The MGB ignition system relied on Lucas distributors throughout, the 25D4 with side-entry cap on early cars to 1967, the 25D4 with top-entry cap from 1967 to 1974, and the 45D4 from 1974 onwards. Some late cars in the 1978 to 1980 period used an alternative Ducellier distributor. Getting components correct for the specific distributor type is essential, caps, rotors, and points differ between types and are not interchangeable. Ignition coils are available in four specifications covering the full production run.
The standard coil with screw-in HT lead suits earlier applications. The chrome bumper coil covers 18GD, 18GG, and 18V engines. The ballasted coil suits rubber bumper and V8 cars. Sports coils are available in ballasted and non-ballasted versions, confirm the system type before ordering.
A rubber waterproof coil cover and stainless steel coil cover are available. HT lead sets cover 25D side-entry for MGB to 1967, 25D top-entry, and 45D for 1975 onwards. The Lumenition Optronic electronic ignition kit is available for chrome bumper 25D distributors with a fitting bracket. Iridium and standard spark plugs are available alongside all associated ignition hardware.