On 2008-04-12, Tim Wescott wrote:
On Fri, 11 Apr 2008 22:19:36 -0400, Al Patrick wrote:

Ivan Vegvary wrote:


If any of the above is true, why don't people, today, put gasoline into
their diesel engines, considering the higher cost of diesel fuel?


I own a diesel F-250 and wouldn't dare do that. I previously, years
ago, owned a Mercedes 300-D and the manual actually stated that - during
cold weather - (I think it was so qualified) one could mix UP TO 30%
gasoline with the diesel fuel. I suspect this was to help prevent the
diesel fuel from congealing.

I have heard stories, unverified, that a diesel will "run away" on
gasoline and over rev the engine, possibly disassembling itself,
internally if not externally. A diesel operates at much higher
pressures than a gasoline engine. The gasoline is far more explosive
than diesel fuel. The diesel uses no spark plug to ignite the fuel.
Instead it uses pressure to explode the fuel.

Take this for as much verification as you think it's worth...

On at least one occasion my dad came home from the fire station with a
story of a truck engine running away when the guys put gasoline in the
tank instead of diesel fuel.

I don't see why this should happen _in theory_ as a diesel is throttled
by controlling the amount of fuel injected, but I could certainly see it
happening in practice if the lower viscosity of gas let it flow at a too-
high volume.

IIRC one shuts down a runaway diesel by shutting off the air. There is
(was) supposed to be an emergency shut-off valve in the intake of every
diesel motor, but in a pinch one could use articles of clothing stuffed
into the intake.


Not in all, just it screaming jimmys...

i