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How Chrysler Invented the Sport Compact Car With Its Dart, Demon, and Duster 340

Mopar’s 340-powered compacts were the budget rockets of their day.

Aaron GoldWriterManufacturerPhotographer

When we say "sport compact," we imagine most people think of cars like the Subaru WRX, Mitsubishi's epic Lancer Evo, or our beloved Honda Civic Type R—small, usually (but not always) imported cars with hot-rodded four-cylinder engines. The sport compact craze is generally acknowledged to have begun in the 1980s, but we say it started further back, just a little more than 50 years ago.

Big Engines for Small Cars

Go back to 1967: Chrysler had just revamped its A-body compacts, with the Plymouth Barracuda getting unique European-themed styling to better compete with Ford's hot-selling Mustang and the newly-introduced Chevrolet Camaro. Meanwhile, the bread-and-butter Dodge Dart and Plymouth Valiant got the boxy, slightly nerdy styling they would carry for the next decade.

Pontiac's 1964 GTO, based on the compact Tempest, had already proven young people would buy a small car with big power, something Chrysler must have had in mind when it sculpted the A-body's new engine compartment. Originally sized for six-cylinder engines and the LA-series small-block V-8, the A-body now had just enough room to accommodate a big block. Plymouth had already stuffed the massive 383-cubic-inch (6.3-liter) V-8 in the Barracuda S, and late in 1967 Dodge followed suit with the big-block Dart GTS.

It's understatement to say the Dart GTS was compromised. Squeezing the 383 into the Dart's engine bay required a convoluted exhaust that cut the engine's output from 325 horsepower and 425 lb-ft of torque in the bigger cars to 280 hp/400 lb-ft. There was no room for air conditioning or a power steering pump. Turning the heavy, slow-ratio steering required so much arm-twirling that drivers probably barely noticed how much understeer the heavy engine elicited. But the Dart GTS was quick, able to turn quarter-mile times in the low 14s. Dodge built fewer than 500, but that was okay—the company had something better in the works.

Enter the 340

Chrysler introduced the 318 cid (5.2-liter) V-8 in 1967, and in 1968 it unveiled a new high-performance version displacing 340 cubic inches (5.6 liters). This was more than just a bored-out 318: It was designed as a high-revving performance engine, with a forged-steel crankshaft, strengthened bearing caps, a double-row timing chain, windage tray, high-flow heads with larger valves, a high-rise dual-plane intake manifold, shot-peened pistons, connecting rods and pushrods, and an aggressive camshaft. Topped with a four-barrel carburetor, it was rated at 275 hp at 5,000 rpm and 340 lb-ft. The horsepower figure has been widely acknowledged as a lie: True gross output (with no accessories attached) was rumored to be closer to 325, with the 275-hp rating intended to keep it competitive in the NHRA's drag-racing classification system.

The 340 engine became the standard powerplant for the 1968 Dodge Dart GTS, which featured the stiffer Rallye Suspension, wider tires, and 10-inch drum brakes borrowed from the mid-size Coronet. A three-speed TorqueFlite automatic came standard, with a four-speed manual on the option sheet. A power-bulge hood, red GTS lettering, and a "GT Sport" bumblebee stripe at the back told the world this wasn't your librarian's Dart.

Available as both a coupe and a convertible, the 340-cid Dodge Dart GTS was seriously quick by standards of the time, able to accelerate to 60 mph in 6 seconds and turn quarter-mile times in the mid-to-high 14s, depending on gearing. Those numbers weren't far off those of the 383, which remained an option.

Sport compact car you say? Yes, because more importantly, the Dodge Dart GTS wasn't just a straight-line machine. It was agile, thanks to the combination of both the engine and the car's light weight. With insurance rates tied to engine displacement, the Dodge Dart GTS 340 was an affordable prospect that could keep up with big muscle cars on dragstrips—and leave them choking on exhaust fumes in the corners. Equipped with the 340 engine, the Dodge Dart GTS was indeed arguably the first true sport compact car.

