BMW S14

BMW S14
S14B23
overview
Manufacturer :	BMW
Production period:	1986-1991
Combustion chamber
Design:	Inline four-cylinder
Displacement variants :	2.0 l (1990 cm ³ ) 2.3 l (2302 cm ³ ) 2.5 l (2467 cm ³ )
Chronological order
Previous model:	BMW M10 or its sports versions
Successor:	BMW S50

The BMW S14 is an engine series from the German motor vehicle manufacturer BMW that was developed for the first BMW M3 , primarily intended for motorsport as a homologation model.

This is a DOHC - rows - four-cylinder - petrol engine in four-valve technology with manifold injection and individual throttle butterflies . It was used in the E30 M3 and, in particular, the Portugal and Italy model BMW 320is of the E30 vehicle series .

The BMW S14 was followed by the BMW S50 in the E36 M3 , but due to the fundamentally different dimensions (cylinder spacing, bore, stroke, external dimensions) and the different engine concept (six instead of four-cylinder), the S50 cannot be considered the successor to the S14.

history

This engine was based on the M10 cylinder block that had already been tried and tested in motorsport and, like this one, had a cylinder spacing of 100 mm. As a test, a cylinder head of the M88 / 3 that had been shortened by two combustion chambers was placed on this cylinder block. The later series cylinder heads were also based on the concept, especially since many results and experiences were available from the tests on the previous M49 and M88 racing engines . The two overhead camshafts are driven by a duplex chain . The mixture is supplied separately for each cylinder via its own intake manifold and throttle valve .

As a series engine, the S14 in the E30 M3 had displacements of 2.3 (S14B23) and 2.5 (S14B25) liters with outputs from 143 kW / 195 PS to 175 kW / 238 PS, for the export market Portugal and Italy there were due to the local ones Luxury tax on vehicles with a displacement of more than 2 liters an S14B20 reduced to this displacement with still 141 kW / 192 PS.

In the first stage of development, the S14 developed around 220 kW / 300 PS in racing, while the 2.5 l, which was used from 1990, even achieved up to 264 kW / 360 PS.

The four-cylinder engine has a crankshaft with five bearings, which, due to its short overall length, is insensitive to torsional and flexural vibrations at the very high speeds that are common in motorsport. The inlet valve bore of the cylinder head taken over is enlarged to 37.5 mm and inclined by 18 °. With a diameter of 32 mm and an inclination of 20 °, the exhaust valves face each other in an almost perfect V to ensure a quick gas exchange. Further increases in performance were achieved by lightening the pistons with milled valve pockets and an oil cooler. The oil pan is equipped with a so-called oil plane to calm the moving oil quantities. This oil plow sits between the crankshaft area and the oil sump.

The engine is controlled by digital engine electronics (DME), which automatically adjusts the cold start behavior without a cold start valve and adjusts the ignition angle and / or the mixture formation depending on the altitude.

Data

engine	Displacement	Valves / cyl.	Bore × stroke	compression	Power at 1 / min	Torque at 1 / min	construction time	Cat
S14B20	2.0 l (1990 cm ³ )	4th	93.4 mm x 72.6 mm	10.8: 1	141 kW (192 hp) at 6900	210 Nm at 4900	1987-1989	without cat
S14B23	2.3 l (2302 cm ³ )	4th	93.4 mm x 84.0 mm	10.5: 1	143 kW (195 PS) at 6750	230 Nm at 4750	1986-1989	with cat
					147 kW (200 PS) at 6750	240 Nm at 4750	1986-1989	without cat
					158 kW (215 PS) at 6750	230 Nm at 4600	1989-1991	with cat
S14B23 Evo II	2.3 l (2302 cm ³ )	4th	93.4 mm x 84.0 mm	11.0: 1	162 kW (220 PS) at 6750	240 Nm at 4740	1987-1988	without cat
S14B25 Sport Evolution	2.5 l (2467 cm ³ )	4th	95.0 mm × 87.0 mm	10.2: 1	175 kW (238 hp) at 7000	240 Nm at 4750	1990	with cat

