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Found some manifold studs late yesterday, that were exactly the correct size & length, for attaching the 36:1 toothed wheel, to the 5K crankshaft pulley. 8mm M1.25 38mm long. The pic below, shows them fitted with some thread locker, in the pulley threads. Four (4) off 35mm OD thick 1/2" washers, Araldited together, made a perfect 9-10mm deep spacer, between the back of the toothed wheel, & the original washer face on the crankshaft pulley. That creates a gap of about 10mm between, between the back edge of the toothed wheel, & the crankshaft pulley V belt edge flange. It is important, that there is no ferrous material, very close to the teeth on the trigger wheel, if the best signal is to be produced from the sensor. This is not an issue, when this wheel is used, with a 3K or 4K crankshaft pulley, as they are only have a 110mm O.D., & the teeth are well clear from any surrounding ferrous metal, of the pulley. I found a website for for a USA manufacturer of trigger wheels, that suggests a clearance gap between the end of the tooth & the face of the Hall sensor, of 3-5 thou, per inch of diameter of the wheel. For this particular wheel, that works out about 0.46mm - 0.76mm clearance. So I assembled it all, & adjusted the sensor position, to one tooth, with a 0.5mm feeler guage. I then rotated the wheel, with the feeler across the face of the sensor, & it neither got looser or tighter, so I'm very happy with the eccentricity of the trigger wheel. Thanks Danel ! The bracket that the Hall sensor is attached to, should not be made of ferrous material, so the magnetic flux to the sensor, is not diverted or "drained", by nearby ferrous material. I have made my bracket out of a thick piece of thick aluminium, which you can spot in the pic above. This trigger wheel setup, is critical, as to whether the result is a flawless & reliable EFI performance or not, so I am making sure, at this point, that it is as good as I can get it. After it is assembled, I'll crank the engine over, & view the sensor pulse output, with an oscilloscope, to see how clean the pulses are. Cheers Banjo

So the 36:1 toothed trigger wheel for the 4K engine arrived, & is now fitted to my 5K engine. The 36:1 toothed wheel will fit 3K, 4K, & 5K crankshaft pulleys, as the mounting points are identical on each. The 3K & 4K crankshaft pullies, are about 110mm O.D., whereas the 5K crankshaft pully is about 145mm O.D. The toothed wheel is 155mm O.D. so sits nicely on the 5K pulley, with the teeth clear of the pulley edge, as seen in the above pic. The toothed wheel, will bolt straight up to the 3K & 4K pullies, but has to be spaced on the 5K pulley. My 5K crankshaft pulley is dished, to take additional pullies, & has a harmonic balancer built into it, so the toothed wheel will crush the harmonic rubber, if bolted up, without a spacer. The centre bolt also needs a spacer behind the toothed wheel, as there is a gap there to the crankshaft pulley, of about14-15mm. Likewise, the 4 off 8mm x 1.25M mounting bolts, will need to be about 35mm long, & need spacer tubes behind the toothed wheel. I'm actually going to use manifold studs, that happen do be available, in that exact size. Makes it a lot easier to assembly, than with bolts, & spacers behind the toothed wheel. This 36:1 toothed trigger wheel, is laser cut from 6mm thick plate, rather than being a machined one, which cost a lot more, to manufacture. Considering it is laser cut, it is of good quality. I set it up with a piece of clamped metal near the teeth, & measured the eccentricity, & lateral run-out, & it was much less than 1mm out. The best & easiest point, to mount the Hall tooth sensor, is off the K engine block A.C. bracket mounting points, just around the corner. You could make a fancy one, that was mounted off the "timing chain cover", but at this stage, that is a lot of work, & will have to wait until another day, when the timing chain cover is off for another reason. Last night, I temporarily hooked up a Honda Hall effect sensor, I got on ebay. I used one of these previously, for counting the starter teeth on the flywheel, & it worked well. I cranked the engine over, without spark plugs, & was greeted with a clean stream of pulses from the Hall sensor, via an opto-coupler & an LED, on a little board, that also produces a 0-5 volt square wave pulse train, for the Speeduino ECU input. Here is a good general video about crank & cam toothed wheel sensors. https://www.youtube.com/watch?v=HW0ENqcxNSg Now I know it all works, I'll take the toothed wheel off, & paint it, as being bare mild steel, it won't take long to rust, in our Qld. weather. Cheers Banjo