Lotus 900 series

It is a common misconception that the Lotus 900 series engines were modified Vauxhall engines. The 900 series was designed by Lotus as their first self developed engine, and due to superficial similarities in dimensions Vauxhall 4 cylinder iron blocks were used as testbeds.

The 900 series engine was introduced in production form as the Lotus 907 in the 1972 Jensen-Healey, and went on to power Lotus into the late 1990s. It is regarded as the first DOHC, 16-valve production engine made.Fact|date=January 2008

904

The initial 2.0 litre Lotus 904 engine was first used in the Lotus "type 62" Europa racecar, and indeed used a Vauxhall iron block, termed the Lotus-Vauxhall engine.

911

The engine was modified into the type 911, which was fully designed by Lotus, used in the winning Lotus Talbot Sunbeam rally and production cars.

907

The Lotus 907 engine, the first production version, was 2.0 L (1973 cc) and was used in the Jensen-Healey and later Lotus Esprit, Lotus Elite and Lotus Eclat. Bore was 3.75 in (95.28 mm) and stroke was 2.725 in (69.24 mm), and a DOHC 4-valve head was fitted, one of the first in modern times. Breathing through dual carburettors, the engine produced 160 hp (118 kW) at 6500 rpm with convert|140|ft.lbf|N.m|abbr=on of torque.

Applications:
* 1972-1974 Jensen-Healey
* 1975-1976 Jensen-Healey "GT"
* 1974-1980 Lotus Elite "S1"
* 1975-1985 Lotus Eclat "S1"
* 1975-1978 Lotus Esprit "S1"
* 1978-1981 Lotus Esprit "S2"

912

Also known as the naturally aspirated "Lotus 910", the stroke was increased to 76.2 mm giving a displacement of 2.2 L (2174 cc).

Applications:
* 1981 Lotus Esprit "S2.2"
* 1981-1990 Lotus Esprit "S3" and "NA"
* 1981 Lotus Eclat "S2.2"
* 1982 Lotus Excel SE

910

Turbocharged engines introduced in 1980 were known as the "type 910", which in high compression configuration produced convert|215|hp|abbr=on and an astounding convert|220|ft.lbf|N.m|abbr=on of torque. The engine was again upgraded in 1990 to the "type 910s" for use in the "Esprit SE" where it produced convert|280|hp through the addition of Delco GMP4 EFI and a water to air intercooler known as the "Chargecooler". In its ultimate incarnation as used in the "Sport 300", "X180R" and "S4s" the engine was capable of convert|300|hp, propelling these cars to 0-60 times in the low 4 seconds.

Applications:
* 1980-1990 Lotus Esprit "Turbo"
* 1990-1993 Lotus Esprit "SE"
* 1993 Lotus Esprit "Sport 300" and "X180R"
* 1993-1996 Lotus Esprit "S4"
* 1995-1996 Lotus Esprit "S4s"

GT3

A 2.0 liter configuration, previously only available in the Italian market where the lower engine displacement meant the vehicle would fall into a lower tax regime, was again utilized from 1996 to 1999 in the Esprit "GT3" models, utilizing the improvements that served the "SE" models making these cars good for convert|240|hp|abbr=on. This was the last application of the 900 series Lotus engine, which had a lifespan of nearly 30 years.