Have you ever wondered what alternate fuel you could run an engine on, if you absolutely had to? Well apparently there were enough people who asked in the comments of Project Farm’s YouTube channel, that Todd decided to actually test the theory out. For the test Todd decided to use K-1 kerosene, as opposed to K-2, due to its lower sulfur content and cleaner burning characteristics.

Starting out with a two-stroke lawnmower engine, compression is tested pre-kerosene, and the engine shutoff switch is removed, so the engine can be run against the engine brake to create load for testing. After the engine is run completely dry of gasoline, eight ounces of kerosene are added.

Surprisingly (or not, depending on your stance before you started the video), the engine fires right up. A quick adjustment of the jetting to smooth the engine out, and it’s purring like a kitten. Even more surprisingly is the engine’s lack of visible exhaust at idle.

The combustion chamber of the lawnmower engine before and after running on kerosene. While tough to measure definitively, after tearing down the other test engines used, Todd surmised that kerosene leaves slightly more carbon deposits than gasoline.

Under load, the engine heats up significantly, and approaches the preignition threshold for kerosene, but continues to run. The engine is then compression-tested and torn down for inspection. Surprisingly there isn’t much noticeable difference after being run on straight K-1 kerosene.

Next, Todd sets up his fuel efficiency tester, which is a 3,200-watt generator, with an electrical measurement device plugged in between the space heater (to generate load) and the generator. That give Todd the ability to quantify the draw on the system, in addition to the runtime with a fixed amount of fuel. The benchmark runtime is 58 minutes for gasoline.

After some hesitancy to start, which required the use of starter fluid to overcome, the initial generator testing under load showed no knock running on straight kerosene, so Todd proceeded to let the generator run through its entire fuel supply. Surprisingly, the kerosene lasted 65 minutes before starting to sputter out. That exceeded the same quantity of gasoline by 7 minutes, or 12-percent.

At that point, it was time for the “max load” test. There, Todd drained the engine of his go kart and filled it up with Kerosene and proceeded to romp it, with slightly surprising results, given the results of the previous tests. Under full throttle in the kart, there was a significant amount of ignition knock at all operating loads.

Looking inside the combustion chamber as ignition occurs, you can see that gasoline (top) burns much stronger and faster than kerosene (bottom).

To combat the knock, Royal Purple Max-Boost octane booster was added in a slightly higher-than-recommended quantity. While it helped the problem a little, it didn’t alleviate a majority of the pre-ignition under full load. However, the combination did perform acceptably under light load.

So Todd’s conclusion? After looking at the torn down engine in detail, he believes there to be more carbon deposits than were on the same components after being run with gasoline. After reviewing the footage from the see-through engine, he points out that the Kerosene was much slower burning, which could lead to those carbon deposits. Will kerosene work as a fuel in an emergency? It will, but not as well as gasoline in most cases – especially in a cold engine.