Generator Tach Drive
 

Can't leave well enough alone. Newest acquisition project is a generator tach drive. I have a '41 flathead which means the fan is mounted on the crank leaving no room for a crank mounted tach drive.


Not interested in an electrical tach, going for period correct.



I've seen some pictures but those have all mounted on the rear of the generator. I have no room there either with two carbs on a hi-rise manifold.


Can anyone refer me to a tach drive setup that mounts on the front of the generator? Don't even know if it exists.


This isn't the first time my 6V Ford internet searches have landed me on SteinerTractor.com. Anything there easily modified for a flathead?

Re: Generator Tach Drive
 

just a thought is a 90deg drive available that would solve your clearance issues

Re: Generator Tach Drive
 

Have never seen one, but that doesn't stop you from creating one. I would also research the drive ratio of the pulleys and whether or not you can get a 90 degree drive that will accurately create the right RPMs for whatever tach you're thinking of using. Mounting off the crank is obviously generating a different ratio than hooking up a tack to the smaller driven generator pulley.

Re: Generator Tach Drive
 

The gen driven ones are rarer than the crank driven ones. I'm not trying to scare you, but I've only ever seen one for sale and it was close to $2K. If you find one, make sure it's complete. I believe it's two clamps that go on the generator, an end cap with a female receiver that is threaded for the cable housing.

Re: Generator Tach Drive
 

Here’s a photo of the generator mounted tach drive.

Re: Generator Tach Drive
 

I've had them on fire trucks ect. for the pump controls. Very common on farm tractors and enpliments- stationary engines. they are out there, check with farm construction repair shops-old time electric repair shops. Massey/fergason used them. Newc

Re: Generator Tach Drive
 

Re: Generator Tach Drive
 

Thanks for the info gentlemen. Saw one on a post about a survivor hot rod barn find a few months ago. Can't remember whether it was here or H.A.M.B. Thought is was so cool. Love to have it for my car.

The car is never done. There's always one more thing to spend your money on.

My car is a '41 Ford Special Business Coupe so there's a VERY short ceiling on what the car would ever be worth but it's fun to take what you have make it what you really want it to be.


It's already so far beyond original that that's not a big factor. It's not a survivor and the interior is nice but incorrect.

Re: Generator Tach Drive
 

Here's another type of a generator mounted tach drive that I saw on an amazing '32 hot rod roadster this summer.

Re: Generator Tach Drive
 

Re: Generator Tach Drive
 

Massey/ Fergason generators have a tack drive off the Rear of the generator. Newc

Re: Generator Tach Drive
 

That makes the most sense to me. Otherwise, on an old Ford with the generator in the stock position, the drive cable would have to make quite a loop or you'll need to use a 90 degree elbow to reduce it. Driven off the back would be ideal.

Re: Generator Tach Drive
 

WORKS ONLY ON TRACTORS ! The tach had different labels on the face like 1sr gear, 2nd gear and third gear ...........and even then it was a guess as to how acurate it was .
I spent some time to make one up for a customer and we just never got it right ????

Re: Generator Tach Drive
 

That's some mechanical coolness right there!

Re: Generator Tach Drive
 

It's not any more gear ratio dependent than a standard tachometer drive.

The RPM is going to be the same regardless of whether its driven off the front or rear of the generator, which will be some ratio of the crankshaft RPM based on the pulley diameters.

In the end it's all just math. Getting the proper reduction in the adapter will be probably the most tricky part of a generator driven tachometer.

Re: Generator Tach Drive
 

I have a 630 Case tractor that has tach drive on back of generator. Don't know if the tractor ones were brand specific or if Delco and others made them.