The potential use of diesel engines in light aircraft

[Lady Heath]

I would greatly appreciate it if there is anyone who has a knowledge on this subject to help me out a little. In brief I have to determine the power, weight and size of each a/c diesel engine and asses their compatibility with any of the current MAF fleet. (some of their a/c include cessna 208, 172, T210, 207)
This is a final year project I have to undertake for my aero-eng course!
I thought I would try this pool of experience!

:)

[jetfueldrinker]

Regarding the use of diesel engines in aircraft; to my knowlidge there are non. The basic reasons are that diesel fuel freezes and goes to candle wax at about freezing point of water, and of course, power to weight ratio of diesel engines is poor compared to petrol engines. I support MAF in some ways, and would like to be of some assistance to them, but I am committed to staying in thr UK for a few years yet (wife, kids in school etc.) Best of luck in your studies, and if you come across a diesel engined aircraft, please let me know.

JFD

[18Wheeler]

Yep, there are plans to use them, if they aren't being used already. I can't remember much more than that, unfortunately, but I guy email me to comment on my tongue-in-cheek ideas for an aero diesel engine, saying that he'd heard that there was a company somewhere in Europe (??) that was doing one similar.

[Cat1234]

I think it was Renault developing the engine, it was in Flight International about two years ago.

------------------
Curiousity killed it

[AVPIN]

jetfueldrinker:

Yes, diesel fuel may wax at low temperatures (if not treated) but JETA1 is ok down to about -40C (assuming no water content)
JETA1 may cause some injection pump problems if the lubricity characteristics are not addressed (AVTUR/FSIIwould probably be ok).

Lady Heath :

There ARE a few manufacturers of GA specificic diesels - I saw at least 2 at the PFA Rally at Cranfield this year - I remember one was a very clever 2-stroke design with 2 pistons per cylinder.
It might be worth dropping the PFA a line for some info - you should find their web-site with a good search engine.

Also saw a French homebuilt (Europa style)with a Vauxhall/Opel 1.8 turbo diesel installation - quiet, clean, good endurance and a very impressive climb.
The only drawback that I could see was the reduction drive for the prop.

[Windy Militant]

Lady Heath : Try the wilksch aeromotive web site
http://www.wilksch.com/
Saw the prototype at Cranfield it looks a useful peice of kit.

[Wide Body]

Dornier used a lot on their flying boats circa 19443

[Diesel Fitter]

Their was an outfit at Oshkosh called I think Delta Hawk or similar - I know they have a web site somewhere.

Better known is Zoche in Munich which you can see at www.zoche.de/diesels.htm (http://www.zoche.de/diesels.htm)

Historical note - there were many diesels in the 1920s - 30s - Maybach, Daimler-Benz for example. And Junkers had one engine used in many transatlantic airliners - a 2-stroke diesel capable of operating up to 50,000 feet in reconnaissance planes.

HTH
Diesel

[Kanga767]

As well as being an Automotive Diesel mechanic, I'm also an LAME on Aircraft from Cessnas to 737's. Firstly, Diesel engines for aviation use will/are run on JetA1, not the traditional diesel oil. The pumping elements/ rotary head depending on the engine is especially hardened to withstand the lesser lubricating qualities of Kerosene. And with the new electronic controls on a lot of the new 'high speed' Japanese/German diesel engines coupled with the advances in weightsaving, the engines are most certainly becoming viable. Bosch, who design the fuel system for the Porshe aero engine also design the diesel injection systems and are no strangers to the demands of design. The Japanese systems (Diesel Kiki and Nippondenso) work with similar systems.

[jetfueldrinker]

Well we learn something new every day! I didn't realise that there were so many developments going on. It is good to see that there is so much R & D about; it gives me faith in the system.

Just one point on a slightly different note; in the traditional piston 4 stroke engine used in aviation, generally a Bendix magneto is used as it produces its own electricity, so in the case of total electrical failure the engin can still run. But this system was designed aeons ago with, seemingly little or no development. Has a brakerless system, similar to that used in car engines been developed yet? Or is anyone working on designing one? I think that the benifits of this type of system (better quality spark, better fuel consumption, less maintenance etc.) should be available to aviation sa well as the motor world. What do you think?

[somefokker]

I seem to remember that the Germans used Diesel engines on some of their aircraft during the war. It might be worth following that thread to get some operational evaluations. Check out the Junkers Jumo 205D vertically opposed diesel which was used on the Blohm and Voss BV 138c-1, or the Jumo 211d-1 inverted vee type as used on the Heinkel He111H-3. Also some aircraft used the BMW 801D radial. Don't know if the "D" suffix means Diesel.
Try contacting the Imperial War Museum, or The Fighter Collection or Old Flying MAchine Company at Duxford.
Hope this helps,
SomeFokker

[Lady Heath]

Hello again all,

Thank-you for all your replies and help!! I posted this topic in the private and tech log forums but didn't get as good a response - I should have come here first!

I thought I'd let you all know of my progress so far:

-I have managed to collate data on 7 aero-diesel engine manufacturers all in competition to deliver their product to the GA market:
-Wilksch Airmotive, Deltahawk, Zoche Aero-Diesels, SMA Morane-Renault, Teledyne Continental, Textron Lycoming and Diesel Air.

-It appears very promising that GA will run on diesels in the near future as a/c are currently being run on 1930's technology!

-There are many advantages of using a diesel:

-engine burns fewer Ib/hphr & jet fuel has more Ib/gallon,
-easy to operate - one power lever only, no alternate air, aux fuel pump, magneto switches, mandatory temp, boost or power restrictions
-no electromagnetic interference due to absence of ignition system
-higher efficiency due to higher compression ratio
-fire hazard reduced as fuel less flamable than avgas
-V-4-design is stout and compact - advanced materials means it is at least 60Ibs lighter than equivalent piston engine
-longer TBO than any piston engine due to simplicity and reduced number of parts
-smoothness (greatly reduced vibration) due to the 2-stroke-cycle having 4 power pulses per revolution
-Durability since Jet A provides more lubricity and no electric system required
-Longer life and in the long term money will be saved on a diesel

I am currently looking at the disadvantages.

Getting all the data from each engine manufacturer is proving challenging but since Wilksch Airmotive has successfully test flown their diesel on a Europa SN-1 I will probably use this as a case study for a basis.
I will then have to carry out a design study of installation of the most suitable diesel unit into the most suitable MAF piston a/c considering its impact on weight, CG, physical installation, payload range, cockpit viz and look at the a/c changes required in order to accommodate the alternative fuels proposed.

Once again thanks for your help and enthusiasm - I will keep you all posted if interested!

BRGDS

Lady Heath

:) :)

[STOL]

I remember looking into this about 10 years ago when I was flying a C207 for a para club. There was someone developing a direct replacement for the IO 540 (can't remember who) which was designed to run on Jet A1. Not the waxing problems of diesel as previously posted. Huge saving on operating costs compared with Avgas equivalent. It seems to have died a death. Lack of funding?? With regard to original post I think it unlikely that one would be developed for the C208 as this is powered by a PT6 so no weight gain + higher required power so not so many commercial applications. Interesting topic and would be interested on info on current developments either on this post or by E-Mail. Diesel light twins. Way to go, as for the disadvantages I sure the chancellor would find some way of taxing it!!

regards..

STOL