In response to :

Date:    Fri, 10 Sep 1999 09:56:24 -0400
From:    Bulley <gmbulley@BULLEY-HEWLETT.COM>
Subject: Re: New 1,9 TDI from VW

While I don't know the specifics on the new Tdi, I can tell you that common
rail injection cannot work on any compression-ignition motor, (like the
Tdi). On a CI motor, the perfectly timed injection pulse of fuel into the
super-heated-compressed air is equivalent to the well-timed spark plug
firing on a lowly gasoline motor. Having the fuel injected on a common rail
(or like CIS), would be like lighting all the spark plugs at one time on a
common gasoline motor. Come-prend-day-vooo?

G. Matthew Bulley

Go to:  http://www.bmw.com/bmwe/pulse/aid/index.shtml  for a presentation of
BMW's Common rail diesel fuel injection.  Opening paragraphs :

         For the first time ever, BMW has used Common Rail in the
         new six-cylinder diesel engine as well as the future
         eight-cylinder diesel, the BMW 740d.

         Why in these two models in particular? Common Rail is a fuel
         injection system with an excellent potential. The advantages are
         especially noticeable in engines with a capacity of over 2.5
         litres and at least six cylinders. In smaller engines, BMW
         prefers distributor injection pumps.

         Common Rail uses the consumption-reducing advantages of
         direct diesel injection without its previous disadvantages
         concerning noise and exhaust emissions.

         A fundamental element of the process is the separation of the
         creation of pressure and the fuel injection. In conventional
         systems, the pressure must be built up again before every
         injection process. With Common Rail, however, there is a
         constant and, in most areas, a freely available pressure level,
         thanks to a high pressure reservoir, the Rail.
        Harvey

        "I live with fear, death, and evil...but sometimes I turn it off and
>        use a Mac." Author Unknown
      Sentenced to be taken to the "Dark Side" in the near future