I hope that you will find these Heuers interesting and will help me find out more about them. I know nothing about oval racing for what I believe they were made.

The watches were for sale on eBay from Spain and I could not resist, as in many years of collecting Heuer stopwatches, have never seen anything like them before.

On the guarantee booklet is printed CHRONOSPORT (UK supplier of timing equipment for motor racing who also operated in the US) 1. may 1970. But there is also another stamp that says SPECIAL M........S. Could that mean that they were supplied by Chronosport as a special order? Sounds likely.

Case back sticker has no ref. number, but I guess they are based on existing Heuer stopwatches equipped with special dials and hands.

The dial has two hands:
Long black hand that rotates in 3 seconds
Short yellow hand that moves into the black field (175.0mph - 165.5mph) after a little more than two rotations. Then after another rotation it moves into the red field (165.0mph - 157.0mph).

My guess is that they are ment for racing on an oval of a certain length. You would time one lap and know the average speed. Indycar or Nascar?

But as cars get faster year by year so you would have to know what speeds to expect and the dial would only be usable for one year.

Any input would be much appreciated.

PS
The Timing Chart for 2 1/2 Miles is a screen dump from eBay USA so is not related to these timers specifically.