Detonation Monitor

[Carter Shore]

There's another school of thought that the dominant
resonant effects are from the mechanical structures of
the engine itself, rather than the dimensions of the
bore. A step impulse input to any structure (like a
detonation wavefront) will cause resonance in several
modes. 
Seems that one accepted method of testing KS is to
bang on the block with butt of a hammer, simulating
the wavefront.
Something as acoustically complex as an assembled
engine block can be difficult to analyze
mathmatically. Instead, actual monitoring of
detonation events with a spectrum analyser, sampled at
various points on the engine, yields empirical
results. 

Consider the following resonant frequencies of Ford
knock sensors, compared to the bore and stroke of each
application.

http://acc-electronics.com/cloud/images/page3_55.jpg

I do not have the bore and stroke dimensions at hand,
but it might be interesting to calculate by formulae
given in previous threads to see what/if any
correlation exists.

The 4.9L application may be tuned for a harmonic, but
who knows without instrumenting one.

Not saying it's so, just throwing this out for
discussion.

Carter



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