Adding Diesel to gasoline

[99LeCouch]

Interesting! Also, bio-diesel is a marvelous cleaner.

Hmm, this would be a fun experiment to do on a lawnmower, then on a slightly larger gravity-fed direct-injection engine.

To the OP: I'm awaiting your results! Keep up the good work!

[Frank Lee]

I haven't really played with adding diesel to a gasser, except for a few rare occasions of putting in a dab for "top end lube".

I have the impression from reading things like Smokey Yunick's work that anything oily in the combustion chamber promotes detonation. I have nothing to go on except the knowledge that diesel is oily, but I wonder if too high a diesel content in a diesel/gas blend would leave oily deposits behind? My thinking is the gassers don't have that nice super high compression and that nice super atomized in-cylinder injector, so the diesel might not combust as completely.

Were I to try it, I think I'd be watching the exhaust pipe, and periodically pulling spark plugs to see if things are getting dirty. Then I'd back off on the diesel or stop.

Which brings me to another guess; lawnmower engines- at least the old side-valve stuff I'm familiar with- have much lower compression than autos so I don't know how much knowledge would transfer over.

By all means play with it, though! There may be a benefit. Who knows, I haven't researched it at all.

[tasdrouille]

I've read that diesel is in the 15-25 octane range. Low grade D2 has an higher octane number. So if you fill 15% with D2 that would be say 25 octane, and 85% Premium at 97 octane, you get a net blend a tad over 86 octane. I'd be willing to try 15% diesel in my Elantra next summer. Not on a regular basis, but just to see how it works out. You could even safely run higher blends provided you keep your foot off the pedal a bit.

Bio Diesel has a very high cetane number, that would make knock matters worse.

That's right Frank. That's why if I would try it I'd crank the WAI as high as I can and keep the revs low to give the diesel fuel as much chance as possible.

[darcane]

Originally Posted by Old Tele man

...octane is a figure of merit of the gasolines' resistance to detonation during compression buildup...diesel doesn't have this problem.

...cetane is a figure of merit of diesels' ignition delay, ie: burning-rate under compression.

When you state "diesel" it helps to know if you are referring to diesel fuel or the Diesel engine cycle. Diesel fuel used in an Otto cycle engine certainly does have the problem of detonation and the octane rating is entirely relevant.

Octane is the rating of a fuel's resistance to detonation during compression. It is NOT strictly measuring gasoline.

Same with cetane. It isn't just for diesel fuel, it is for any fuel. And you should know the cetane rating of any fuel you put in a Diesel cycle engine.

Mike

[basslover911]

So ANYONE willing to test this out?

Buller.... buller...

[Christ]

There have been a couple eventual volunteers, and once I get the verdict on whether my Van is going to be totaled by the insurance company or not, I'll throw some fuel in my fuel.

I've put alot worse stuff in my fuel tank, a little diesel ain't gonna hurt nothin'.

[pgfpro]

I was going to try some in my work truck but I need to concentrate on my Hoonda fo now.

[Christ]

I should clarify - I"ll put diesel fuel in the gasoline tank of my Van before I pull it off the road and convert it to run on the OM616.

[The Atomic Ass]

Well, I'm game. Not this winter though, but in the spring when temperatures start rising.

The nice part about the Ninja is that the tank is EXACTLY (within 0.05 gallons) 4 gallons when it sputters out and you have to switch the petcock to reserve. Also, high-compression! 12.5:1

A thought occurs, however. I've heard that diesel is 7lbs/gal, while gas is 6lbs/gal. Would the 2 differently weighted liquids stay mixed for any duration in a gravity-feeding tank? I figure in a looped FI system, the fuel pump will mix the two while it pumps, but I don't have that benefit in the Ninja. Thoughts on this?

[Christ]

They're of differing viscosity, as well. Good question. I guess I'll have to get a glass jar and put equal amounts of both fuels in it and see if they stratify.

Hmm.. if fuel/water emulsion is good, and fuel/gas mix is good, is fuel/gas/water emulsion even better? We may never know...

PS - You're really going to try it on the Ninja? Don't get me wrong, I don't think it's a bad idea, but I just didn't see anyone wanting to try this on an exotic-type engine.