Saab H engine

The Saab H engine is a redesign of the Saab B engine, which in turn was based on the Triumph Slant-4 engine.

Despite the name it is not an H engine or horizontally opposed engine, but a slanted inline-4. The H engine was introduced in 1981 in the Saab 900 and was also used in the Saab 99 from 1982 onwards. H stood for high compression; higher compression was part of the update from B to H engine. It continued in use in the 900/9-3, 9000, and 9-5. The 2003 GM Epsilon-based 9-3 switched to the GM Ecotec engine, leaving the 9-5 as the sole user of the H engine. The H family of engine was used in the first-generation 9-5 until it was discontinued in 2010. The tooling and know-how was sold to BAIC. The latter B2X4 and B2X5 engines have in practice nothing in common with the early B engines except cylinder spacing.

All versions feature a grey cast iron block and an aluminum head with a single or double overhead chain driven camshafts. SOHC engines use two valves per cylinder and DOHC versions use four valves per cylinder with a pentroof chamber, the valve angle being 22 degrees from vertical. All engines use flat inverted bucket type valve lifters, hydraulic in the case of DOHC engines.

The engines were given numbers, for instance B201 is a 2.0-litre (20) engine with one camshaft.

B201
B201 is the original H engine with two valves per cylinder and a single overhead camshaft. It was introduced in 1981 and unlike the B engine it did not have the central shaft which used to power the distributor, oil- and coolant pump. Instead the distributor is located at the front of the cylinder head and directly driven by the camshaft, while the integrated waterpump was replaced with a separate unit to the rear of the engine.

It was available with 100 PS at 5200 rpm using a single carburettor, 108 PS at 5200 rpm using a dual carburettor, 118 PS at 5500 rpm using Bosch K-Jetronic fuel injection and a turbocharged, fuel injected version with 145 PS at 5000 rpm. In 1986 an intercooled version of the turbo engine also became available, it produces 155 PS at 5500 rpm.

Valmet Automotive in Uusikaupunki also planned a downsized 1.6 liter version of B201, to better suit Finnish vehicle tax laws. Downsizing was made by using a narrower cylinder bore. The prototype engine produced 92 PS at 5400 rpm, fitted with Bosch K-Jetronic fuel injection. One such prototype engine is displayed in the Uusikaupunki Saab museum.

B202 and B212
In 1984, Saab added a 16 valve cylinder head with double overhead camshafts. They retroactively renamed the 8-valve version the B201 and used B202 as the name of the new multi-valve unit. Another notable addition to the B202 was hydraulic valve lifters and Ecopower ("ep" in Italy, "(900)S" elsewhere), with a pre-heated catalytic converter for reduced emissions.



In 1991, Saab introduced a 140 bhp 2.1-litre naturally aspirated 16 valve version of this engine, with an increased displacement of (2119 cc) and a resulting name of B212. The inlet manifold was enlarged and redesigned for better and greater flow. The intake manifold and the head from the 2.1-litre constitute a well-known replacement for 1985-1993 16 valve, 2.0-litre turbocharged Saabs. Power increase is modest at stock boost but becomes much more evident at higher boost levels.

Engine builder John Nicholson also developed a Formula Three engine from the B202, for use in a Reynard 853 chassis. This version one of the first to use Saab's direct ignition system (SDI) and produced 165 PS at 5600 rpm. Its other strength was high power in an unusually broad powerband for a naturally aspirated racing engine.

B204 and B234
A major redesign of the H engine came in 1990 in the form of the new B234 for the Saab 9000. The B234 featured an increase in stroke from 78 mm to 90 mm, increasing the displacement to 2.3 liters. With this increased stroke also came a new engine block with increased deck height to make sufficient room for the increased stroke length without being forced to use shorter connecting rods, and in-block counter-rotating balance shafts for reduced vibration (NVH). There are two generations of B234 engine, one made from 1990-1993, the other from 1994 to 1998. The later motors had a revised oil sump system, head, timing cover, and different bell housing pattern. Unlike the previous B202, the block was no longer angled, but straight, something that made it unsuitable for the 900 model with its gearbox under the engine, built into the engine oil sump. The longer stroke B234 was last produced in 1998, that being the last year for the 9000 model. The B234 was selected as one of Ward's 10 Best Engines for 1995 and 1996.

