Guys,
Just got back from the auto parts store where I noticed a manual on Diesel engine
servicing. It covers most of the popular European models and describes the
modern fuel injection systems in fairly good detail, with cross sectional drawings.
Of particular interest was the Volkswagen Audi Group "Pump Duse" which from the German
means "pump injector". Here the injector has the pump built into the top of
it and it is driven by a rocker off the cam shaft all on top of the cylinder
head.
This system of combining the high pressure pump with the injector has been
used for a while in larger diesel engines and also smaller aircooleds, but I
think VAG are the first to use it for car engines. Sometimes this
arrangement was called a unit injector and cheaper to make and fit than
separate devices, with no high pressure line to connect between them.
Of key interest is the fact that the timing of the injection event or
multiple events is controlled by an electromagnetic solenoid which activates
the injection nozzle. This way the EMU can control the exact timing of each
cylinder depending on the load and the emissions etc etc.
The book also stated that the effect of compressing the fuel to 20,000 psi
in the pump duse, raised its temperature so significantly that frequently a
fuel cooler had to be used (underneath the car) before the fuel could be
returned safely to the plastic fuel tank.
So imagine a Listeroido with a new cast aluminium / cast iron head, with a timing belt
driven overhead cam which worked both valves and the new pump duse (from a
VW dealer). A simple EMU is made from a microcontroller to sense the
flywheel position and the load, and control the magnitude and profile of the
injection.
The veg oil is automatically heated by the pump process.
The engines in the new VW Golf TDI and Jetta/Passat are exceptional in terms
of torque and fuel consumption. Could perhaps the introduction of some modern
fuel injection and valve gear improve the fuel economy and reduce emissions on
the Listeroid?
Any thoughts?
Ken