Misplaced Pages

#774225

87-477: The V6 PRV engine is an overhead cam V6 automobile engine designed and manufactured by the company "Française de Mécanique" for PRV , an alliance of Peugeot , Renault and Volvo Cars . Sold from 1974 to 1998, it was produced in four displacements between 2.5 L and 3.0, and in both SOHC and DOHC and 2-valve and 4-valve per cylinder configurations. Originally carbureted, it adopted fuel-injection for improved emissions compliance and improved performance, and

174-413: A 1.5-liter OHV straight-4 with four valves per cylinder as far back as 1914 but did not use this engine until after World War I . It produced appr. 30 bhp (22.4 kW) at 2700 rpm (15.4 kW/liter or 0.34 bhp/cid). In the 1920 Voiturettes Grand Prix at Le Mans driver Ernest Friderich finished first in a Bugatti Type 13 with the 16-valve engine, averaging 91.96 km/h. Even more successful

261-549: A 360.8 cid (5.8-liter) straight-4 (0.22 bhp per cubic inch). Over 2300 of these powerful early multi-valve engines were built. Stutz not only used them in their famous Bearcat sportscar but in their standard touring cars as well. The mono block White Motor Car engine developed 72 horsepower and less than 150 were built, only three are known to exist today. In 1919 Pierce-Arrow introduced its 524.8 cid (8.6-liter) straight-6 with 24 valves. The engine produced 48.6 bhp (0.09 bhp per cubic inch) and ran very quietly, which

348-453: A DOHC configuration gradually increased after World War II, beginning with sports cars. Iconic DOHC engines of this period include the 1948–1959 Lagonda straight-six engine , the 1949–1992 Jaguar XK straight-six engine and the 1954–1994 Alfa Romeo Twin Cam inline-four engine. The 1966-2000 Fiat Twin Cam inline-four engine was one of the first DOHC engines to use a toothed timing belt instead of

435-464: A DOHC engine was built in 1910. Use of DOHC engines slowly increased from the 1940s, leading to many automobiles by the early 2000s using DOHC engines. In an OHC engine, the camshaft is located at the top of the engine, above the combustion chamber . This contrasts the earlier overhead valve engine (OHV) and flathead engine configurations, where the camshaft is located down in the engine block . The valves in both OHC and OHV engines are located above

522-686: A Volvo was the B280, installed in the Volvo 760 from 1987 to 1990 and in the Volvo 780 (all model years). The Volvo 262 C was also fitted with the PRV, the first years with the B27 and the last years with the B28. The B280 was significantly changed; only the engine block remained the same as the B27/B28, the rest is different. The B280 was also installed in a small number of 960s in 1991. In 1984,

609-859: A four valve per cylinder engine was the 1973 Triumph Dolomite Sprint . This Triumph used an in-house developed SOHC 16-valve 1,998 cc (122 ci) straight-4 engine that produced 127 bhp (47.6 kW/liter, 1.10 bhp/cid) at introduction. The 1975 Chevrolet Cosworth Vega featured a DOHC multi-valve head designed by Cosworth Engineering in the UK. This 122-cubic-inch straight-4 produced 110 bhp (82 kW; 112 PS) at 5600 rpm (0.90 bhp/cid; 41.0 kW/liter) and 107 lb⋅ft (145 N⋅m) at 4800 rpm. The 1976 Fiat 131 Abarth (51.6 kW/liter), 1976 Lotus Esprit with Lotus 907 engine (54.6 kW/liter, 1.20 bhp/cid), and 1978 BMW M1 with BMW M88 engine (58.7 kW/liter, 1.29 bhp/cid) all used four valves per cylinder. The BMW M88/3 engine

696-460: A four-valve design. The three-valve design was common in the late 1980s and early 1990s; and from 2004 the main valve arrangement used in Ford F-Series trucks, and Ford SUVs. The Ducati ST3 V-twin had 3-valve heads. This is the most common type of multi-valve head, with two exhaust valves and two similar (or slightly larger) inlet valves. This design allows similar breathing as compared to

783-433: A four-valve engine, a five-valve design should have a higher maximum RPM, and the three inlet ports should give efficient cylinder-filling and high gas turbulence (both desirable traits), it has been questioned whether a five-valve configuration gives a cost-effective benefit over four-valve designs. The rise of direct injection may also make five-valve heads more difficult to engineer, as the injector must take up some space on

870-585: A fully enclosed-drivetrain), the American Liberty L-12 V12 engine, which closely followed the later Mercedes D.IIIa design's partly-exposed SOHC valvetrain design; and the Max Friz -designed; German BMW IIIa straight-six engine. The DOHC Napier Lion W12 engine was built in Great Britain beginning in 1918. Most of these engines used a shaft to transfer drive from the crankshaft up to the camshaft at

