MGB/Megasquirt Ignition

Megasquirt 1 with Extra firmware (MS1/Extra) allows for control of the ignition advance. It requires a trigger input and provides a coil driver. Once working the advance curve can be created using a 12 x 12 table. The control of the coil uses constant energy techniques. For my MGB I decided to retain the distributor to create and distribute the spark to the 4 plugs. Instead of the mechanical contacts I used the optical-trigger used by the Crane XR700 ignition module.It is available as a replacement part. The Crane XR700 has been around for some time and has proven reliability on my car.

The distributor must be locked to give no mechanical or vacuum advance. Any of the Lucas distributors will work. I used a 45D since it is the cleanest looking when the vacuum advance device is removed.