Diesel Plus Gas

Just thinking about it I don't think that sounds like such a good idea.

I'm thinking preignition, detonation scenarios.

I could be wrong though. My dad told me he had a Deusenberg that, due to it's high compression, would run on diesel after it was started on gas and run a while to get up to temp. He had to remember to switch it back to gas and run it a while before shutting it down and it smoked badly during switchover. He used a 1 gallon tank on the firewall for gas with a dual-tank switchover valve and put the diesel in the main tank. He didn't say much about the mileage except that diesel was cheaper than gas then (great depression era).

Diesel was cheaper than gas up until the '70's or so when GM, Volkswagon and a few others started putting diesel engines in passenger cars to burn "cheap" diesel fuel.

Demand went up, cost of diesel fuel went up, it cost trucks more to fuel up hence it cost more to ship goods by truck, hence the gost of goods shipped by truck went up.

Then the use of diesel in cars dropped off but the price never really went much below gasoline.

Now it does make sense to use diesel engines in cars, not because of "cheap fuel" but because diesel vehicle will generally get better milege than a comprable gasoline powered car.

As far as running a diesel on a mix of gas and diesel - I wouldn't try. If you are getting poor milege I'd first suspect a plugged fuel filter, fouled plugs, plugged air filter or perhaps it's cam shaft(s) have gotten out of time.

Travis

A conversion not for the faint-of-heart (OR the weak -of - wallet). Have heard many tales of severe engine damage caused by erroneously pumping petrol into the tank.

Problem is: Petrol "octane#" rates resistance to 'pre-ignition' (a RESISTANCE to ignition from heat + compression), whilst Diesel's "cetane#" rates the fuel's ABILITY to initiate combustion under very much the same conditions. Very much the opposite requirements.

In Otto engines burn rate is controlled by speed of flame front propagation, in Diesel, by rate of fuel delivery.

I have read of this it was quite common in the fifties. Charles Taylor's textbook(s) 'Internal Combustion Engine Design and Practice' has a section describing the ins and outs and theory behind it. Yes it did give better miles per gallon and cleaner exhaust. Down side was the extra complexity of metering the gas. I don't know how well it would work with todays common rail computer controlled injection since it is no longer a case of pumping extra fuel in for more throttle opening....

Quite possibly your Isuzu truck need a bigger engine or the valve timing varied to suit your requirements better.

I`m not so sure about the Diesel but..... Kerosene seems to work just fine.....and is even cheaper. Gasoline is used to start the engine and afterwards switched to kerosene. It is often used in outboards from Yamaha, and Honda has also generators that work on the same principle. My dad found it out by accident when my little brother put kerosene instead of gasoline in his old Toyota Hi-ace. He did not notice anything weird until he wanted to fill up the lamps and found the Kerosene jerry can empty and the gasoline jerry can full.....(some background info, He`s a farmer and there is no electricity where he lives) anyway the Toyota still runs today and.... it is often fed some kerosene..

Be careful with the Kerosene. It does work as a fuel but it is much dirtier than diesel and in most states they will give you a nasty fine if they catch you using it in a vehicle. It is a popular trick for truckers who are trying to cut down fuel costs (not that I blame them at this point).

I would expect that the major issue with using diesel (or Kerosene) in a gas engine would be the timing of the ignition. The diesel is very likely to explode early in the compression cycle, leading to a case of really bad knock. In the case of a very hot cylinder it could even ignite during injection and that would be VERY bad. This will reduce the efficiency of the engine and probably induce significant wear and tear on the whole system.

Diesel and Kerosene both have a higher energy content than gasoline. Is the loss of efficiency due to poor ignition timing greater than the gain by using a fuel with a higher energy content? I am not sure. I am pretty sure that doing this will void any warranty the vehicle has and it is very likely to screw up any form of high performance engine that is out these days.

You may get something like this to work on an older vehicle, but I wouldn't bet on it being worth the money.

Good luck if you try it and please report back any results.

-Doug

It is true... Diesel Ignites in an untimely manner in a gas engine....

A friend of mine accidentally pumped Diesel in her VW Jetta..

The engine was running almost exclusively on detonations out of time and after purging the tank and the engine.. It always ran with a clonking noise ... She had t get rid of the car ... the repairs were too expensive ...

