For those of you who run a tachometer on your Model T, what works best with the buzz coil?
Hi Jim: I realize you are thinking of an electronic tachometer. However, for several years, I too dreamt of installing a tachometer in our '12 Touring. I didn't want to go modern, but preferred to stay authentic for the early period for our T. Finally about five years ago on eBay, I purchased a "New Old Stock" Stewart-Warner mechanical tachometer 0-2500 RPM with a black metal body. The vintage appears to be early 20's.I checked the measurements closely and with a little bit of luck, I purchased a Stewart Model 26 speedometer case and mount, identical to the correct speedometer in our '12.Several hours work and I was able to "shoehorn the tachometer into the speedo case". Next how to drive it? All the literature I could find on mechanical tachometers related that they were always driven at camshaft speed to reduce the wear on internal parts. I purchased an angle drive that permitted me to drive a suitable cable to the tach, via a short shaft that I passed directly thru the commutator!
This installation worked quite smoothly, but to my chagrin, the readings were obviously double the true rpm of the engine! Back to the drawing board!
I had "assumed" the angle drive to be 1:1 ratio whereas in fact it is a 2:1 angle drive.(I should have checked before starting the process!)As a result I made a new drive, taken from the front of the crankshaft, via a serpentine pulley, the same diameter as the crank pulley, and suitably mounted the angle drive to drive the tachometer. I am happy to report that it now works beautifully. See a few photos on the subject. Good luck in your efforts. Tom
The Tinytach apparently works good according to what some folks have posted over the years. Their only problem is a built in battery that's not replaceable - you buy a new tach when the battery runs down. 5 year battery life. Prices vary according to model. I have no experience with them.
I really like your set-up, William. Thanks for the link, Garnet. I am toying with purchasing this one:http://m.ebay.com/itm/4-Digital-LED-Punch-Tachometer-Speed-Meter-RPM-Hall-Proxim ity-Switch-Sensor-/271729387590?nav=SEARCH
I have installed one like Jim posted above on my speedster. I don't have power run to it yet so I don't know how well it works. I drilled a pocket into my aluminum crank pulley and epoxied the magnet flush into it. Then I made a simple bracket to hold the sensor above it. Then all you have to do is connect the wires. In this picture you can see the magnet and the bracket. I'll let you know how it works as soon as I can get it hooked up.
I use the trusted "Ears Tachometer"...I wind the motor up till i get to about 15 MPH, shift to high, and never look at the dash again until i turn the key to shut her off.
I notice in Williams's pics that there is an alternator on his T.
FWIW, I've heard about tachs that use the alternator for an RPM source.
Dug up another nice shot of the mechanical tachometer in our '12 Touring. Enjoy. Tom