957-446: A large cylinder head to accommodate the camshaft or an extra set of valves to increase the volumetric efficiency , so that with the same displacement as an OHV engine, the OHC engine will end up being the physically larger of the two mostly due to the enlarged cylinder head. The other main advantage of OHC engines is that there is greater flexibility to optimise the size, location and shape of

SECTION 10

#1732851846775

1044-622: A multi-valved Golf GTI 16V . The 16-valve 1.8-liter straight-4 produced 139 PS (102 kW; 137 bhp) or 56.7 kW/liter, almost 25% up from the 45.6 kW/liter for the previous 8-valve Golf GTI engine. The GM Quad 4 multi-valve engine family debuted early 1987. The Quad 4 was the first mainstream multi-valve engine to be produced by GM after the Chevrolet Cosworth Vega . The NA Quad 4 achieved 1.08 bhp (1 kW; 1 PS) per cubic inch (49.1 kW/liter). Such engines soon became common as Japanese manufacturers adopted

1131-484: A number of Peugeot, Citroën and Renault cars until 1997. While Renault were working forced induction into the PRV, Peugeot and Citroën developed their own 24-valve engines as an option in the 605 and XM respectively. The compression remained the same as the Renault 12v, but the pistons differed, as did some of the timing gear , and the heads were re-engineered to allow easier maintenance (the camshaft being fitted from

1218-640: A production based engine, and as a 90° V6 has greater room between banks than a 60° V6 for a more optimal induction system, Alfa Romeo used the PRV as a basis as it had been used in the Lancia Thema , a car which shared its platform with the Alfa Romeo 164, as well as the Fiat Croma and Saab 9000. Other sources declare that the 90° V6 engine in 1996 Alfa Romeo 155 V6 Ti is based on a 2.6 L V8 from 1970 Alfa Romeo Montreal with two cylinders removed, as allowed by

1305-521: A rallying legend in the 1970s winning many domestic and World Championship events. Other cars claiming to be first are the Jensen Healey , launched in 1972 which used a Lotus 907 belt-driven DOHC 16-valve 2-liter straight-4 producing 140 bhp (54.6 kW/liter, 1.20 bhp/cid). All of these, although mass-produced, are also of relatively limited production, so it is argued that the first widely available and popularly priced mass-production car with

1392-408: A slight increase in torque. For homologation Evolution I (1989) and Evolution II (1990) models were produced that had a redesigned engine to allow for a higher rev limit and improved top-end power capabilities. The Evo II engine offered 235 PS (173 kW; 232 hp) from 2463 cc (70.2 kW/liter). Saab introduced a 16-valve head to their 2.0-liter (1985 cc) straight-4 in 1984 and offered

1479-486: A smaller and more fuel-efficient V6. The PRV engine followed a standard V8 90-degree cylinder bank configuration rather than the customary 60, but had its crankpins 120 degrees apart. The Maserati V6 of the Citroën SM followed a remarkably similar pattern of development. The 1973 energy crisis , and taxes levied against engine displacement greater than 2.8 litres made large V8 engines less attractive, and expanded

1566-589: A split-plane crankshaft rather than the Ferrari-type flat-plane. The engine was constructed by Ducati rather than Ferrari, and was produced from 1986 through 1991. The Quattrovalvole was also used by Lancia for their attempt at the World Sportscar Championship with the LC2 . The engine was twin-turbocharged and destroked to 2.65 litres, but produced 720 hp (537 kW) in qualifying trim. The engine

1653-407: A three-valve head, and as the small exhaust valves allow high RPM, this design is very suitable for high power outputs. Less common is the five-valve head, with two exhaust valves and three inlet valves. All five valves are similar in size. This design allows excellent breathing, and, as every valve is small, high RPM and very high power outputs are theoretically available. Although, compared to

1740-606: A timing chain. In the 1980s, the need for increased performance while reducing fuel consumption and exhaust emissions saw increasing use of DOHC engines in mainstream vehicles, beginning with Japanese manufacturers. By the mid-2000s, most automotive engines used a DOHC layout. Multi-valve A multi-valve or multivalve engine is one where each cylinder has more than two valves (an intake , and an exhaust ). A multi-valve engine has better breathing, and with more smaller valves (having less mass in motion) may be able to operate at higher revolutions per minute (RPM) than

1827-407: A total of two camshafts (one for each cylinder bank). Most SOHC engines have two valves per cylinder, one intake valve and one exhaust valve. Motion of the camshaft is usually transferred to the valves either directly (using a tappet) or indirectly via a rocker arm . A dual overhead cam , double overhead cam , or twin-cam engine has two camshafts over each bank of the cylinder head, one for

SECTION 20

#1732851846775

1914-465: A two-valve design, Toyota and Yamaha changed the 4A-GE to a four-valve after a year of evaluation. It produced 115-140 bhp (86-104 kW) at 6,600 rpm (54.2-65.5 kW/liter) and 109 lb⋅ft (148 N⋅m) at 5,800 rpm. To compensate for the reduced air speed of a multi-valve engine at low rpms, the first-to-second generation engines included the T-VIS intake system. In 1986 Volkswagen introduced