I think it would be easier to replace the gas motor for a Diesel Motor

I am stipulating that Gas = Gasoline and that the original poster meant to add a mixture

of Diesel + Gasoline to a Gasoline Engine (4 stroke Otto Cycle).

My above observation describes what happens when you run a Gasoline engine with Pure Diesel. Thats the bad extreme... But it leads me to believe that a Gasoline+Diesel mixture in other ratios cannot be good for your gasoline engine.

From Previous posts I gather that such a mixture in a Diesel engine may be ok.

PS I see why the question:

a ) If Diesel Packs more energy than gasoline,

b ) and hypothetically, for some reason the ratio of a Gasoline-Diesel Mixture made it impossible for the diesel to be ignited by pressure alone in a Gasoline engine.

We might have some sort of efficiency improvement.... But I would be very nervous to try it.

The unknown being point " b) "

You are "Barking up the wrong tree!!"

Wrong sort of Gas, we are talking Gaseous not Petrol!!

Hi Aussiviking

I assume you are Australian where Gas means LPG.

Just google "Diesel gas "

Lots of info available.

Sthatty

Just not a great idea. Too many possibilities for problems as listed by others in this discussion. I've had to fix several vehicles over the years when someone tried this and it caused engine damage.

Here's a point: It's almost always someone who knows someone who's done something like this and it works great. Very rarely, the person who's done it is the "direct contact".

It's just like UFO's never appear over Yankee Stadium during the 9th inning of a New York/Boston baseball game; it's always some lonely deserted rural road miles from civilization.

I remember being on a jobsite where somehow, some gasoline ended up in the fuel tank of our boom truck. When it was started up, the gasoline/diesel mix created such heat that the chrome exhaust stacks turned completely blue and the pistons melted to the block. Needless to say, that was the end of one detroit diesel.

Okay my first response is no you would lose milage. Gasoline is 115,000 BTU per gallon, diesel is 130,500 BTU per gal. However others seem to have heard this myth ,so I am interested if anyone can explain how you would increase your mileage.

The only thing I can think of is , I've heard under certain circumstances an extremely high ratio of diesel to gasoline, can can result in a class a explosive. This of course could give a whole new meaning to the word detonation where a diesel is concerned.

http://bioenergy.ornl.gov/papers/misc/energy_conv.html

http://yarchive.net/car/diesel_mix_expl.html

I ran out of time while adding the citation on the dangers of mixing the two fuels, seems the rumors I've heard have some validity. I would at least research the potential dangers before undertaking this endeavor.

The prize is already claimed for a private space launch, attempting to orbit your diesel pickup will not gain you any money, and probably result in a Darwin award.

G'day, AV.

I've just read the replies and one thing is troubling me - the guys from the US are thinking gasoline and I think you have in mind gas ( gasseous fuels) LPG (propane) LNG ( liquified natural gas) and the like. Diesel engines are routinely made run on LNG. they are converted from diesel by a fairly intricate process which converts them to spark iginition. The gas tolerates very high compression ratios. Nearly all city buses here (main cities anyway - Syd, Bris, Melb) use LNG or CNG as there is a huge dividend in the reduction of harmful emisions, certainly no carbon particulate (soot).

Maybe it's this process the blokes were thinking about?

Cheers,

Stu.

Seems to me there's little doubt he's talking about gasoline, however you could be right.
Not sure what you meant by is that a Chrysler in my avatar, but there's a 440 sixpack nozzled in that desert bird. And you're right compressed natural gas will tolerate a lot of compression, I've seen some articles on guys using it in dragracing and having very good luck with it.

PS. He types with an accent, picked up a couple of words in his posts that are not commonly used here in the US , so you may well be right, he may not be talking about gasoline hopefully he'll clarify this for us.

Stu's right, I immediately thought "petrol" on this one.

Also saw a comment on "Kerosine", in other parts of the commonwealth that would refer to "paraffin"

The conversions of diesel to CNG or LPG that I have heard of involved injecting the gaseous fuel into the intake manifold and enough diesel fuel was used to ensure ignition. There was no switchover to spark ignition. Do a GOOGLE on the topic and you should find several companies that either do the conversions or supply the parts.

I have even heard of such a technique being used on LNG tankers, the "boil off" from the LNG tanks would be used to supplement the diesel fuel to the engines but the engines were conventional marine diesels capable of running on diesel alone when there was no LNG 'boil off" available.

aussiviking,

You may add about 5% gas to diesel and experience a slight; may I emphasize slight performance improvement especially in cold weather. However I recomend against such activity due the consequences far out weigh any benefit.

