The L-series engine has been available in 4 specifications.
84 bhp (63 kW) Turbo/Non-intercooled (ceased production in 2000)
99bhp (73 kW) Turbo/intercooled
103 bhp (78 kW) Turbo/intercooled
113 bhp (83 kW) Turbo/intercooled
Bore – 84.5 mm (3.33″)
Stroke – 88.9 mm (3.5″)
Displacement – 1994 cc
Firing order – 1-3-4-2
Compression ratio – 19.5:1
Boost pressure – 14 (D, VP37 pump models), 17psi (25/45/ZR/ZS models)
The L-Series engine commenced production in 1995 and was Rovers first in-house designed and manufactured direct injection diesel engine. It is derived from the established Perkins MDi Prima engine used in the Austin Montego, Austin Maestro, and LDV Sherpa van. The L series is extremely versatile and has been fitted in the Land Rover Freelander, Rover 200 Mk3, Rover 400 Mk2, Rover 600, and European versions of the Honda Accord and Honda Civic. A development of the L series engine (The G-Series) featuring a modern common-rail fuel injection system was underway when MG-Rover ceased production, but the company’s closure prevented it from being fully developed and released.
There are several forms of this engine.
The first is a non intercooled, mechanically controlled fuel injection system. This version is available in Rover 200 and Rover 400 models and the model designation ends in “D”, i.e. SD, SLD etc., etc.
The second is intercooled and has an electronically controlled fuel injection system. This version is available in Rover 200, Rover 400 and Rover 600 models. The model designation ends in “Di”, i.e. SDi, SLDi etc., etc.
The last and most recent engine is intercooled and also has an electronically controlled injection system which is slightly more advanced and produces more torque than earlier models as earlier intercooled models and either more or less power depending on the ECU map installed. This is the version that is used in the Rover 25, Rover 45, MG ZR, and MG ZS.
All versions use Bosch fuel injection equipment of various designs.
The Di engines use a VP37 fuel pump
The 25/45/ZR/ZS engines use a VP30 fuel pump
The engine is extremely environmentally friendly in terms of its emissions. It is almost quiet in operation owing to its two stage fuel injection & ECU controlling fuel for most models and timing for them all. The engine is installed with an oxidation catalytic converter to reduce the diesel fuel.
Sensors around the engine give feedback to the ECU regarding injection timing, engine speed, fuel and coolant temperature, boost pressure etc to ensure that optimum running conditions are maintained.
The basic engine is a conventional 4 cylinder with 2 valves per cylinder operated by a single overhead camshaft and hydraulic tappets.
The block is made of cast iron with aluminum alloy head and sump. A Garret GT15 turbo charger supplies boosted air. A modulated, either air or water cooled exhaust gas recirculation (EGR) system is incorporated into the intake/exhaust system to reduce NOx emissions.
All accessories, (PAS, aircon, water pump, vacuum pump, alternator) are all driven off a single poly-vee-belt drive with and automatic tensioner. Camshaft and injection pump drives are via two multi-toothed belts with either automatic or manual tensioners dependant on the engine age, (earlier models have auto tensioners).