The B202 was still being produced in 1993, but for the new generation Saab 900 being released in 1994 a new 2.0L engine was required. This new engine, the B204, was based on the 9000's B234, but in order to make the engine fit in the 900 the engine had to be shortened. This meant that a new chain drive for the camshafts was required to reduce the length of the engine. The B204 engine was available with natural aspiration in 900, 9000 and 9-3 in the form of 2.0i (B204i), with a low pressure turbo in the form of 9000 and 9-3 2.0t (B204E) or Saab 900 and 9-3 2.0T (B204L). B204R was briefly available in the 1999 9-3 Aero (U.S. market 'SE') model. B204 was in production in the Saab 9-3 until 2000, when it was replaced by B205.

With the introduction of the OBDII compliant B204 (also coincidental with the introduction of Trionic T5.5) Saab embarked on a new concept they termed as "Ecopower" where engines were designed for high power output while also delivering exceptional economy and low environmental impact.

Turbocharged engines used Garrett T25 turbochargers and the B234R (9000 Aero manual) used a Mitsubishi Heavy Industries TD04HL-15G-6 in model year -93 and TD04HL-15T-6 later on.

The B204 and B234 are regarded by engine tuners as the preferable engine for performance tuning over the later B205 and B235 engines as the internals are of a higher strength. The later models had lightened internal components to improve efficiency and fuel economy but limit the total power output when the engine's software is revised to increase the boost pressures and specific power output. The B204 engine became a very popular engine swap for Vauxhall and Opel Astra, Calibra, Cavalier and Vectras with the GM T-body platform, in Scandinavia in the mid 2000s—the engine uses the same mounting positions due to sharing the same platform. In the UK it is swapped into rotary equipped Mazda RX8, in Ukraine and Russia it is a swap option for Daewoo (now Chevrolet) models of similar age.

Note: The primary difference between the B204L and the B204R is with the intercooler, the turbo, the wastegate 'base boost' setting.

B206
The B206 is a version of the B204 but without the dual balance shafts. It was only offered as a naturally aspirated engine B206I producing 133 hp, seemingly a Europe-only option in 1994 non-turbo 900 NGs. This engine is popular among Saab tuners in Sweden (e.g. Trollspeed) due to the lack of balance shafts but with presumably equal strength as the turbo blocks with balance shafts.

B205 and B235
The B205 and B235 engines are an evolution of the B204 and B234 engines. They were introduced in the 1998 Saab 9-5 giving reduced fuel consumption and emissions with improved refinement. The changes included lightweight internal components:lighter valves, softer valve springs, lighter pistons, and lower-drag oil pump. Another development was the introduction of the Trionic 7 torque demand type engine management system. Trionic 7 equipped engines have the black direct ignition casing on top of the engine rather than the red of the Trionic 5. <!-- almost 3 years, about time to delete it... The B205 and B235 are considered less robust than their predecessor and therefore less suitable for performance tuning.

In 2005, it was announced that 1998-2003 B205 and B235 engines suffered from oil sludge-related failures. The failures are a result of a revised piston ring setup that was intended to reduce friction but caused excessive blow-by into the crankcase - as well as by a new positive crankcase ventilation (PCV) system used on these models that was not capable of handling this excessive blow-by. Due to the poor crankcase ventilation, combustion by-products contaminate the oil, causing its additives to break down prematurely. Especially in the case of short trips, the engine oil does not reach full operating temperature for a sustained amount of time. When this occurs, these contaminates (mostly water, various unburned hydrocarbons, and acids formed by nitrogen oxides and sulfur oxides and water) are not readily able to evaporate, making the situation even worse. Where the blow-by gases settle directly on the metal surfaces of the engine, a build up of "varnish" results.

