Crank sensor and Reluctor positioning

[Sprocket]

I am looking to use the standard sensor for now, the 16v will use a different, custom reluctor ounted with the pulley.

The flywheel mounted reluctor is currently 36 -2, TDC and BDC missing teeth. I will modify this and weld on another tooth at BDC, giving me the 36-1.

What i Need to know is where the sensor is in relation to the missing tooth at TDC. For example, if i were to use Ford's EDIS (wich i am not) the missing tooth would be at TDC and the sensor would be at 90 deg BTDC. what is the sensor location in relation tho the missing tooth at TDC for normal DIS operation with VEMS

[rob@vems.co.uk]

Two missing teeth are not uncommon on high compression engines, but IIRC the teeth are missing 180deg from each other? This is similar to what Renault were doing at the time, it lets the ECU know that theres a cylinder at TDC, but it doesnt know which one - the distributor sorts that out.

Trigger wheels are often a 'black art' and welding one on may cause problems that we can't even guess at.

The position of the missing tooth is not so important as we can set a trigger_tooth in the configuration, then define its position BTDC.

After talking to the guys who've done a number of installs with custom triggers I personally would do one of two things:
a) Cut off all the teeth except for one either side that will pass the sensor 90deg BTDC, and sort a cam sensor.  I'd use the Honeywell 1GT1 http://www.pe-ltd.com/Downloads/hall_effect_GT1.pdf sensors for this.
b) Use a known good trigger pulley setup, I know that Chris Good is running a 36-1 on his MS'ed Mini

[cliffb75]

Rather than weld a tooth on, might be better to get some machined off.

Rob and the developers went through this with me, and convinced me that we don't really need that many teeth for acceptable accuracy. one tooth per cylinder is enough.

How about that as an option?

[Sprocket]

MMMM, I think i will add a tooth, its not going to be that difficult, I have another flywheel knocking about with another reluctor ring so i can rob the teeth off that and tack them on. Really dont see it being an issue.

Cam sensor is difficult on the A series. I want to dump the dizzy on the 1400 so i wont use that.

I have a custom crank trigger kit form Specialist Components for the A series but i want to keep that for the 16v for now. The real aim is to get it to work with the original sensors

I picked up the unsprung AP racing friction plate from MiniSpares today, I have the MG Metro Turbo clutch pressure plate already so Im gonna have a go on Sunday

So I still need to line up the sensor 90 degrees before TDC

[rob@vems.co.uk]

Where is the sensor currently?  You can adapt the triggering software configuration to cope with most missing tooth and sensor positions.

[Sprocket]

I thought you needed either one missing tooth or more than two, so that with the software, the ECU knows where TDC on #1 cylinder is for DIS to work

Missing teeth at 180 degrees apart, the ECU cannot decide which coil to fire for the right cylinder without some sort of other cam position. This is something at this time i cannot do. Using the MPi block would allow this as it has one already, Camshafts are limited to mild profiles though

Anatomy of the Rover Mini SPi (MPi very similar) crank shaft position sensor





Sensor is mounted in the Flywheel housing just below the starter motor as indicated, you can just see the hole and its fixings


Crank sensor looks like this


Very neat package TBH

[rob@vems.co.uk]

I thought you needed either one missing tooth or more than two, so that with the software, the ECU knows where TDC on #1 cylinder is for DIS to work

Crank sensor looks like this


Very neat package TBH

I was talking about with the 36-1 trigger wheel.  You can stick with the stock trigger location.