Oh, NOOOOO! SNAFU: Diesel in a gasser

[N1VSM]

So, the local Nat'l Guard borrowed my M37 for the 4th parade. They had a great time with it, carried veterans, pulled a trailer, etc. I was happy that they could use it, as I was out of town (about 2500 miles out of town) on the 4th. They were so appreciative that they topped off the tank before they returned it. They put in about 6 gal. of Diesel, because in the Natn'l guard kid's experience, everything Military is Diesel.

The snag is that my truck has the original 230 in it. The tank already had 15+ gal of gas in it. I do have a filter between my gas tank and electric fuel pump.

In this potenitally nasty state, it was driven 1-2 miles without complaint. I plan on draining the (full ) tank & draining the fuel line.

Questions:
(1) Which is more dense, Diesel or gas? If gas is more dense (which I doubt) I am in luck!
(2) what can I use flush out the tank, pump and lines?
(3) Is there any chance I my carb suvived this unscathed? How can I tell?
(3a) If not, how do I rescue my carb?
(4) Same as questions 3 and 3a for my engine.

Oh, well. the 230 needed a rebuild anyway.

The upside of this is that the Natn'l guard may be able to get me a T/O Diesel engine. Hmmm .... stay tuned.

[Lifer]

Hmmm! A multi-fuel M37!

When they put the diesel fuel in the tank, it got diluted by the gas already in there, and I doubt that there's enough to damage anything. It may be a little harder to start, it may have some loss of power, and it will smoke a bit, but it shouldn't do any real damage.

Draining it and putting in fresh gas will make you feel a lot better, though, so go for it. Just don't make the poor reservist feel too bad about his screw-up.

[hbb]

As lifer said it will not hurt a thing except smoke a lot and be low on power. as for power you might add some octane booster if you feel the need but the best is just drive it 40-50 miles and keep the cylinder temp up and refuel with a little higher octane fuel to further dilute the remaining diesel out of the gas and all will be good. An overhaul or replacement by the Guard Unit would be something I would not pursue at this time.

hb

[N1VSM]

I'm certainly not stressed about it. Come to think of it, I'm not stressed about much (or in denial). I'm sure the Guardsman was more embarrassed than anything, but I certainly won't demand anything of them.

I was just a bit nervous since it was my impression that diesel kills gassers, but I suppose that applies most for new fuel-injected cars and not as much to a 58 year old leaky 230.

Any dissenting opinions to just toughing it out?

[MSeriesRebuild]

I'm certainly not stressed about it. Come to think of it, I'm not stressed about much (or in denial). I'm sure the Guardsman was more embarrassed than anything, but I certainly won't demand anything of them.

I was just a bit nervous since it was my impression that diesel kills gassers, but I suppose that applies most for new fuel-injected cars and not as much to a 58 year old leaky 230.

Any dissenting opinions to just toughing it out?

I wouldn't worry about it, now if it were the other way around, (gas in a diesel), you would have a serious issue. Just keep topping off with fresh gas, you'll soon overcome it.

[k8icu]

You basically have 2 stroke engine fuel now... Gotta Lawnboy that needs gas? I agree with everyone above put fresh in it and drive it all will be good. The luck was that it was like 15 gals of gas and 6 diesel...if the ratio had been closer like a 50-50 mix then I'd be saying drain it and start fresh.

Oh and make sure you stencil the fuel opening MOGAS or GAS or GASOLINE ONLY...

[Rick C]

Charles said it best. Gas in a Diesel is a BAD situation but my buddy put diesel in his chevysilerado and drove it like that until next fill up. Smoked like crazy but it survived.
Rick

[Cal_Gary]

I recommend at a minimum draining out the tainted fuel and refilling with fresh gas. Diesel engines run with a compression ratio of 22 and 1/2 to 1 in order to fire the diesel fuel. I once saw a MUTT head split right down the middle because some dud dumped 5 gallons of diesel in the tank during a night march-too much strain for the 4-banger to handle.
Gary

[m15256]

Your 230 flat head isn't developing enough compression for the diluted diesel fuel to fire. You're just burning oily gas. You'll probably have to clean the spark plugs soon. Don't worry about it.

[Teoma]

If anyone else experiences this kind of dilemma(I assume that it has been resolved by now) diesel fuel is essentially oil. The downside is that it will lower the octane rating of your fuel making your engine more prone to detonation. With modern gas and the low compression ratio of these flatheads, a 25% diesel mix shouldn't be a problem. At worst, you may have to retard your timing a bit.
The downside is, as some mentioned, your engine is going to be smoky and I wouldn't recomend hauling heavy loads until the contaminated fuel works it's way through the system.
Now gasoline in a diesel engine creates an explosive situation ie a 6 cyl diesel running on gasoline is potentially a six cylinder grenade

[pfrederi]

Brings back memories...
We had an M151a1 in the motor pool that wouldn't start. it would pop and stutter but not start. Typical motor pool approach throw parts at it till it worked. New plugs, points...nada. Motor Sgt figured it had to be the oil pressure safety switch. Whilst they were replacing that I stuck a stick in the gas tank to make sure it had fuel...after a few minutes I realized the stick was still wet/oily. More research revealed some rocket scientist had put DF2 in. Siphoned out most of the tank and refilled with MOGAS. Still had to crank for ever to purge the fuel line and carb but then she fired up and ran fine. No lasting impact.