Tuesday, December 20, 2005

More on the World Engines

The first of the "world engines" in the United States with key advanced technologies - variable valve timing and a flow-control valve intake manifold - will be sold by Chrysler. The engines were designed jointly by Chrysler, Mitsubishi, and Hyundai, and will be made and used by all three - in rather different configurations (Mitsubishi even has a three-cylinder variant!). Chrysler is using dual-variable-valve technology to control both intake and exhaust valves; Hyundai is using a different variable-valve package. The result of this, as well as different intakes and other packaging details, will probably result in different power outputs for each of the three companies using the same basic engines.

The engines made by Chrysler will be in three displacements, all familiar to Chrysler owners (because all three are similar to the current Neon/Stratus engine): 1.8, 2.0, and 2.4 liters. The 2.4 should reach 170 horsepower and 165 lb-ft of torque, which is roughly 20 hp better than the current 2.4 and about the same as the old intercooled 2.2 turbo (Turbo II). At the same time, they will reach ULEV II emissions standards and increase gas mileage by 5% over the current line. Some of the gain is due to variable valve timing, with continuously variable phasing of both the intake and exhaust valves ("dual VVT"). Though Chrysler has been late to the variable valve party, it will be the first company to offer dual VVT in the United States on entry-level vehicles - using a Mercedes system. The heads are wedge-shaped.The engines are designed to be turbocharged and supercharged, partly through over-engineering of the block, and use of large water jackets and metal areas around each siamesed cylinder.

Noise, vibration, and harshness are addressed through an isolated valve cover and damped oil pan, a variety of select-fit parts, and the flow control valve ("variable") intake manifold. The bell housing is designed for a tighter than usual connection to the transmission, hopefully eliminating the oil leaks that often come to high-mileage engines. The engine has a high-pressure, die-cast aluminum block and will be built in a new joint-venture plant in Dundee, Michigan; blocks for the Dundee engines are made by J.L. French of Wisconsin.

The engines built in Dundee will most likely be used entirely in Chrysler vehicles at first, though we'd expect Mitsubishi to use the same engines for their American-made Eclipse and Galant. We have no word on the fate of the plant that makes the current 2.0, 2.4, and 1.8.

Who is actually designing the engines?

Reportedly, the basic block was designed by Hyundai, and Chrysler and Mitsubishi then made a large number of modifications to make it more efficient and adapt it to their uses and technologies. Most of the packaging/dressing components, such as intake manifolds and valve timing equipment, appear to have been developed by each partner independently and will be used independently as well. For example, the variable valve timing was developed by Mercedes and is used on the V6 in the E-Class. J.L. French makes the blocks for American engines, with Nemak providing head castings from Mexico.

While some have said that Chrylser paid $57 million in royalties to Hyundai for design work, an informed source noted that the funding for GEMA was put togther by all the partners, and that $57 million was just DCX's share of the GEMA funding. GEMA itself is a separate company from DCX, MMC, and Hyundai, and it pays royalties to external and internal partners and patent holders.

According to the Dodge Caliber press release:Chrysler Group brought its engineering expertise to the World Engine program in the areas of cylinder port and intake manifold design using advanced Computational Fluid Dynamics tools. Chrysler Group engineers led the development work on dual Variable Valve Timing (VVT), as well as an integrated 2:1 oil pump/balance shaft assembly. Chrysler Group also refined the engines for exceptional smoothness and sound quality.

Clever stuff

The plastic intake manifold has equal-length runners with electrical flow control valves that, when closed, increase air tumble by blocking over half the intake port. Over 3,200 rpm, the valves are opened to allow full airflow. The valve cover is also composite (plastic) and has a variety of vibration-reducing seals.

The electro-hydraulic dual valve timing system uses oil under pressure to adjust timing (both intake and exhaust) using cam phasing so that timing is continuously variable. There is little overlap at idle and more overlap at speed, to permit built-in exhaust gas reburning without a pump. The exhaust cam can move through 35 degrees; the intake through 40 degrees. The cams ride on tappets that come in four dozen very similar thicknesses; the tappets are automatically matched to the individual heads during assembly, eliminating the need to adjust valve lash.

While all the engines use essentially the same block, displacement is changed by shortening the stroke or using thicker piston liners. The pistons themselves have short skirts and friction-reducing graphite patches. The crankshaft is forged steel, is located above the balance shaft/oil pump, and draws oil from the oil pan; it includes an integrated pump. The blocks are all automatically measured at the factory and key components such as pistons and bearings are matched to individual engines to reduce machining and noise, while increasing engine efficiency.

Why are they designing and building engines with two competitors?

Total World Engine production, from two plants in Dundee, two in South Korea, and one in Japan, is expected to be 1.8 million engines per year. Each participating company will see far higher volumes, offsetting engineering costs (by amortizing them over more units) and allowing cost savings from parts purchasing as well. Many components, including pistons, valves, rods, fuel injectors, and camshafts, are outsourced; by raising the volume, the Global Engine Manufacturing Alliance (GEMA) can reduce the price of these as vendors are also able to amortize engineering costs over higher volumes. The result will, according to GEMA, save $100 million per year for DCX. There are also price savings from having similarly designed assembly plants, albeit in different countries.

Capital investment has further been reduced by standardizing machining centers, using commonly available machines, and by running the plant in the US 294 days per year.

According to GEMA, Chrysler actually took the lead in development of the dual variable valve timing system. "Flexible machining centers in a hospital-clean manufacturing environment are the basis to the GEMA business model," said GEMA President Coventry. "Compared to the traditional transfer line process, this model incorporates part recognition and automatic changeover features to allow different products to flow down the line seamlessly; even allowing for a batch size of one. An even greater benefit that machining centers give us over transfer lines is uninterrupted flow, even if there is machine downtime. In the end, we're creating a final product with higher precision, better performance and durability that greatly exceeds each partner company's previous standards."

The Chrysler Group will take the lead in operating the two Global Engine Manufacturing Alliance facilities in Dundee, Mich. GEMA is investing more than $700 million in the 1 million square-foot plant, which will create approximately 550 jobs in Southeast Michigan. Each of the two Dundee plants will have capacity of 420,000 units per year.

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