[Vwdiesel] New to list

[LBaird119 at aol.com]

> In a CI engine, it takes time to inject the diesel fuel into the cylinder
>  and it burns in more of a constant pressure environment

  I'm no engineer and I believe Roger is but.. (correct me if I'm wrong)
Doesn't
the traditional "knock" that we all know and love so well, come from a
rapid pressure rise in the cylinder?  The TDI is quieter because it injects
the fuel at two points rather than just the one so it's pressure rise is
more controlled.  According to your description it seems more likely
for a gas engine to knock than a diesel.  Much of the burning in a gas
engine can happen in the upper exhaust and that's why in the 70's they
pumped air into the exhaust manifolds.  They reduced emissions by
improving the burn that was happening in the manifold and downpipe.
Not to mention that gas EGT's seem to be capable of running about
50% higher than diesel.  Of course that's heat rather than pressure
but it's due to later burn I believe.
  Just opening my mouth again!  ;-)
     Loren