Engines

Engines used by French automaker Renault SA have historically been referenced in technical specifications along two distinct systems:

    * a purely numeric system used from the origins of the company until the mid-1980s

    * an alphanumeric system in use since then

Numbering systems

Numeric

The numeric engine referencing system used until the mid-1980s was simply the chronological sequence of engine development projects. Thus, variants based on the same engine block may have unrelated numbers.

Alphanumeric

The system in use since the mid-1980s is of the format XnY-zzz where

    * X is a letter specifying the engine family

    * n is a one-digit code specifying the engine architecture as follows:

         1. Petrol engine with single-barrel carburettor and parallel valves (a layout often but not always associated with an overhead valve design)

         2. Petrol engine with double-barrel carburettor and parallel valves

         3. Petrol engine with single- or multi-point fuel injection and parallel valves

         4. Petrol engine with four valves per cylinder

         5. Petrol engine with single-barrel carburettor and cross flow valve layout (includes also a direct petrol injection F engine)

         6. Petrol engine with double-barrel carburettor and cross flow valve layout

         7. Petrol engine with multi-point fuel injection with half-spherical combustion chambers and 4 valves per cylinder (includes also an early 16-valve version of the F-type engine)

         8. Diesel engine with indirect injection (prechamber)

         9. Diesel engine with direct injection

    * Y is a one-letter indicator of displacement:

          A: under 750 cc

          B-U: from 750 to 2250 cc in 50 cc, then 100 cc increments as displacement increases

          V-Z: above 2250 cc in increments larger than 100 cc

     * zzz is a three-character alphanumeric code (usually starting with 7 or A) referring to key details of the variant's configuration (e.g., turbocharged, implemented in a specific vehicle, manual or automatic transmission, catalytic converter or not, etc. An odd number refers to an engine configured for automatic transmission, while an even number is meaning manual gearbox.)

Engine families

A

The A engine was an all-aluminium overhead valve inline 4 designed in the mid-1960s for the Renault 16 and produced in three variants:

    * A1K: 1470 cc

    * A1L: 1565 cc

    * A2M/A3M: 1647 cc

B

The B family (for the Billancourt factory where it was produced, also referred to as the Ventoux engine)) was a cast-iron overhead valve inline-4 designed in the mid-1940s for the 4CV and also used in the Renault 4 and Dauphine:

    * 748cc (out of production before alphanumeric codes were introduced)

    * 782cc (out of production before alphanumeric codes were introduced)

    * B1B: 845 cc

 C

 The C family (for the Cleon factory where it was produced, also referred to as Sierra in early variants) was a major evolution of the B type, being also a cast-iron overhead valve inline-4, designed in the early 1960s for the Renault 8. An extremely sturdy, low-cost design, it was continuously refined over its 35-year career and was used in every supermini and compact Renault type up to and including the 1992 Twingo:

     * C1C (689): 956cc (65x72); 32 kW

    * C1E (688): 1108cc (70x72); 28-34kW

    * C1G: 1237cc (71,5x77); 40 kW

    * C3G: 1239cc (74x72); 40 kW; monopoint injection

    * 810: 1289cc (73x77; out of production before alphanumeric codes were introduced); 32-47kW

    * C3J: 1390cc (75,8x77); 43 kW; monopoint injection

    * C1J/C2J (847): 1397cc (76x77); 43-52kW normal aspiration / 77-88kW Turbo

    * C6J (840): 1397cc (76x77 with hemispherical head); 68 kW normal aspiration, 79-116kW Turbo

    * C7K: 1430cc (76x79)

 D

 The D family is the successor to the smaller versions of Type C, introduced in the mid-1990s, and is a cast-iron overhead camshaft inline-4 that powers the Renault Twingo:

    * D4F: 1149 cc

    * D7F: 1149 cc

A 1000 cc D7D version was abandoned after early development.

E

The E family (for Energy) is the successor to the larger versions of Type C. It is a cast-iron overhead camshaft inline-4 introduced on the Renault 19 in 1988 and widely used in the Clio and Megane lineups:

    * E5F/E7F: 1171 cc

    * E5J/E6J/E7J: 1390 cc

    * E7M/E4M: 1598 cc

F

The F inline-4 family (for Fonte, French for cast iron) was the successor to the A family. Launched in 1981 on the Renault 9 and Renault 11, it has been the mainstay of Renault's engine lineup through the early 2000s in a succession of increasingly powerful petrol and Diesel variants in overhead camshaft configurations. It was also Renault's first production four-valve design. It is being replaced by the M engine.

    * F1N/F2N/F3N: 1721 cc

    * F7P: 1764 cc

    * F3P: 1794 cc

    * F4P: 1794cc (evolution of the F3P, 16V with variable valve control on the inlet camshaft)

    * F3R/F4R/F7R: 1998 cc

    * F5R: 1998cc (direct fuel injection - IDE - only 2 years in production, used in the Megane Coupe and the Laguna II)

    * F8Q/F9Q: 1896 cc

G

The G engine was designed in the late 1980s to be a modular family of overhead camshaft inline 4- and 5-cylinder petrol and Diesel engines. A G7R petrol and a G8T Diesel variant were in development when Renault announced a merger with Volvo who was designing its own modular family along the exact same lines. The group made the business decision to cancel all G development save for Diesel versions. Despite the breakdown of the merger in 1993, Renault used Volvo petrol engines (Type N) in its mid- and full-size models until the early 2000s

    * G8T/G9T: 2188 cc

H

The H engine is an overhead camshaft engine developed jointly with Nissan, who refers to it as the HR engine.

