The GM Family I is a straight-fourpiston engine that was developed by Opel, a former subsidiary of General Motors and now a subsidiary of PSA Group, to replace the Vauxhall OHV, Opel OHV and the smaller capacity Opel CIH engines for use on small to mid-range cars from Opel/Vauxhall. The engine first appeared in the Opel Kadett D in 1979, and shortly afterwards in its Vauxhall badged sister – the Vauxhall Astra Mk.1 in 1980. Despite this, the previous Opel OHV engine continued to be sold in entry level versions of the Opel Kadett/Astra and Corsa throughout the 1980s.
The Family I is informally known as the "small block", since it shares its basic design and architecture with the larger Family II unit (correspondingly known as the "large block"), which covers the mid range and higher engine capacities up to 2400cc.
The Family 1 engines are inline-four cylinder engines with belt-driven single or double overhead camshafts in an aluminum cylinder head with a cast ironengine block. GM do Brasil versions were also capable of running on ethanol. These engines share their basic design with the larger Family II engine – for this reason some consider the Family I and Family II to be the same series and instead use the terms 'small block' and 'large block' to distinguish between the two. Over the years there has been overlap between the two types as the smallest capacities of the Family II have also been manufactured with larger capacity versions of the Family I block.
Early build versions of the engine gained a notorious reputation for camshaft and follower failure – this was largely due to a special lubricant being used in the engine during the running in period, which would be changed for conventional oil at the first service. Many owners (familiar with the servicing requirements of the older overhead valve units that the Family I/II replaced) would often exacerbate the problem by changing the oil themselves within the running in period. Opel solved the problem by improving the metallurgy of the camshaft and followers, and changing the lubrication specification. Another issue (also common to the Family II), revolved around the water pump, which sits in an eccentric shaped housing and doubles as the timing belt tensioner. If poor quality antifreeze (or if no antifreeze was used), corrosion would jam the water pump in its housing making it impossible to tension the belt. Later versions of the engine incorporate a separate tensioning/jockey pulley for tensioning the belt.
GM do Brasil specializes in SOHC, petrol-powered and FlexPower (powered with ethanol and/or petrol, mixed in any percentage) engines. GM Brasil also made 16-valve versions of the 1.0 engine. The 1.0 L 16v was available in the Corsa line-up from 1999 to 2001.
There are two iterations of the 1.2-liter Family 1 engine. As originally introduced it was called the 12ST (also A12ST and S12ST in versions for the Austrian, Swiss, and Swedish markets), it used a 77.8 mm (3.06 in) bore and a 62.9 mm (2.48 in) stroke to produce a displacement of 1,196 cc (73.0 cu in). This version, only carburetted, was used in the Opel Corsa.[4] In around 1990 a new, version with 72.0 mm × 73.4 mm (2.83 in × 2.89 in) bore and stroke, a narrower bore version of the existing 1.3-litre version, displacing 1,195 cc (72.9 cu in), replaced the original design. This was also available with single-point fuel injection and with catalytic converters.
The SPE / 4 or (Smart Performance Economy 4 cylinders) engines are an evolution of the Econo.Flex engines that were made in Brazil at the Joinville plant. There are two available displacements: 1.0 L and 1.4 L. They feature an SOHC head with 2-valves per cylinder, and is fed by a multi-point fuel injection system, which allows it to run on either E100 (pure ethanol) or E25 gasoline (standard in Brazil). Major differences between previous engines include reduced friction, lowered weight, individual coil-near-plug ignition, and a new cylinder head design.
This was the first engine in this family, featuring a Lotus-developed 16-valve cylinder head and a cast-ironcylinder block which was essentially the same as in Opel's 8-valve engines. C16XE was available only in Corsa GSi, model years 1993 and 1994. C16XE was not yet badged Ecotec, and for later model Corsas and Opel Tigras it was replaced with X16XE Ecotec engine. The main difference between C16XE and X16XE Ecotec is emission control, C16XE lacks EGR and AIR-system, although the cylinder head is designed to enable these features. Other differences between C16XE and later versions of the engine include intake manifold, C16XE has a plastic upper intake manifold, which was replaced with a cast aluminium manifold, and fuel injection system, C16XE uses Multec fuel injection with MAF sensor and later models used Multec fuel injection with MAP sensor. Also, while C16XE had its own exhaust front section design, for X16XE it was replaced with a front section used also in Opel Astra, probably as a cost-saving measure.
Updated version introduced from 2000, with lighter cast-iron cylinder block and camshaft driven by toothed belt. Features EGR valve and electronic throttle for reduced emissions.
Daewoo Motors licensed and produced a variant of the Family 1 engine. These engines were built exclusively at Bupyeong engine plant and marketed as E-TEC. Like all Family 1 engines they feature a toothed belt driven valvetrain, a cast-iron engine block and an aluminum cylinder head. Most models feature Euro III-compliancy, and the 1.4 L (1399 cc) and 1.6 L (1598cc) versions employ variable intake geometry. With the release of Chevrolet Cruze, the factory has been converted to produce the Ecotec Family 1 Gen III block.
The new Generation III or Gen III engine entered production in Spring 2005. These engines replaced both the previous generation Ecotec engines as well as Daewoo's E-TEC 16V engines. These engines are manufactured at Szentgotthárd, Hungary, Bupyeoung, Korea, Toluca, Mexico and Yantai, PRC (SGM).
In contrast to their predecessors, the Gen III engines feature lighter cast-iron blocks, as well as higher compression ratios. These engines also implement DCVCP (Double Continuous Variable Cam Phasing technology, a variant of VVT), piston cooling by oil jets, and an integrated catalytic converter. Non-turbocharged variants feature the TwinPort (Variable-length intake manifold) technology.
Reliability improvements include a wider camshaft drive belt, and a water pump no longer driven by it.
