The Mercedes-Benz M 103 is a 15-degree, straight-6 crossflow cylinder head automobile engine and was in production from 1984 to 1997. It is a single overhead cam design with 2 valves per cylinder. The M 103 was replaced by the M 104 starting in 1989. This engine received several updates over the years of production, one of the updates was a change from a "heart shaped" to a "HEMI" spherical combustion chamber.
Specifications
The only mechanical differences from the M 103 3.0 L to the M 103 2.6 L were the smaller bore and intake valves, with a slightly different airbox. The CIS-E components between 2.6 and 3.0 variants are all shared for any given model year with the exception of the ECU making engine swaps from 2.6 to 3.0 virtually bolt-in.
Car model 260 300 Engine type M 103 E 26 M 103 E 30 Production period 1984–1997 Layout Configuration Straight-six Bore pitch Cylinder bore Piston stroke Displacement Max. engine speed 6,200/min Combustion Principle Internal combustion engine Mode of operation Four-stroke Fuel type gasoline Fuel octane 95 RON/85 MON · 91 RON/81MON via plug-in jumper located in the engine compartment Fuel system CIS-E (Continuous Injection System) Ignition system electronic engine control unit Firing order 1–5–3–6–2–4 Valvetrain SOHC Valves per cylinder 2 Configuration V-shaped overhead crossflow Camshaft drive simple roller-type chain Aspiration Naturally aspirated Compression ratio 9.2 : 1 Management Lubrication pressure circulation with wet sump Oil capacity Cooling water cooled engine cooling Coolant capacity Starter motor electrical motor · since Jan 1988: Performance Power w/ catalyst @ engine speed 5,800/min 5,700/min Torque w/ catalyst @ engine speed 4,600/min 4,400/min Power w/o catalyst @ engine speed 5,800/min 5,700/min Torque w/o catalyst @ engine speed 4,600/min 4,400/min Applications W 201 190 E 2.6 W 124 260 E · 300 E 2.6 300 E W 126 260 SE 300 SE · 300 SEL R 107 300 SL R 129 300 SL W 463 300 GE Isdera Isdera Spyder 036i
Data accuracy
The M 102 and M 103 engine family has with the M 104 E 30 a common piston stroke of 80.25 mm. As only one decimal place is usually given, a large number of publications are in circulation with the incomplete specification of 80.2 mm. This applies in particular to more recent publications after production was discontinued. As a result, the inaccurate figures of 2,597 cc instead of the actual 2,599 cc for the 2.6 l engine and 2,960 cc instead of 2,962 cc for the 3.0 l engine have become established.
There is no evidence anywhere that there are two crankshafts with different strokes.
Car model 200 230 260 300 Engine M 102 M 103 · M 104 Engine type M 102 V 20M 102 E 20 M 102 E 23M 102 E 23/2 M 103 E 26 M 103 E 30M 104 E 30 Configuration Straight-four Straight-six Cylinder bore
References