2001-416: A two-valve engine, delivering more power . A multi-valve engine design has three, four, or five valves per cylinder to achieve improved performance. In automotive engineering , any four-stroke internal combustion engine needs at least two valves per cylinder: one for intake of air (and often fuel ), and another for exhaust of combustion gases. Adding more valves increases valve area and improves

2088-464: Is also used to improve engine performance. The 1908 Ariès VT race cars had 1.4 litre supercharged single cylinder engines with four valve per cylinder desmodromic systems. (Source: [1] ) The 1910 Isotta-Fraschini Tipo KM had a 10.6 litre inline 4 with single overhead camshaft and four valves per cylinder and it had one of the first engines with fully enclosed overhead valve gear (source: Isotta Fraschini Tipo KM [1] and [2] ) The first motorcar in

2175-517: Is possible. The first known automotive application of timing belts to drive overhead camshafts was the 1953 Devin-Panhard racing specials built for the SCCA H-modified racing series in the United States. These engines were based on Panhard OHV flat-twin engines, which were converted to SOHC engines using components from Norton motorcycle engines. The first production car to use a timing belt

2262-453: Is that the system used to drive the camshaft (usually a timing chain in modern engines) is more complex in an OHC engine, such as the 4-chain valvetrain of the Audi 3.2 or the 2 meter chain on Ford cammers. Another disadvantage of OHC engines is that during engine repairs where the removal of the cylinder head is required, the camshaft engine timing needs to be reset. In addition, an OHC engine has

2349-413: Is the only DOHC PRV. This car still holds the top speed record at 24 Hours of Le Mans set in 1988. By taping over the engine cooling intakes to improve aerodynamics, the team managed to push the car to 407 kilometres per hour (253 mph) on the 5 kilometres (3.1 mi) straight before the engine was destroyed. Volvo began to withdraw from the PRV consortium in the late 1980s and the year model 1991

2436-535: The Duesenberg Model J , which was powered by a DOHC straight-eight engine. The 1931–1935 Stutz DV32 was another early American luxury car to use a DOHC engine. Also in the United States, the DOHC Offenhauser racing engine was introduced in 1933. This inline-four engine dominated North American open-wheel racing from 1934 until the 1970s. Other early SOHC automotive engines were the 1920–1923 Wolseley Ten ,

2523-527: The Mazda B8-ME ) use a single fork-shaped rocker arm to drive two valves (generally the exhaust valves) so that fewer cam lobes will be needed in order to reduce manufacturing costs. This has a single large exhaust valve and two smaller intake valves. A three-valve layout allows better breathing than a two-valve head, but the large exhaust valve results in an RPM limit no higher than a two-valve head. The manufacturing cost for this design can be lower than for

2610-838: The R-series engines, the Mazda B8-ME , and the Chrysler 3.5 L V6 engine . The V12 engines of many World War II fighter aircraft also used a SOHC configuration with four valves for each cylinder. The 1993 Mercedes-Benz C-Class (OM604 engine) was the first 4-valve diesel-engined car. Peugeot had a triple overhead cam five-valve Grand Prix car in 1921. In April 1988 an Audi 200 Turbo Quattro powered by an experimental 2.2-liter turbocharged 25-valve straight-5 rated at 478 kW/650 PS@6,200 rpm (217.3 kW/liter) set two world speed records at Nardo , Italy: 326.403 km/h (202.8 mph) for 1,000 km (625 miles) and 324.509 km/h (201.6 mph) for 500 miles. Mitsubishi were

2697-554: The Stutz Motor Company introduced a 322 cid (5.3-liter) dual camshaft 32-valve straight-8 with 156 bhp (116 kW) at 3900 rpm, called DV-32. The engine offered 0.48 bhp per cubic inch. About 100 of these multi-valve engines were built. Stutz also used them in their top-of-the-line sportscar, the DV-32 Super Bearcat that could reach 100 mph (160 km/h). The 1935 Duesenberg SJ Mormon Meteor's engine

V6 PRV engine - Misplaced Pages Continue

2784-452: The V8 engine can still be seen in the resulting V6 engine : its cylinder banks are arranged at 90°, instead of the much more common 60°. V8 engines nearly universally feature 90° configurations, because this allows a natural firing order . V6 engines, on the other hand, produce even firing intervals between cylinders when their two banks of cylinders are arranged at 60°. 90-degree V6 engines, like

2871-505: The Volvo 264 , designated the B27 by the automaker. Adoption was swift, and the PRV V6 had been sold in at least five different models by the end of 1975. The B27 was used in the Volvo 264/265 until 1980. The B28 was also used in the Volvo 264/265 and in a rare version of the 240 GLT (244/245 GLT 6) between 1980 and 1983, and in the Volvo 760 between 1982 and 1986. The last version of the PRV engine in

