Aviation Jet Fuel...Can it be used? - PeachParts Mercedes-Benz Forum

Greg Fragano · #1 07-08-2003, 01:48 PM

Aviation jet fuel is a refined diesel fuel, and I've been told that there isn't any top end lubricating properties associated with it. I have access to large quantities of waste jet fuel. If I were to mix it 50/50 with pump diesel, would I get enough top end lubrication? If I were to use 100% jet fuel and added, let's say, 16 oz. of Marvel Mystery oil for every 20 gallons of fuel, would that be sufficient enough top end lubrication? This fuel will be burned in a 1980 300D, non-turbocharged vehicle (110K). Thanks for your opinion in advance!

Greg Fragano
Dallas, Texas

Gilly · #2 07-08-2003, 04:26 PM

Use 100% Jet-A and dump the Marvel Mystery Oil in your left shoe. It'll run fine.

Gilly

rwthomas1 · #3 07-08-2003, 08:53 PM

I dunno, I have a buddy that was a diesel tech in the service. Apparently the military runs their "multifuel" diesels on something like jetA. He was always changing injection pumps. This may be a moot point with the MB pump as it is lubed with engine oil but I would add some sort of lubricity additive or 2-cycle oil just in case. If you were getting the fuel for free it would seem very inexpensive to dump a quart of something in the tank when filling up. RT

Gilly · #4 07-08-2003, 09:03 PM

Jet-A, Jet-B, Aviation Kerosene, Diesel #1, Diesel #2, It's all kerosene, it'll work fine.

Gilly

P.E.Haiges · #5 07-09-2003, 12:26 AM

RWThomas1,

Only the "crankcase " of the MB injection pump is lubricated my engine oil. The barrels and plungers are lubricated by the fuel as are the injectors.

GREG,

The only top end lubrication you have to worry about is the top end of you injection pump where the fuel lubricates the barrels ans plungers. So a little top lube wouldn't hurt since you get the fuel for free.

P E H

Maxwell · #6 07-09-2003, 12:31 AM

Just run redline, good idea anyway.

Dusty-NZ · #7 07-09-2003, 12:49 AM

I have a friend who has run Jet A-1 fuel drains in his 180b for many years (about 25 that I can think of ) and hundreds of thousands of miles .
The only problem he had was wearing out an injector pump because of the water in the fuel , but he has sorted that part of it out now and continues to get good performance and economy , as you would expect .

psfred · #8 07-09-2003, 12:57 AM

Hate to put a damper on this idea, but JetA is NOT kerosene OR anthing like #2 diesel, and I could not use it unless you cut it about like you would gasoline. I would also expect the same response as adding 20% gasoline -- lower power and smoke.

Kerosene is roughly the C8-C22 carbon length linear hydrocarbon "cut" from crude oil, diesel is roughly C12 to C34 including the aromatic fractions in that boiling point range. Diesel has some additives put in, kerosene does not. JetA is about C6 to C18 or so, if I remember correctly (I was trying to identify some hydrocarbon contaminant floating around after a flood, never did find out what it was, but it wasn't jet fuel). I'ts also mostly non-linear hydrocarbon. JP4, in case anyone is interested is "wide cut" gasoline -- C2 to C12 or so, crude distillate only, and in spite of someone insisting (rather strongly) that it is "military spec" I don't believe anyone still provides it.

JetA is considerably more volatile and is composed of mostly lighter hydrocabons, not the C12-C34 spec for #2 diesel, and I could guess has about the lubricity of gasoline -- in other words, bye bye injector pump. You will also have serious starting problems.

It's meant for use in turbine engines (read no high pressure injection pump) and must have a very low pour point (remember, it's 80 below F at 35,000 ft in the winter).

Nice thought, but I'd check with someone who knows fuels (like your local petroleum refinery) before you run it in an MB.

