Home
Location
About Us
Join
Biodiesel

100 Fairfield Street
Behind Piccadilly Station
Manchester M1 2WR

0845 373 2769

info@greengoldbiodiesel.co.uk

Green Gold Biodiesel and engine technology

Advances in technology have rapidly altered the type of diesel engine to be found under most bonnets over the last 6 years and with it the ability to use higher blends of biodiesel. Until the late 1990s indirect injection was predominant, where the fuel, pressurised to 2000psi by a crankshaft driven pump, was first squirted into a cavity in the cylinder head, but separate from the main combustion chamber. As demands for better fuel efficiency, more power and less pollution became more pressing, a new system was invented, “common rail”.

This new method differed immensely from its predecessors, being electronically controlled by a series of sensors supplying information to an electronic control unit which optimised combustion at all engine speeds and load. In addition injection pressures increased tenfold to 20,000psi, and the system included many additional refinements like multi stage injection, pre and post combustion injection and exhaust gas recirculation to name but a few.

This level of engine management though can cause a problem when biodiesel is used, as the viscosity is different from fossil, as is the oxygen content and the ease with which it atomises, all of which can cause the sensors to “misread” and try and alter settings to compensate, to the detriment of economy, smooth running and emissions. The extreme pressure can cause separation of any trace elements in fuel derived from recycled oils or from poorly filtered fuels, which can result in coking and gumming of injectors, or in extreme cases make the management system close down. Finally, many anti pollution devices fitted on the latest cars can be damaged by high levels of biodiesel resulting in worse emission levels, particularly in the case of particulate traps.

These technological advances have resulted in manufacturers like VW who previously supported use of high levels of biodiesel reducing their recommendation to B5 when their high pressure “pump deuse” system and particulate traps were introduced.