The Engine Upgrades & Alternatives category covers modifications and performance alternatives to the original MGA engine specification, together with the cooling upgrades that support sustained higher loads. The MGA was designed in an era when sustained high-speed motoring was less common than today, and owners who use their cars for continental touring, spirited driving on A-roads, or trackday events often benefit from targeted upgrades to oil cooling, cooling system capacity, and engine output. Two sub-categories are available within this section: Oil Coolers and Performance Engines.
Performance Engines
Performance engines are available for all three pushrod variants as Club Stage II assemblies, offering meaningful gains in power and torque over the standard specification. The Stage II package includes an engine backplate, modified camshaft, gas-flowed cylinder head, balanced flywheel, clutch, pistons, conrods and crankshaft, vernier duplex timing gears, and a choice of increased capacities. Stage II engines are available for the 1500 (1489cc), 1600 (1588cc), and Mk II (1622cc), with the option of further capacity increases where a bigger-capacity rebuild is planned. They carry a twelve-month unlimited-mileage guarantee and are intended as a definitive mechanical improvement rather than a compromise, the balanced rotating assembly alone transforms the character of the engine.
Full specification sheets are available on request.
Oil Coolers
Oil cooler kits are the most popular cooling-related upgrade for the MGA. The three-bearing crankshaft concentrates bearing loads across fewer journals than a later five-bearing design, making oil temperature control important for long-term bearing health. MGOC oil cooler kits are available in two layouts: the Original Type with unions pointing down through the radiator duct panel (matching the 1600 Mk II factory arrangement), and the Accessory Type with unions pointing up through the radiator diaphragm panel, supplied with either rubber or stainless braided hoses. Cooler row options run from 10-row for mild use to 19-row for tuned engines or very hot climates.
A thermostatic bypass valve can be added as a separate item for owners concerned about over-cooling during warm-up. The Twin Cam chassis is pre-drilled to accommodate oil cooler pipe routing, and for 1600 Mk II export cars (chassis 102737 coupé / 102950 roadster onwards) the oil cooler was factory standard, owners of these variants should refer to the Original Type kit.
Wider Cooling and Engine Reliability Upgrades
Related engine-cooling and reliability upgrades are stocked elsewhere in the catalogue and are worth noting for owners planning a comprehensive improvement programme. A higher-pressure radiator cap (7 lb in place of the original 4 lb) is a period upgrade introduced during MGA production itself, the change point was chassis 71832 on the 1500, introduced to address boiling under hard use, and still available to suit earlier cars. A Kenlowe electric cooling fan kit replaces the mechanical engine-driven fan with a thermostatically controlled electric unit, delivering full airflow regardless of engine speed, eliminating parasitic drag at cruising speed, and reducing under-bonnet noise, a separate thermo-switch kit fits in the top hose where the fan mounting is not standard. Long-life coolants such as Forlife, formulated for mixed-metal cooling systems containing cast iron, brass, copper, and steel, protect the MGA's original radiator and heater matrix from the corrosion that can result from modern antifreeze formulations attacking the lead solder in period components.
These items are stocked under the main MGA Cooling section and the Accessories ? Service & Lubrication and Cooling ranges.
Ordering Notes
When ordering engine upgrades, specify the variant (1500, 1600, Mk II, or Twin Cam) and, for the oil cooler, whether an Original Type kit (factory-style routing, unions down) or an Accessory Type kit (upwards-pointing unions, rubber or stainless braided hoses) is preferred. For a Stage II engine, the source engine prefix (15GB, 15GD, 16GA, or 16GC) determines the correct bore size and base build, current availability is confirmed when the order is placed. Wider cooling, electric fan, and coolant upgrades are cross-referenced to their respective catalogue sections.