    * H4Jt: 1397cc (turbo-charged petrol engine used on Renault Megane; unveiled late 2008)

    * H4M: 1598cc (petrol engine used on Renault Samsung SM3; unveiled April 2009)

J

The J family (also referred to as the Douvrin engine) was an all-aluminium overhead camshaft inline-4 overhead camshaft design jointly developed with PSA. Introduced in 1977, it was phased out in 1996 by the F series.

     * J5R/J6R/J7R: 1995 cc

    * J6T/J7T: 2165 cc

    * J8S: 2068 cc

 K

 The K type is a major evolution of the E type.

     * K4J: 1390 cc

    * K4M: 1598 cc

    * K7M: 1598 cc

    * K9K: 1461 cc

L

The L type is an aluminium overhead camshaft petrol V6 developed jointly with PSA, who refer to it as the ES engine:

Renault used this engine first in the Laguna in 1997, shortly after it became available in the Safrane, and the Espace rated 194 PS (143 kW). Engines after 2001 got a new injection system and variable valve timing, this variant is rated 211 PS (155 kW), was being used in the Avantime, and the Laguna II V6. The engine was also used in the Clio V6, rated 230 PS (169 kW) in the phase 1 vehicles, and 255 PS (188 kW) after the facelift.

    * L7X: 2946 cc

M

The M engine is an overhead camshaft engine developed jointly with Nissan, who refers to it as the MR engine. Only one Diesel version is in use at Renault as of mid-2006, though the petrol versions already launched by Nissan will almost certainly be used as well

     * M9R: 1995 cc (diesel engine used in Nissan Qashqai, Renault Scenic, Laguna, Vel Satis and Espace; launched early 2005)

    * M4P: 1798cc (petrol engine still under development, bore 84.0 mm (3.31 in), stroke 81.1 mm (3.19 in). It will produce approximately 125 hp (93 kW) @ 5300rpm)

    * M4R: 1997cc (petrol engine used on Renault Clio III and Laguna III; launched November 2006)

 N

The N engine is Renault's internal designation for the modular overhead camshaft inline-4 and inline-5 sourced from Volvo in the 1990s and used on the Laguna and Safrane sedans:

    * N7Q: 1948 cc

    * N7U: 2435 cc

P

The P engine is an overhead camshaft Diesel V6 sourced from Isuzu and used in the Laguna III Coupe, Vel Satis sedan and Espace minivan:

    * P9X: 2958 cc

R

The R engine was a 1.2L engine used in the Renault Clio until 1997.

S

The S engine was a cast-iron overhead valve inline-4 Diesel engine sourced from Italian engine manufacturer SOFIM. It has been used in the Trafic and Master utility van and the Safrane sedan since 1981:

    * S8U/S9U: 2445 cc

    * S9W: 2799 cc

V

The V engine is Renault's internal designation for the Nissan VQ engine, an overhead camshaft V6 used in the Vel Satis sedan and Espace minivan. The V designation is also used for an unrelated diesel V6 engine jointly developed by Renault and Nissan, used in the Renault Laguna coupe and designated V9X.

    * V4Y: 3498 cc

    * V9X: 2993 cc

X

The X engine (referred to as XZ and XY by PSA) was an all-aluminium overhead camshaft inline-4 jointly developed with PSA. Introduced in 1974, it powered the ill-fated Renault 14 midsize car and was phased out in 1982 by evolutions of the C series:  

    * X1G: 1219 cc

    * X2J: 1360 cc

Z

The Z engine, also known as the PRV engine, was an aluminium overhead camshaft V6 developed jointly with PSA and Volvo in the early 1970s. Introduced in 1975 on the Renault 30, it also powered the 25, Safrane, Laguna, Espace, and Alpine.

    * Z7U: 2458 cc

    * Z7V: 2664 cc

    * Z6W/Z7W: 2849 cc

    * Z7X: 2975, then 2963 cc

More Information and Pictures on: http://en.wikipedia.org/wiki/List_of_Renault_engines

Without going into too much details, the first cycle starts with the mixture of fuel / air (blue) being drawn in, which is then compressed by the upward motion of the piston. For optimum performance and efficiency, the spark must ignite the fuel at just the right moment (engineers call it TDC, top dead centre). This is where the octane rating of a fuel comes in. A lower octane rating fuel will ignite on its own due to the high pressure and temperature, before the spark is being delivered. This condition is called pre-ignition or auto ignition, which is not something you would want unless you are talking about a diesel engine (compression ignition).


Anyway in petrol engine, pre-ignition will result in "pinging," a condition when the engine sounds like "marbles" rolling around inside it due to the many uncontrolled explosions all happening at the wrong time. And of course, a higher octane fuel will be able to withstand higher pressure and temperature before being ignited. High performance engines usually run on higher compression ratios, thus requiring higher octane fuels. And if you are still up for more information, octane is measured ("calibrated") against a mixture of iso-octane (Octane-100) and heptane (Octane-0). A fuel of 97-octane has equal auto-ignition properties to a mixture of 97% iso-octane and 3% heptane.