burning gas in a diesel

[swynx]

Quite some time ago I was waiting at work for the clock to change so I could clock out. So I was reading this odd magazine on the table. Some magazine with farmers and mom and pop inventions. Like a v8 chain saw. Moon shine stuff. New plows. Yada yada. Very interesting.

Don't quote me on this. I had just worked 15 hours it was the end of the week and 5 a.m and I was reading fast trying to finish the article before my room mate left.

Started reading this article about some guys who rebuild tractors that found a way to burn gasoline in a diesel by vaporizing it. In a gas car you only burn like 30% of the fuel. By vaporizing it in a diesel they've been able to burn up to I believe they said 90% and speculate up to 100 MPG. <<<( not entirely sure on the MPG part; just know it was an astronomical amount)

Only problem is they were having a problem efficiently/ steadily injecting the fuel to the engine.

Any one know any thing about this or have more on it?

 

[adsm08]

Well I know the part about only burning about 30% of the fuel in a gasser is wrong. When everything is working correctly you burn all the fuel, but you only get about 30 to 33% thermal efficiency, meaning that of the 100% of the heat produced from burning 2/3 of it go to making things hot and one third goes to expanding gasses and pushing pistons down.

I suppose I could see running gas in a diesel, but you would have to severely retard the injector timing so you don't destroy the engine, and even then you might have issues with damaging the fuel system.

 

[tmcalavy]

Sounds like some folks playing with another version of the vapor carb concept. There's a kit out there that you can buy to add to your vehicle...forget the exact physics involved, but it uses the venturi effect to pull gas into a chamber where it is vaporized and then metered down into the intake...vapor injection I guess. Then there's one where you use electrodes to separate the hydrogen from water, collect it and inject it into the intake...almost went for that one and might still, but the engineering on the hydrogen generator/separator looked a little shakey to me. Right now I'm looking at a new electric motor for bicycles...replacement back wheel with a round hub that contains the motor and batteries and charger...controlled by your smart phone mounted on the handlebars. Set the speed you want to go and take off...pedaling or not, but you're also charging the batteries when you pedal. After awhile, all of this alternative energy stuff makes the Amish mode of transport pretty appealing...oats n' grass, a little water, small acreage and good old hoss power.

 

[lil_Blue_Ford]

Sounds fishy to me.

Diesels burn by compressing the fuel/air mixture until it achieves combustion. There are no spark plugs. Gasoline is more volatile but compression doesn't set it off, you need a spark.

That said, I have heard of burning "sweet crude" or "light crude" oil in both gas and diesel engines (it works better in a diesel). Likewise I have also heard of adding kerosene to diesel to help keep it from jelling in cold temperatures (and that bottle of injector cleaner you just dumped in your gas tank was probably mostly comprised of kerosene).

 

[RonD]

Diesel fuel has 15% more energy than gasoline by volume, this is why diesel engines have better MPG ratings in similar weight vehicles.

Diesel engines also have better thermal efficiency in converting combustion into "movement".

So outside of the practical problems of running gasoline in a diesel engine, why the "f" would you want to?
lol

Gasoline has LESS energy per gallon, doesn't matter how you vaporize it, the MPG would go DOWN.
So there would be only a downside.......no upside

 

[85_Ranger4x4]

That said, I have heard of burning "sweet crude" or "light crude" oil in both gas and diesel engines (it works better in a diesel). Likewise I have also heard of adding kerosene to diesel to help keep it from jelling in cold temperatures (and that bottle of injector cleaner you just dumped in your gas tank was probably mostly comprised of kerosene).

Kerosene is similar to diesel but without the lube, the lube is what "gells" in cold weather. When you add Kero to diesel you are thinning it down so there isn't as much lube to gel. But then your pump and injectors are not as well lubricated.

Cold snaps before the fuel guy switches to winter diesel (drier) helps me sell A LOT of fuel filters.

Some old farm diesels would start on gas to warm up and then switch to diesel. IH was big into it at one time (1940's-50's) They are kinda crazy, they have a dizzy, carb and intake on one side and a pump, lines and nozzles on the other. It is fun at a show to see a newbie trying to figure out why a diesel has a carb. All they can do on the gas side is idle, they can barely drag their sorry selves around.

