A Short History of Diesel Enrichment

Cleaning Up Emissions

Mr Hubart an eminent mathematician, had predicted that inexpensive crude oil &fuel would cease by the year 2005, so to prolong the life of the oil fields, experiments were started to reduce our dependency on crude oil. In the late 1980’s experiments were being run to clean up the emissions produced by all the common fuels. Catalytic converters to reduce CO, and CO2, on petrol engines, and additives to diesel to reduce soot and particulates.

Combining Fuels

Experiments during this time by engineers had differing results as they tried combinations on fuels to propel vehicles, one of these was LPG and diesel, others were CNG and vegetable oil, Petrol and diesel, Alco-fuels and synthetic fuels. It was reported that a static single stroke diesel engine could run on 10% diesel and 90% LPG but when this was repeated in a road vehicle, the engine suffered from star-fire as the fuel burned trough the top of the piston, and the engine was destroyed, after that 2 Cummings engines running on 50-50 Diesel / LPG also suffered from Star-Fire, when the mid 1990’s arrived most systems were using 10-30% LPG and 90-70% diesel, delivered to an engine via a mixer unit and allowing the Nock sensor a device that senses over fuelling that is fitted to the engine and thereby reduce the diesel (lots of engines died of star fire at low revs).

The Challenge

The problem was the mix LPG / Diesel was too much at low rpm so the maximum savings of these early systems would be as low as 5-10% fuel cost savings. We have now moved away from that type of system and our competitors who are still using the Nock sensor to trim back diesel, we on the other hand are controlling both fuels simultaneously which means that we have fuel cost savings across the whole of the RPM range not just when the vehicle is driving against the fuel limiter. We are reducing pollution and improving MPG and can prove that the engine life will be extended just like the petrol engines that run on LPG.

Why do we get a saving from combining the two fuels?

If we look at the chemical makeup of fuels a two patterns emerge:

1. The bigger the molecule the slower the burn.
2. Liquids and gases burn in different ways

Most of the fuels we are burning are known as a hydrocarbon, which means they are made up of hydrogen and carbon molecules of differing lengths. The hydrocarbon family start with methane and finish with heavy oils.