use

S14B20
- 1987–1990 in the BMW E30 as a 320is
S14B23
- 1986–1990 in the BMW E30 as M3
S14B25
- 1990 in the BMW E30 as M3

literature

Karl H. Hufstadt: BMW Portraits. Paul Rosche: A brilliant engine designer. Stories about history . Egmont VGS, Cologne 2003, ISBN 3-8025-1520-X .
Helmut Hütten: Fast engines - dissected and coiffed . 10th edition. Motorbuch Verlag, Stuttgart 1994, ISBN 3-87943-974-5 .
Stefan Knittel: BMW Profile, Volume 8: Touring and Sports Cars . 1st edition. Egmont VGS, Cologne 2007, ISBN 3-8025-1622-2 .
Karlheinz Lange: History of the engine - engine of history (BMW dimensions 1 + 2) . 1st edition. BMW Mobile Tradition, 1999, ISBN 3-932169-04-2 .
Karl Ludvigsen: BMW Racing Cars: Type 328 to Le Mans V12 . Iconografix, 2007, ISBN 1-58388-201-4 (English).
Werner Oswald, Eberhard Kittler: All BMW automobiles since 1928 . 1st edition. Motorbuch Verlag, Stuttgart 2000, ISBN 3-613-02053-X .
James Taylor: Original BMW M-Series . MBI Motorbooks International, St. Paul, Minn. 2001, ISBN 0-7603-0898-5 (American English).

Web links

Individual evidence

↑ The sports legend: The BMW M3. In: www.7-forum.com. BMW press release, March 30, 2006, accessed on April 18, 2012 .

Timeline of BMW gasoline engines for passenger cars since 1961
Number of cylinders	Conception	1960s										1970s										1980s										1990s										2000s										2010s
Number of cylinders	Conception	0	1	2	3	4th	5	6th	7th	8th	9	0	1	2	3	4th	5	6th	7th	8th	9	0	1	2	3	4th	5	6th	7th	8th	9	0	1	2	3	4th	5	6th	7th	8th	9	0	1	2	3	4th	5	6th	7th	8th	9	0	1	2	3	4th	5	6th	7th	8th
3	1.5 l																																																						B38

4th	(1.5–2.0 l)		M10
																													M40
																															M42
																																			M43
																																				M44
																																											N40
																																											N42
																																													N45
																																													N46
																																																N43
																																																				N13
																																																				N20
																																																							B48
	High performance motor																											S14

6th	Small six-cylinder (2.0-3.0 l)																		M20
																																M50
																																				M52
																																										M54
	Large six-cylinder (2.5-3.5 l)									M30
																																															N52
																																																	N53
																																																N54
																																																			N55
																																																									B58
	High performance motor																			M88
																														S38
																																		S50
																																						S52
																																										S54
																																																								S55

8th	3.0-4.4 l																																	M60
																																						M62
																																											N62
																																																		N63
	High performance motor																																							S62
																																																			S63
																																																	S65

10	High performance motor																																														S85

12	5.0-6.6 l																												M70
																																				M73
																																													N73
																																																			N74
	High performance motor																																	S70
Number of cylinders	Conception	0	1	2	3	4th	5	6th	7th	8th	9	0	1	2	3	4th	5	6th	7th	8th	9	0	1	2	3	4th	5	6th	7th	8th	9	0	1	2	3	4th	5	6th	7th	8th	9	0	1	2	3	4th	5	6th	7th	8th	9	0	1	2	3	4th	5	6th	7th	8th
Number of cylinders	Conception	1960s										1970s										1980s										1990s										2000s										2010s

[1] The sports legend: The BMW M3. In: www.7-forum.com. BMW press release, March 30, 2006, accessed on April 18, 2012 .