Adding a Spyder dash?

[b74eqcm]

I'm thinking about adding a spyder dash to my 63 Monza Coupe (102/4 speed). Is there a place on a 102 hp engine to add the sending unit for the cyl head temp gauge? And will the tach work with a Pertronix setup?

Thanks!

Jim T.

[spyderman64]

You can buy an adapter from Clark's to mount a temp sender in the left cylinder head. The tach works fine with a Pertronix.

[bbodie52]

The cylinder head temperature gauge sending unit (thermistor) uses different threads to fit the unit into the 140 hp or turbo cylinder heads found in Spyders or Corsas. The adaptor offered at the bottom of the catalog page is needed to provide a proper fit to other heads. A good thermistor is hard to find and often expensive. Alternately a VDO or similar aftermarket cylinder head temperature gauge can be fitted, but the style will not be a perfect match. These aftermarket gauges usually utilize a sending unit that fits under a spark plug.

http://www.corvair.com/user-cgi/catalog ... IN&page=51

Cylinder head temperature sensing units

The Spyder and Corsa had head temperature gauges. The sender is a thermistor, not to be confused with a thermocouple — which requires an amplifier.

The thermistor is a resistor that varies according to heat. Basically works the temp gauge the same way the gas tank sender works the gas gauge. The thermistor is fairly durable, except the porcelain insulator which tends to get damaged when the engine is worked on. AC made the Corvair thermistor and even sold it to some of the small aircraft folks — way back then.

This Google search will provide you with some sources for aftermarket cylinder head temperature gauges — if you want to try that approach...

https://www.google.com/search?newwindow ... ZUSPzsJalY

...And will the tach work with a Pertronix setup?

The tachometer should work fine with a Pertronix-based distributor. The Pertronix module substitutes transistor-based switching triggered by a magnetic pulse for the mechanical ignition points, but in either case an on/off connection to Chassis Ground is what the ignition coil sees. The tachometer sensor wire bridges off of the negative side of the coil, and the tachometer electronics counts voltage pulses seen at the coil negative terminal and translates those pulses into an instrument display in RPM, calibrated for a six cylinder engine.

Here are some Spyder instrument panel detail pictures. It is interesting to note that Chevrolet engineers included a cast mount area to support a Powerglide automatic transmission shift lever, even though the Spyder was never offered with a Powerglide transmission. Perhaps GM considered offering the custom instrument panel as an option on the Monza — even if it had an automatic transmission. But such an option was never offered to the public...

[b74eqcm]

Thank you!

[66vairguy]

The heads with the thermistor sender had different threads AND A DEEPER HOLE. Do not attempt to rethread the snap switch head hole (do NOT drill it deeper or you'll ruin the head). You need the adapter to install the thermistor. See http://www.corvair.com/user-cgi/search.cgi?part=C10888" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;


The tachometer will work with a Petronix unit. The tachometer was well designed and is tolerant of voltage and dwell variations. On the LM units the meters are failing due to high mileage and the large sweep arc. The EM units have a narrower arc and the meters tend to last longer. The circuit boards are repairable. There are TWO calibration procedures after a repair - one electronic, the other mechanical (meter). Best left to someone with experience.

The speedometers have a trip odometer in addition to the regular odometer and the added "load" to turn the gears, combined with the fact the lubricant is dried up after decades, usually means the odometer(s) do not work. If they still work I highly recommend you find a good old fashioned speedometer shop to lubricate the speedometer and calibrate it. If kept lubricated the speedometers will last a long time. Again - not something for an amateur to do. Parts are getting scarce.

[terribleted]

Do not forget you will also need the underdash switch bezel from a Spyder or some other bracket to mount your wiper switch and lighter to.