Question:
How do we fit the crankshaft sensor? We cant see anything to attach a bracket to so we can fit it so it points upwards.
Alternatively, is it possible to rotate the trigger wheel either to one of the other possible positions around the pulley to enable us to mount it elsewhere?

Answer:
We mount the crank sensor at 6 o’clock on the engine is for a several of reasons;
1. Because we like to run everything dry sump for motorsport, we simply put an extra lug on the front of the sump pan and you have the ideal mounting position for a crank sensor.
2. This part of the engine being furthest forwards makes a nice stable position for the shortest possible mount which keeps the sensor stable. If the bracket gets longer, it would become a bit like a ruler being pinged over the edge of a desk and the bracket and stabiliser required to prevent this becomes very hefty. I have seen brackets on some engines over 13mm thick vibrate just like a ruler at specific rpms, which causes the ECU to miscount the time between teeth on the trigger wheel.
3. You don’t necessarily have to move the trigger wheel, you just instruct the ECU of the new position of the sensor. The only problem with this is that you have to calculate it carefully and then check it with a strobe.
4. The problem with mounting the sensor anywhere else in the 360-degree circle of the crank trigger wheel is where do you mount it as you have to miss cambelts, alternator belts and potentially oil fittings, then you also have the length of the bracket which we have already gone into. All of which adds to the complication.

For those engines that have to be wet sump due to regulations, we always used the tin sump pans. We fabricated two steel plates which were welded to the sump vertically and spread apart sufficiently to bolt and alloy block between them that would hold the crank sensor in the same way it does on the dry sump version. We would always make the block slightly too close so that the sensor could be shimmed away from the trigger wheel to give the optimum setting rather than aiming for the optimal gap and potentially ending up with something that was too big. Unfortunately these were only ever fabricated in the workshop and no drawings were ever done or photos taken because it was over 25 years ago.

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