The BMW E30 M3 is an iconic car that marked an era in the world of compact sports cars. One of the key reasons behind its exceptional performance is the engine that powered it: the BMW S14. This four-cylinder, double overhead camshaft (DOHC) petrol engine was used in the E30 M3, as well as in the E30 320iS and the E36 320i Super Touring.
The BMW S14 was based on the BMW M10 engine block and the cylinder head of the BMW S38 six-cylinder engine, with two cylinders removed. It was designed specifically for sporty performance and was used in both road and racing applications. Although the S14 did not have a direct successor in production BMWs, the BMW S50 six-cylinder engine was responsible for powering the next generation of the M3.
One of the distinctive features of the S14 are the two independent throttle butterflies used in the intake system. This configuration allows greater control over airflow and contributes to improved throttle response.
The BMW S14 was offered in several versions with different displacements and power levels. The initial version, the S14B20, had a displacement of 1,990 cc and produced 141 kW (189 hp) of power at 6,900 rpm and 210 Nm of torque at 4,900 rpm. This version was sold exclusively in Portugal and Italy.
The S14B23, which was the engine used in the E30 M3, had a displacement of 2,302 cc and offered different power levels. Early versions produced 147 kW (197 bhp) at 6,750 rpm and 230 Nm of torque at 4,750 rpm. In April 1989, the Ravaglia and Cecotto limited editions of the M3 were launched, equipped with an S14B23 developing 158 kW (212 bhp). From September 1989, this more powerful version became the standard engine for the E30 M3.
The S14B23 EVO2 was an upgrade to the engine which offered 162 kW (217 bhp), or 158 kW (212 bhp) when fitted with a catalytic converter. Finally, the S14B25 EVO3 had an increase in displacement to 2,467 cc and delivered 175 kW (235 hp) of power.
The BMW S14 engine is highly valued for its quick response, distinctive sound and spirited performance. It has become a cult item among car enthusiasts and has left an indelible mark on BMW’s history and on the legacy of the legendary E30 M3.