If it were a good idea I'd expect it would have been discovered sometime during the past 100 years and become a highly recommended method today by diesel engine manufacturers.

I recall a show on cable not too long ago that made mention of propane injection for diesel engines. this would boost performance similar to NOS in a gasoline engine.

I am sure that this is along the same lines as a permanent injection system. There should be aftermarket companies like Banks or Bully that would have a commercial system.

I wonder, though, if you have the same issues with chemical resistance of the fittings and gaskets that you do with NOS. would NGas or propane be corosive?

I assume that Gas as in Butane and Propane was meant, not petrol....

I did Google this a long time ago and it would appear that in India, some Diesel Buses have been converted to running on Gases such as Butane & Propane. How I am not aware.....but it would appear that mainly large diesels can be converted, I have as yet not heard of a small diesel being converted.....but if it has been done, I am sure that someone on CR4 can provide a proper link to a website!!

Andy,

ALL diesels can be converted. Our cities are full of gas fuelled bus engines, and more are coming on-line every day. Some engine companies offer LNG, CNG, ex factory. Some are more difficult, read more expensive, than others to swing over. The mainstream population doesn't get involved because most of them don't really care about the planet. Only their wallets.

I founded and owned a Company which did gas-fuel conversions.

Cheers,

Stu.

Hi Stu! Hope you can add 'more light than smoke'; i'm (now) assuming that that the gaseous fuel conversions spoken of would consist of the previously mentioned admixture of fuel gas + air, at a level below the lean limit of combustion, then ignited with a small injection of diesel fuel to bring combined charge to combustion.

Have always wondered what would result if the "carbueretted' fuel were an alcohol, instead. Purpose to be: cool by (latent heat) evaporation, allowing more compression, still, while reducing NOx emissions.

Additional benefit: no high pressure vessels on a moving vehicle.

Comments solicited!

Cheers,

Don

They used to run Model T Fords and Deere farm tractors on distillate (kerosene) which is not so different from the blend you propose. Also the Waukesha-Hesselman, a spark-ignition distillate engine. Low compression is the key, but it is hard starting in cool weather so lots of the old farm tractors would be started on gas and switched over to distillate. The Model T's had a four to one compression ratio so could handle the kero, but a modern high compression engine would not handle it very well. Besides, Diesel is more expensive than gas so you would have to get a pretty sizeable gain in mileage to make it cost effective.

The first tractor I ever drove with 12 years old was just such a beast, petrol for starting and stopping, paraffin for running when fully warmed up!!

Even in warm weather it would not start on paraffin!!! You had to drain the carb and get petrol into it first!!

Funny but also serious. Thanks.

Cottonmouth,

Good answer.

I like your soap box. Most people can not think for themselves. If the media was not behind Obama he would still be sitting in church listening to his pastor rant and rage on the white establishment in the US. If the oriental people and the hispanics have integrated into the US so well why are some blacks still struggling? Is it us or them that have the problem? With so many good blacks in the US, sooner or later they will tell the whiners to shut up, get rid of the chip that is on their shoulder and get to work making yourself better - like we all have to do. Now I will get off my soapbox.

You failed to mention Ron Paul. I love that guy. I really wish he were not so maligned.

You have an agreeable Texan here. Don't worry, it'll pass.

Hi,

If you contact Alternative Engine Technologies Pty Ltd 1300 LPGLPG (1300574574) they can do it for you.

One cuntomer got a 32% cost down on country driving, on average a $15000 installation. Its a patented technology and Aussie owned.

www.alternativeengine.com

Ben

Peter,

A different twist on your question - Diesel fuel added to a petro (gasoline) engine in small quantities is helpful. My dad on his gasoline powered tractors would add a quart of diesel fuel to the 300 gal tank. He claimed this would increase upper cylinder lubrications.

Another chap told me to add transmission fluid to the crankcase just before changing oil. The additives would clean the engine's insides. I don't do either now days but they seemed like good ideas.

Russ

It is not a good idea. it is true that diesel engines have better milage and higher torque per liter of fuel but it is due to higher energy content of diesel and a more uniform burning habit of diesel fuel. The engine works on different principles such as compression ignition versus electrical ignition in gas engines. You might want to try changing your engine and transmttion if your car is very old and mechanics in your country is cheap. else just sell and buy a diesel car...

