Rally Clock Identification

With the recent interest in rally clocks I thought this article might to be useful to all Zcar owners who have rally clocks or those interested in searching for this elusive clock .

The rally clock manufactured by "JECO" was produced in two different models. The early rally clock, 70-73 240Z, known as the 2-knob clock has a separate box called an oscillator attached via a wiring harness. The later rally clock, 74 -76, is identified by a single knob, a calendar, and  no oscillator box. This later version was manufactured by" CITIZEN" and designed for the 280Z.

Early 2-knob Rally Clock
The  rally clock with oscillator was used in the early 70's in Japan and available here in the US through the Datsun dealer as a special order. The oscillator box was separate from the clock but attached by a wiring harness. The oscillator supplies power and timing for the motor in the clock body that runs 24/7. Without the oscillator the clock will not work. If you don't have a working oscillator the clock is a nice table decoration.

There are four distinct functions of this rally clock which allows the user to reset the sweep hand to the 12 o'clock position, stop the sweep hand in place, set clock time and move the inner clock dial.

There were also two oscillator versions, early and late, and both look identical. The early version is identified as having a high pitched or humming sound which comes from a tuning fork. This is one of the most unique oscillator arrangements and for those who remember the Bulova Accutron of the 60's this is a very close copy.

The later version of this oscillator box eliminated the tuning fork by replacing it with a quartz oscillator. In addition 50% of the components of the original oscillator box were eliminated by integrated circuits which were proprietary to JECO. The advantage of this late box is that it is very simple and not as fragile as the earlier version(tuning fork).  However, parts are not available for this box. Oscillator boxes are also interchangeable with either the early or late clock body's.

Oscillators can hum and make noise but that doesn't mean they will keep time. A working oscillator must do both. The latter is what most boxes fail to do.

Caution:
The 2-knob rally clock is very delicate and should only be serviced by capable and experienced hands. The way this box is constructed indicates it was not designed to be serviced and there are two micro ribbons that can be damaged by simply opening the box.  One can inadvertently damage the oscillator box /components rendering it beyond repair and this also applies to the clock body.  Certain parts are not available and close doesn't work with this clock.  The only external adjustment on this clock  is the clock speed.

 

Late 2-knob Rally Clock 

The late 2-knob rally clock was built around 1974 and has the 280Z style bezel, mounting bracket and electrical connector.  The oscillator can be either the early or late version . I have only seen only a few of these later versions and I believe they are very rare.
Serial numbers don't seem to mean much as I have seen very low numbers on this version and higher numbers on the 2-knob early 240Z clocks.

The mechanism and functions are the same in both early and late 2-knob versions. The connector plug on this later version has the ground and lighting connections in the six pin connector(same as the 280Z). This clock is a direct plug in for the late 260Z through 78 280Z.

Calendar or Single Knob Rally Clock
The single knob or calendar rally clock was made for the 280Z, 1974-76,  and has the clock face plate that matches the numbers of these years. The sweep hand  cannot be controlled, the clock center dial is fixed and the clock has a calendar for the days of the month.

No oscillator is need for this clock as it is self contained. The clock mechanism is the same as the basic 280Z clock but is very accurate and reliable. The same problem exists with this mechanism as the standard 280Z.  The capacitors / transistor deteriorate with age and need to be replaced. Accuracy and reliability of this clock is just as good if not better than the early 2-knob rally clock.

I hope this clarifies the differences between the Rally Clocks. Please contact me if you have further questions.

Ron Bradley