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trigger wheel on Camshaft ??
Valtra - 7/5/12 at 03:13 PM

My Strada Abarth cylinder head that I'm planning to fit on my 1.6 twink has a distributor drive I may be able to utilise for a trigger wheel, rather than drilling and tapping the cast dished crank pulley .....or am I barking up the wrong tree ?

paulf - 7/5/12 at 03:57 PM

The crank shaft gives a more accurate position reference but it would be possible if you fitted a 72 tooth wheel with 2 missing teeth for Edis set up as the cam shaft runs at half engine speed.
Paul

rusty nuts - 7/5/12 at 03:58 PM

The cam only rotates at 1/2 engine speed which may cause a problem ? but it might be possible

SPYDER - 7/5/12 at 04:24 PM

It should be OK to use a camshaft mounted trigger. My Toyota 3SGE engined car uses the original trigger wheel in it's cam end mounted dizzy. It only has 24 teeth, one of which I have removed to give a 24-1 trigger wheel.
Although this gives fewer teeth per full engine cycle it does tell the ECU which cylinder is which and has enabled me to run sequential ignition using coil on plug units.
I am using Megasquirt V3. You will need to ensure that your chosen ECU can be configured to suit.

Geoff

Valtra - 7/5/12 at 07:57 PM

Would a 72 tooth wheel of say 100mm diameter be feasible?

matt_gsxr - 7/5/12 at 08:41 PM

Should be fine as long as your ECU can handle it. The only case where it would get messy is if you have variable cam timing.

mcerd1 - 7/5/12 at 09:40 PM

it might not be as hard as you think to fit a trigger wheel to the crank...

got any pics ?

Valtra - 7/5/12 at 09:50 PM

quote:
Originally posted by matt_gsxr
Should be fine as long as your ECU can handle it. The only case where it would get messy is if you have variable cam timing.


This is a 30 year old Fiat engine ... so, no

Valtra - 7/5/12 at 10:04 PM

quote:
Originally posted by mcerd1
it might not be as hard as you think to fit a trigger wheel to the crank...

got any pics ?


Not any picks at the moment still in the planning stage , but what I do have is a Strada Abarth head sat on my bench that I could spend a few afternoons fettling ready to fit on my engine once it comes out to cure the Oil pressure problems I'm getting . The "new " head has a distributor drive off the exhaust cam which would not only supply a convenient place to work, rather than down in the depths of the engine bay, it would be a piece of cake to make a nice firm adjustable mount for the sensor by utilising the old Dizzy body.

I can see how the cam running at half speed could cut down the accuracy of the timing, it was just an elegant solution that's all.