2958-468: The odd-fire and even-fire Buick V6 and the Maserati V6 seen in the Citroën SM . The dates following each entry denote the introduction of a PRV V6-equipped models. The PRV was also the basis for the 90° V6 engine used by Alfa Romeo in the 155 V6 Ti in the 1996 DTM/ITC season from Silverstone onwards. The engines in that series required the use of bank separation angle and cylinder bore spacing from

3045-513: The 190 E 2.3-16 produced 49 hp (36 kW) and 41 ft•lbf (55 N•m) of torque more than the basic single overhead cam 2.3 straight-4 engine on which it was based offering 185 hp (138 kW) at 6,200 rpm (59.2 kW/liter) and 174 lb⋅ft (236 N⋅m) at 4,500 rpm. In 1988 an enlarged 2.5-liter engine replaced the 2.3-liter. It offered double valve timing chains to fix the easily snapping single chains on early 2.3 engines, and increased peak output by 17 bhp (12.5 kW) with

3132-526: The 1903 Marr Auto Car SOHC engine built in the United States. The first DOHC engine was a Peugeot inline-four racing engine which powered the car that won the 1912 French Grand Prix . Another Peugeot with a DOHC engine won the 1913 French Grand Prix , followed by the Mercedes-Benz 18/100 GP with an SOHC engine winning the 1914 French Grand Prix . The Isotta Fraschini Tipo KM — built in Italy from 1910–1914—

3219-437: The 1917 Stutz straight-4, White Motor Car Model GL 327 CID Dual Valve Mononblock four, and 1919 Pierce-Arrow straight-6 engines. The standard flathead engines of that day were not very efficient and designers tried to improve engine performance by using multiple valves. The Stutz Motor Company used a modified T-head with 16 valves, twin-spark ignition and aluminium pistons to produce 80 bhp (59 kW) at 2400 rpm from

3306-500: The 1920s when these DOHC engines came to Alfa road cars like the Alfa Romeo 6C . In 1916 US automotive magazine Automobile Topics described a four-cylinder, four-valve-per-cylinder car engine made by Linthwaite-Hussey Motor Co. of Los Angeles, CA, USA: "Firm offers two models of high-speed motor with twin intakes and exhausts." . Early multi-valve engines in T-head configuration were

3393-438: The 1922 Type 29 Grand Prix racer and the legendary Type 35 of 1924. Both Type 29 and Type 35 had a 100 bhp (75 kW) 2-liter SOHC 24-valve NA straight-8 that produced 0.82 bhp (0.61 kW) per cubic inch. A.L.F.A. 40/60 GP was a fully working early racing car prototype made by the company now called Alfa Romeo . Only one example was built in 1914, which was later modified in 1921. This design of Giuseppe Merosi

3480-427: The 1925-1948 Velocette K series , the 1931-1957 Norton International and the 1947-1962 Norton Manx . In more recent times, the 1950-1974 Ducati Single , 1973-1980 Ducati L-twin engine , 1999-2007 Kawasaki W650 and 2011-2016 Kawasaki W800 motorcycle engines have used bevel shafts. The Crosley four cylinder was the last automotive engine to use the shaft tower design to drive the camshaft, from 1946 to 1952;

3567-417: The 1928-1931 MG 18/80 , the 1926–1935 Singer Junior and the 1928–1929 Alfa Romeo 6C Sport . Early overhead camshaft motorcycles included the 1925–1949 Velocette K Series and the 1927–1939 Norton CS1 . The 1946–1948 Crosley CC Four was arguably the first American mass-produced car to use an SOHC engine. This small mass-production engine powered the winner of the 1950 12 Hours of Sebring . Use of

V6 PRV engine - Misplaced Pages Continue

3654-618: The Frankfurt Auto Show in September 1983 after it set a world record at Nardo, Italy, recording a combined average speed of 154.06 mph (247.94 km/h) over the 50,000 km (31,000 mi) endurance test. The engine was based on the 2.3-liter 8-valve 136 hp (101 kW) unit already fitted to the 190- and E-Class series. Cosworth developed the DOHC light alloy cast cylinder head with four large valves per cylinder. In roadgoing trim,

3741-531: The PRV, experience uneven firing, which can be addressed using split crankshaft journals. 90° V6 engines are shorter (less tall, not less long) and wider than 60° engines, allowing lower engine bay hood/bonnet profiles. First-generation PRV engines (1974–1985) featured uneven firing order. Second-generation PRV engines (introduced in 1984 in the Renault 25 Turbo ) featured split crankshaft journals to create evenly spaced ignition events. Other similar design examples are

3828-502: The PRV. The most powerful versions they built were in the Atlantique 300 at 207 kilowatts (281 PS; 278 bhp) from a turbocharged, 12-valve 3.0 L iteration, and they successfully raced at the 24 Hours of Le Mans with the 600LM with a twin turbocharged , 24-valve 3.0-litre, pushing out over 450 kilowatts (610 hp) in race spec, and the road-going spin-off, the 400GT managed 300 kilowatts (408 PS; 402 bhp). This used

