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35-506: Compared with its M70 predecessor, the M73 features an updated roller-rocker valve-train and an increased displacement, due to a bore increase of 1 mm (0.04 in) ending with a cylinder bore of 85mm and a stroke increase of 4 mm (0.16 in) to have a final piston stroke of 79mm. While most other engines in the BMW range had switched to dual overhead camshafts with four valves per cylinder ,

70-431: A piston engine , the bore (or cylinder bore ) is the diameter of each cylinder . Engine displacement is calculated based on bore, stroke length and the number of cylinders: The stroke ratio , determined by dividing the bore by the stroke, traditionally indicated whether an engine was designed for power at high engine speeds ( rpm ) or torque at lower engine speeds. The term "bore" can also be applied to

105-480: A "blue flame" rather than yellow had been touted in Chevrolet advertising since 1934. The 1953 Corvette used a unique version of the high-pressure 235 engine with mechanical lifters, the same slightly higher-lift camshaft as used in the 261 truck engine and three single-barrel, side-draft Carter Model YH carburetors to produce 150 hp (112 kW). From 1954 to 1962, the high-pressure 235 engine with solid lifters

140-474: A 7.1:1 compression ratio, and correspondingly lower power output: 108 hp (81 kW) versus 115 hp (86 kW) with the Powerglide. A fully pressurized lubrication system with shell type main bearings in lieu of poured babbitt and aluminum pistons were also introduced in 1953, but only in the higher-output Blue Flame version in cars ordered with the Powerglide transmission. The alleged benefits of

175-505: A Diesel engine (i. e. no engine throttling). Due to the lower LHV of a hydrogen-air mixture, and the fact that the engine was designed as a Bi-Fuel (petrol and hydrogen) engine, the power output is reduced by 38 per cent compared to the petrol only version of the engine. Applications: Due to more stringent emissions standards, the 1999 model year marked the addition of an electronically heated catalyst, variable MAP thermostat, and water cooled alternator. Applications: In 1989, as part of

210-503: A drastic make-over in 1964 to conventional "wedge" combustion chambers, then modified again for stud-mounted rocker arms, and finally underwent an even greater re-design to become the modern 5.7 liter hemi. All of these engines retain the original 4.460" bore pitch distance set down in 1956. "Hybrid" is the term commonly used to identify an engine modified for high performance by adapting a cylinder head from another (sometimes completely different) brand, size, model or type engine. Note: using

245-586: A feasibility study, BMW's engine development department produced a four-valve version of its V12 engine. Only one engine was produced, having an up-sized variant of the M70B50 engine called the M72B54. Bore and stroke was increased to 85mm and 79mm and the total displacement of 5.4L was achieved, matching the values of the standard M73 engine. The power and torque both increased to 265 kW (355 hp) and 530 N⋅m (391 lb⋅ft) respectively. Bore (engine) In

280-495: A higher 7.5:1 compression ratio, and larger intake valves to produce more power. The pushrod cover on the side of the engine also no longer extended across the cylinder head, to eliminate oil leaks. In 1953 the 235 engine became standard equipment in all Chevrolet passenger cars except the sedan delivery body (which continued to use the older 216 until 1954), but when coupled to the standard three-speed manual transmission (called Thrift-King in that guise) it featured solid lifters,

315-467: A later head of the same engine "family" isn't a true hybrid, but mere modernization. In some cases, two heads from the donor (source) engine are joined end-to-end to match the number of cylinders on the subject engine (such as using three cylinders each of two V8 heads on a Chevrolet inline-six). Identical or extremely similar bore pitch is what makes this possible, or (almost) impossible. Chevrolet Stovebolt engine The Chevrolet Stovebolt engine

350-404: A main bearing. Since the start-up expense of casting an engine block is very high, this is a strong incentive to retain this dimension for as long as possible to amortize the tooling cost over a large number of engines. If and when the engine is further refined, modified or enlarged, the bore pitch may be the only dimension retained from its predecessor. The bore diameter is frequently increased to

385-571: A third single Siemens control unit, called EML. The engine utilizes four knock sensors mounted on the heads, a cam position sensor mounted on the right head and two crank sensors, one for each ECU. Throttle by wire is used. Similar to its predecessor, the M70, spark distributors are still present for each cylinder bank. The hydrogen versions of the engine feature a λ ≥ 3.0 {\displaystyle \lambda \geq 3.0} lean burn concept, which allows quality torque control similar to

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420-616: Is a straight-six engine made in two versions between 1929 and 1962 by the Chevrolet Division of General Motors . It replaced the company's 171-cubic-inch (2.8 L) inline-four as their sole engine offering from 1929 through 1954, and was the company's base engine starting in 1955 when it added the small block V8 to the lineup. It was completely phased out in North America by 1962, but GM continued to build it in Brazil until 1979. It

