Crank Trigger Signal (was monitoring RPM)

[Andrew F. Gunnesch]

On Mar 4, 10:18am, Dave J. Andruczyk wrote:

> Whats wrong with putting a hall sensor really close to hte flywheel teeth,
> as there is prolly close to 100 or more teeth on that and the sharp edges
> may be enough to trigger the sensor, another pickup could be used to
> detect TDC, so you can have both rpm, and position, with a decent amount
> of resolution.   Renault had a similar system for their ignition, as it
> used a crank trigger sensor that read larger "teeth" (they look like
> square blocks right behind the flywheel teeth) and missing teeth at tdc.

This is true, but I've often seen SBC motors which chipped or broken
flywheel teeth.  They're in an abusive environment, and can be damaged
without TOO much effort.  I'd rather replace the sensor on the front of
a motor than pulling the transmission to swap a flywheel, personally :)