3915-574: The added cost of a DOHC valve train . The Ford design uses one spark plug per cylinder located in the centre, but the Mercedes design uses two spark plugs per cylinder located on opposite sides, leaving the centre free to add a direct-to-cylinder fuel injector at a later date. The 1989 Citroën XM was the first 3-valve diesel-engined car. Examples of SOHC four-valve engines include the Honda F-series engines, D-series engines, all J-series engines,

4002-510: The block, and were known as "tower shafts". An early American overhead camshaft production engine was the SOHC straight-eight engine used in the 1921–1926 Duesenberg Model A luxury car. In 1926, the Sunbeam 3 litre Super Sports became the first production car to use a DOHC engine. In the United States, Duesenberg added DOHC engines (alongside their existing SOHC engines) with the 1928 release of

4089-415: The camshaft. Timing belts are inexpensive, produce minimal noise and have no need for lubrication. A disadvantage of timing belts is the need for regular replacement of the belt; recommended belt life typically varies between approximately 50,000–100,000 km (31,000–62,000 mi). If the timing belt is not replaced in time and fails and the engine is an interference engine , major engine damage

4176-470: The combustion chamber; however an OHV engine requires pushrods and rocker arms to transfer the motion from the camshaft up to the valves, whereas an OHC engine has the valves directly actuated by the camshaft. Compared with OHV engines with the same number of valves, there are fewer reciprocating components and less valvetrain inertia in an OHC engine. This reduced inertia in OHC engines results in less valve float at higher engine speeds (RPM). A downside

4263-461: The crankshaft and the camshaft is commonly used in diesel overhead camshaft engines used in heavy trucks. Gear trains are not commonly used in engines for light trucks or automobiles. Several OHC engines up until the 1950s used a shaft with bevel gears to drive the camshaft. Examples include the 1908–1911 Maudslay 25/30 , the Bentley 3 Litre , the 1917-? Liberty L-12 , the 1929-1932 MG Midget ,

4350-501: The danger of valve float . Some engines are designed to open each intake valve at a slightly different time, which increases turbulence, improving the mixing of air and fuel at low engine speeds. More valves also provide additional cooling to the cylinder head. The disadvantages of multi-valve engines are an increase in manufacturing cost and a potential increase in oil consumption due to the greater number of valve stem seals. Some single overhead camshaft (SOHC) multi-valve engines (such as

4437-543: The engine with and without turbocharger (65.5 kW/liter and 47.9 kW/liter respectively) in the Saab 900 and Saab 9000 . The 2.0-liter Nissan FJ20 was one of the earliest straight-4 mass-produced Japanese engines to have both a DOHC 16-valve configuration (four valves per cylinder, two intake, two exhaust) and electronic fuel injection (EFI) when released in October 1981 in the sixth generation Nissan Skyline . Peak output

SECTION 50

#1732851846775

4524-646: The first appears to have been the 1969 Nissan Skyline , using the Nissan S20 six cylinder DOHC four-valve engine. This engine was also fitted to Nissan Fairlady Z432 racing edition. For a four-cylinder engine, the first mass-produced car using a four valves per cylinder engine was the British Ford Escort RS1600 , this car used the Cosworth BDA engine which was a Ford 'Kent' block with a Cosworth 16 valve twin cam cylinder head. The car went on to become

4611-683: The first commercially available turbocharged PRV V6 was sold in the Renault 25 V6 Turbo . This was the first to be even-fire with split crankpins , and was the first of the second generation, and indeed EFI engine of any sort. Turbocharged versions went on to be used in the Renault Alpine GTA V6 Turbo (essentially the same engine as the 25 Turbo at 2.5 L (2,458 cc), Renault Alpine A610, and Renault Safrane Bi-turbo – both with 3.0 L (2,963 cc) low compression. Naturally aspirated 2963 cc and 2975 cc versions of both low- and high-compression 3-litre engines appeared in

4698-415: The flow of intake and exhaust gases, thereby enhancing combustion , volumetric efficiency , and power output . Multi-valve geometry allows the spark plug to be ideally located within the combustion chamber for optimal flame propagation. Multi-valve engines tend to have smaller valves that have lower reciprocating mass , which can reduce wear on each cam lobe, and allow more power from higher RPM without

4785-486: The head. After making five-valve Genesis engines for several years, Yamaha has since reverted to the cheaper four-valve design. Examples of the five-valve engines are the various 1.8 L 20vT engines manufactured by AUDI AG, the later versions of the Ferrari Dino V8 , and the 1.6 L 20-valve 4A-GE engine made by Toyota in collaboration with Yamaha. For a cylindrical bore and equal-area sized valves, increasing

