Doug, Here is what I got out of the factory manual. Hope this helps.

C. Smith


Colin, I am getting ready to do some more 555 printed circuit
boards. What are your recommendations on the final op amp schematic?
I would like to use low power, single supply Ti CMOS 8 pin dip technology.

I think two or three op amps, one for each rotor, with leaning pots, seems
like the way to go. Those can be on the mother board mounted
behind the instrument panel and feed control voltage to one or more
555 systems.

I am also thinking of mounting
one of the cheap $80 12 bit AD to D data acq system back there
with the USB interface to monitor the 555 EFI system and its
sensors on a notebook computer. Add a few ten dollar pressure
sensors and lots of things are possible. The A to D can also handle
the fuel flow read out and fuel totalizer in software.

http://www.hytekautomation.com/

I just came up with another idea using a tiny electronic load cell
out of a cheap bathroom scale incorporated into the motor mount to
measure prop torque. Knowing prop torque and prop RPM you know HP
out of the gear box. The A to D system can measure that as well.
I got the idea by watching the TV program Deconstructed on the Science
Channel. I'll appropriate  Robin's bathroom scale :)

The Data Acq system is a great instant diagnostic and installation
development tool. Also some sharp programmer could do some software
for the PC to act as a real time engine monitor. A lot of source
code for PC drivers is on the Hytek Automation web site.

The whole system will give us near airliner glass cockpit
diagnostic functionality or better :)

Paul Lamar