Vac pump drive for ignition timing pickup?

Has anyone successfully employed a geared or belt driven ignition timing pickup driven from a vacuum pump drive? I know mine is over driven 21:16 (1.31:1) and would have to be reduced back down, but on the H2, it?s in a great place to do something with. Thanks.

rjcthree said:

Has anyone successfully employed a geared or belt driven ignition timing pickup driven from a vacuum pump drive? I know mine is over driven 21:16 (1.31:1) and would have to be reduced back down, but on the H2, it’s in a great place to do something with. Thanks.

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I built a timing pickup device to go in place of the mag for my 320. I am now looking at options for the 540, but it has a 1.5:1 mag drive. I thought about gearing, but it makes the machining job much harder (no cnc for me). I will probably make a ring to go on the crank instead. I have an old flywheel with the 7" pulley, so will be difficult to put magnets on it (not much meat to work with).

Even if you want to make a gear redution setup, you may have a hard time getting off the shelf gears to get the reduction done right, unless you have the tooling to cut your own gears.

Larry