'Muscle cars' rev up again

Is the beefy, high-powered V-8 engine reallym doomed? Or was its reported demise over the last few years premature?

Judging from the 5-liter V-8 in the Ford Mustang GT and the Mercury Capri RS, the high-output engine still has more than a few puffs left in it. And if not a V-8, then a beefed-up V-6, mainstay of the GM lineup for the 1980s and beyond.

Indeed, the ''muscle car'' is making a sharp comeback, a decade after the last real US-built muscle cars hit the street.

The ''muscle-car era'' ended abruptly with the increase in antipollution controls and the prospects for sharply higher fuel prices down the road. Now the engineers are ''thinking muscle'' once more as Detroit puts horsepower and performance back into its cars, although only on a selected basis at the moment.

And the cars are setting a fast pace in the showroom, often going out the door almost faster than they came in.

Too, the auto factories are giving the power-bent, do-it-yourself enthusiast a hand with performance-oriented parts and advice. Chevrolet, for instance, even puts out a book entitled ''Chevrolet Power,'' a tome that shows the mechanic how to modify a stock-built engine, install special parts, and recapture the muscle era of a decade or two ago.

Turbocharging is making deep inroads in the auto industry - and not only for diesel engines - and this means performance when you step on the gas. Saab has just introduced its second-generation turbo for its 900 series, for example.

''Engineers, among other things, are working on faster-burn engines for better performance as well as economy,'' says Louis E. Lataif, general manager of the Ford division.

Encouraging the trend is the lower price for fuel and the demand by some drivers for more get-up-and-go under the hood.

Auto buyers skirted the GM J-cars when they hit the market last year because of poky performance. To attract more buyers, GM was forced to introduce a faster engine. And the same with Ford with its high-output engine for the Ford EXP and Mercury LN-7.

The 5-liter, V-8 Ford engine in the Mustang-Capri, mated with a manual 4 -speed overdrive transmission, is a powerhouse on wheels. It has a special camshaft, a larger-venturi carburetor, and a larger, more streamlined exhaust system and dual-inlet, low-restriction air cleaner. I could only get about 16 miles per gallon in a several-hundred-mile drive in the Mustang.

The new 5-liter Mustang has better acceleration than the 5-liter Mustang of three years ago and zips from 0 to 60 miles an hour in 6.9 seconds, according to one magazine. The carmaker lists the acceleration at between 7 and 8 seconds.

Competing with the Mustang are the Chevrolet Camaro Z-28 and Pontiac Firebird Trans-Am, both sharply redesigned for 1982, as well as a number of imports - the turbocharged Datsun 280ZX and Mazda RX-7, both from Japan, for example, as well as a bevy of high-powered cars from Europe. The new 4-wheel-drive Audi Quattro will top 130 mph and the pickup is, for want of a better word, exhilarating.

''The muscle cars of the mid-'60s disappeared because they didn't make much sense in an energy-conscious world,'' according to Philip E. Benton Jr., head of North American sales for Ford.

''But American demand for performance products never went away; it just matured into a desire for reasonably priced cars offering strong straight-line power combined with outstanding handling and good fuel economy.''

Not everyone is excited about the rebirth of higher-output cars on the highway, however.

Attacking what he labels as ''an arrogant, antisocial example of corporate irresponsibility,'' Richard E. McLaughlin, registrar of motor vehicles in Massachusetts, took exception to a 1981 ad for the Datsun Turbo ZX which declared that its owners ''own the road.''

''Nobody 'owns the road' in the United States of America,'' asserted Mr. McLaughlin in a letter to Nissan Motors Corporation in the USA.

''We never needed 'muscle cars' - and with our current energy crisis they are even less to be tolerated,'' he said. ''A 50 mph speed in 5.1 seconds is scarcely compatible with a national 55 mph speed limit.''

Even so, the move to more power on the road is clear.

To further underscore the move, Ford Motor Company last year set up a Special Vehicle Operations Department which has two purposes, according to Michael Kranefuss, director.

''One, we design and build performance versions of Ford and Lincoln-Mercury cars. Second, we use motorsports to develop the performance and technological capability and image of our products and create excitement in our dealerships.''

The first high-performance racing car, based on the Mustang and Capri, will be available for sale in 1983, says Kranefuss.

''It will be powered by a turbocharged, electronically fuel-injected, 2.3 -liter, 4-cylinder engine which uses an intercooler for about 10 percent additional power,'' he reports. ''It will have a 5-speed manual transmission, 4 -wheel disc brakes, and an extensively revised suspension.''

The ''hot car'' is back, asserts Ford - for the street as well as the track.