Hi all,

I'm up to where I now need to design the distributor system for my V12 engine. I want to run the bottom end of the distributor shaft directly from the crankshaft via two perpendicular gears. This is where I start to perhaps over-think things or not think clearly enough (I'm not sure). I'm pretty sure that the way to go is via helical gears as in this picture......

but this old picture is actually an example whereby the distributor is being driven via a camshaft (disregard my red writing as that indicates my need). The beauty with this example is that the camshaft because of it's small diameter, allows for the two gears to have the same diameter and therefore a 1:1 ratio for ignition purposes which makes things easy peasy. Obviously, a crankshaft is certainly a lot thicker in diameter and will require a bigger gear, therefore I am going to lose this ratio and that is where my head gets foggy with gearing!

I know I can get many different types of gears to play with from Traceparts so that's no problems (I prefer to stay away from Toolbox when possible) but the advice I'm seeking is :-

Is this the proper type of gearing to use (Helical)?

How can I maintain a 1:1 ratio with two different diameters (is that even possible)?

And yes, I did try google.........

Dave.