I've never looked at it...but Mmmmm Gear drive....like the whine of a supercharger belt.

MadMax...oh yeah!

Quote:
these sensors hve a strong magnet in them and generate a pulse when the steel tooth passes it the teeth on the wheel are about 5mm long , i didnt work out what that is in degrre terms , the wheel is made of 1mm thick steel laser cut i think it was about 150mm diameter air gap of 1-1.5mm
will try to get photo of it

Yep, 2 litre with the 2.4 head on it..
Only running the 72 cams in it so it runs out of huff at about 8200. It's setup for hillclimbing..

Made 203 at the wheels last time at 7500, with the scatter and a miss, which was a promising start...Should have found another 10hp, I think we'll be on the hard road after that... There's a 76 exhaust cam sitting on the shelf if I get excited...

Is this a 2 litre FJ20DE?

It's downright scary to think of 6 degrees of scatter on something running near the limit...
You've got me thinking about the 8 miles of timing chain in the FJ now.....I guess it's two short ones, not a thumping great long thing like the L motors...

The dizzy on the FJ is driven off a little short camshaft and jackshaft in the block.
I was using a trigger wheel of my own design and an optical module in the dizzy to get a sync and cylander pulses, and using two Mitsi coils in wasted spark configuration for ignition. I reckon the slop in the dizzy drive was responsible for my scatter problem...
Interestingly enough, a good mate of mine found that the very last of the FJ rotor arms had two whopping great wings on them. Even though he isnt using the dizzy for HT distribution, he left the rotor and cap in place, and found the scatter was hugely reduced. We reckon Nissan cottoned on to it, and the two wings give some air resistance to cut out the slop!! He also ran a 10.1 @146 last time out, so he's doing something right...!

I've sorted my problem with the 60-2 wheel. Turns out the electromotive setup gives a sine wave, the ECU was expecting more of a sawtooth...

Now, off to the dyno to wind the spark in.....I really want to crack 220 at the wheels out of this one....

I ended up with about 6 degrees scatter with a pickup of the end of the cam on the L series. This was due to timing chain slap. The L series engine gave the same scatter from the stock dissy drive under load on the dyno.

This mod was not one of the best I have ever done. It made me think that the cam timing must be experiencing the same timing scatter. As a result I am making up a new roller sprocket tensioner for the timing chain that sits up near the cam gear and will remove all the chain whip on the trailing side of the chain.

At least the A series timing chain is not subject to the same problem as the L series if the parts are in good condition.

I spoke to Steve Newing about this recently,he is a very sucessfull circuit racer here in oz and has experimented with this aswell.He told me that the "timing scatter" you talk of is due to torque flex in the distributor shaft and is about 4 degrees on an A series,even worse on a L series which is about 8 degrees.Pretty crap when you imagine your total timing could vary between - say - 30 and 38 degrees btdc on each high rpm throttle change.His solution was to use the dizzy only to direct the high energy to the corect plug and to make a crank angle sensor like is being discussed here,the sensor he uses is a magnetic one similar to a Terratrip wheel probe sensor.The end result was a beautifull 'crisp' sounding A series weapon........just like mine

A Hall Effect sensor needs to see a magnet doesn't it, you cant just wave a piece of steel past it...?

Sunny, is the EL Falcon pickup an inductive one?
What sort of size was the lug on the wheel you were picking up?

yeh i've set up crank trigger ign to a wolf3D computer
Avdanced Engine Management Systems (AEMS) the computer makers supplied the timing disc and a pick up which turns out to be the same as the EL Falcon sensorI used a Air Cond. crank pulley machined off the outer V section flattened (vertical) the inner section of the V this gave me a face to bolt the timing disc to.
I used the Air Cond. bolt holes to mount the sensor from a piece of alloy flat bar

I am currently making up some laser cut plates bolting on the end of the crank pulley, to crank trigger L series engines. (Hall effect).

Will see how they go in a month or two.
Off the end of the cam it had 4-5 degrees scatter from timng chain slap. Hence the new roller L series timing chain tensioner we are making.