4872-432: The intake and exhaust ports, since there are no pushrods that need to be avoided. This improves the gas flow through the engine, increasing power output and fuel efficiency . The oldest configuration of overhead camshaft engine is the single overhead camshaft (SOHC) design. A SOHC engine has one camshaft per bank of cylinders, therefore a straight engine has a total of one camshaft and a V engine or flat engine has

4959-715: The intake valves and another for the exhaust valves. Therefore there are two camshafts for a straight engine and a total of four camshafts for a V engine or a flat engine. A V engine or flat engine requires four camshafts to function as a DOHC engine, since having two camshafts in total would result in only a single camshaft per cylinder bank for these engine layouts. Some V engines with four camshafts have been marketed as "quad-cam" engines, however technically "quad-cam" would require four camshafts per cylinder bank (i.e. eight camshafts in total), therefore these engines are merely dual overhead camshaft engines. Many DOHC engines have four valves per cylinder. The camshaft usually operates

5046-403: The low compression bottom end common to the Renault turbo engines, coupled to 24-valve cylinder heads with bespoke rockers and tappets. Peugeot too allowed a small group of engineers to create a team for endurance racing , and after a few years the team grew to be called WM Peugeot. The ultimate version of the car used a low compression 3.0-litre bottom end coupled to bespoke twin-cam heads. It

5133-456: The market for smaller displacement engines. Additionally, Renault needed a V6 engine to fit in its new model, the Renault 30 . Renault's internal designation for the PRV was Z-Type. Machinery for assembling the engines arrived at Douvrin in early June 1973, and buildings for producing the engines were finished in January 1974. The first PRV engines were officially introduced on 3 October 1974 in

5220-513: The multi-valve concept. The 1975 Honda Civic introduced Honda's 1.5-liter SOHC 12-valve straight-4 engines. Nissan's 1988–1992 SOHC KA24E engine had three valves per cylinder (two intakes, one exhaust) as well. Nissan upgraded to DOHC after 1992 for some of their sports cars, including the 240SX . In 1988, Renault released a 12 valve version of its Douvrin 4 cylinder 2.0l SOHC. Mercedes and Ford produced three-valve V6 and V8 engines, Ford claiming an 80% improvement in high RPM breathing without

5307-913: The number of valves beyond five decreases the total valve area. The following table shows the effective areas of differing valve quantities as proportion of cylinder bore. These percentages are based on simple geometry and do not take into account orifices for spark plugs or injectors, but these voids will usually be sited in the "dead space" unavailable for valves. Also, in practice, intake valves are often larger than exhaust valves in heads with an even number of valves-per-cylinder: Turbocharging and supercharging are technologies that also improve engine breathing, and can be used instead of, or in conjunction with, multi-valve engines. The same applies to variable valve timing and variable-length intake manifolds . Rotary valves also offer improved engine breathing and high rev performance but these were never very successful. Cylinder head porting , as part of engine tuning ,

SECTION 60

#1732851846775

5394-406: The opposite end for example). This engine was however extremely expensive, and suffered cam wear problems. This was due to the exhaust valves sharing a single lobe, while each inlet valve had its own lobe. This was at least partially solved by the use of ceramic followers as one of a succession of recalls. Meanwhile, French supercar manufacturer Venturi had been developing their own versions of

5481-588: The original 300 PS (221 kW; 296 hp) 3.0-liter version the Toyota 7 engine participated in endurance races as a 5.0-liter (4,968 cc) non-turbo V8 with DOHC and 32-valves. It produced 600 PS (441 kW; 592 hp) at 8,000 rpm (88.8 kW/liter) and 55.0 kg⋅m (539 N⋅m; 398 lb⋅ft) at 6,400 rpm. There is much discussion about which was the first 'mass-produced' car to use an engine with four valves per cylinder. For six cylinder engines, and considering special versions of mass-produced cars,

5568-449: The rights to the Crosley engine format were bought by a few different companies, including General Tire in 1952, followed by Fageol in 1955, Crofton in 1959, Homelite in 1961, and Fisher Pierce in 1966, after Crosley closed the automotive factory doors, and they continued to produce the same engine for several more years. A camshaft drive using three sets of cranks and rods in parallel

5655-742: The rules, however the FIA homologation documentation shows the homologated production engine was a "2850cm³" capacity "V6" engine. The bore spacing of the Montreal engine was too close to be suitable for the 155 V6 Ti in any case. Limone invented the "Montreal V8" story to throw the press off the scent and to satisfy FIAT management who were unhappy that a non-FIAT group developed engine was being used. Overhead cam Single overhead camshaft (SOHC) engines have one camshaft per bank of cylinders . Dual overhead camshaft (DOHC, also known as "twin-cam" ) engines have two camshafts per bank. The first production car to use

