Camshaft sensor for ECU

Guys, i'd like to run a cam sensor so i can use sequential injection, have any of you done it?

If so what did you use & where did you mount it? Pics would be very helpful!

I have a variable reluctor/pickup coil epoxied in the rocker box of a 440.
More detail at the bottom of page 4 at the link below.


www.dotheton.com/forum/index.php?topic=39120.45


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Well i have no idea what's going on there! lol

I was hoping i could use a hall effect cam sensor fixed somehow in the cam cover, i need to figure which cam lobe to read

Judt when i think of it, is a hall or magnetic sensor more suitable?

A variable reluctor/Kawasaki pickup coil is a small AC generator.
I believe it is positive on approach and negative after it passes.
The 440 has rocker arms, so the only place available was at the end
of the cam with a fabricated two lobe ring.
Are you sure a cam lobe has the right profile foe a hall effect sensor?

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"Are you sure a cam lobe has the right profile foe a hall effect sensor?"
so how do you measure that? I'm not getting on ya Rex. But what do you mean?

The electronic ignition system on some of the old pushrod V8s had a hall effect sensor
and a wheel with a fin for every cylinder. Those 'fins' were squared off on the end that spins
past the hall sensor. Variable reluctor/the Kawasaki pickup coil ramps up to a point and
then ramps down. A camshaft lobe ramps up then down. I'm not saying it won't work with
a hall effect, just that the trigger wheels I've seen for fuel injection seem to have squared teeth.




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I know the one we fitted to Storm (FJ1100 cam cover) was a real ballache. I think the guys spark eroded the cam to fit a square "peg", as I think hall effect sensors need an edge to read. You won't be able to use a cam lobe. I want to do the same thing on my turbo so if I get any further info I'll let you know.

Lorcan wrote: I know the one we fitted to Storm (FJ1100 cam cover) was a real ballache. I think the guys spark eroded the cam to fit a square "peg", as I think hall effect sensors need an edge to read. You won't be able to use a cam lobe. I want to do the same thing on my turbo so if I get any further info I'll let you know.

I know you from somewhere! :woohoo:

I know of a guy that will know Lorcan, i just hope he sees the thread as im pretty sure he has done it already using megasquirt

I forgot to add, i talked to a guy who owns a dyno shop not that long ago, he took no1 throttlebody vacuum tube & put some kind of sensor on it, it then told the ECU that the inlet valve was open on that cylinder so everything was worked out from there as it sensed the pulse. I just need to find out what kind of sensor that was now, must be some kind of pressure sensor

Oh & it does work, he sets up full on race bikes

*edit* maybe just a secondary MAP sensor on vacuum no1 now that i think about it

Sounds interesting.

A Hall sensor is usually most effective with a rotating magnet passing it (as in the Dyna S). And they are not as robust as a reluctance pickup. They are much cheaper, though. Obviously, it would be difficult to fix a permanent magnet onto the camshaft somewhere.

The reluctor pickup should be able to work using the valve's cam. Since you are not concerned with exact timing, and only want to know which cyclinder is about to fire, the gradual profile of a cam is not a problem. With a simple opamp circuit, you can convert the signal into a short positive pulse detecting the approaching cam, or receding cam. But it's still not easy mounting a pickup under a valve cover like on the 750 twin. (By the way, nice job on the 440, Nebr_Rex)

I agree on trying a vacuum sensor. Much easier than fitting electronics into the head . I just don't know if the vacuum sensors are fast enough at 8000 RPM, though, to give any precision. Actually, the sensor is probably fast enough, but the question is will the air in the connecting tube propagate the vacuum to the sensor, or will it dampen the pulse too much. As long as they are connected with a very short piece of tubing to the intake manifold, it should probably work. And since you are not concerned with exact timing, it may work fine.

The raw vacuum sensors are tiny, and a bit fragile, but at least they are cheap, and easy to work with. I recommend the Honeywell NBPDLNN015PGUNV sensor. It's gauge pressure to 15 psi, so can go down to near perfect vacuum levels and still produce a meaningful signal. This is important because you have to be able to detect the peak while constantly monitoring the average, as the absolute values will change a lot depending on the throttle movement and RPM etc. Without correcting for the average vacuum, the peak will easily be obscured. So basically you are trading mechanical simplicity for some electronic complexity.

Hey Lou! Keeping well?, thamks for jumping in! Will a MAP sensor not work then?

It may not but i'd love my turbo to be running at 16 or so PSI so i was going to use a second 3 bar map sensor (after investigatiing if it will work)