Take away the direct injection and boost from a diesel and the only advantage is economy. It will take more cubes to compete with a gas engine of similar design (if you consider a single barrel carb similar to a mechanical injection system)... and is going to be taking advantage of the time the gasser is going to sit at the fuel barrel to really stay ahead of it because even with the cube advantage they still usually lag a little unless someone has messed with the smokescrew (which cuts into fuel economy)

As someone that doesn't run them day in and day out the cold weather starting of a gasser is huge. My '53 WD-45 had been sitting for two weeks, last night in the low 40's it didn't roll over two times and it was running. No engine heater, ether, glow plugs or lucky rabbits foot required, from experiance it will do the same when it is 40* colder. For me that is a huge advantage for a gas.

 

[bmerr98]

... Then there's one where you use electrodes to separate the hydrogen from water, collect it and inject it into the intake...almost went for that one and might still, but the engineering on the hydrogen generator/separator looked a little shakey to me...

I looked into this a while back but let the idea go when I got into all the things you have to do to fool the O2 sensors and such, especially with Fords, which have very tightly regulated and computerized fuel systems. I think it might be good in older motors without all the high tech add-ons of later model vehicles though.

 

[simpler=better]

Compression ratio. Even low comp GM diesels run at 17:1 CR. Or the high end of the spectrum,a Merc 21.5:1 CR plus turbocharging.

You can spray propane on direct-injection diesels, and use the diesel to ignite the propane.

On indirect diesels you can spray water/ethanol/methanol and let the diesel ignite it

If you feed gasoline through the injection pump it will cause scoring of any moving parts, making for a really expensive paper weight.

HHO is a bullshit scam. Oversimplified you're wasting electricity to vaporize an element. So unless you're getting the catalyst and element for free, and setup a huge volume crapcan, it's a waste of time and money.

 

[adsm08]

Diesels burn by compressing the fuel/air mixture until it achieves combustion. There are no spark plugs. Gasoline is more volatile but compression doesn't set it off, you need a spark.

You don't need a spark to light off gas, you can do it with compression. It' just harder to do. Spark knock is the fuel lighting off before the spark is thrown in.

Also, the glow plugs can be used to light off gasoline under high pressure. It's just really bad for them. It will eat the end off doing that.

A diesel engine can run on gas, it just won't run long before you need a new one.




I think one of the big things that gets people about the two types of fuel is the distinction of Octane vs Cetane.

Octane (the ratings for gas) is the substances resistance to ignition. The higher the number the harder it is to get it burning. That is why you don't run 91 grade gas in your Ranger.

Cetane is a rating of how easy it is to get it to burn. Cetane is backwards from Octane, high numbers burn easier. 100 Cetane will light off it you look at it funny.

 

[kryptonitecb]

HHO has been mathematically proven to not have any gains. The energy you use to make H is more than what it can produce by ignition. If the conversion method could be made more efficient it would work.

Propane added to the intake is proven way to offset mpg. However I haven't seen the numbers that prove it to be more cost efficient than just having a well tuned engine.

Sent from my SAMSUNG-SGH-I547 using Tapatalk

 

[pjtoledo]

its called electronic fuel injection, I've heard it works pretty good.
then theres this new-fangled stuff called Gas Direct Injection, runs about 2000 psi at the injectors. It matches the diesels in efficiency.

FYI, one of the reasons diesels get good numbers is that no fuel is wasted during scavaging.
likewise, the Gas Direct Injection engines don't waste fuel then either.

there are other systems that use fuel in vapor form, both propane and compressed natural gas go in as a vapor. biggest gain there is emmissions, not more power per unit of fuel.

yes I know diesels can make a ton of power on propane, they also use a gazillion units of fuel doing so.

Perry

 

[feellnfroggy]

You don't need a spark to light off gas, you can do it with compression. It' just harder to do. Spark knock is the fuel lighting off before the spark is thrown in.

.

isnt this usually due to high carbon on the valves? (dirty valves)

 

[adsm08]

isnt this usually due to high carbon on the valves? (dirty valves)

In a normal engine yes, the most common cause of spark knock is carbon build up on the valves or piston. It creates a "hot spot" that acts as an ignition source.

But if you go get yourself a nice HIPO high compression engine (I'm thinking something in an 11 or 12:1), add a little forced induction, fill the tank with 87 octane, well.... yeah, once you get it to temp it is going to knock like a diesel.