “Energy Density”
I was using this concept in this thread about etherless fuel to illustrate the idea of lowering the ED of a fuel in hopes of matching the fuel metering system to a higher ED fuel. I do believe that Greg did not agree with the concept of energy density. I hope this clarifies this concept.
One more thing: I noticed this week an advertisement for a DDD head for the OS 1.60 engine. In the advertisement it showed and talked about a plastic venture reducer installed into the carb to make the required adjustments to the higher ED fuel. I do believe the mag was “RC Flyer”. The reducer looks like it made the intake about 30 percent smaller.
I do think this sort of reducer would be helpful to converted engine like the nice little Norvel .074
Have fun,
Kelly
I've been resistant to the concept of reducing the bore in the throttle of our converted engines because I've found that with glow, the manufacturer seems to err on the conservative side to make sure that ganging of tolerances are taken care of. It works and works well but being the power nut that I am, I typically bore out glow throttles for more of that magic and because I run muffler pressure, generally have no problems. If I run diesel, I leave the bore alone, (most times) and that can work too, most times.
With a 40% ether mix, I've had no problems on the .06 and .074 in the air. However, as we play with more exotic fuels, this may be a bigger consideration. Elsewhere on this thread or on YouTube, this has been contradicted in some cases.
With the wonderful little Norvel .074, if converting to diesel and you have concerns, you can swap in the .06 barrel. This has a smaller bore and is a drop in replacement. Thanks, Kelly, for bringing that up, I had forgotten and will be something to do as we fly our new strange brews.
Greg,
As per above, I think Kelly WAS referring to the changes usually required in carburetion when playing with differing fuels. Sometimes it's hard to express exactly what you mean on the first go around. When I did my first article in FM back in 97, it was my first experience doing such a thing. No literary genius I, Frank Fanelli was still pleased that all he had to change was a few commas here and there. I had to admit to him that the article took a year to write, off and on, as some of the work was done. The text in the article had been rewritten and revised many, many times, perhaps two or three dozen. Even now, as I read it, I mentally make changes realizing this or that had not been made entirely clear.
And maybe it's me but as I go back to some previous posts on this thread, I get new understandings of the issues that have come up as we go along. Ping and detonation was one.
Stewart,
That explains how I blew the rod in the .15 with the no oil, all biodiesel fuel. I've never seen a pin suffer such galling against softer aluminum. I suppose there might be a way of determining RELATIVE viscosity? As in, fill a small eye dropper and note the time it takes to empty with, say castor, and compare that to your other oils? Or do the same using a larger container for mixed fuel containing different ingredients.