Maximum advance

[Eric Fahlgren]

> programmatically combine the pressure transducer data together with the
> crank angle data, to create a pressure-volume (PV) diagram for a given
> cylinder.  Then you would have a good visual representation of the entire
> cylinder experience, including peak combustion pressures and phasing of
> same.  The number of things you can deduce from a PV diagram are endless.

Are there other useful diagrams of this sort?  I'm thinking of a
(just made this up) PQ diagram where

   Q = cos(a) * sin(b)
   a = angle between rod and bore centerline, as the rod aligns
       with the bore, this goes to 1.0
   b = angle between rod and crank throw, as the rod/crank angle
       goes to 90d this goes to 1.0

which describes the vector component of the pressure that is
actually doing useful work (or so it seems to me).  The Q term
is interesting in and of itself, so I think I'll write a little
plotter that produces a bunch of curves for various rod/stroke
ratios (and maybe with bore offsets, too).

-- 
Eric Fahlgren                            Mechanical Dynamics, Inc
efahl at adams.com                          Ann Arbor, Michigan, USA
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