The air filter arrangement changed with each fuel system generation. Carburettor models use a round pancake-style housing on top of the carburettor with a circular paper element. Two housing types exist, without temperature control duct (some markets up to 1980) and with a temperature control duct that blends warm exhaust manifold air with cold air. SPi and MPi models use a rectangular air filter box with a panel element.
Confirming your fuel system type is essential when ordering.
Engine Breathing, Carburettor Models
The crankcase breathing system routes gases from the flywheel housing oil separator and timing cover to the carburettor via Y-pieces and T-pieces. Hose configurations differ between the HS4 (with separate routing for small bore and 1275cc engines), the HIF44 (Cooper) and the HIF38 (non-Cooper). The Cooper carburettor model additionally incorporated an anti-run-on valve in its vacuum and breather arrangement.
Engine Breathing, Injection Models
SPi and MPi models use a breather rail system connecting the flywheel housing and timing cover to the throttle body. SPi and MPi cars also use an evaporative loss control system with a charcoal canister capturing fuel tank vapour, a thermostatically-switched system fitted to the SPi and MPi engines from 1991, with a similar but distinct charcoal canister arrangement also used on the HIF38 non-Cooper carburettor models from 1992 to 1994. The carburettor and injection canister systems are not interchangeable.
MGOC Spares Range
Within the MGOC Spares Classic Mini catalogue, this category covers air filter elements for all carburettor and injection variants, air filter housings, temperature control valves, warm air hoses, breather hoses and clips for all carburettor types, oil separators, Y-pieces, T-pieces, breather rails, anti-run-on valves, vacuum hoses, charcoal canisters, purge valves, evaporative loss hoses and all associated clips, grommets and fixings.