455-456: Is always larger than the inside diameter of the cylinder (the bore and piston diameter) since it includes the thickness of both cylinder walls and any water passage separating them. This is one of the first dimensions required when developing a new engine, since it limits maximum cylinder size (and therefore, indirectly, maximum displacement), and determines the length of the engine (L4, 6, 8) or of that bank of cylinders (V6, V8 etc.). In addition,

490-451: The Corvette ). This engine had a 216.48-cubic-inch (3.5 L) displacement with a bore and stroke of 3 + 1 ⁄ 2 by 3 + 3 ⁄ 4 inches (88.90 mm × 95.25 mm). A four-bearing crankshaft was added, along with 6.5:1 compression pistons, for 85 hp (63 kW). A new cylinder head in 1941 increased output to 90 hp (67 kW), and 6.6:1 compression gave

525-576: The GMC straight-6 engine , the Buick Straight-eight , and the Chrysler "Slant 6" ) the bore pitch is additionally extended to allow more material between the main bearing webs in the block. For example, in an L6 the first pair (#1 & 2), center pair (#3 & 4), and rear pair (#5 & 6) of cylinders that share a pair of main bearings have a smaller pitch than between #2 & 3 and #4 & 5 that "bridge"

560-466: The Type A , produced from 1935 to 1947, was a reverse engineered copy of the 207 Chevrolet engine, with 62 hp (46 kW) power output and 94 percent of the compression ratio of the Chevrolet original. Applications: A 181-cubic-inch (3.0 L) version with a 3 + 5 ⁄ 16  in ×  3 + 1 ⁄ 2  in (84.14 mm × 88.90 mm) bore and stroke was also introduced in 1933, in

595-419: The 1949 model 92 hp (69 kW). This generation did not use a fully pressurized oiling system. The connecting rods were oiled using an "oil trough" built into the oil pan that had spray nozzles that squirted a stream of oil at the connecting rods (which were equipped with "dippers"), thus supplying oil to the rod bearings . Rod bearings were made of babbitt cast integral with the rod. The bearing

630-638: The 2-3 ton truck ("lorry") market and in a crash program based the design on the basic architecture of this "Stove Bolt" engine, except that they added detachable shell main and con-rod bearings and pressurized lubrication. That Austin engine, in six-cylinder form, post war known as the Austin D-Series , went on to power cars such as the Austin Sheerline and Princess , and the Jensen Interceptor and 541 . Austin also lopped off two cylinders to create

665-480: The 27 hp (20 kW) Series AA Capitol, and sales of the Model A surpassed Chevrolet by 1929. Chevrolet had been considering switching to a six-cylinder engine since 1925, and the ascendency of the Model A precipitated the switch. Chevrolet had long been known for its " valve-in-head " design in the previous four-cylinder engine, so General Manager William S. Knudsen and marketing executive Richard Grant insisted that

700-632: The BS1 engine and in that form various versions, with various capacities, powered cars such as the Austin 16 , A70 Hampshire and Hereford , A90 Atlantic , the Austin-Healey 100 -4 and the Austin Gipsy , a generation of commercial vans, as well as some models of the iconic London black taxi (FX3 and FX4) . In 1941 a 235.5-cubic-inch (3,859 cc) version of the 216 engine was introduced for use in large trucks. Both

735-563: The M73 used a single overhead camshaft and with two valves per cylinder. However, BMW engineers did create a prototype four-valve per cylinder V12, called the M72, which developed 265 kW (360 PS; 355 hp) and 530 N⋅m (391 lb⋅ft) of torque. However, this 48-valve engine did not fulfill the comfort demands of the large sedan class in all respects and, as a result, did not go into production. These engines have two separate Bosch Motronic engine control units , which are connected to

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770-626: The block and head) between three paired (siamesed) cylinders, and a slightly higher lift camshaft. This engine was offered as a step up from the 235 starting in 1954. It was offered in parallel with the GMC V6 engine in 1960 until 1963, when it was discontinued. The 261 US truck engine had mechanical lifters and was available from 1954 to 1962. The 235 and 261 truck engines were also used by GMC Truck of Canada (GMC truck 6-cylinder engines were also used in Canada). The 1955–1962 full-size Canadian Pontiac car had

805-498: The bore and stroke of 3 + 9 ⁄ 16  in ×  3 + 15 ⁄ 16  in (90.5 mm × 100.0 mm) were increased over the 216. This engine had the same oil "dipper system" as the 216. The 235 was introduced to the Chevy passenger car line in 1950, coupled to the new Powerglide automatic transmission , and 3.55:1 rear differential. The new version used with the Powerglide transmission featured hydraulic lifters ,

