2011+ VM Motori V6 Diesel Engines Used by Chrysler
VM Motori started supplying Chrysler in 1992, with the Chrysler Voyager’s diesel option. Today, VM Motori powers several European Chrysler and Jeep cars, as well as (as of Februrary 2011) the Chevrolet Captiva, London Taxi, Megastar van, and Maxus van. Today, two VM engines are used by Chrysler: the 2.8 (Wrangler, Voyager, and Cherokee) and 3.0 (Grand Cherokee, 300C/Thema.) The Maserati Kubang is reportedly to use a highly modified version of the 3.0 liter V6 as well.
|2010 Mercedes||2011 VM |
The A 630 direct-injection V6 diesel has Fiat’s Multijet II technology, and delivers more horsepower and torque with greater efficiency, lower emissions, and, one analyst wrote, higher grade internal materials. Built by VM Motori and developed with Fiat Powertrain, it hits a peak 177 kW (241 hp DIN) at 4,000 rpm and 550 N•m (406 lb-ft) at 1,800-2,800 rpm. This engine was reportedly developed for General Motors, as was a 2.9 liter version that was dropped while still unfinished (meant for EuroCadillacs). Neither was used by GM.
Fuel economy for the new 3.0-liter turbo 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 engine. CO2 emissions (combined cycle) are also reduced by 17 percent, now at 218 g/km; this is partly a result of new-generation, 2000 bar injectors with MultiJet II technology (Chrysler Europe specified 1800 bar pressure, but this is likely on the lower power version).
The version to be used by Chrysler in the Jeep Grand Cherokee, Ram 1500, and possibly/likely other vehicles, may have more power or torque as a result of using MultiAir and other recent Fiat technologies. Maserati is reportedly developing a twin-turbo version of this engine (for Maserati cars, not Jeeps or Rams), according to forum member RVC, with one prototype having sequential turbos and the other having parallel turbos.
VM Motori, once owned by Detroit Diesel, is now owned 50/50 by General Motors and Fiat Powertrain.
VM Motori A630 Engine Structure and Features
The diesel engine uses a compacted graphite iron, 60-degree block with aluminum cylinder 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. Weight of the fully dressed new engine is 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 architecture has stiffened construction, including a bedplate that provides a rigid and stiff carrier for the forged steel crankshaft. This cuts noise from the lower reciprocating assembly and results in lower vibration and harshness. The oil pump is a rotary vane type.
The two-piece aluminum oil pan has been designed to provide strength and contribute to the quietness of the engine. The lower pan has been reinforced for off-road use. Crankcase capacity is 7.7 L (2 gal). The heads are aluminum. 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; each valve is driven by 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.
2.8 and 3.0 VM diesels
|Engine||2.8 L||2.8 L||2.8 L|
|2.8 L||2.8||3.0 L|
|Displacement||2776 cc||2776 cc||2776 cc||2776||2776 cc||2776||3000 cc|
|Cylinders||4 in line||4 in line||4 in line||4 in-line||4 in line||4 in-line||V6|
|Max Power in kW (hp)||110 (150)||120 (161)||120 (163)||130 (177)||130 (177)||149 (200)||177 (241) / |
|184 (241) |
|Torque in Nm (lb-ft)||360 (265)||360 (265)*||400 (295)||302/339|
|410 (302)||302 (410) / |
|550 / |
|Gas mileage||25/33||28 comb.|
|21/27 (2005)||28 comb|
|Tier II B / Euro 4||Euro 4|
* In some early models this was listed at 400 (295) ** automatic / manual transmission
Lightweight, cast-aluminum pistons minimize friction. The compression ratio of the new diesel engine is now 16.5:1, reduced from 18.1:1 on the previous model, for cleaner combustion. All main bearings are a “lead free” design for reduced environmental impact during construction and later recycling of the engine.
VM A 630 Diesel Engine Performance Features
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.
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.
Past VM diesels used in Chrysler vehicles
Starting in 1992, Chrysler Voyagers and Grand Voyagers used a 2.5 liter Model ES diesel from VM Motori, which had timing gears. In 1996 or 1997, they switched to the model GS (similar to NS) with timing chains. The only visible differentiator is the injection pump — whose model ends in 975 for the chains and in 963 for the gears. (Alfa Romeo used VM diesels from 1979 to 1997.) The NS and GS 2.5 liter four-cylinder engines had a bore of 92 mm and a stroke of 94 mm; a compression ratio of 20.95:1; 23.6 inches of vacuum at idle; pushrod-driven overhead valves; indirect fuel injection, using a precombustion chamber; a four-stroke cycle; and an electronically controlled rotary injection pump incorporating a vacuum fuel pump. The engine code on these are stamped on the forward-facing side of the block as a three-digit code with letters and numbers.
