Twin Knob Rally Clock Install in to an early S30z

[gav240z]

Hi everyone,

Since finding any information about these clocks is so scarce and I had to figure this out from scratch. I thought I'd share the info with others as it may help someone else lucky enough to have 1 of these clocks and it can serve as an educational piece for others who are interested in this sort of thing.

 

So to begin with this is what the clock and oscillator box look like.

 

These mounting photos were provided by Alan T (HS30-H) here:

http://www.classiczcars.com/topic/22917-rally-clock-clocks/?p=203553

 

The oscillator box is attached via a long piece of wiring loom, I had read that the oscillator is mounted on the firewall, but I didn't know exactly where?

 

There is also a positive and negative wire that goes to the clock unit itself. These are exactly the same as the standard clock as shown here:

 

Looking at this diagram helped me figure out where to mount the oscillator box.

 

 

But then I got to the car and was confused when I saw this?

 

 

I thought maybe it went near the kick-panel?

 

On the other side was the fan unit and I didn't think it would go directly under there?

 

It turns out you need to pop out the little square tabs in the firewall insulation.

 

It felt weird removing something that had been on the car for 40+ years untouched and left there from the factory for this specific purpose.

 

Behind the 2 tabs are bolt holes and from the diagram above it looks like the screw that fits into them is the same as that which holds the 3 center gauges into the dashboard.

 

I brought 1 spare with me from another dashboard I have.

 

But I didn't have the same for the other side of the bracket so I used another temporary bolt for now. I'll get another 1 of these bolts for the other side to match later.

 

On top of the oscillator box is a label that says UP, which means mount upwards obviously.

 

So I did just that

 

Next I installed the clock, I removed the old clock as you would any other gauge. The tricky part was getting the now polished and scratch free Rally Clock into position without damaging it. This was actually a little tricky and I had to turn the clock on it's side get it near the gauge pod hole and then turn it 90 degrees again to face the front of the dash and I managed to put it into the gauge pod without any damage etc.. It seems the clock has a little less space around it mainly because of the glove box.

 

Then I screwed the retaining nut into place and put the globe in as with any other gauge. The only difference was that I had to plug the oscillator loom in also. So I had to feed the loom over and around the heater/fan blower unit and it was the perfect length to plug right into the oscillator.

 

How it looks installed on the S30z.

 

Finally I put a small little video together to show the clock working and in action and how you use it. Which is basically what this image shows.

 

Video

[PB260Z]

Nice work Gav and very detailed instructions it looks fantastic and certainly not something you see everyday.

 

Cheers

 

PB

[gav240z]

Hey thanks mate. Yeah I'm really happy with it, it is certainly an intricate little thing. I forgot to mention on the video it emits a low frequency hum. It isn't very loud like I've read some people say it is so maybe if they are loud is is a sign of wear or faulty oscillator box. You can hear the mechanical noise of the clock gears moving if you listen carefully.

 

Sort of adds to its charm. Pressing the right hand knob resets the sweep hand or zeros it. Which I figured out after the video.

 

I wanted to install it because I asked Ron what kind of maintenance they need. He told me best thing to do is keep it running. When old electronics sit unused they can deteriorate. So best thing is to keep it humming along.

 

Not sure what I'll do about the second 1 yet but I might set it up in my house and have it running since HS30 00150 might not be on the road for a while yet.

[PB260Z]

Not sure what I'll do about the second 1 yet but I might set it up in my house and have it running since HS30 00150 might not be on the road for a while yet.

 

Would make a cool desk clock. Maybe make a little dash pod out of fibreglass and incorporate small 12VDC power supply in it ?

 

Or sell it to someone on here 

 

Cheers & Merry Christmas mate.

 

 

[gav240z]

I figure this was probably the most relevant place to put this, here is a photo of the internals of an oscillator box (you can see the tuning fork) and all components used in it.

 

 

The tuning fork is quite unique apparently where as the rest of the box is relatively standard 1970s electronic components.