Adding the Crank Angle Sensor to the Mazda Transmission
Drill a 0.700“ hole for the VR sensor. That's a 45/64” drill. Or a 11/16“ and massage it a bit with a Dremel sanding drum. I found out that if you just drill an 11/16” hole, it is just tight enough where you can get a press fit with the VR sensor into the bellhousing hole. So you don't need to weld on a bushing, you just press fit the crank sensor into the hole and epoxy seal it in place. Make SURE you leave a small air gap between the flywheel and sensor!!!
With the engine and trans bolted up again you can use a depth gauge and measure the depth between the outside surface of your transmission to the top of a tooth on the flywheel trigger wheel. You want an air gap of about .010“ to .032”. So subtract that from your measurement. I got a bushing that allowed the crank angle sensor to fit snugly into and shaved it down to get the proper depth so the sensor fit inside the transmission but with a .010“ air gap to the flywheel teeth.
Shown here is the “trial fit” with JB weld. You can either do this with a bushing or leave the hole 11/16” and press fit the sensor into the hole instead of using a bushing to hold it.
Original post from Silent Dawn fe3 B series swap writeup on the mazdatrucking.com forum