Adding Diesel to gasoline

[asimmons04]

Originally Posted by tjts1

You don't need to be insulting just because you think you're right. And yes, you are advocating for it.

You need to clearly specify:
There is NO evidence that there is any FE benefit here
This DOESN'T work on EFI engines which makes up 99% of the vehicles on the road today
It HAS NOT been tested on emissions controlled vehicles.
There are UNKNOWN long term consequences of putting diesel fuel into a gasoline engine in any proportion.

EFI engines actually probably handle SLIGHT mixtures even better due to the fact they can sense knock, rich/lean mixtures in exhaust, and can adjust fuel input, as well as ignition timing and in newer cars even intake/exhaust valve timing.

NOW, I know you guys dont know me but I'm going to put your mind at ease before I go into some detail. I have a degree in automotive machining. My knowledge, what little I have, seems to fill a hole in the wealth of information you guys have. Your all actually right.

Diesel actually, if you wanted to compare apples to apples, has MORE detonation resistance, which in gas, is rated by Octane level. So yes, it would in theory RAISE your octane level. If diesel had a "low octane" rating, per say, they would not be able to run 14:1 or higher compression. YES, Diesel engines are compression ignition engines. But the fuel allows for it, producing more torque when its all said and done... What do you do when you build a race engine with 12:1 compression? You need a fuel that will NOT burst into flames too soon at that pressure, so you go HIGHER burn resistance, be it race gas (110 octane?) or Methane, or...Ethanol based fuel. E85 actually is about 110 Octane... but only a car designed to be able to adjust valve timing, and advance ignition timing far enough, can actually run it (flex fuel cars) which brings me to your diesel theory...

I'm staying out of the Carb'd discussion because with the right tuning equipment, you can manually adjust a carb'd engine to run on anything that makes fumes. You adjust everything from the ignition to the air/fuel ratio and idle, all that. But in an EFI.... lets break it down...

You run 10% diesel in your gas mix. OK here is what happens.
The mix is sprayed in, the gas ignites, igniting the d as well. The D burns slower, much like 110 octane gasoline. The engine will sense the extra unburned fuel in the exhaust. Your ECU will adjust several ways. It will either spray less fuel because it thinks its running to rich a mixture, and you will save fuel but lose a little power due to less actual fuel (energy potential) being in the cylinders. That is ONE way.
Another way your ECU may adjust is to keep spraying the same amount of fuel and just increase the ignition timing. If you have a TBI setup you may have a distributor and I'd suggest running your 10% mix a couple miles then advance your timing a little. You'll not save fuel if you or your ECU does this, but you may gain a little hp. It will be like running higher octane fuel and advancing your timing a little to adjust, in an old school car, except your ECU can do this for you. NOW... Here is my suggestion...

The 10% or whatever mix would work BEST for you in one of two situations.

Either you have a Flex Fuel car that can run on anything from 87 to 110 octane (e85) and your car can SERIOUSLY make good use of that extra ignition resistance (octane, per say) just as it would on E85. But without the alcohol hehe. Plus, nobody around here even sells E85 so yeah. You could have your own sortof mix.

The other scenario to BEST get a benefit is if you have EFI and you put your mixture in, drove it somewhere to get it good and in your fuel system, and get someone to redo your ECU tune WITH THAT FUEL IN IT. It would actually recalibrate your entire ECU setup to run that type fuel if its within engines adjustment ranges, and your car can make the best power/economy from it.

Now at low percentage mixtures I'm pretty certain even a regular EFI car would have some sort of way to adjust for the mix. I just put the above two as the BEST CASES. What would be really awesome is a Flex Fuel car with a custom tune, simply due to the fact they have Variable Valve Timing, as well as the ignition timing and all the other junk, plus direct injection.

You might COULD run a 50/50 mix in one then. Not sure.

ANYWAYS I am just adding to what you guys have already stated. Your all pretty awesome. And any google search telling you Diesel is more prone to detonation is an idiot. Pour gas on something, and throw a match. Do the same with diesel. See the difference. LOL I could get into the actual specifics of how diesel actually has a higher burn resistance "octane", but thats not as fun as burning stuff.

[asimmons04]

forgot to add this.

probably best to reset your ECU when you change fuel mixes. That forces your ECU to relearn a new fuel map for the new mixture. It will learn what mixtures to use at what load/rpm/temp, etc.

If nothing else, pull the battery cable off and attempt to start the car for a moment to clear it out.



if anyone wants to email me anything,

66mustangdriver@gmail.com

I also work at OReillys Auto Parts...so I can likely get some good info from companies or our tech data at work. So yeah. Feel free to shoot me a message sometime.

[Frank Lee]

Originally Posted by asimmons04

Diesel actually, if you wanted to compare apples to apples, has MORE detonation resistance, which in gas, is rated by Octane level. So yes, it would in theory RAISE your octane level. If diesel had a "low octane" rating, per say, they would not be able to run 14:1 or higher compression. YES, Diesel engines are compression ignition engines. But the fuel allows for it, producing more torque when its all said and done... What do you do when you build a race engine with 12:1 compression? You need a fuel that will NOT burst into flames too soon at that pressure, so you go HIGHER burn resistance, be it race gas (110 octane?) or Methane, or...Ethanol based fuel.

ANYWAYS I am just adding to what you guys have already stated. Your all pretty awesome. And any google search telling you Diesel is more prone to detonation is an idiot. Pour gas on something, and throw a match. Do the same with diesel. See the difference. LOL I could get into the actual specifics of how diesel actually has a higher burn resistance "octane", but thats not as fun as burning stuff.