840-454: The bore of a locomotive cylinder or steam engine pistons . The term bore also applies to the cylinder of a steam locomotive or steam engine . Bore pitch is the distance between the centerline of a cylinder bore to the centerline of the next cylinder bore adjacent to it in an internal combustion engine . It's also referred to as the "mean cylinder width", "bore spacing", "bore center distance" and "cylinder spacing". The bore pitch

875-422: The limit of minimal wall thickness, the water passage is eliminated between each pair of adjacent cylinders, the deck height is increased to accommodate a longer stroke, etc. but in general if the bore pitch is the same, the engines are related. As an example of development, the Chrysler 277" polyspheric V8, first introduced in 1956, was gradually increased in size by bore and stroke to 326" by 1959, then received

910-471: The lower priced Series CC Standard, and used again in the 1934 Series DC Standard. It made a peak 60 hp (45 kW) at 2300 rpm, and peak torque of 125 lb⋅ft (169 N⋅m) at 1200-2000 rpm. The compression ratio in the 1933 model was 5.2:1, and was increased to 5.35:1 in 1934. Production of this version ended after 1934, and the Standard used the 206.8 cubic inch engine thereafter. The Stovebolt engine

945-401: The new six-cylinder design also use overhead valves. The new engine was mockingly called the "Cast-Iron Wonder" and "Stovebolt Six" for its seemingly old-fashioned design, but it was famously advertised as "a six for the price of a four" to great success: the Chevrolet was priced only $ 100 more than the Model A, and the brand regained the sales lead from Ford in 1931. When introduced in 1929

980-474: The positions of the main bearings must be between individual cylinders (L4 with 5 main bearings, or L6 with 7 main bearings - only one rod journal between main bearings), or between adjacent pairs of cylinders (L4 with 3 main bearings, L6 or V6 with 4 main bearings, or V8 with 5 main bearings - two rod journals between main bearings). In some older engines (such as the Chevrolet Gen-2 " Stovebolt " inline-six,

1015-461: The six-cylinder was 193.9 cubic inches (3.2 L) in size and produced 46 hp (34 kW). This engine used a forged steel crankshaft with three main bearings and cast-iron pistons . Bore and stroke were 3 + 5 ⁄ 16  in ×  3 + 3 ⁄ 4  in (84 mm × 95 mm). A balanced crankshaft was introduced for 1932, while a higher (5.2:1) compression ratio increased output to 60 hp (45 kW). This engine

1050-472: Was adjustable for wear by removing copper shims placed between the rod cap and connecting rod. In this way specified oil clearance could be maintained. If the crankshaft were to be turned undersized, or if the bearing was damaged or worn out, rod and bearing were replaced as a unit, typically at the dealership. This engine was also used in GM's British Bedford truck . In the late 1930s rival Austin decided to get into

1085-593: Was replaced by the Chevrolet Turbo-Thrift engine . The new six-cylinder engine was introduced in 1929 Chevrolet cars and trucks, replacing the company's first inline-four . The 1927 Chevrolet Series AA Capitol had sold very well—over a million units sold as compared to about 400,000 of Ford's Model T —but Ford had introduced a new model in the autumn of 1927: the Model A . The Model A, with its improved 40 hp (30 kW) four-cylinder, compared favourably to

BMW M73 - Misplaced Pages Continue

1120-476: Was significantly re-engineered for the 1937 model year, distinguished from the earlier 1929-1936 engines by having a redesigned crankcase with four main bearings in lieu of the older engine's three bearings. It is often known as the "Blue Flame" engine, although that name was only officially applied beginning in 1953, and then only for the 235ci version coupled to the Powerglide automatic transmission (including in

1155-492: Was used from 1947 to 1953, and the 235 was used in 1954 light-duty trucks only. Medium-duty GMC trucks used US-built GMC engines in the 248, 270, and higher sizes prior to 1954. In 1954, a 260.9-cubic-inch (4.3 L) truck engine was introduced as an optional Jobmaster engine for heavy-duty trucks. This engine was very similar to the 235 engine, except for a different block casting with a larger piston bore of 3 + 3 ⁄ 4 inches (95.25 mm), two extra coolant holes (in

1190-497: Was used in all Chevrolet passenger cars from 1929 through 1932. Applications: The original 194 CID engine was replaced with an improved 206.8-cubic-inch (3.4 L) variant (the stroke was increased to 4 inches (101.6 mm)) in 1933, introduced in the Series CA Eagle . This newly revised engine put out 65 hp (48 kW), and was produced until 1936, with compression rates between 5.2:1 to 6:1. Toyota 's first engine,

1225-421: Was used in some trucks. From 1956 to 1962, all 235 engines used in cars had hydraulic lifters. The 235 is known as one of the great Chevrolet engines, noted for its power and durability. It was replaced by the third generation 230 from 1962. Canadian-production GMC trucks also used the 216 and 235 Chevrolet straight-six engines as their base light-duty truck powerplant in the late 1940s and early 1950s. The 216

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