Chrysler had new diesel engines for export markets in 1999. The VM Motori 2.5 was used in minivans and Jeeps, and the 3.1 was in the Grand Cherokee; both used:
- Common Rail Fuel Control (CR) with a high-pressure pump to achieve 1,500 bar injection pressures, for better spray atomization, maintained throughout the full engine speed range.
- Pilot injection — a fuel spray which precedes the main spray to initiate combustion, to reduce noise.
- Four valve direct injection brought 15% better fuel efficiency than indirect injection; the injector was centrally located.
- Cooled EGR (optional) to cut emissions.
- Swirl Control (optional) at the cylinder head intake matched the air motion in the combustion chamber with the needs of the engine, without sacrificing the amount of flow. One port was tangential for maximum flow, while the other was designed to induce swirl to air entering the combustion chamber, based on engine load and speed.
- A special NOx catalyst.
The revised 2.5 litre diesel had dual balance shafts off the crank in the oil sump for reduced vibration. Gas mileage was 15% better than the older 2.5 diesel, with more power, thanks to a variable geometry turbocharger (VGT) and other new features.
The 3.1 liter (3125 cc) five-cylinder engine used on the 1999-2001 Grand Cherokee had an electronic injection pump, direct injection, and electronically-controlled, vacuum-actuated exhaust gas recirculation. The 3.1, created largely by adding a cylinder to the 2.5, featured variable fuel-injection timing, a quick-sensing inlet-side positioned thermostat, and coil-on-plug ignition. A hybrid-cooling system combined inline electric and engine-driven fans, allowing the engine fan to idle at a lower speed (250-300 rpm vs. a typical 650-700 rpm), decreasing noise and vibration. A secondary thermostat control cut power consumption by 12% or 4.5 kW (6 hp).
The 3.1 liter VM diesel engine was designed to operate 240,000 km (150,000 miles) under normal conditions without part replacement other than normal maintenance items. An automatic serpentine belt tensioner increased average accessory belt life to 160,000 km (100,000 mi).
The new turbodiesel engine boosted power and torque by 20% over the 2.5 liter unit, for up to 12.5% better acceleration, a higher top speed, and more load-carrying and towing capacity. A drive-by-wire "electronic accelerator" controlled the throttle. The intercooled diesel had a bore of 92 mm (3.62 inches) and stroke of 94 mm (3.70 inches), with a cast iron block and cylinder head with two valves per cylinder. Peak horsepower of 103 kW (138 hp) was achieved at 4,000 rpm; peak torque was 384 Nm (283 hp); and gas mileage in the Grand Cherokee was rated at 11.7 liters per 100 km.
2.5 liter (R425)*
|Jeep Cherokee (XJ)||Jeep Grand Cherokee (WG)||Dodge Dakota (R1)||Jeep Cherokee (KJ)||Chrysler Voyager (ES)||Chrysler Voyager (GS)||Chrysler Voyager|
|Max power in kW (hp)||85 kW (114)||85 kW (114)||85 kW (114)||105 kW (140)||85 kW (114)||85 kW (114)||105 kW (140)|
|Torque in Nm (lb-ft)||300 Nm (221)||300 Nm (221)||300 Nm (221)||340 Nm (251)||262 Nm (193)||262 Nm (193)||340 Nm (251)|
The Grand Cherokee eventually switched to the Mercedes 2.7 diesel, then the Mercedes 3.0, which generated 218 hp and 376 lb-ft of torque.
The R 428 2.8 engine generated 150 horsepower and 265 lb-ft of torque (in 2005, 160/295), with a 17.5:1 compression ratio, in the minivans and Cherokee 4x4 (where it was rated at 148/266 and hooked up to a five speed automatic). This powerplant had a belt drive, dual overhead cams driving four valves per cylinder, and a common rail fuel system pressured to 1,600 bar (23,000 psi). The engine itself was cast iron, with an aluminum cylinder head. Redline came at a generous 4,300 rpm (electronically governed); gas mileage in the 2005 Jeep Cherokee with automatic was 21 city, 27 highway.
The 2.8 is essentially an enlarged-chamber version of the R425 engine; because the R425 used wet liners, only changes to the liner, piston, and camshaft were necessary. The engine ended up with 10% more torque at lower rpm. Like the 2.5 liter R 425, it had finger followers on the camshaft. An optional VGT turbocharger increased the power output to a class-leading 177 CV in some applications.
* Figures are from VM Motori. Some inconsistencies were found in their tables.