Aurelio Lampredi Aurelio Lampredi (16 June 1917 – 1 June 1989) was an Italian automobile and aircraft engine designer. Born in Livorno, he began his career before World War II at Piaggio, moved to Isotta Fraschini, and then joined Reggiane. This time he des ...

, the Fiat Twin Cam (also known as the Lampredi Twin Cam) was an advanced

inline-four A straight-four engine (also called an inline-four) is a four-cylinder piston engine where cylinders are arranged in a line along a common crankshaft. The vast majority of automotive four-cylinder engines use a straight-four layout (with the e ...

automobile engine produced from 1966 through 2000 as a

Fiat Fiat Automobiles S.p.A. (, , ; originally FIAT, it, Fabbrica Italiana Automobili di Torino, lit=Italian Automobiles Factory of Turin) is an Italian automobile manufacturer, formerly part of Fiat Chrysler Automobiles, and since 2021 a subsidiary ...

Lancia Lancia () is an Italian car manufacturer and a subsidiary of FCA Italy S.p.A., which is currently a Stellantis division. The present legal entity of Lancia was formed in January 2007 when its corporate parent reorganised its businesses, but it ...

engine until it was replaced by the "family B" Pratola Serra engine series. The engine was produced in a large number of displacements, ranging from and was used in Fiat,

Alfa Romeo Alfa Romeo Automobiles S.p.A. () is an Italian luxury car manufacturer and a subsidiary of Stellantis. The company was founded on 24 June 1910, in Milan, Italy. "Alfa" is an acronym of its founding name, "Anonima Lombarda Fabbrica Automobili." ...

SEAT A seat is a place to sit. The term may encompass additional features, such as back, armrest, head restraint but also headquarters in a wider sense. Types of seat The following are examples of different kinds of seat: * Armchair (furniture), ...

and Morgan cars. The Fiat Twin Cam engine has been widely used in

motorsport Motorsport, motorsports or motor sport is a global term used to encompass the group of competitive sporting events which primarily involve the use of motorized vehicles. The terminology can also be used to describe forms of competition of two ...

and has been the most successful engine in the history of the

World Rally Championship The World Rally Championship (abbreviated as WRC) is the highest level of global competition in the motorsport discipline of rallying, owned and governed by the FIA. There are separate championships for drivers, co-drivers, manufacturers and t ...

. Fiat and Lancia won a total of ten World Rally Championships for Manufacturers using engines based on the Lampredi Twin Cam engine.

Design

The engine uses the block of the OHV 124-series unit first found in the

Fiat 124 The Fiat 124 is a small family car manufactured and marketed by Italian company Fiat between 1966 and 1974. The saloon superseded the Fiat 1300 and was the basis for several variants including a station wagon, a four-seater coupé ( 124 Sport Cou ...

with some modifications to accept the belt drive for the

camshaft A camshaft is a shaft that contains a row of pointed cams, in order to convert rotational motion to reciprocating motion. Camshafts are used in piston engines (to operate the intake and exhaust valves), mechanically controlled ignition systems ...

s. The head itself is made in three pieces, one carrying the

combustion chamber A combustion chamber is part of an internal combustion engine in which the fuel/air mix is burned. For steam engines, the term has also been used for an extension of the firebox which is used to allow a more complete combustion process. Interna ...

and valves and one separate casting for each camshaft in tunnel type bearings. The valves had an included angle of 65 degrees. The engine featured a revolutionary new method for adjusting the valve clearance. Usually at that time in

DOHC An overhead camshaft (OHC) engine is a piston engine where the camshaft is located in the cylinder head above the combustion chamber. This contrasts with earlier overhead valve engines (OHV), where the camshaft is located below the combustion c ...

engines like from

Jaguar The jaguar (''Panthera onca'') is a large cat species and the only living member of the genus '' Panthera'' native to the Americas. With a body length of up to and a weight of up to , it is the largest cat species in the Americas and the th ...

, small shims were placed on the valve stem inside the

bucket tappet A tappet is most commonly a component in an internal combustion engine which converts the rotating motion of the camshaft into linear motion of the valves, either directly or indirectly. An earlier use of the term was for part of the valve gear ...

s, thereby necessitating the removal of the camshafts to get access to these shims to adjust the valve clearance, making for time consuming and very expensive maintenance work. Lampredi’s design placed the shims on top of the tappets where they could be removed with the camshaft ''in situ'' after the tappets were pressed down with a special tool. This design was patented for Fiat and was used in the engines of the 128 and 130, and even the Ferrari/Fiat Dino V6 engine was converted to this system. Fiat was a pioneer in engine development during the time period, using belt driven camshafts and

aluminium alloy An aluminium alloy (or aluminum alloy; see spelling differences) is an alloy in which aluminium (Al) is the predominant metal. The typical alloying elements are copper, magnesium, manganese, silicon, tin, nickel and zinc. There are two principal ...

heads. Earlier Fiat Twin Cam engines were actually

O.S.C.A. O.S.C.A. (Officine Specializzate Costruzione Automobili—Fratelli Maserati S.p.A.) was an Italian manufacturer of racing and sports cars established 1947 in San Lazzaro di Savena, Bologna, by the Maserati brothers, and closed down in 1967. The ...

designs.

Applications

Lampredi's twin cam engine was first seen in the Fiat 124 coupé of late 1966, but was later made available in a large number of cars.