5742-402: The spark plugs. Only two cars were built. Ferrari developed their Quattrovalvole (or QV) engines in the 80s. Four valves per cylinder were added for the 1982 308 and Mondial Quattrovalvole , bringing power back up to the pre- FI high of 245 hp (183 kW) . A very unusual Dino Quattrovalvole was used in the 1986 Lancia Thema 8.32 . It was based on the 308 QV's engine, but used

5829-646: The starting point for both Mercedes' and Rolls-Royce's aircraft engines. Mercedes created a series of six-cylinder engines which culminated in the Mercedes D.III . Rolls-Royce reversed-engineered the Mercedes cylinder head design based on a racing car left in England at the beginning of the war, leading to the Rolls-Royce Eagle V12 engine. Other SOHC designs included the Spanish Hispano-Suiza 8 V8 engine (with

5916-447: The timing between each camshaft and the crankshaft. This affords better fuel economy by allowing a broader torque curve. Although each major manufacturer has their own trade name for their specific system of variable cam phasing systems, overall they are all classified as variable valve timing . The rotation of a camshaft is driven by a crankshaft . Many 21st century engines use a toothed timing belt made from rubber and kevlar to drive

6003-437: The top of the engine. Large aircraft engines— particularly air-cooled engines— experienced considerable thermal expansion, causing the height of the cylinder block to vary during operating conditions. This expansion caused difficulties for pushrod engines, so an overhead camshaft engine using a shaft drive with sliding spline was the easiest way to allow for this expansion. These bevel shafts were usually in an external tube outside

6090-414: The valves directly via a bucket tappet . A DOHC design permits a wider angle between intake and exhaust valves than in SOHC engines, which improves the air-fuel mixture's flow through the engine. A further benefit is that the spark plug can be placed at the optimum location, which in turn improves combustion efficiency . Another newer benefit of DOHC engine design is the ability to independently change/phase

6177-516: The world speed record of 170 km/h. Robert Peugeot also commissioned the young Ettore Bugatti to develop a GP racing car for the 1912 Grand Prix. This chain-driven Bugatti Type 18 had a 5-litre straight-4 with SOHC and three valves per cylinder (two inlet, one exhaust). It produced appr. 100 bhp (75 kW; 101 PS) at 2800 rpm (0.30 bhp per cubic inch) and could reach 99 mph (159 km/h). The three-valve head would later be used for some of Bugatti's most famous cars, including

6264-490: The world to have an engine with two overhead camshafts and four valves per cylinder was the 1912 Peugeot L76 Grand Prix race car designed by Ernest Henry . Its 7.6-litre monobloc straight-4 with modern hemispherical combustion chambers produced 148 bhp (110 kW) (19.5 HP/Liter(0.32 bhp per cubic inch)). In April 1913, on the Brooklands racetrack in England, a specially built L76 called "la Torpille" (torpedo) beat

6351-464: Was 148 hp (110 kW) at 6,000 rpm and 133 lb⋅ft (180 N⋅m) at 4,800 rpm. The FJ20 was also offered with a turbocharger, producing 188 hp (140 kW) at 6,400 rpm and 166 lb⋅ft (225 N⋅m) at 4,800 rpm. Following Nissan's lead, Toyota released the 1.6-liter (1,587 cc) 4A-GE engine in 1983. The cylinder head was developed by Yamaha Motor Corporation and was built at Toyota's Shimayama plant. While originally conceived of as

6438-605: Was Bugattis clean sweep of the first four places at Brescia in 1921. In honour of this memorable victory all 16-valve-engined Bugattis were dubbed Brescia . From 1920 through 1926 about 2000 were built. Peugeot had a triple overhead cam 5-valve Grand Prix car in 1921. Bentley used multi-valve engines from the beginning. The Bentley 3 Litre , introduced in 1921, used a monobloc straight-4 with aluminium pistons, pent-roof combustion chambers , twin spark ignition, SOHC, and four valves per cylinder. It produced appr. 70 bhp (0.38 bhp per cubic inch). The 1927 Bentley 4½ Litre

6525-468: Was a 419.6 cid (6.9-liter) straight-8 with DOHC, 4 valves per cylinder and a supercharger. It achieved 400 bhp (298.3 kW) at 5,000 rpm and 0.95 bhp per cubic inch. The 1937 Mercedes-Benz W125 racing car used a supercharged 5.7-liter straight-8 with DOHC and four valves per cylinder. The engine produced 592-646 bhp (441.5-475 kW) at 5800 rpm and achieved 1.71-1.87 bhp per cubic inch (77.8-85.1 kW/liter). The W125 top speed

6612-526: Was an asset to the bootleggers of that era. Multi-valve engines continued to be popular in racing and sports engines. Robert M. Roof, the chief engineer for Laurel Motors, designed his multi-valve Roof Racing Overheads early in the 20th century. Type A 16-valve heads were successful in the teens, Type B was offered in 1918 and Type C 16-valve in 1923. Frank Lockhart drove a Type C overhead cam car to victory in Indiana in 1926. Bugatti also had developed

