BMW M50
Template:Infobox automobile engine
The BMW M50 is a straight-6 DOHC petrol engine which was produced from 1990 to 1996. It was released in the E34 520i and 525i, to replace the M20 engine.<ref>Template:Cite web</ref>
In September 1992, the M50 was upgraded to the M50TÜ (Technische Überarbeitung, "technical revision"). This was BMW's first engine to use variable valve timing.<ref name="bmwn54tuners.com">Template:Cite web</ref> Called single VANOS by BMW, the system adjusted the phasing of the intake camshaft.<ref>Template:Cite web</ref>
The M50 began to be phased out following the introduction of the M52 engine in 1994.
The E36 M3 is powered by the S50 engine series, which is a high output version of the M50.
Design
A significant advance over its M20 predecessor, the M50 features dual overhead camshaft (DOHC) with four valves per cylinder (the M20 has a single overhead camshaft with 2 valves per cylinder), coil-on-plug ignition, a knock sensor and a lightweight plastic intake manifold.<ref>Template:Cite web</ref> Both engines use an iron block with an aluminum alloy head.<ref>Template:Cite web</ref> The redline is 6,500 rpm for the M50B25 and 6,750 rpm for the M50B20 (7,000 rpm for S50 models), the same as the final version of the M20.
The location of the oil pan (sump) varies according to the model the M50 is installed in. It is in the front on the E34 5 Series (like the M20),<ref>Template:Cite web</ref> whereas it is in the rear on the E36 3 Series.<ref>Template:Cite web</ref>
Models
| Engine | Displacement | Power | Torque | Years |
|---|---|---|---|---|
| M50B20 | Template:Cvt | Template:Cvt at 6,000 rpm |
Template:Cvt at 4,700 rpm |
1990-1992 |
| M50B20TÜ | Template:Cvt at 5,900 rpm |
Template:Cvt at 4,200 rpm |
1992-1996 | |
| M50B24TÜ | Template:Cvt | Template:Cvt at 5,900 rpm |
Template:Cvt at 4,200 rpm | |
| M50B25 | Template:Cvt | Template:Cvt at 6,000 rpm |
Template:Cvt at 4,700 rpm |
1990-1992 |
| M50B25TÜ | Template:Cvt at 5,900 rpm |
Template:Cvt at 4,200 rpm |
1992-1996 | |
| S50B30 (EU) | Template:Cvt | Template:Cvt at 7,000 rpmTemplate:Efn |
Template:Cvt at 3,500 rpm |
1992-1995 |
| S50B30 (US) | Template:Cvt at 6,000 rpm |
Template:Cvt at 4,250 rpm |
1994-1995 | |
| S50B30GT | Template:Cvt at 7,100 rpm |
Template:Cvt at 3,900 rpm |
1994-1995 | |
| S50B32 | Template:Cvt | Template:Cvt at 7,400 rpm |
Template:Cvt at 3,250 rpm |
1995-2000 |
M50B20
The Template:Cvt M50B20 was introduced with the 1990 520i. It has a bore of Template:Cvt, a stroke of Template:Cvt and produces Template:Cvt. The compression ratio is 10.5:1.<ref name="bmwheaven">Template:Cite web</ref>
Applications:
Template:Anchor M50B20TÜ
The M50B20 was updated with single VANOS in 1992. Peak torque became available at 4,200 rpm.<ref name=bmwheaven /> It produces Template:Cvt at 5,900 rpm and Template:Cvt at 4,200 rpm. The compression ratio was raised to 11.0:1.
Applications:
Template:Anchor M50B24TÜ
This is a Template:Cvt engine used in the Thailand and Oceanian markets.<ref>Template:Cite book</ref> It is based on the Template:Cvt M50B25TÜ with the stroke reduced to Template:Cvt and produces Template:Cvt at 5,900 rpm and Template:Cvt at 4,200 rpm. The compression ratio is 10.5:1.
Applications:
M50B25
The Template:Cvt M50B25 was introduced with the 1990 525i and 525ix. It has a bore of Template:Cvt, a stroke of Template:Cvt and produces Template:Cvt at 6,000 rpm and Template:Cvt at 4,700 rpm.<ref name=bmwheaven /> The compression ratio is 10.0:1.
Applications:
Template:Anchor M50B25TÜ
The M50B25 was updated with single VANOS in 1992, resulting in peak torque becoming available at 4,200 rpm. It produces Template:Cvt at 5,900 rpm and Template:Cvt at 4,200 rpm.<ref name=bmwheaven /> The compression ratio was increased to 10.5:1.
