Factory Tach?

Factory Tach

Where did you get this? Pretty neat.

This looks like a "clock delete spacer" with a needle from the speedo or fuel gauge.

I have this "spacer" on my plain Jane '79 Regal in place of the clock. The turbo has the clock with the gauge pkg. I often thought about going to the salvage yard to pick up a couple of these spacers and "rig up" a tach from it. The only problem would be that once it was calibrated, I would need to stencil in the numbers to make it look factoryl. Anyways, somebody executed this pretty well.
 
Bingo! That's exactly what it is. :)


But it gets even better. The Tach itself is from a G-body Cutlass and are VERY common in the junkyard and already set up for the V6 (or V8).

Assembled, it fits in the instrument cluster without cutting. The only thig left is wiring, which will need a small hole drilled into the cluster.


12 o'clock is 3000 rpm. The only bad point is that 6 grand of tach = 8 hours full sweep, so the hash marks don't line up well. Instead of numbers,I was thinking of adding color bars at the important points, like the red line. The bars would compliment the lights in the boost guage (green, yellow, orange). So far, so good.
 
OK now I see, I have had to dig out a pic of my dash & hold it next to your pic to see. Been wondering why it had no numbers on it. Pretty uncommon for a tack. Where do you get the logo?

I don't have the clock option on my carjust that spacer and have been wondering what to put there. I thought of a Tach, oil pressure, knock sensor, boost guage, a clock or just having BFH make me a 6 logo for it.
 
That's the emblem off the radio bezel.

It actually uses the clock's housing, the clock delete's faceplate, and a speedo needle. So far nothing to complicate. I bought some tiny screws and nuts from Radio Shack to mount the Olds tach to the delete's faceplate. And ten I used two screws from behind for pins to keep the needle between 8 and 4 o'clock (like the Olds faceplate had.)

I also made a new clear cover for it, since the clock's cover has a hole in it for the adjsuting knob.

I just need to attach the dash light and make a wiring harness. It needs four wires altogether. I figure one more trip to the junkyard to get a connector for the tach trigger wire at the distributor.



When I done, I'll make some jigs for drilling the holes in the faceplate and the clear cover. :)
 
You should beable to use the old face plate from the olds to line up marks for the delete spacer plate.
If you rotate the the unit so that the needle starts at 8:00
6k on tach should be at 6:00
I know you already drill & mounted the unit, just a thought
Jim
 
O rpms is at about 8 o'clock already. If you look just above the "u" and "r" you can see the pins (screws). I did consider mounting it so the redline was straight up at 12:00.

Maybe the olds hash marks would wash off with a solvent. But I don't think I could ever make new numbers and hash marks that would look right. I'm not to worried about the actual numbers, I just need some markings for reference points. Zero, idle, shift point and redline.

The tach can also be set for a V8, which would change the scale. Maybe on V8 it would be better. Once I get it installed, I will calibrate it against my scan tool.


I also remeber Starc Traxler telling me about an aftermarket tach that uses spacing equal to hours, so the clock plate would be perfect. But the Olds tach was only $10 and once the rivets are removed, it mounts very easily with two screws. I'd be to afraid of messing up a $50+ tach. :eek:

Instead of a "Turbo 3.8 Litre" emblem, just about any hatpin would work also. I nice V6 logo would look great.
 
Rich-
I'm curious to know what tach uses the clock style markings. Is it something you can find in a parts store or is it a special order deal?
 
I can't remember the name of the company. It shouldn't be to hard to figure out. It would just need zero and 6,000 to be opposite each other, then it would work.

Another idea similar to this tach would be to place a real boost gauge inside the boost light panel, but still keeping the lights working. Now that would be cool. :cool:

And then some LED's somehwere that show rich/lean. And an LED for the torque convert clutch. And.... :)
 
The TC LED would be easy, just use a old 3 pruge lighted switch.
Use the prunge that controls the light to signal when the TC enguages (sp) I did this to test my TCS. It failed, When I would manually enguage the TC it would lock at idle but as soon as I took off the TCS would disenguage. But the switch light worked showing me when the TC would lock for short periods of time.

I like the idea of the boost guage with the boost lights :D
 
A little update:

I went to the junkyard and grabbed the signal connector that hooks in under the distrbutor cap. I just need to solder new wire on to it, run it along the dash wiring harness, through the speedo grommet and through a hole in the instrument cluster.

Then it needs a ignition power source from the fuse block. The ground and the dash light power are already in the pod from the clock.

There are a lot of little steps, but it hasn't beem any harder than putting a model car together. The only major parts are the tach itself, an old clock and a clock delete faceplate.


The junkyard by me sells the Olds tachs for $10 a peice. Not a bad deal for a factory tach. :)
 
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