6699-478: Was appr. 200 mph (322 km/h). The 1967 Cosworth DFV F1 engine, a NA 3.0-liter V8 producing appr. 400 bhp (298 kW; 406 PS) at 9,000 rpm (101.9 kW/liter), featured four valves per cylinder. For many years it was the dominant engine in Formula One, and it was also used in other categories, including CART , Formula 3000 and Sportscar racing . Debuting at the 1968 Japanese Grand Prix in

6786-497: Was later increased to 3.0 litres and increased power output to 828 hp (617 kW). The 1984 Ferrari Testarossa had a 4.9-liter flat-12 with four valves per cylinder. Almost 7,200 Testarossa were produced between 1984 and 1991. In 1985 Lamborghini released a Countach Quattrovalvole , producing 455 PS (335 kW; 449 hp) from a 5.2-liter (5167 cc) Lamborghini V12 engine (64.8 kW/liter). The Mercedes-Benz 190E 2.3-16 with 16-valve engine debuted at

6873-515: Was launched in 1969. The FM factory was built in Douvrin near Lens in northern France. The PRV engines are sometimes referred to as "Douvrin" engines, though that name is more commonly applied to a family of straight-fours produced at the same time. In 1971, Volvo joined Peugeot and Renault in the creation of PRV, an equally-held public limited company (plc). PRV originally planned to build V8 engines , although these were later scrapped in favor of

6960-492: Was of similar engine design. The NA racing model offered 130 bhp (0.48 bhp per cubic inch) and the 1929 supercharged 4½ Litre (Blower Bentley) reached 240 bhp (0.89 bhp per cubic inch). The 1926 Bentley 6½ Litre added two cylinders to the monobloc straight-4. This multi-valve straight-6 offered 180-200 bhp (0.45-0.50 bhp per cubic inch). The 1930 Bentley 8 Litre multi-valve straight-6 produced appr. 220 bhp (0.45 bhp per cubic inch). In 1931

7047-603: Was offered in turbo and biturbo versions in a limited number of vehicles made by Renault, Chrysler Motors , and French supercar manufacturer Venturi . It was gradually replaced after 1994 by another engine jointly developed by Peugeot-successor PSA and Renault , known as the ES engine at PSA and the L engine at Renault . In 1966, Peugeot and Renault entered a cooperative agreement to manufacture common components. The first joint subsidiary, La Française de Mécanique (also called Compagnie Française de Mécanique or simply FM )

7134-509: Was one of the first production cars to use an SOHC engine. During World War I, both the Allied and Central Powers ; specifically those of the German Empire 's Luftstreitkräfte air forces, sought to quickly apply the overhead camshaft technology of motor racing engines to military aircraft engines. The SOHC engine from the Mercedes 18/100 GP car (which won the 1914 French Grand Prix) became

7221-472: Was the 1962 Glas 1004 compact coupe. Another camshaft drive method commonly used on modern engines is a timing chain , constructed from one or two rows of metal roller chains . By the early 1960s most production automobile overhead camshaft designs used chains to drive the camshaft(s). Timing chains do not usually require replacement at regular intervals, however the disadvantage is that they are noisier than timing belts. A gear train system between

7308-401: Was the first Alfa Romeo DOHC engine. It had four valves per cylinder, 90-degree valve angle and twin-spark ignition. The GP engine had a displacement of 4.5-liter (4490 cc) and produced 88 bhp (66 kW) at 2950 rpm (14.7 kW/liter), and after modifications in 1921 102 bhp (76 kW) at 3000 rpm. The top speed of this car was 88-93 mph (140–149 km/h). It wasn't until

7395-413: Was the last year for the PRV in a Volvo, shifting its powerplant reliance onto in-house inline engines : the successor to its PRV-powered 760, the 960, debuted with a new inline six "white block" Modular engine . Peugeot , Renault and Citroën continued using the PRV until 1997. After producing 970,315 units, production of the PRV V6 was stopped on 15 June 1998. The original engineering work done on

7482-467: Was used in the 1920–1923 Leyland Eight luxury car built in the United Kingdom. A similar system was used in the 1926-1930 Bentley Speed Six and the 1930-1932 Bentley 8 Litre . A two-rod system with counterweights at both ends was used by many models of the 1958-1973 NSU Prinz . Among the first overhead camshaft engines were the 1902 Maudslay SOHC engine built in the United Kingdom and

7569-405: Was used in the 1983 BMW M6 35CSi and in the 1985 BMW M5 . The 1978 Porsche 935/78 racer used a twin turbo 3.2-liter flat-6 (845 bhp/630 kW@8,200 rpm; 784 Nm/578 ft.lbs@6,600 rpm). The water-cooled engine featured four valves per cylinder and output a massive 196.2 kW/liter. Porsche had to abandon its traditional aircooling because the multi-valve DOHC hampered aircooling of

#774225