BMW S14

The BMW S14 engine is a series of German car manufacturer BMW.

It is a DOHC inline four- cylinder gasoline engine in four-valve technology with fuel injection. He came in the BMW M3 E30 and the special BMW Italy - 320is model of vehicle series E30 used.

History

This engine was based on the already proven in motorsport M10 cylinder block. On this cylinder block tentatively a shortened two combustion chambers cylinder head of the M88 / 3 was set. The later series cylinder heads were based on the design, especially from the experiments to the previous racing engines of the type M49 and M88 many results and experiences templates. The dual overhead camshafts are driven by a duplex chain. The mixture is supplied for each cylinder separately through its own intake manifold and throttle body.

As a series motor the S14 had the E30 M3 engine displacements of 2.3 ( S14B23 ) and 2.5 ( S14B25 ) there were liters with outputs ranging from 143 kW/195 hp to 175 kW/238 hp, for the export market to Italy because of local luxury tax vehicles with more than 2 liters capacity reduced to just these S14B20 engine capacity with 141 kW/192 hp yet after all.

In racing the S14 developed in the first stage as a 2.3 liter 220 kW/300 hp, which even reached as of 1990 employed 2.5 liter up to 264 kW/360 hp.

The four-cylinder engine has a five -bearing crankshaft, which is insensitive to torsional and bending vibrations in the usual motorsport very high speeds due to their short length. The input valve bore of the acquired cylinder head enlarged to 37.5 mm and tilt by 18 °. The exhaust valves are 32mm in diameter and 20 ° inclination thus opposite in an almost Perfect V in order to ensure a fast charge cycle. Further performance gains were achieved by facilitating the piston with milled valve pockets, and an oil cooler. The oil pan is equipped with a so-called windage tray to the oil volume to calm down. This windage tray sits between the crankshaft and the oil sump area.

Controlled, the motor of a DME ( Digital Motor Electronics ), the fully automatic cold start performance without cold start valve adjusts, and depending on altitude adjusts the ignition angle and / or the mixture formation.

Data

Use

• S14B20 1987-1990 the BMW E30 320is as