crankshaft/flywheel encoder patterns

[Mazda Ebrahimi]

RABBITT_Andrew at mv8.orbeng.com.au wrote:
> 
> can anyone out there tell me what encoder patterns people are using
> (especially on production engines) and what sensors are used also?
> 
> ie:
> 
> Ford EEC-4's, 36-1 pattern, inductive crank sensor, hall effect cam
> sensor.
> 
> I'm trying to find out what's out there and how common-place 60 tooth
> encoders are.  (trying to justify a 60 tooth design).
> 
> thanks (in advance) for your help
> 
> Andrew Rabbitt
> Orbital Engine Company

Hi Andrew,

Dodge uses 8 pulses on the crankshaft along with one pulse on the camshaft sensor on 
their 5.2L and 5.9L Magnum engines (I hope this is helpful?!)

I'm currently building a fuel injection box.  I'm basing my design on 180 teeth on the 
crank and one pulse on the cam (rising on TDC on #1 and falling on #6).  My 
justification for this decision was that the crank tooth wheel will generate a pulse for 
every degree of rotation (rising or falling).  I'm doing this to make my programming 
somewhat easier.  In effect, the toothwheel will serve as my physical system clock.  
Instead of using PWM channels (I have eight available on the processor), I'm using 
counters driven directly by the tooth wheel.  So when I figure out my injector duty 
cycle (let's say 50%), I will load the counter for every injector with a value of 360 
(half of 720).  There will be no further interruptions to the processor.  When the count 
is over, the injector will turn off and continue its count to 720, when it will reload 
again.

I am interested in your thoughts on this approach.

Best Regards, Mazda