Rich Thomas wrote: > Sensor on the crankshaft pulley and an LED or LCD display? Would not be > hard to make with a simple sensor, chip and display. (Not that I know > how to do that yet, but I have been reading about it quite a bit and am > going to order a kit to start some PIC programming. This kind of stuff > appears to be really simple, only a few dollars worth of parts too). >
Here's a how-to page for doing it on a VW, using an optical encoder on the injector pump sprocket and a 4-cylinder gasoline engine tach: http://www.4crawler.com/Diesel/CheapTricks/Tachometer/index.shtml You could do something similar on a Mercedes using the crank sprocket, although it'd be a little trickier to mount everything right. Since the crank turns at twice the speed of the camshaft or injector pump, you'd use an encoder wheel with two light and two dark segments, instead of four.
