On May 20, 12:08 am, "Morgans" wrote:
"Peter Dohm" wrote

Your location is not obvious from your email. In most of the world,
diesels are available in a wide variety. In the US, where fuel
consumption is only estimated from total mass flow and emission content at
the exhasut, the choices are currently quite limited, and I am really not
very happy with any of the choices. The 2 liter VW (Passat) is an all
iron engine, and about all I know is that it is about 100 pounds heavier
than its gasoline stablemate--which is partially aluminum. There are also
V6 diesels offered in the Mercedes E320 and the Jeep Liberty, but I know
even less about them. There are probably others that I haven't seen, and
Isuzu has said that they will be back in the diesel market when the
regulations have stabilized.

Personally, I really do like the diesel idea--so I plan to take a very
close look if/when any of the lighter small diesels (such as the 2 liter
Mercedes) become available here.

One thing that everyone should keep in mind, is that automotive diesels run
on diesel fuel, and everyone wanting diesel engines for their airplanes is
going to want to use jet fuel.

Jet fuel does not have the good lubricating properties that diesel fuel has,
and may tend to wear out the automotive fuel pumps in short order.

I read somewhere that Thielert spent half of what they spent on
modifications to the engine, in designing a fuel pump that would be durable
enough.

Something to keep in mind.
--
Jim in NC
--
Jim in NC

Not I,

And I dare say there are a few other fellows on this board who are
looking at SVO, Biodiesel, and Ethanol as practical alternatives.
Ethanols lower energy density means you have to carry more of it, but
since it is more resistant to detonation you can run substantially
higher compression ratios. I don't imagine it will be too long before
the bean patch is replanted with corn or rape seed and fuel is boot-
legged right on the tarmac.

In central and south america ethanol has been in aviation use for a
while. Biodiesel has better temperature tolerances than SVO, but it
still isn't serviceable without additional engineering due to gelling.
Given that is the case, there is basically no gain from using
biodiesel over SVO so personally, I think SVO is the way to go. It has
better energy density than ethanol, the flip side of course is that it
has a very high and variable gel temperature. But an engine designs
specifically for SVO _can_ design around this problems, and would
still accept biodiesel and pump-diesel easily. kerosene.... once in a
while. But not recommended.

Germany has a national fuel standard for SVO, and Elsbett has done
extensive work in solving injector coking problems associated with
SVO. So with SVO the engine is heavier, but offset by lower fuel
load, and a slightly shorter TBO, but given the price of 100LL, the
shorter TBO is offset by the fuel savings. Fuel availability would
actually be easier logistically speaking than the current system, once
it is adopted.

The only issue, is that the _only_ company to design an engine
specifically for SVO at this point is Elsbett. There are dozens of
kludges being sold for cars, but no ground-up designs. Funny that
people go to all the trouble of innovating a new engine, and don't
innovate where the fuel is concerned.

-Matt