First manufactured in 1959, the Mini was introduced as the Mini Minor by Morris Garage, of MG fame. It has since switched ownership a number of times, with BMW being the current owner of the Mini franchise. The engine used on the Mini has evolved through the years, with the primary engine variations being the Metro 850, 998, 1098 and 1275 cubic-centimetre engines. Identification of Mini engines depends on locating and decoding the engine number, with referencing necessary for certain sections of the Mini engine number.
Locate the engine number. According to Mini Mania, the Mini engine number is found on a plate riveted to the front of the engine block, just below the thermostat housing. There is a large hose attached to the thermostat housing that originates on the radiator.
Write down the Mini engine number. This is an alphanumeric code consisting of 11-plus positions, with the first eight positions used for identification and the following numbers being a consecutive serial number based on assembly line production. A typical Mini engine number might read "99H907PH101."
Decode the Mini engine number. In the example, "99H907PH" is the essential section for identification. According to Mini Mania, the example decodes as follows: "99" identifies a 998 cubic-centimetre engine, with "85" designating an 850cc and "12," a 1275cc. "H" identifies a transverse, or front-wheel-drive engine. The next three digits, "907," identify the transmission, engine type and engine installation details. This section should be referenced to the listing found on Mini Mania, as the information contained in the three digits is extensive. "907" designates an engine with a mechanical fuel pump, a negatively-grounded alternator, Metro engine identification and a standard-ratio gearbox. The last two positions, "PH," identify a carburettor engine with a clean-air package that is high compression. "L," instead of "H," designates a low-compression engine.
A listing found on Mini Mania matches select Mini engine numbers with certain Mini models and years (see Resource 1).