Austin Seven Distributor Rotors
Taken from the Lucas Overseas Technical Correspondence Course
Section 3 - Coil Ignition
"The most noticeable feature of our rotors is the extended electrode. Most of you know that the reason for this is to prevent back running of the engine (not backfiring).
The important point is always to have the correct lead of rotor in the distributor.
The direction of rotation of our distributors is always given viewed from the driving end.
Therefore the extension of the electrode must always point in the direction of rotation.
The rotors on the left and centre will both be fitted to clock distributors; that on the right to anti-clock distributors."
The Austin Seven Motoring Pages