The inadequate crankcase ventilation allows the PCV system components themselves to fall victim, as the poor ventilation of the blow-by gases allows them to condense into an acidic soup that attacks and dissolves the PCV hose rubber. This further compromises the effectiveness of the system and introduces fragments of hose rubber into the crankcase. Once the inadequately vented combustion products have depleted the motor oil additives, the oil will start to oxidize rapidly and form a soft sludge material. The oxidized oil is also much more susceptible to thermal breakdown when circulating through the turbocharger. This breakdown leads to the formation of hard carbon particles, in a process known as turbo coking.

As a result, the aforementioned oxidation byproducts (soft sludge, harder carbon deposits, and hose rubber fragments) will then start to agglomerate. If not caught in time, the agglomerate can clog the extremely fine wire mesh at the end of the oil pump pickup tube, resulting in a loss of oil pressure. This resulted in several cases of rod bearing failure, premature turbocharger failure, as well as other lubrication-related failures. The sludge problems can be repaired under a special extended warranty for 8 years and unlimited miles. However, in order to take advantage of this warranty, SAAB requires their oil change intervals to be met and receipts presented to verify this.

A BioPower flexible-fuel variant capable of running on gasohol mixtures containing as much as 85% ethanol (E85) became available in 2006. Coupled with a turbocharger, the engine can take advantage of the higher octane rating of ethanol and boost power. A 9-5 with a 2.0t BioPower engine produces 150 PS on gasoline and 185 PS on E85.

B235R engines with manual transmissions also have an overboost function, providing 370 Nm for up to 20 seconds. In 2002 B235R was uprated to 250 PS, but since the engine already produced 250 hp during overboost in 2001 it had no effect on performance. The 2000 model was slightly less powerful, producing about 240 hp during overboost. In 2006 the B235R was uprated once again, this time also adding some new hardware, a new air inlet to the turbocharger and associating compressor housing, this increased the output to 260 hp. From 2008 all U.S. market 9-5 models are powered by this 260 hp B235R engine.

At the 2006 Los Angeles International Auto Show, Saab showed off a variant of the 9-5 SportCombi equipped with an ethanol fueled BioPower version of the 2.3-litre engine, producing 310 hp and 440 Nm of torque.

The base version was used on the first generation Saab 9-3 and Saab 9-5, with power output varying across the models and markets.

The B205E/L and the B235E use Garrett GT1752S turbochargers, while the B205R and B235L/R use Mitsubishi Heavy Industries TD04HL-15T-5.

BAIC
BAIC offers the Saab H engine in various configurations on several of its models. The B205RGA and B235RGA, 2.0 and 2.3 litre turbo engines are available similar to those used in Saabs. Further BAIC offers a smaller 1.8 litre displacement version named B185RGA. This version was developed to meet requirement for government vehicle with maximum displacement of 1.8 litres. BAIC continued the development of the Saab H engine. In 2015, a B236R prototype was unveiled at the Shanghai Autoshow. This engine design incorporates variable valve timing and an EGR system which allows the engine to comply with Euro 6 emission standards.

The BAIC BJ40L is available with a 201 hp engine named B201R and a 231 hp engine named B231R. A 177 hp engine named B205EFA is offered in the Senova X65. The BAIC BJ80 is also available with the 231 hp B231R engine variant. The B201R and B231R models do not use Saab's Trionic engine management system and direct ignition cassette.

Successor to the Saab H-Engine
The H-engine ended production with the 1st Generation Saab 9-5 in 2009 when the intellectual property was transferred to BAIC. Starting in 2003 with the 9-3 Sport Sedan, Saab began utilizing the L850 engine Ecotec. Beginning in 2010 with the 2nd generation 9-5, all Saabs utilized the Ecotec. There were some technologies carried over into the Ecotec line from the Saab H-engine, but for the most part there is very little similarity between the two engine families. Saab continued to use its Trionic engine management system with the Ecotec.