Originally Posted by gizmag

Because it’s less reactive and won’t burn so easily, gasoline could normally never fuel a diesel engine. However, the fuel-injected diesel becomes a kind of liquid spark plug, providing a kick-start for ignition.

Diametrically opposite... one must be wrong.

To run a Briggs and Stratton on kerosene requires LOWERING the compression ratio- they stack two head gaskets.

Smokey Yunick says any oil that gets into the combustion chamber causes detonation.

All three of these things indicate oily stuff as having lower detonation resistance. I'm gonna go with U of W, B&S, and Smokey being right.

[tjts1]

You've got to be kidding.

Originally Posted by asimmons04

EFI engines actually probably handle SLIGHT mixtures even better due to the fact they can sense knock, rich/lean mixtures in exhaust, and can adjust fuel input, as well as ignition timing and in newer cars even intake/exhaust valve timing.

Do you know the difference between octane and cetane? Why don't you go look that up.

Originally Posted by asimmons04

NOW, I know you guys dont know me but I'm going to put your mind at ease before I go into some detail. I have a degree in automotive machining. My knowledge, what little I have, seems to fill a hole in the wealth of information you guys have. Your all actually right.

Could have fooled me.

Originally Posted by asimmons04

Diesel actually, if you wanted to compare apples to apples, has MORE detonation resistance, which in gas, is rated by Octane level. So yes, it would in theory RAISE your octane level. If diesel had a "low octane" rating, per say, they would not be able to run 14:1 or higher compression. YES, Diesel engines are compression ignition engines. But the fuel allows for it, producing more torque when its all said and done... What do you do when you build a race engine with 12:1 compression? You need a fuel that will NOT burst into flames too soon at that pressure, so you go HIGHER burn resistance, be it race gas (110 octane?) or Methane, or...Ethanol based fuel. E85 actually is about 110 Octane... but only a car designed to be able to adjust valve timing, and advance ignition timing far enough, can actually run it (flex fuel cars) which brings me to your diesel theory...

Do you have any idea how a compression ignition engine works? Diesel engines only inject fuel directly into the combustion chamber at TDC after the compression stroke precisely because the fuel has a low octane. Diesel has an octane number of ~20 depending on where you buy it. It is very prone detonation. Don't believe me? Look it up.

Originally Posted by asimmons04

ANYWAYS I am just adding to what you guys have already stated. Your all pretty awesome. And any google search telling you Diesel is more prone to detonation is an idiot. Pour gas on something, and throw a match. Do the same with diesel. See the difference. LOL I could get into the actual specifics of how diesel actually has a higher burn resistance "octane", but thats not as fun as burning stuff.

Detonation due to compression and flammability are 2 very different things. I'm surprised you don't know that.

[UFO]

wow

[mikehallbackhoe]

if I remember right, on a site called mpg research a few years back, someone tried mixing 10%diesel with gasoline. it didn't save them any money, so the idea was dropped.

[Christ]

Originally Posted by Frank Lee

Diametrically opposite... one must be wrong.

To run a Briggs and Stratton on kerosene requires LOWERING the compression ratio- they stack two head gaskets.

Smokey Yunick says any oil that gets into the combustion chamber causes detonation.

All three of these things indicate oily stuff as having lower detonation resistance. I'm gonna go with U of W, B&S, and Smokey being right.

I'm not reading the entirety of this thread, but what Gizmag said is completely incorrect. If a diesel engine is running, it WILL run on gasoline. Most will not start on it, because the fuel has too low of a viscosity to create the proper pressure using the injection pump.

I've personally run my VW IDI (basic IDI design) on gasoline for about 20 minutes to get to a diesel filling station. Once I shut it off, I had to purge the gasoline from the fuel line and bring diesel up to the pump in order to get it to start again. (This is done, in this case, by cranking the engine).

The pumps are lubricated by excess fuel flow... gasoline will not lubricate them properly. Doing this long-term = bad idea.

I've done the Kerosene thing, too... one stage hotter plug, double the head gasket, and some manuals ask you to tune the jet in the carb, as well, though I can't remember which way (and have never had to do it).

I've gone so far as to have a 70's 3 horse briggs running on 50/50 gas/kero without modifying the engine, just changing the spark plug and turning the idle screw up. It was hard to start, and seemed to run a bit hotter, but seemed equal in working torque and power, as well. It's not even close to "cheaper" to do this anymore. However, if I could get one to run on used engine oil/trans fluid, that'd be sweet.

[lindsayjim]

Update: My van is still running well, performance numbers the same as last year's report. Replaced OEM oxygen sensors at 125,000 miles, still on the OEM cat. Have not blown up yet ... although UFO's concern is noted and it is a legitimate concern, at least at low ambient temperatures. I have not done the calculations so I'm keeping the fuel pump submerged and considering static discharge when fueling. Probably should do the math and see what the critical temperature for reaching a combustible mixture in the closed vessel actually is....

FourBinLabs: What were your test results?

[lindsayjim]

Opps .... Sorry Mort it was your post that I just mistakenly attributed to UFO ...

MORT is correct about the partial pressures .... !

[bandit86]

If you google octane booster it is 99% kerosene. Kerosene is similar to diesel. Octane booster calls for 1% to bring up octane rating b 3 points. I ran 30 percent in my discovery, the truck did not like it. At 10% or under it runs nicer, better, does not ping at all.

Funny, I had this topic posted 3months ago and the replies were full of nay Sayers who never tried it.