I do believe that JP-10 jet fuel was a mixture of #2 fuel oil (diesel) and gasoline plus a few other additives. I don't know the ratio's of the mix. A very volatile mix. I think the aircraft industry has gotten away for it to a great because of it has a very low flash point.

Back in 1980 I bought a Chevy wagon with a diesel engine. In the winter I'd mix about 10% gasoline with the diesel to prevent fuel from turning to gel. The performance of the engine did increase and I did blow up the engine and broke a crank shaft. But it took a few years.

I believe the gasoline molecules will fit between the #2 oil increasing the BTU/gal output and increasing the flammability.

When I was a kid I'd take kerosene and add it to my carburetored engines gas tank. The car ran very poorly.

I do not understand why people believe that adding petrol to a diesel tank will increase performance, the energy in petrol is lower than in diesel.....so a small performance loss would have been more likely to my mind. Probably only a few % though.

What is far more important though is the loss of lubrication, this means that the diesel pump suffered most. I never added more than 5%, carefully measured too at each and every fill up.......

A diesel engine with a lot of petrol (my wife did this many years ago!), runs far too hot and ejects its cooling water eventually!!! I do not know the percentage exactly she managed, but probably around 66% (maybe more!) petrol is what she had....

I had to fit a new cylinder head (due to a crack caused by the overheating), but after filling up fully on diesel correctly, adding a pint of lube oil (for the injectors and injector pump) and also refilling the cooling system with water, she was able to drive home first about 100 miles.

The engine was still going strong 200,000 kms later when we sold it!!

There have been available much better additives around since the 80's to keep the diesel flowing and of course, a diesel pre-heater fixes the problems even better.

Nowadays in Germany, after October we get ONLY winter diesel which is good down to -22°C, but most cars have the heater anyway, so even if it got colder, it would not matter......

I do not understand why people believe that adding petrol to a diesel tank will increase performance,

The comment pertains to the way gasoline inhibits gelling of #2 diesel and at the time was cheaper than other additives for that malady.

I was speaking about the claimed performance increase, so please read the post that I was answering as well.....it was not written in Russian!

Yes the performance increase is inherent to the fact the fuel may not gel and may perform.

Actually, if the gel does happen, then you are right as the "gelled" engine will not even run!!

The actual performance claim was that it ran faster than with just diesel, but I think not!!! Someone was just kidding themselves!!

JP-8 (the current military jet blend) and Jet-A (the commercial version) are essentially kerosene with additives to reduce static electricity, corrosion, and absorption of water. The actual blend is refinery cuts taken at a specific point in the cracking process. A specific range of cuts (different temperatures) gives you a specific blend of fuel (gasoline, kerosene, diesel, etc.).

If it is LPG you mean it is used by a few in New Zealand with commercial kits available.

Rex Dev.

Look at this site:

http://www.dieselsecret.com/

It has a method for making very cheap fuel for diesel engines without a complicated process. It has their additive, a 5% gas content and used cooking oil plus a cetane additive. I forget what else. It actually seems to be a good alternative to the high price fuels.

Yes, they are selling something, but it is not a scam like the water to fuel schemes which are basically telling you commonly know tuning and other procedures which you can find readily on the 'net without spending any money.

I have a good friend who runs his diesel generator on it. He likes the smell of it much better than the diesel!

good luck!

Hello Bill,

My uncle runs this and swears by it, but I'm leery of anything he is involved in

By not removing the glycerin, this is not bio diesel, but what are the BTUs compared to diesel?

Brad

This comment brings into question something i had not previously thought: how ugly ARE the residuals from the manufacture of "bio-Diesel"?

Many chemicals are involved.

sidevalveguru,

The simple version is: oil + sodium hydroxide + methanol + water = Bio Diesel + glycerin + water with traces of methanol. The glycerin is usable from soap to perfumes, the water is reusable. Bio Diesel has a environmental impact of table sugar in its finished form. The rest depends on the person doing the esterification.

When you filter out the used cooking oil is the worst of it, if you do your home work and do it right.

Brad

The glycerin is usable from soap to perfumes,

Not only that glycerin is hypophilic, its is quite extensively in the baking industry to keep its products moist.

phoenix911

International harvester built tractors that were dual fueled and they worked very well. We would start them on gasoline and when the cylinder heads were hot and the exhaust manifolds were warm enough you could switch over to the main fuel tank which was filled with kerosene in winter and fuel oil in summer. Ran well and plowed many fields with the combination fuel tractors. IHC M, IHC H, both were called farmalls.

