20SEH

Family II engine
Overview
Manufacturer	General Motors
Also called	D-TEC Flex-Power MultiPower Big-block Camtech
Production	1980–1999(Opel) 1981–2009 (Holden) 1981–present (GM do Brasil)
Combustion chamber
Configuration	Straight-4
Cylinder block alloy	Cast iron
Cylinder head alloy	Aluminium
Combustion
Oil system	Wet sump
Cooling system	Water-cooled
Chronology
Predecessor	Opel CIH engine Holden Starfire engine
Successor	GM Ecotec engine (2.0 – 2.4 L) Family 1 engine (1.6 – 1.8 L)

SOHC
Overview
Manufacturer	General Motors
Also called	8-valve
Production	1980–present
Combustion chamber
Displacement	1,598 cc (97.5 cu in) 1,679 cc (102.5 cu in) 1,796 cc (109.6 cu in) 1,998 cc (121.9 cu in) 2,198 cc (134.1 cu in) 2,405 cc (146.8 cu in)
Cylinder bore	80.0 mm (3.15 in) 82.0 mm (3.23 in) 84.8 mm (3.34 in) 86 mm (3.4 in) 87.5 mm (3.44 in)
Piston stroke	79.5 mm (3.13 in) 86 mm (3.4 in) 100 mm (3.9 in)
Valvetrain	Single overhead cam
Compression ratio	8.0:1 9.2:1 9.5:1 10.0:1
Combustion
Fuel system	Throttle-body fuel injection Multi-point fuel injection
Fuel type	Diesel Gasoline Ethanol

DOHC
Overview
Manufacturer	General Motors
Also called	TWIN-TEC
Production	1987–present
Combustion chamber
Displacement	1,799 cc (109.8 cu in) 1,998 cc (121.9 cu in) 2,198 cc (134.1 cu in) 2,405 cc (146.8 cu in)
Cylinder bore	81.6 mm (3.21 in) 86 mm (3.4 in) 87.5 mm (3.44 in)
Piston stroke	86 mm (3.4 in) 94.6 mm (3.72 in) 100 mm (3.9 in)
Valvetrain	Double overhead cam
Combustion
Fuel system	Multi-port fuel injection
Fuel type	Gasoline

The Family II is a straight-4 piston engine that was originally developed by Opel in the 1970s, debuting in 1979. Available in a wide range of cubic capacities ranging from 1598 to 2405cc, it simultaneously replaced the Opel OHV, Opel CIH and Vauxhall Slant-4 engines, and was GM Europe's core powerplant design for much of the 1980s.

The engine features a cast iron block, an aluminium head, and a timing belt driven valvetrain. The timing belt also drives the water pump. It was first used in the Opel Kadett D, Ascona B, Corsa and their corresponding Vauxhall sister models, the Astra, Cavalier and Nova. Many General Motors subsidiaries, including Daewoo, GM do Brasil, GM Powertrain, and Holden have used this design.

By 1986, the Family II unit had completely supplanted the CIH engine as Opel's core 4-cylinder powerplant. although the 6-cylinder versions of the CIH continued in the larger Omega and Senator models until 1995.

In 2004, a 2.0 L MultiPower engine was made available for the taxi market which could use gasoline, alcohol and natural gas.

The Family II also spawned two diesel variants, the 1.6 L and 1.7 L. These engines are sometimes referred to as "Big-block" engines by enthusiasts; in contrast to the smaller Family 1 engines which are sometimes referred to as the "Small-block" engines.

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Wikipedia