MILFORD, Mich. - Expect General Motors' powertrains to get more camshafts, electronics, gears and aluminum.
The automaker is packing more technology into its engines in a bid to keep pace with competitors and government regulators.
GM also is slashing the number of engine families it produces, and is trying to decide whether to scrap some of its remaining pushrod engines.
The company offered a glimpse of its plans at a recent technology bazaar at its Milford test track.
Some of these technologies, including common-rail direct fuel injection and cylinder deactivation, are on the drawing boards. Others, such as the auto-shifting manual transmission due in 2001, are sched-uled for production.
The Clean Air Act has prompted much of GM's engine research. New powertrains will help the automaker cut tailpipe emissions dramatically.
Compared with 1998 levels, GM expects to reduce carbon monoxide emissions by 40 percent, hydrocarbons by 80 percent and oxides of nitrogen by 90 percent by 2005.
GM also is beginning to reap the fruits of its labors to design standardized 'world' engines. For example, GM plans to reduce the number of four-cylinder engine families from seven to three by 2005.
'The first strategy we're acting on is to refine our portfolio to a smaller, more flexible stable of brands,' said Arv Mueller, vice president and group executive of GM's Powertrain division.
In North America, GM faces a major test of its engine-family strategy in 2002, when it introduces a new generation of aluminum truck engines code-named Atlas.
The Atlas engine family will power GM's next-generation compact pickups and sport-utilities. To save money and simplify design, the double-overhead cam inline engines will share up to 80 percent of their parts.
The range will include 2.5-liter four-cylinder, 3.5-liter five-cylinder and 4.2-liter six-cylinder engines.
To reduce engine vibration, the four- and five-cylinder units will feature twin counter-rotating balance shafts. To improve emissions, all will have a variable valve timing mechanism on the exhaust camshaft.
GM also displayed a turbocharged version of the five-cylinder engine, but it did not specify production plans.
A space-saving feature on four-wheel-drive versions of the Atlas is a cast-aluminum oil pan with a tunnel for the front axle. The front differential will bolt to the side of the pan.
Looking for ways to boost fuel economy for its larger vehicles, GM is tinkering with a cylinder cutoff system for pushrod V-8 engines that GM calls 'displacement on demand.'
Reminiscent of the Cadillac 8-6-4 engine built in 1981 and 1982, this system is improved with faster electronics and better solenoids.
When the engine is idling or under low engine load, a controller shuts down the fuel injectors in four cylinders.
Meanwhile, the solenoids control the supply of oil to the engine's collapsible valve lifters. When the oil flow is interrupted, the lifters collapse and disengage the camshaft from the valves.
When the motorist hits the gas to speed up, the solenoids reactivate the oil flow, expanding the lifters and re-engaging the valves.
GM engineers say the cylinder cutoff could improve fuel economy by 6 to 8 percent.
Other GM innovations include:
A prototype five-speed automatic transmission for front-wheel-drive cars equipped with engines up to 3.0 liters.
Code-named X20F, the new transmission uses only two gear sets instead of the three found in most five-speed automatics.
For more compact packaging, GM engineers put all internal components on one side of the engine block. By contrast, conventional front-drive automatics are wrapped around the engine. The design allows the X20F to fit in the same space as a manual transmission, leaving plenty of room for an all-wheel-drive configuration.
An auto-manual transmission slated to appear in 2001 on a small car for Europe and South America. The transmission will be paired with a 1.2-liter engine at half the price of a conventional automatic.
A common-rail fuel-injection system for future generations of gasoline-fueled cars and trucks. Worth about a 10 percent fuel economy gain, the injectors feed from a single high-pressure pipe for better fuel atomization and injection control.
The displays at GM's show-and-tell highlight the contradictions that the automaker faces in the global marketplace.
For example, one table featured a belt-driven continuously variable transmission that can increase a small car's fuel economy by 7 percent. That is potentially a big plus in overseas markets.
Nearby, engineers stood proudly next to a powerful big-block V-8 engine. Scheduled for its debut next year, the V-8 was stroked from 7.4 liters out to 8.1 liters.
Yet another contradiction involves GM's lingering affection for pushrod engines. GM still produces large numbers of pushrod engines for cars even though rival carmakers have embraced overhead cam engines.
In an effort to exploit the high-tech image of multivalve powertrains, GM will increase the number of overhead cam engines built annually from a projected 4 million in 2000 to 6 million in five years or so.
Does that mean the pushrod is dead?
Not yet, said Mueller. GM is trying to decide whether to plow money into its existing pushrod engines to meet future emissions and fuel economy regulations, or scrap them in favor of multivalve engines.
Said Mueller: 'We're looking at a number of options. We have to pick the technology that's right for each market.'