Master of Cylinders [ Revived GM Engine ]

Forbes via Yahoo! ^ | Wednesday August 21, 4:58 pm Eastern Time | Jonathan Fahey

[jae471]

Master of Cylinders

After 20 years of hibernation, engines that can shift on the fly from eight cylinders to four and back again are rumbling awake.

On a recent ten-minute drive near a General Motors site in the stop-and-go suburbs of Pontiac, Mich., a prototype pickup truck switched from eight cylinders to four cylinders and back again--32 times. No one onboard noticed a thing.

The truck held a new V-8 engine that shuts down four cylinders on the fly whenever they aren't needed. The aim: to improve fuel economy without sacrificing brawn. These engines boost gas mileage up to 25%, the equivalent of trimming 1,500 pounds of steel off a 4,000-pound truck.

Americans love their SUVs and pickups, but most times they drive them as if they were cars; the monsters pack far more power than they use. With the new engine, "You can still pull your 14,000-pound Airstream if you want to," says Samuel Winegarden, GM's chief engineer on the project. "But many, many people in this country drive their SUVs and trucks around not heavily loaded."

GM (NYSE:GM - News) tried this 20 years ago in Cadillacs, with embarrassing results. The car's computer wasn't sufficiently powerful to adjust the engine timing precisely enough to make the switch seamlessly. "All that bumping and banging and clanging was not what customers were looking for, particularly in a Cadillac," Winegarden says. The option was dropped after 18 months.

The mechanical control that shuts off cylinders has changed little from the 1981 version, but now the computer--equivalent to an early 1990s Macintosh--runs at 50 times the processing speed and holds 100 times the memory. Mercedes-Benz uses a similar system in its $118,000 S600 sedan. GM will put the engines into more prosaic, higher-volume vehicles. About 100,000 midsize trucks will get the engines in 2004. By 2007 GM plans to sell up to 2 million copies a year. The only clanging GM hopes to hear would come from its cash register: The new engines will cost no more to build than the current ones.

[ImaGraftedBranch]

You know what? It still won't satisfy the environazi's.

[AdA$tra]

I wonder how many other things we couldn't do in 1981 that would work great now with current computer technology. I remember those engines....yikes. Actually it was a bad car year all around, just starting to come back from the Carter years destruction of the American automobile industry.

[eddie willers]

Whatever happened to the Wankle?

[Looking4Truth]

Whatever happened to the Wankle?

That'd be the Wankel (If I remember the sp.)rotary engine in 70's Mazdas. Don't know much on their specs but I haven't seen them around anymore.

[tubebender]

My sister and her husband had one of those. They are indepted to their son for doing a good job of keeping it going for almost 20 years. They almost had to give it away to get rid of it. The only thing worse was the GM diesel in those cars.

[going hot]

The master cylinder???

Whatever happened to his sidekick rock bottom? Or for that matter, what about the professor, or poindexter??

[razorbak]

The Wankel rotary engines had tremendous power to weight ratio. And you would think the rotary design would be so much more efficient that it would greatly increase gas mileage over the normal rod and piston engine. But it didn't. The gas mileage was terrible. Worse than some big
V-8s.

[jenny65]

You know what? It still won't satisfy the environazi's.

I really don't care if it does or not. But it does call into question all the bitching from Detroit about not being able to produce a fuel-efficient car without sacrificing power or safety. What a bunch of horse-hockey.

[DeFault User]

Let's hope GM now has better engineers than employed during the Roger Smith period. What a bunch of junk they put on the road with the X-cars, diesels in gasoline engine blocks, and self-destructing transmissions.

[budwiesest]

Whatever happened to the Wankle?

Don't know, but I rode in an RX7 on some mountain roads with a friend and don't recall if he ever shifted up to third gear.

Didn't they start to red-line at 10K rpm? Man-made products will have a hard time working in this kind of enviornment unless designed for the space shuttle or something (bearings, seals, gaskets, etc.).

Once on a test drive in a Dodge Ram diesel I was doing 70mph at about 1800 rpms. Power to the piston?

[ATOMIC_PUNK]

X-cars, diesels in gasoline engine blocks, and self-destructing transmissions

Heck thats all i thought GM made

[opinionator]

The Wankel returns in the form of the RX-8. Visit Mazda's website for more info.

[Wonder Warthog]

"That'd be the Wankel (If I remember the sp.)rotary engine in 70's Mazdas. Don't know much on their specs but I haven't seen them around anymore."

Last I heard, they were doing quite well as engines for small prop-driven airplanes (low moving parts count, high reliability)--though that info is several years old. No cars using them (except for the Mazda RX-7's that are still on the road).

[DeFault User]

The '82 Pontiac Phoenix was the last GM car I owned and am likely to own. (I'll reconsider when GM starts placing cars on Consumer Reports recommended list.)