For those of us who were young, impressionable hot rodders in the '50s and '60s, there was one piece of equipment that was absolutely mandatory for our cars, a Sun tachometer. It seems as though any car with performance potential, real or imagined, was equipped with one. The only variation was the method of mounting.
One method of mounting was to screw them to the top of the dash, presumably to be at "eye level," so the tach and flagman at the drags could be seen at the same time. Then, when the tach's needle hit the appropriate number, it would be in the line of sight for ultimate power shift.
The other common method of mounting was somewhat more clandestine. Those who drove sleepers (typically, meek looking sedans with dog-dish hubcaps and lots of horsepower under the hood), strapped theirs to the steering column with a huge hose clamp so as not to give away any secrets. Regardless of where it was mounted, if your car was hot, it had a Sun two-piece tachometer.
These early tachs had a number of noteworthy features and their appearance was certainly one. The chrome face, as well as the distinctive mounting cup, set them apart from the other designs that were available. And of course, the fact that many big-time drag racers used them didn't hurt their popularity either. These tachs were also unique in that they required a separate transmitter. That's why they were referred to as the two-piece style.
Usually located under the hood, the transmitter was specific to the engine and electrical system, such as six-cylinders and twelve-volts, eight-cylinders and six-volts. The transmitter required four electrical connections: ground; distributor side of the coil; plus on the tach head; minus on the tach head. In addition to the components that sent the required signal to the tach, the transmitter featured a removable plug that gave access to an adjustment screw that could be used to stabilize the meter reading. It contained a unique 1.35-volt battery that made it all work.
While two-piece tachs were the hot setup in their day, when Sun introduced the self-contained Super Tach--it didn't require a transmitter and featured a larger, easier to read scale--the switch was on. Suddenly, the old two-piece design wasn't the one to have and you could hardly give one away. But then, times change, don't they.
Today, more and more builders are looking for traditional accessories that will add a period perfect touch to their street rods (or early musclecars). One of the most sought after items is a two-piece Sun tach. While they are getting harder to find, the real problem is that the battery for the sending units is scarce--it hasn't been produced for quite some time. In addition, any two-piece tach you're likely to find is probably less than pristine. But don't fret, because for every problem, there is a solution. If the problem is how to make a Sun tach look good as new, and operate even better, the answer can be found at Williamson's Instrument Service.
In business for over 19 years, Williamson's is a family operation. Paul Williamson runs it along with his daughter and son-in-law, Sande and Ron Beliles. The trio specializes in the cosmetic and mechanical restoration of virtually any instrument. They are known in the restoration world for outstanding quality and workmanship. They also offer a host of services for street rodders, including the conversion of gauges from 6- to 12-volt operation. They also offer complete restoration services for Sun tachometers. As with all the instruments they restore, Williamson's can resurrect a Sun tach and bring it back to its original configuration, or if the customer desires, can install any of a variety of scale faces. In addition, they can also fix the fatal flaw in the sending units by doing away with the battery (some senders had one, others had two). Williamson's has developed a method of powering the sending unit internally, with no modifications visible from the outside.
Not only does the modification do away with the nearly impossible to find battery, but it also eliminates the need to make adjustments to the transmitter in order to study the meter. The end result is a vintage looking instrument that works as well as a contemporary design.If you have an operating tachometer and all it needs is cosmetic restoration and/or a battery conversion, ship it off to the Williamson's and they'll do what needs to be done. However, if you are dealing with a tach that is in an unknown condition, or are scouring the local swap meets to find one, Ron offers a few tips.
To determine the condition of one of these tachs, hold it so the dial face is vertical and at eye level. Held this way, the needle should be close to zero. With a quick flick of the wrist, rotate the meter and watch the movement of the needle. The needle should move up and then return to the same place (If the needle stops in a different location, remove the meter from the case--as stated below--and place a small piece of tape to the end of the pointer. This will keep it from moving in shipping. If this is done, there is a good chance it can be repaired). If the tach clears the first hurdle, you're ready to go on to the next. For the next test you may want to enlist the help of a friend. Using a 1 1/2-volt battery, and a short pair of jumper wires, quickly touch and release the terminals on the back of the tach (plus on the battery goes to plus on the tach, minus goes to minus) while watching the needle. A quick flash of the terminals should make the needle deflect almost full scale, another good thing. But remember, this is a touch and release maneuver, not a sustained connection. If the tach passes these two tests, you have a restorable piece. If the needle is free and it fails this test, pass on this tach and keep looking.
Now, if your tach only flunks the first test, all is not lost and it may be repairable. If the needle is stuck, don't bang the tach around, or worse yet, pry on the needle. These units are fragile and you'll do more harm than good. The best procedure in this scenario is to remove the two nuts on the back of the tach (found at the 9- and 3-o'clock positions) and carefully remove the meter from the case. Next, with a piece of tape half the size of a postage stamp, secure the tip of the needle to the dial. This will prevent any further damage. Then, carefully box it up and ship it off to Williamson's so they can have a look. With today's nostalgia trend, it seems as though we're looking for stuff that at one time we couldn't wait to replace.
Fortunately, there are folks like the crew at Williamson's to help turn back the clock and make what's old, new again. Now, if I could just figure out where I put that old 8.5 tach and sending unit the Sun would shine again.
 There are some accessories...  There are some accessories a hot rod has to have. On the top of the list is a Sun tach. This is a sample of Williamson's Instrument Repairs workmanship, a beautifully restored Sun two-piece tachometer and sending unit. |
 This is a "before" example...  This is a "before" example and is somewhat typical of tachs found at swap meets. As long as the meter is salvageable, most can be restored. |
 Paul Williamson (left) has...  Paul Williamson (left) has spent two decades repairing and rebuilding instruments of all kinds. If it can be fixed he, along with the team of Ron and Sandi Beliles, can do it. Another Williamson specialty is replacing the damaged tubes on mechanical temperature gauges. |
 Williamson's pioneered the...  Williamson's pioneered the conversion that eliminates the battery (the rectangluar piece under the pen) from the sending unit. Completely hidden, the conversion is undetectable from the outside, and the tachs work better than when they were new. |
 Sun tachs came with a variety...  Sun tachs came with a variety of dial designs, some were for general aftermarket applications, others for GM installations. Williamson's can refurbish any of them, or install a different face to fit a specific need. |
 As part of the restoration...  As part of the restoration process, all the original lettering on the sending unit is redone by silk screening. The tach face has also been redone. TChe application in this case is a '62 Chevy. |
 |