What makes the M88/S38 engine unique?
The M88 and S38 engines are evolutions of the 24-valve inline-six developed for the mid-engine M1 supercar. Like that engine, both the M88 and S38 have a four-valve crossflow cylinder head (with 37mm inlet valves and 32mm exhaust valves) designed for better breathing at high rpm and a pair of 264-degree camshafts. They also share a displacement of 3,453cc via a bore of 93.4mm and a stroke of 84mm. However, for their application in the E28 M5, the M88 and S38 have unique pistons and connecting rods, as well as a more advanced Bosch ML-Jetronic fuel injection system. To save costs, both engines utilize the standard steel M30 crankshaft and wet-sump lubrication system. Many other smaller items, such as the ignition system, are shared with the regular 5 Series as well.
The M88 and S38 engines are evolutions of the 24-valve inline-six developed for the mid-engine M1 supercar. Like that engine, both the M88 and S38 share a displacement of 3,453cc (via a bore of 93.4mm and a stroke of 84mm), and both have a four-valve crossflow cylinder head (with 37mm inlet valves and 32mm exhaust valves) designed for better breathing at high rpm. However, for their application in the E28 M5, the M88 and S38 have unique pistons and connecting rods, as well as more advanced Bosch Motronic fuel injection/engine management. To save costs, both engines utilize the standard steel M30 crankshaft and wet-sump lubrication system. Many other smaller items, such as the ignition system, are shared with the regular 5 Series as well.