Fiat

* 1966-1974 124 Sport coupé * 1966-1985 124 Sport Spider * 1970-1974 124 Special T * 1972-1976 124 Abarth Rally * 1967-1972 125 * 1972-1981 132 * 1981-1985 Argenta * 1977-1983 131 * 1977-1980 131 Abarth * 1982-1988 Ritmo * 1984-1989 Ritmo 105TC, 125TC, 130TC * 1983-1990 Regata * 1985-1996 Croma * 1988-1995 Tipo * 1990-1999 Tempra * 1994-1997

Coupé A coupe or coupé (, ) is a passenger car with a sloping or truncated rear roofline and two doors. The term ''coupé'' was first applied to horse-drawn carriages for two passengers without rear-facing seats. It comes from the French past parti ...

Lancia

* 1972-1984

Beta Beta (, ; uppercase , lowercase , or cursive ; grc, βῆτα, bē̂ta or ell, βήτα, víta) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Modern Greek, it represents the voiced labiod ...

* 1973-1984 Beta Coupé/HPE/Spider * 1975-1982 Beta

Montecarlo Monte Carlo (; ; french: Monte-Carlo , or colloquially ''Monte-Carl'' ; lij, Munte Carlu ; ) is officially an administrative area of the Principality of Monaco, specifically the ward of Monte Carlo/Spélugues, where the Monte Carlo Casino is ...

* 1976-1977 Beta Scorpion * 1982-1983 Rally 037 * 1980-1984

Trevi The area of freedom, security and justice (AFSJ) is a collection of justice as well as migration & home affairs policies designed to ensure security, rights and free movement within the European Union (EU). Fields covered include the harmonisati ...

* 1983-1993

Delta Delta commonly refers to: * Delta (letter) (Δ or δ), a letter of the Greek alphabet * River delta, at a river mouth * D ( NATO phonetic alphabet: "Delta") * Delta Air Lines, US * Delta variant of SARS-CoV-2 that causes COVID-19 Delta may also ...

* 1988-1993 Delta Integrale * 1982-1989 Prisma * 1984-1994 Thema * 1989-1997 Dedra * 1993-1999 Delta mk2 * 1994-1998

Kappa Kappa (uppercase Κ, lowercase κ or cursive ; el, κάππα, ''káppa'') is the 10th letter of the Greek alphabet, representing the voiceless velar plosive sound in Ancient and Modern Greek. In the system of Greek numerals, has a value o ...

* 1997-1998 Kappa Coupe

Morgan

* 1982-1986

Morgan Plus 4 The Commodore Plus/4 is a home computer released by Commodore International in 1984. The "Plus/4" name refers to the four-application read-only memory, ROM resident office suite (word processor, spreadsheet, database, and graphing); it was bill ...

Alfa Romeo

* 1988-1991 Alfa Romeo 164 2.0 Turbo 8V * 1992-1997

Alfa Romeo 155 The Alfa Romeo 155 (Type 167) is a compact executive car produced by Italian automobile manufacturer Alfa Romeo between 1992 and 1998. It was unveiled in January 1992 at Barcelona, with the first public launch in March 1992, at the Geneva Motor S ...

FSO

* 1973-1975

Polski Fiat 125p Polski Fiat 125p is a motor vehicle manufactured between 1967 and 1991 in Poland under a Fiat license by the state-owned manufacturer Fabryka Samochodów Osobowych (FSO). It was a simplified and altered variation of the original, Italian-made Fia ...

Monte Carlo * 1973-1977

Akropolis * 1978-1989

FSO Polonez The FSO Polonez is a motor vehicle that was developed in Poland in collaboration with Fiat and produced by Fabryka Samochodów Osobowych from 1978 to 2002. It was based on the Polski Fiat 125p platform with a new hatchback design by Giorgetto G ...

One version was the CHT (for "Controlled High Turbulence"). This version was mainly used in the first generation Fiat Croma and used a special head and intake with auxiliary intake ducts to provide a better fuel and gas mixture under low or partial acceleration. This meant considerably improved fuel mileage.

Displacements

Engine Codes

Motorsport

The Fiat Twin Cam engine has been widely used in

and has been the most successful engine in the history of the

. The World Rally Championship for Manufacturers has been won by Fiat and Lancia, using engines based on the Lampredi Twin Cam engine, for a total of 10 years. The four valve version made its first appearance in the Group 4 competition version of the Fiat 124 Spider Abarth, where it had 1.8 litres. Group 4 regulations at that time allowed the use of a cylinder head of a "free" design. This engine still used a three-piece cylinder head design with an included valve angle of 46 degrees. In later years motorsport regulations were changed so that the use of four valve heads was only possible when the homologated cars had four valve heads. Therefore, the homologation series of the Fiat 131 Rally Abarth came with a two-litre version of the four valve engine. These engines were later used in the mid-engined Lancia 037, where they were supercharged and eventually enlarged to 2.1 litres. In addition to the titles in the World Rally Championship, the Fiat Twin Cam equipped the Lancia Beta Montecarlo turbo, that won the

World Sportscar Championship The World Sportscar Championship was the world series run for sports car racing by the FIA from 1953 to 1992. The championship evolved from a small collection of the most important sportscar, endurance, and road racing events in Europe and No ...

for two consecutive seasons in 1980-1981. The Fiat Twin Cam has also been used in hot rods and kit cars, with an aftermarket kit to swap one into the Morris Minor. Fiat 131 Abarth of Walter Röhrl at 1980 Rallye Sanremo

Fiat 131 Abarth of Walter Röhrl at 1980 Rallye Sanremo

Footnotes

{{Reflist

Twin Cam An overhead camshaft (OHC) engine is a piston engine where the camshaft is located in the cylinder head above the combustion chamber. This contrasts with earlier overhead valve engines (OHV), where the camshaft is located below the combustion cha ...

Straight-four engines Gasoline engines by model