Can a diesel engine run on gasoline?

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Discussion Overview

The discussion centers around the feasibility of running a diesel engine on gasoline, exploring the differences between the two fuels and their ignition processes. Participants examine theoretical and practical implications, including potential mechanical issues and real-world experiences.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Exploratory

Main Points Raised

  • Some participants assert that gasoline requires a spark for ignition, while diesel ignites through compression, suggesting fundamental incompatibility.
  • One participant mentions that while a diesel engine might run on gasoline for a short time, it could lead to significant engine damage.
  • Another participant describes a personal experience where a diesel car temporarily operated on gasoline without sustaining damage, although performance was notably reduced.
  • There is a discussion about the characteristics of diesel and gasoline fuels, highlighting their differing ignition properties and measurement indices (Cetane for diesel and Octane for gasoline).
  • Some participants speculate that gasoline could ignite if injected at the correct timing, though this remains uncertain.
  • Concerns are raised about mechanical issues related to lubrication and the nature of combustion when using gasoline in a diesel engine.
  • One participant suggests that pre-cooling intake air and fuel might help achieve a high compression ratio necessary for ignition.
  • Another participant notes that carbon build-up in diesel engines could potentially aid in igniting gasoline, but warns of the risks associated with using gasoline in a diesel injection system.

Areas of Agreement / Disagreement

Participants express a range of views, with some arguing that a diesel engine cannot effectively run on gasoline, while others share anecdotal evidence suggesting it is possible under certain conditions. The discussion remains unresolved, with no consensus on the overall feasibility.

Contextual Notes

Participants highlight various limitations, including the dependence on specific engine conditions, the potential for mechanical failure, and the unresolved nature of combustion characteristics when using gasoline in a diesel engine.

jethead
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I haven't read or heard about anywhere, but is it possible to run a diesel engine on gasoline/petrol?
 
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No. Gasoline requires a spark to start the process, although a very hot spot in a cylinder can cause pre-ignition (but still requires the spark to get the ball rolling to create the hot spot).
 
Gasoline must be atomized by carburetor or fuel injector, then ignited with spark.
Diesel is atomized by high-pressure pump & injector, then ignited through compression.

Trying to run a diesel with gas: there may be some miracle by which it would work, but only for a very short time. You would probably have to take the engine pieces home in a bag, though. :-p
 
I read that in a diesel engine, ignition occurs when atomised diesel fuel is injected into the hot, highly compressed gas slightly before the piston has reached the top dead centre. So I was thinking that the same method of ignition could be used in a gasoline engine.
 
My aim is to use low octane fuel in high compression engine without pre-ignition.
 
Diesel and gasoline are two fuels that have completely different characteristics. A good diesel fuel will be easy to ignite and will have a short ignition delay period because you want the fuel to ignite almost instantaneously. A good gasoline will be defined by the opposite: the more compression the fuel can withstand before detonating, the better it is (hence, difficult to burn).

Diesel fuels are measured with the Cetane index and gasoline with the Octane index. If a fuel performs well on an index it usually performs badly on the other.
 
diesel car can run on gas...for a limited period..case in point.. my girl friend filled my VW diesel with gasoline..there was enough diesel in the fuel system to restart tha car after she finished filling the tank ..and modern electronics controlled the mixture enough to quench detonation...the perfromance was dramacticlly reduced ( she picked me up after the car was fueled) ...but when it was shut off..it would not restart as all the diesel fuel had been consumed..had to call tow truck and the VW dealer had t o drain the fuel tank...no engine damage was suffered..duration of time running on gas was about 15 minutes...10 miles
 
Well, there's no saying that gasoline won't ignite when injected at the correct timing.
 
There are plenty of mechanical issues (fuel pump and injector lubrication problems, for instance) to contend with as well as the uncontrolled burn you will end up with.
 
  • #10
Well, then I guess pre-cooling of intake air and fuel, and a good liquid cooling system will help in achieving the high compression ratio.
 
  • #11
RangerMike, your diesel ran because of the carbon build-up in the cylinders which was preheated by the diesel fuel operation before the gas got there. You will find out soon enough (unfortunately) the damage that "dry" gasoline does to a diesel injection system. :(

So, will a diesel engine run on gas? "Kinda" I guess is the best reply- without the fuel switch over, the simple answer is no. Although I must say there is experimentation going on to make a gas engine that will ignite by compression... there sweems to be problems with emissions at this point- NOx in particular.
 

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