Tach with Lil fuel gauge
 

I found one after searching dozens of yards. I cleaned it up, painted the needles and installed it and the fuel gauge works. Does any one know how many pulses the tach needs to work? I have a few options for signal out put for the cummins but need to know the pulses so I can order the right unit.

The donor truck was a top kick with the 8.3 or something non turbo cat engine.

Re: Tach with Lil fuel gauge
 

Now you just need a clock.

Re: Tach with Lil fuel gauge
 

Yes sir, when I find one worth using.

Re: Tach with Lil fuel gauge
 

I just went to look at a shortbed frame and can across a cluster just like that I paid the guy cash right there offered him 100$ for it... We got to talking and he is I ended up with an amazing deal, frame, can complete with interior and a new fuel tank and sender all for 300$

That's the beauty about old chevy owners they pass on the generosity to each other

Re: Tach with Lil fuel gauge
 

Cat Diesel Tach. I believe it runs off a tap in the windings of the alternator so Pulley diameter ratio and the number of poles in the alternator will all enter into it. If you're not driving it with the same Diesel alternator with the same diameter crank pulley you'll have some head scratching to do.

I'd start by setting up a bench experiment to drive the tach with a DC power supply, audio frequency generator, and frequency counter. Then I'd record the frequency to RPM relationship every 500 RPM.
Then I'd attach the frequency counter to a stator tap on the AC side of the diodes in your alternator and observe the frequency vs RPM from the alternator...

Some "Light Reading" :D
http://www.cumminsforum.com/forum/89...ring-tach.html

http://www.dieselplace.com/forum/63-...lead-tach.html

http://www.turbodieselregister.com/t...for-tach-drive

http://forums.qrz.com/showthread.php...r-driven-Tachs

Re: Tach with Lil fuel gauge
 

Is that km/h? 140 mph speedo would be cool....

Re: Tach with Lil fuel gauge
 

Yes kilometers, he's in Canada. I wonder if you could regear the speedometer gears to make it read correctly as MPH.

Re: Tach with Lil fuel gauge
 

Hatzie, it is all making sense now, guess I have to make a trip to the wreakers where the gauge came from and measure the crank and alt pulley and pull the alt. I have to spend a few hours searching here again too see if anyone has got one of these tach to work.

Re: Tach with Lil fuel gauge
 

The speedo is in kph. The iroc speedo might be 140 mph.

Re: Tach with Lil fuel gauge
 

all you need is a dakota digital dsl-1 hooks to the altnator and give you your 8 cly pulse out put you would need for a cummins ive done it on a few of my trucks

Re: Tach with Lil fuel gauge
 

For a Gasoline engine tach...
His tach is off a Cat Diesel in a 40-60 series heavy hauler and it's going on his Cummins...

"The donor truck was a top kick with the 8.3 or something non turbo cat engine."

Re: Tach with Lil fuel gauge
 

150mph speedo even better

http://i1269.photobucket.com/albums/...1E6874D383.jpg

Re: Tach with Lil fuel gauge
 

Many of the GM medium duty trucks with diesel engines used a magnetic pickup mounted near the flywheel for the tachometer signal.

Here's some info from an old GM service bulletin:

http://i175.photobucket.com/albums/w...ps9a8ccae6.jpg

http://i175.photobucket.com/albums/w...psf3cf0618.jpg

http://i175.photobucket.com/albums/w...psfd9d0e8b.jpg


If this applies to your tach, the required pulses per revolution will equal the number of teeth on the donor truck's flywheel.

Re: Tach with Lil fuel gauge
 

The plot thickens...
Bunch of worthwhile info out there in TSB sheets...

Re: Tach with Lil fuel gauge
 

Where did you get that from? That is great info, I must have really good look at the donor truck, see which it is. I should have scratched down the vin.

Re: Tach with Lil fuel gauge
 

i would love one of those clusters, guess i need to keep my eyes peeled

Re: Tach with Lil fuel gauge
 

looks good,nice score!

Re: Tach with Lil fuel gauge
 

I have a few TSBs from the 70's but haven't had time to scan them. You see them at swapmeets sometimes. I've seen that one before but I don't believe it's in my hardcopies.

Re: Tach with Lil fuel gauge
 

I had a little time today to play with the tach and hook it up to my 89 gmc plow truck, it worked but at 2000rpm it read 250rpm. At idle it read just off the peg.

I've searched for shops in my area for someone to get me sorted with figuring out the pulses per but came up with nothing. I'm hoping that the Dakota digital box will work with its adjustability.

Re: Tach with Lil fuel gauge
 

that cat motor is a 3208. its a v8 so the gas v8 tach will work back and forth. as long as sender is the same. alt or mag or what ever still 8 pluse

Re: Tach with Lil fuel gauge
 

I went through this hooking mine up. It picks up off the flywheel teeth. I found a magnetic pick up, drilled a hole in the bellhousing and wired one wire to ground with the other to the tach. It works, but is off since the 454 uses a 168 tooth flywheel and the medium duty trucks use different counts on their flywheels.