An oil cooler reduces engine oil temperature by passing it through a small radiator, typically mounted in the airflow ahead of the main coolant radiator. Oil coolers were a common feature of MGA production across several variants: the Twin Cam chassis was pre-drilled to accommodate oil cooler pipe routing, and oil coolers were fitted as standard to 1600 Mk II export cars from chassis number 102737 (coupé, July 1961) and 102950 (roadster, August 1961). On home-market pushrod cars the oil cooler was an optional extra, and many pushrod MGAs used for enthusiastic driving, competition, or in warmer climates have had oil coolers fitted at some point in their lives.
Why Oil Cooling Matters
Engine oil loses its viscosity and load-carrying ability as temperature rises. On the MGA's three-bearing pushrod engine, where the bearing loads are concentrated across fewer journals than a five-bearing design, maintaining correct oil temperature contributes to bearing longevity. The Twin Cam engine, with its high compression ratio and hard-working internals, generates correspondingly more heat and benefits particularly from an oil cooler, although the broader reliability issues associated with Twin Cam pistons and head gaskets were primarily linked to high compression, fuel quality, and ignition timing rather than oil temperature alone.
Twin Cam Installation
The Twin Cam chassis front crossmember is pre-drilled for the oil cooler pipe routing, with the cooler mounted ahead of the main radiator. The oil lines run from a take-off point on the engine block, along the chassis frame, to the cooler and back. Twin Cam oil cooler pipework is specific to the Twin Cam installation because of the different engine position and block take-off arrangement, and is not interchangeable with pushrod oil cooler kits.
1600 Mk II Factory Oil Cooler
From chassis number 102737 (coupé) and 102950 (roadster), all 1600 Mk II cars destined for export markets left the factory with an oil cooler as standard equipment. The Mk II radiator duct panel was modified with piercings to accept the cooler unions pointing downwards, the catalogue distinguishes between the duct without piercings (1500 and 1600) and with piercings (1600 Mk II). From chassis 103030 onwards, the oil cooler flexible pipe nuts were changed from brass to steel.
The original-type Mk II oil cooler kit uses unions pointing down through the radiator duct panel, with steel pipes and rubber hoses.
Accessory Oil Cooler Kits
For pushrod cars retrofitting an oil cooler, the accessory-type kit is an alternative to the Mk II factory layout. In accessory kits the cooler unions point upwards and the hoses route through holes in the radiator diaphragm panel. Accessory kits are available with either rubber hoses or stainless braided hoses for greater durability and resistance to abrasion. Both kit types include the block adaptor, hoses, mounting hardware, and fixings required for installation.
Cooler Size Options
Oil coolers are available in a range of core sizes measured by the number of rows: 10-row, 13-row, 16-row, and 19-row. The 10-row and 13-row coolers suit standard road use for most MGA applications. The 16-row cooler provides additional capacity for spirited driving or use in warmer climates. The 19-row cooler is intended for tuned or performance engines, or cars used in consistently hot conditions.
A thermostatic bypass valve can be added separately to either kit where the owner wishes to prevent the oil being over-cooled on start-up or during short runs in cold weather, particularly relevant for UK winter driving.
Ordering Notes
When ordering oil cooler components, specify whether the car is a pushrod (1500, 1600, or Mk II) or Twin Cam, and whether a factory-layout original kit or an accessory-type kit is required. For 1600 Mk II cars originally fitted with the factory oil cooler, the original-type kit matches the factory routing. For pushrod cars being retrofitted, either layout can be used. Individual components, hoses, cooler elements, gaskets, and unions, are also available separately for replacement on existing installations.