Cosworth HB Spark Box Repaired

We like at good challenge at Modatek! We were recently faced with the problem of a broken spark (ignition) box that one of our customers was running on their Cosworth HB engine, fitted to a Benetton Formula 1 car.

The easy answer would have been to replace this box with a modern unit, but our customer was adamant that we retain the authenticity of the car and engine and try and find a way to repair the existing box. As we always strive to help our customers keep their cars as authentic as possible, it was a case of “challenge accepted”!

This particular spark box was manufactured over 30 years ago, but we were able to track down the original drawing of the circuit boards that it contained. Working with an electronics specialist, after extensive removal of the old potting compound, we were able to identify and replace the parts on the circuit board that had failed. A quick buzz of the spark box on the test rig confirmed that the repairs were successful, and the box was quickly refitted to the car with no further issues found.

As the root cause of these failures was identified as vibration, we also helped our customer install the repaired box with anti-vibration mounts, so we expect it to last for another 30 years!