[Land-speed] Knock sensor placement on flathead!

[Greg Meyers]

> I wonder if central placement might be a concern?
The more mechanical mayhem, the easier it is to confuse a microphone.....
Can I find a quiet place  in the rear of the block where detonation in the
front can still be heard.....

Solid lifters may
> have enough background noise to cause a concern
Yes, they do, and at the same relative frequency as detonation.  I have
tried in the past to keep the sensor away from the "lifter chest", across
the head gasket from them.

- wonder if  those
> sensors can be adjusted for sensitivity????
Anything has its optimal resonant frequency at which it would be more
Likely to react, but the sensors themselves aren't usually modified for
that.  The device which is connected to them, however, may have filters
which are tunable (like on your high end stereos) to send thru some
frequencies and stifle others.  The analogy of the volume control on your
stereo brings up the signal which has passed thru the filters.  When the
frequency is the same, the shape of the wave, phase shift and harmonics may
need to be analyzed to characterize what made two different sounds at the
same frequency.  60 cycle hum from your fluorescent lamp sounds different
than 60 cycles from a string bass.
> 
> Just some random thoughts . . . .
I may need to just screw the thing down in various places and look at the
frequency analysis with a free-ware program on my laptop.....

Thanks!
Greg