The year 1969 saw the introduction of a new entry-level Dart coupe called the Swinger, because what else would you name a youth-oriented car in 1969? Like the top-of-the-line Dodge Dart GTS sport compact, the Dart Swinger was also available as a Swinger 340. Though it couldn't be had as a convertible, its $2,836 base price made it $400 cheaper than the Dart GTS. Dodge sold some 20,000 Swinger 340s, nearly triple the sales of the Dart GTS, which it discontinued after '69.

Rise of the Duster and Demon

Chrysler in 1970 revamped its Plymouth Barracuda and introduced a near-twin, the Dodge Challenger. These cars moved to a new platform, called the E-body, to better compete against the Mustang, Camaro, and Firebird. Replacing the Barracuda as the sort-of-sporty-Valiant was the new semi-fastback Duster. Of course, there was a Duster 340 version, which had all of the same sport compact car go-faster bits as Dodge's Swinger 340. Plus, it was $250 cheaper, 70 pounds lighter, and had more contemporary styling. Plymouth sold nearly 25,000 Duster 340s for 1970, while sales of the Swinger 340 dropped to just shy of 14,000.

Dodge got its own version of the Duster in 1971, which it called the Demon. The Demon replaced the Swinger as keeper of the magic 340, and sales of the '71 sport compact cars were more closely matched between the divisions: Dodge sold nearly 11,000 Demon 340s while Plymouth moved 12,866 Duster 340s. (Meanwhile, Plymouth got its own version of the Swinger, called the Scamp, though it couldn't be had with the 340 engine.

While Dodge's and Plymouths' 1971 340 sport compact cars were more competitive with each other, more important was that they were better than the competition. In the January '71 issue, our sister publication, MotorTrend, pitted a Dodge Demon 340 against a 350- (5.7-liter) powered Chevrolet Nova SS, an AMC Hornet SC 360, and a Comet GT, Mercury's version of the Ford Maverick. MT complained that the Demon's steering was numb, but its handling was the best of the bunch. And it was quick—0-60 in 6.5 seconds and the quarter-mile in 14.49 at 98.25 mph. The 285-hp Hornet was hot on its heels at 6.7 and 15.0 seconds, but the 270-hp Nova turned in a pitiful performance—0-60 in 8.5 seconds and the quarter in 15.92, not much quicker than the Comet GT, which had a 302-cid (5.0-liter) engine with a two-barrel carburetor that put out a mere 220 hp. Chrysler's 340 cars would never outsell Chevy, but they remained a constant irritant.

1972: The Beginning of the End

1972 was the year it all started to unravel. The industry switched from gross to net horsepower ratings, and the 340's new advertised horsepower figure of 240 corresponded to the old 275 net figure. Unfortunately, the 240-hp rating was now a lot closer to reality. Ever-tightening emissions standards prompted Chrysler to reduce the 340's compression ratio—which had already ticked down from 10.5:1 to 10.25:1 in 1971—to a more sedate 8.5:1. The camshaft was milder, the intake valves smaller, and the forged crankshaft was switched out mid-year for a cast crank.

MotorTrend didn't test a Demon or a Duster 340 that year, but in an October 1971 article called "The Last Roundup," it found the 1972 Plymouth 'Cuda 340 two seconds slower in the quarter-mile than the 1970 'Cuda 340 it had tested.

Despite the softening of the engine and a market shift away from muscle cars, sales of the 340-powered A-body sport compact cars remained strong right through 1973. (That was also the year Dodge yielded to the protests of the church-going old biddies and changed the Demon's name to Dart Sport.)

The 360: It Ain't Over 'Till It's Over

The OPEC oil embargo began in October 1973, right about the time Chrysler replaced the 340 V-8 with the more emissions-friendly 360 (5.9 liter). First introduced in 1971, the 360 was designed as a low-cost engine with good low-end torque. It was intended to bridge the gap between the 318 and the big-block 383 in Dodge and Plymouth's full-size cars (Polara, Monaco, Fury) and pickup trucks.

