Thanks to Doug Hetrick for making numerous corrections. See VM four-cylinders.
Created in 1947, VM Motori was named after its creators, Claudio Vancini and Ugo Martelli, who built the first Italian diesel engine. It was air-cooled and had direct injection. Water cooled diesels arrived in 1974, but did not appear in regular production cars until 1979 — in the Alfa Romeo Alfetta. The first VM diesel in a Chrysler was in the Voyager, in 1992.
VM Motori started supplying Chrysler in 1992, with the Chrysler Voyager’s diesel option; it was owned by Detroit Diesel at the time, spent some time being owned 50/50 by General Motors and Fiat, and is now entirely owned by Fiat. VM Motori currently powers several European Chrysler and Jeep cars, as well as (as of February 2011) the Chevrolet Captiva, London Taxi, and other vehicles. [See VM four cylinder diesels]
Two VM engines are currently used by Chrysler: the 2.8 (Wrangler, Voyager, and Cherokee) and 3.0 (Grand Cherokee, 300C/Thema.) The Maserati Levante and Ghibli also use this engine, with twin turbochargers and other tuning changes.
The A 630 direct-injection V6 diesel uses Fiat’s Multijet II injection system. Developed with Fiat Powertrain, VM’s new V6 diesel hits a peak 177 kW (240-241 hp DIN) at 4,000 rpm and 550 N•m (406 lb-ft) of torque at 1,800-2,800 rpm. This engine was originally developed for General Motors, for eventual use in European Cadillacs, but GM never used it.
The engine is capable of both transverse and longitudinal mounting with cooled EGR in the heads and a vacuum pump being an integral part of one of the cams. A 250 horsepower version is supercharged.
Early US-spec Jeep Grand Cherokees and Ram 1500s with this engine tended to have SCR catalytic conversion system problems. These issues were resolved by February 2015; some needed recalibration, some needed new converters.
Fuel economy for the 3.0-liter diesel engine (as used in the Grand Cherokee) is 8.3 L/100km on the combined cycle, an improvement of 17% over the prior diesel. CO2 emissions (combined cycle) are 17% lower, at 218 g/km, partly a result of new 2000 bar injectors (Chrysler Europe claimed 1800 bar pressure, but this is likely on the lower power version).
RVC pointed out that the A630 V6 is used on European Chrysler vehicles; the Jeep Grand Cherokee and Ram 1500, as sold in North America, have been modified to deal with lower-quality fuel and stronger emissions rules, and carry the code L630.
In 2012, VM announced that the engine would be upgraded to meet the Euro 6 emissions standards in 2015, and that the Cento plant would be expanded to support much larger production volumes with the sale of their engines in Ram and Jeep vehicles in North America.
The diesel engine uses a strong compacted graphite iron block with aluminum heads and a two-piece structural aluminum oil pan. Bore is 83 mm (3.27 in) and stroke is 92 mm (3.62 in) for a total displacement of 2987 cm3 (182 in3). Bore spacing is 96 mm (3.78 in).
The engine is compact and lightweight, with overall dimensions of 695 mm (27.36 in) in length, 729 mm (28.7 in) in width and 697.5 mm (27.46 in) in height. Fully dressed, it weighs 230 kg (507 lbs); on its own, it is 220 kg (485 lb). The engine was designed for either transverse or longitudinal mounting.
The crankcase has stiffened construction, including a compacted graphite iron bedplate that provides a rigid carrier for the forged steel crankshaft, cuttng noise and vibration. The oil pump is a rotary vane type.
The oil pan was reinforced for off-road use; the crankcase capacity is 7.7 L (2 gal). Pistons are cooled with the aid of oil jets; exhaust gas recirculation is water-cooled.
Chain-driven, dual overhead camshafts drive four valves per cylinder, through finger followers. Intake valves measure 28 mm (1.1 in), and exhaust valves are 24.5 mm (0.96 in) in diameter. Combustion-chamber volume is 24.68 cm3 (1.51 in3).
A forged-steel crankshaft is supported by four main bearing journals fitted with four-bolt main bearing caps incorporated into the bedplate. Externally balanced, the crankshaft measures 442.2 mm (17.41 in), reducing the overall packaging requirements of the engine. Connecting rods, with an overall length of 162.9 mm (6.41 in), are constructed of cast iron.
Lightweight, cast-aluminum pistons minimize friction. The compression ratio is 16.5:1, reduced from 18.1:1 on the previous model, for cleaner combustion. All main bearings are lead free for reduced environmental impact during construction and later recycling of the engine.
The induction system includes swirl control to optimize combustion. Fitted between the intake system (the intake manifold is polyamide and glass fiber) and the combustion chamber, the swirl control effectively provides an ideal air/fuel mixture at all levels of engine speed.
MultiJet II uses a balanced solenoid valve; the injector is capable of making up to 8 injection per cycle with the possibility of managing the two main injections in a single modular profile (IRS – Injection Rate Shaping) reducing consumption and polluting emissions of around 2% compared to a traditional injector, with a drastic reduction in noise levels.
A single Garrett VGT 2056 turbocharger has variable turbine geometry (as with the Chrysler Turbo IV from many years back). Compact and lightweight, the turbocharger provides near-instant response and includes an air-to-air intercooler.
Fuel economy for the Jeep Grand Cherokee with the 3.0-liter turbo diesel engine is rated at 10.3 L/100 km on the urban cycle and 7.2 L/100 km on the extra-urban cycle. For the combined cycle, the fuel economy is rated at 8.3 L/100 km. The engine is designed to run on EN590 ultra-low-sulfur diesel fuel.
Cast-iron exhaust manifolds funnel exhaust to a close-coupled diesel oxidation (SiMoCr cast iron) catalyst and standard diesel particulate filter. Euro 5 emissions are met through an exhaust-gas recirculation (EGR) system that includes an EGR valve with DC motor and a high-performance EGR cooler with bypass valve. Each cylinder has a central direct injector with cooled EGR (exhaust gas recirculation) as an integral part of the cylinder heads. The vacuum pump is incorporated into one of the camshafts for greater efficiency.
CO2 emissions are reduced to 270 g/km for the urban cycle and 188 g/km for the extra-urban cycle. Combined-cycle CO2 emissions are now 218 g/km.
VM four-cylinder diesels
Jeep Grand Cherokee diesel is sold in Europe in the Laredo, Limited, and Overland lines; Laredo and Limited have a choice of gas V6 and the diesel, while Overland buyer can get any engine, including the Hemi. A low-output version of the diesel is standard on Laredo, optional on Limited; it is rated at 140 kW (190 hp DIN) of power at 4,000 rpm and 440 N•m (324 lb-ft) of torque across 1,600-2,800 rpm.
The high output version was chosen for the American Ram 1500 and Jeep Grand Cherokee. It is rated at 240 hp @ 3,600 rpm and 420 lb-ft of torque at 2,000 rpm.
The engines use a SinterCast CGI block and bedplate cast in Brazil, and sent to VM’s Cento factory. Production is expected to hit 100,000 for 2013, and move up to 145,000 around 2015. The VM-designed injection system is built by Bosch, while Honeywell supplies the turbochargers.
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