Applications:
M50B30TÜ concept
Template:Unreferenced section In 1993, BMW Individual created a concept of BMW E34 530iX called Enduro Touring. Only one car was produced, having an up-sized variant of M50B25TÜ engine. Bore and stroke was increased and the total displacement of 3.0 was achieved. The power and torque both increased to Template:Cvt and Template:Cvt respectively.
S50
Template:Infobox automobile engine The S50 is the high performance version of the M50 which was used in the E36 M3, replacing the four-cylinder BMW S14 engine used in the E30 M3. Like the M50, the S50 has an iron block and aluminum head with four valves per cylinder.
In the United States, a less powerful engine called the "S50B30US" was used, which shares more in common with the regular M50 engine than the other S50 versions.
S50B30
The S50B30 was used in most countries, except for the United States.Template:Efn The S50B30 produces Template:Cvt, has a bore of Template:Cvt, a stroke of Template:Cvt and a compression ratio of 10.8:1.<ref>Template:Cite web</ref><ref>Template:Cite web</ref> The redline is 7,200 rpm. The S50 has an individual throttle body for each cylinder, single-VANOS (variable valve timing on the intake camshaft), Bosch Motronic M3.3 engine management and redesigned intake and exhaust systems.<ref name="mregistry-e36"/><ref name="drive-my.com">Template:Cite web</ref>
The limited edition "M3 GT" model from 1995 produced Template:Cvt.<ref name=mregistry-e36>Template:Cite web</ref> It had different camshafts and a redesigned sump and oil pump.
Applications:
- 1992-1995 E36 M3 (except for U.S.)
S50B30US
In the United States, the 1994-1995 model years of the E36 M3 are powered by the S50B30US, a Template:Cvt engine which produces Template:Cvt.<ref name=mregistry-e36 /><ref>Template:Cite web</ref> This engine is more closely related to the standard M50 engine and has the same compression ratio as the M50B25TÜ,<ref name=mregistry-e36 /> but uses a different camshafts, crankshaft, connecting rods, and pistons. The bore is Template:Cvt, the stroke is Template:Cvt and the redline is 7,000 rpm.<ref>Template:Cite web</ref>
The S50B30US motor was created as a compromise to make the E36 M3 a reality in the United States. Unlike in Europe, the E30 M3 was considered a business failure in America. American customers did not see the value proposition of this vehicle compared to a 325i, and due to this, E30 M3s sold poorly in the United States with just over 5,000 units sold. For comparison, the 325i sold just under 350,000 units. Because of this, BMW of North America planned on canning the M brand in the US, and with it any plans to bring the E36 M3 to America. This was until an editor for the BMW Car Club of America, Bob Roehmer, encouraged BMW CCA members to mail BMW of North America letters asking them to bring the car to the United States. This worked, with many BMW CCA members promising to buy an E36 M3 if it was brought to the United States at a reasonable price. To meet this caveat, Erik Wensberg, the manager of the BMW M Brand in North America, decided to remove the European spec S50 motor, and replace it with a M50 motor that was tuned by the BMW M division. This motor would become the S50B30US, and would only be found in American spec E36 M3s. <ref>Template:Cite web</ref>
In 1996, the S50B30US was replaced by the BMW S52 engine (in the United States and Canada only). This motor was a derivative of the M52, and while it maintained the same 240 horsepower as the S50B30US, it gained 11 ft lbs of torque and increased displacement from 3000cc to 3200cc <ref>Template:Cite web</ref>
Applications:
- 1994-1995 E36 M3 (U.S. only)
S50B32
In 1995, the S50B32 replaced the S50B30 in world markets.Template:Efn Power output increased to Template:Cvt<ref>Template:Cite web</ref> and the displacement increased to Template:Cvt, due to an increased stroke of Template:Cvt and a slight increase in bore to Template:Cvt.<ref>Template:Cite web</ref>
The S50B32 has double-VANOS (variable valve timing on both camshafts) and a secondary oil pick-up was added.<ref>Template:Cite web</ref> The compression ratio is 11.3:1 and the redline is 7,600 rpm.<ref>Template:Cite web</ref> Engine management is the Siemens MSS50, with 3 knock sensors.
Applications:
- 1995-1999 BMW M3 (E36) (except Canada and the United States)
- 1996-2000 BMW M Coupé and M Roadster (except Canada and the United States)