Peter

Gilly · #9 07-09-2003, 07:30 AM

Another name for jet fuel is "Aviation Kerosene" so it certainly is "Kerosene". It stinks like Kerosene (I've had the stuff running down my sleeves and soaked to my armpits in it, thanks to some leaky aircraft fuel valves of the "single point" variety, as I'm sure any former flightline personnel can relate to) so I can attest, it's just REAL nice Kerosene. Looks like it (kind of a straw color, as the fuel companies desribe it) and smells like it. Works great in these portable heaters, and we had customers (now I don't know if this was on-the-level or not for tax purposes) who brought in Mercedes (and one guy with one of those 5.7 Olds Diesels, this was in the mid-80's) for fill-ups of Jet-A.
I specifically didn't mention JP4 because I realize it is cut with Gasoline. I'm sure it's still made for the military in high performance aircraft. "Mil-Spec" can be applied to most anything, JP4 is different than JetA, but I think Uncle Sam is about the only customer for JP4, except for the handful of people who own their own fighter.
I'm no jet engine mechanic, but I can't believe there isn't a pretty darn high pressure pump in the fuel system somewhere. In the case of an airliner, I would think there would be several pumps involved in getting fuel from the wing tanks to say an engine mounted on the tail or rear of the fuselage.

Gilly

ps We also refuelled ground support equipment, such as aircraft heaters, tugs, and KVA (generators), that were all clearly labelled "Diesel Only" with JetA.

#10 07-09-2003, 09:58 AM

I spoke with an service technician at a local diesel fuel injection repair shop. He said that jet fuel is similar to diesel except that it is more refined. He said airlines run jet fuel in all of their ground equipment which has diesel engines. Because jet fuel is more refined than diesel, you will have to add a lubricity additive. This is what I was told by someone who appeared to know what they were talking about. However, I can't personally verify anything they said. I hope this helps.

Scott

#11 07-09-2003, 10:48 AM

I can't imagine that Jet A costs less than diesel fuel unless you plan on stealing it.

Have a great day,

mplafleur · #12 07-09-2003, 12:41 PM

The 2-stroke diesel that is being developed that I want to put into the plane that I am building is spec'd to run on Jet A (JP5) or #2 diesel. (with no additives)

adamb · #13 07-09-2003, 01:37 PM

The military has striving for a "single fuel battlefield" so as to ease logistical support. All diesel engines in the military, like the Chevy engine in the Hummer, or the new 7 tons and all the generators and other diesels, run on Jet fuel. They try to stick with JP-8, but they can run JP-4 or 5 in a pinch. I know that the military doesn't put any additives in this jet fuel, but the newer motors are designed such that they do not require as much lubricity as our old ones like the 617s. The fuel pump chanbers in the 617s definitely need the extra lubricity in my opinion.
I drove around Iraq as a FAC in a 7 ton and we often fueled up at FARP locations with the same stuff put in Harriers and helicopters, allJP-8 (same as jet a+). It is possible to get this for free, but you have to follow aircraft that are about to shut down and catch the return fuel that gets dumped out in a bucket after shut-down.
Have fun, Adam

psfred · #14 07-09-2003, 07:34 PM

Note that the MB engines are NOT multifuel vehicles!

A B52 will run on all sorts of fuel, but JP4 gives the best power and weighs less -- not that its safe to use or anything.

Jet A is NOT "more refined" kerosene, it's a different product, made up of different hydrocarbons. Some are the same, mostly the part you smell, but it doesn't have the same characteristics, and MB specifically recommends against using straight kerosene, let alone a ligher hydrocarbon mix. For one thing, a 617 won't start with diddly on it, and will be way down on power (less BTU per volume of fuel).

I'd check with MB or a diesel service before running the stuff, it's not worth a ruined IP.

Peter

Gilly · #15 07-09-2003, 09:21 PM

I still contend it is a member of the Kerosene family.
Here is a link:
http://auto.howstuffworks.com//question105.htm

Gilly