folks;
im trying to measure the rpms on my marine deisel engine by some means by measuring it on the flywheel. i had something of a brainwave yesterday and i was wondering if you folks could help. im thinking about buying one of the non contact tachs for rc planes and using it on the flywheel if i used a sharpie marker and made a thick line across the center (to act as the "prop"). the flywheel is about 3.5 inches across, and the absolute max it will be spinning is 3000 rpms. will this work or will i need to paint the whole flywheel for better contrast, or will it even work then?