For its role in the A-bodies, Chrysler did its best to make the engine a worthy 340 successor. Engineers added the 340's hot camshaft, heads, intake manifold, and four-barrel carburetor to bring it up to 245 hp, a 70-hp increase versus the two-barrel version used in the full-size cars, and 5-hp more than the outgoing 340. For the most part, it worked: One magazine pitted a 1974 Dodge Dart Sport 360 against a 350- (5.7-liter) powered '74 Chevy Nova SS. The testers turned a quarter-mile time of 14.68 seconds, a remarkable number for 1974; more importantly, it was nearly a half-second quicker than the Chevy.

But the oil embargo had put the brakes on big-engine sales. Chrysler offered the 360 in 230-hp trim for 1975, and 220 hp for 1976, the Duster and Dart Sport's last year. Their supposedly-sporty replacements, the Dodge Aspen R/T and Plymouth Volare Road Runner, would also offer a 360 for 1976—but with a paltry 170 hp and a mandatory automatic transmission.

The 360 would have its own muscle-car resurgence, returning in the early 1990s as the Magnum 5.9 to power muscle-bound versions of the Dodge Dakota R/T, Durango R/T, and Jeep Grand Cherokee, while the Neon ACR and SRT-4 would set new standards for the sport compact car market.

For the moment, however, Chrysler—and most of the American automotive business—is out of the sport compact business. But let's not forget it helped to invent it.

 

1968 Dodge Dart GTS 340 Specifications
PRICE: $3,163 (base)
TOTAL SOLD: 6,183
ENGINE: 5.6L OHV 16-valve V-8/275 hp @ 5,000 rpm, 340 lb-ft @ 3,200 rpm
CARBURETOR: 4-barrel
TRANSMISSIONS: 4-speed manual, 3-speed automatic
LAYOUT: 2-door, 5-passenger, front-engine, RWD coupe
L x W x H: 195.4 x 71.6 x 54.0 in
WHEELBASE: 108.0 in
WEIGHT: 3,038 lb
0-60 MPH: 6.4 sec (est)
TOP SPEED 108 mph (est)

 

1971 Dodge Demon 340 Specifications
PRICE: $2,721 (base)
TOTAL SOLD: 10,098
ENGINE: 5.6L OHV 16-valve V-8/275 hp @ 5,000 rpm, 340 lb-ft @ 3,200 rpm
CARBURETOR: 4-barrel
TRANSMISSIONS: 4-speed manual, 3-speed automatic
LAYOUT: 2-door, 5- or 6-passenger, front-engine, RWD coupe
L x W x H: 192.5 x 71.6 x 52.8 in
WHEELBASE: 108.0 in
WEIGHT: 3,360 lb
0-60 MPH: 6.5 sec
TOP SPEED 106 mph

 

1974 Plymouth Duster 360 Specifications
PRICE: $3,288 (base)
TOTAL SOLD: 3,969
ENGINE: 5.9L OHV 16-valve V-8/245 hp, 320 lb-ft
CARBURETOR: 4-barrel
TRANSMISSIONS: 3-speed manual, 4-speed manual, 3-speed automatic
LAYOUT: 2-door, 5- or 6-passenger, front-engine, RWD coupe
L x W x H: 194.1 x 71.8 x 53.1 in
WHEELBASE: 108.0 in
WEIGHT: 3,315 lb
0-60 MPH: 6.9 sec (est)
TOP SPEED 101 mph (est)

 

1976 Dodge Aspen R/T 360 Specifications
PRICE: $3,832 (base)
TOTAL SOLD: 1,400 (est)
ENGINE: 5.9L OHV 16-valve V-8/170 hp @ 4,000 rpm, 280 lb-ft @ 2,400 rpm
CARBURETOR: 2-barrel
TRANSMISSION: 3-speed automatic
LAYOUT: 2-door, 5-passenger, front-engine, RWD coupe
L x W x H: 197.2 x 72.8 x 53.1 in
WHEELBASE: 108.5 in
WEIGHT: 3,620 lb
0-60 MPH: 8.6 sec
TOP SPEED 92 mph (est)