Adding cam sync to a BMW M10 engine

[CamB]

I'm looking at the logistics of adding a cam sensor to my M10 engine (60s - 80s 4 cylinder).

I was hoping to mount a Honeywell GT101 sensor through the cam cover and pickup off just one of the cam sprocket retaining bolts. As there are 4 bolts, this would mean raising one high enough away from the others to provide a distinct signal. What I had in mind was replacing a bolt with a longer one and a spacer so its head is at least 5mm higher (based on the spec sheet looking for a >5mm high "tooth") than the other bolts.

Would that work? Or will the other bolt heads - being raised themselves from the cam sprocket - introduce a chance of error?

[mattias]

On an M30 I still own I used three stainless steel bolts, and one regular bolt which was  raised about 5 mm just to make sure, and it worked.

[CamB]

Thanks. I didn't think of stainless steel (probably because I am totally not an engineer, and don't even play one on TV). I would usually shy away from it for anything that requires strength but I guess the sprocket is dowelled to the cam, so the bolts probably aren't doing much (and are only 8.8 by the looks of that pic - not mine by the way)...

I will do some bench testing I think, if I can rig something up.

Which means I can avoid drilling an accurate hole and mounting the sensor for a while, which will be the real challenge for my limited skillset and tools...