Basically the exhaust manifold had fins that projected into the intake manifolds and heated the incoming air fuel mixture to vaporize the fuel for combustion. Upon shut down we would switch to gasoline to flush out the heavier fuel to start the tractor again later. Fuel bowl had a quick drain if you forgot to change over. Magneto ignition and crank start so if you forgot to change over you knew it quickly.

As for increase in mileage I don't think a modern car would be able to make the conversion to diesel operation. If the car was carburetor equipped then it would be possible. but, very expensive and you could buy something else diesel equipped for less.

I have never been able to mix gasoline and diesel and get good results. I have had good results on running on drip gas from the many pipelines that crossed our mountain when I was a kid in W.Va. Another way to cut the cost of transportation in the days gone by.

When you add gas (and I'm guessing that you mean gasoline or petrol, not gas as in LPG etc) to diesel you have to add the extra volume and therefore energy to your calculations. So, as I read your question, if you add, say, 10% gas to diesel you must base your mileage calculation on 1.1 litre of fuel, not one. Also the difference in calorific value and price per litre should be considered to see if the cost per mile is beneficial.

Gas as in Gaseous and LPG, not Gas as in petrol.....sorry......just read the whole Blog through, many others have made the same mistake, it shows that using the wrong terminology (as most US Citizens do in this particular case in hand), can cause misunderstandings!!!

When I was a just a newbie in the business I remember looking into a carburetor throat and wondering about the statement. Then My Dad explained that a torch in English manuals was a flashlight. He went on to tell me that a lift was an elevator, a boot was the trunk, etc. Always wondered if someone would really put a lit torch into a potential explosive atmosphere.

If they could find one, I'm sure they would - fortunately, torches are in rather short supply these days. They'd probably grab the nearest flashlight thinking "I sure hope this will do instead..."!

& you don't have a 'blue tipped wrench (spanner)' handy while working on vintage projects?

How do you manage?

Consider where you heard it............in a bar.

My brother in law had an old Volvo marine engine which stated it was "tri fuel". It could run on gasoline,"paraffin"[whatever that really is] and kerosine. I never saw it run on kerosene. It had a carb and no injectors that I saw. I think it was from the late 50's or early 60's. about 60 hp I think. 4 cylinder. it ran faster on diesel and louder. the fuels did not run together, just a fuel petcock to change from one to the other.

Paraffin is the stuff you usually burn in oil lamps, it smells a bit like jet fuel when burning.

Older petrol engines for farm equipment and the like, would be started on gasoline and switched over to paraffin when warm. You had to either remember to switch back to petrol for the last 5 minutes or you would have to drain the carb of paraffin before starting again!!
The engines ran on 80 octane or higher gasoline and were around 6:1 compression only....from memory!

You remember the same as i do; this not even close to being thermally efficient (worse, even, than a standard petrol engine!)

The only gain here was the (formerly) much lower cost of the "oil" when compared to gasoline.

Yup and I think that paraffin was subsidised for farm work.....

My uncle's farm in the 50's still had oil lamps for lighting!!! and no running water (just a well) and its own sewage treatment plant for making compost!!

Cool Beans!!

Where was this farm?

Near to Horsham UK.

This is termed bi-fuel. Gas = Natural gas not petrol. Done since the 50's. European trucks do this. Didn't catch on in USA. Google bi-fuel. There are 7-8 companies doing it. ComAp is one of the best. Clean Air Power tried it for trucks, but their system didn't work well at least 4 years ago I rejected an industrial installation they couldn't fix after 2 years.

How it works:

Imagine you are on cruise control in your diesel truck. Then I dump natural gas into your air filter. The engine will rev up (like spraying in ether). The cruise control will slow it down (less diesel) but the balance of fuel is natural gas. Your cruise control is stupid and doesn't know where the fuel is coming from, it is just holding the speed the same and cutting back diesel to do so.

At bit dangerous, but done all the time. The down side is you need tanks to hold compressed natural gas, some fancy computer controls, and a valve body under your air filter. Might be $5000-$10,000 cost for small vehicle. Pays off on long haul trucks, but not for Joe Home Owner. The industrial version I deal with are $25,000 + $15,000 installation.

Cheers