Spark ignition Diesel engine, AKA your car

[5speed5]

Just a suggestion.
If you're going to try this, maybe try it with varying mixtures of gasoline + diesel.
Start out with 25% diesel, then 50% diesel, etc.

[mechman600]

Originally Posted by 5speed5

Just a suggestion.
If you're going to try this, maybe try it with varying mixtures of gasoline + diesel.
Start out with 25% diesel, then 50% diesel, etc.

I've thought of that too. The whole entire point, really, is ultra-lean burn. With gasoline, more than 16:1 is no good for economy, but with diesel, super lean works, obviously, as there is no throttle plate. It would be interesting to see how a diesel/gasoline mixture would react to ultra-lean.

[gone-ot]

...a LOT of people during WWII ran their cars on gasoline+kerosene (or used white-gas) due to war-time "rationing"

...my Dad told me about "wrapping" the fuel line (loosely) around the exhaust manifold to enable running on the gas+kerosene mixture AFTER the engine was fully warmed up; had to switch (valve) between two different tanks in the process: start on gas, warm-up on gas; then switch over to kerosene for driving. Of course, EPA didn't exist then!

[bestclimb]

mom filled her chevy astrovan with diesel once. she drove it home on the gas in the line and while it was warmed up. The next day we were able to get it to start and run very very badly. It would not drive we drained the tank and filled it with gas, after a while of cranking and barely running. We got it to run once the diesel was out of or diluted in the systems.

A jet engine running Jet A (diesel more or less) uses a spark plug to ignite the fuel charge in the hot section during starting.

[IsaacCarlson]

never tried it though...

[mechman600]

Originally Posted by IsaacCarlson

My 1947 John Deere M can run on all three
never tried it though...

Nice. My dad had a 1947 John Deere G All Fuel. Gasolene, Distillate, or Kerosene. We tried it on Kerosene once, but I was too young to remember what happened....

[TimG]

Mechman-

Some people that know better than me or you insist that compression ratio DOES make a difference in the efficiency in the diesel cycle. See

The Diesel Engine

Even though the compression cycle is an "air spring" that regains it's energy in expansion, the expansion includes the added heat of the fuel burning... so they are not equal.

College was a long time ago, but I remember being sursprised that the diesel cycle is actually less efficient than the otto cycle also- the greater efficiencies of diesel engines come from their higher compression ratios, mainly, and secondarily from the higher heat content of the fuel.

[Big Dave]

I hate to tell you this, but it has already been done. There is nothing new under the sun – particularly in the way of engines.

Back before the First World War, the Germans built some kerosene (the Germans called it paraffin at the time) spark ignition engines for U-boats. Prior to that all of Mr. Holland’s submarines were gasoline-powered on the surface. Given the volatility of gasoline, early subs were unmitigated fire hazards which gave a lot of scope for reports of “…lost with all hands.” Kerosene and diesel (No. 1 and No. 2 middle distillate) have a much lower vapor pressure and as described are much less of a fire hazard. These engines did work, after a fashion. They ran and didn’t blow up (like gasoline subs) and in fact one paraffin-engine U-boat (the U-9) was quite successful.

The paraffin engines were nowhere near as powerful as either gasoline of diesel engines of the same size. The flame-front of kerosene is nowhere near as fast as that of a mixture of air and gasoline vapor. The paraffin boats were slow on the surface. The famous U-9 (and all paraffin boats) also had another characteristic they had to overcome: The paraffin engine smoked like a coal-fired battlecruiser. The plume could be seen for miles. She could only run of the surface at night or in an area where she could not be spotted.

But paraffin was abandoned when capable diesels came along (read after the invention of Herr Bosch’s fuel injector). The paraffin boats finished the war as training boats.

I’m not entirely sure what mechman600 is driving at. If he has a source of cheap kerosene, use it in a diesel instead. Diesels run just fine on kerosene. I’ve done it myself. If you have straight mechanical injection put a dollop of motor oil in the kerosene to reduce wear on the injector pump.

You might get that bike to run, but it will run poorly and smoke like a steam locomotive.

[5speed5]

Originally Posted by TimG

Mechman-

the greater efficiencies of diesel engines come from their higher compression ratios, mainly, and secondarily from the higher heat content of the fuel.

Also, from the lack of a throttle in the air intake.

[mechman600]

Originally Posted by Big Dave

I’m not entirely sure what mechman600 is driving at. If he has a source of cheap kerosene....
....You might get that bike to run, but it will run poorly and smoke like a steam locomotive.

You seem to see right through me! I have access to free diesel fuel. Like I said, I give this whole idea a 5% chance. If it doesn't work, at least I had fun trying. If it does, I'll be laughing my ass off.