Читать книгу 1970 Plymouth Road Runner - Scott Ross - Страница 9
ОглавлениеNEW STYLING, NEW COLORS, NEW “SYSTEM”
The third-year Plymouth Road Runner debuted in 1970 with front-end styling that foreshadowed a major restyling of Chrysler’s B-Body platform in 1971. Steel Rallye road wheels were a popular option; they are now being reproduced. (Photo Courtesy David Newhardt)
The third-year Plymouth Road Runner still retained its original character as a purpose-built stripped-down muscle car that provided exceptional performance and rugged reliability. The 1970 model was an evolution of the two previous models, so it was not substantially changed, but it did receive some important updates. Although a multitude of small improvements were made, the most noted and recognizable changes were to its interior and exterior styling.
It arrived in the nation’s Chrysler-Plymouth dealers in September 1969, and Plymouth’s Styling studios developed a new look inside and out to distinguish it from the previous model years. The third-year Bird wore new front fenders, rear-quarter panels, grille, taillights, and bumpers, as did its GTX/Satellite/Sport Satellite/Belvedere stablemates. They also shared a new, squared-off look front and rear, with a “center scoop” motif to the grille and rear body above the bumper. Carried over from 1969 were the coupe/hardtop roof, convertible top, and all the windows.
The Road Runner for 1970 combined that updated styling, which included simulated scoops on the rear-quarter panels and new optional Rallye road wheels on the outside, plus a new dash, Pistol Grip 4-speed shifter and high-back bucket seats, with a proven high-performance powertrain and chassis. It was all wrapped up in the strongest and lightest-weight midsize passenger car platform made in 1970.
As a member of the Chrysler B-Body family, the Road Runner used Chrysler’s Unibody unit-body construction method, which “surrounds you in strength” thanks to stout structural members welded into and underneath the body.
Since 1960, using state-of-the-art computer technology, Chrysler’s body engineers added structural strength to new body designs where needed, resulting in a unit-body assembly that was more resistant to flexing and bending than a conventional (body on frame) body was without the added weight of a full frame underneath the car. The resulting squeaks and rattles come from body bolts and connectors coming loose as the car ages.
Unibody, therefore, was the ideal method for constructing high-performance car bodies, such as the Road Runner’s. For the severe-service applications such as the 426 Hemi, additional structural reinforcements were developed and welded in the appropriate bodies-in-white before they were made ready for primer and paint. After all, Chrysler engineered its high-volume B-Body platform to carry its full range of engines, from the standard 225 Slant Six and 318 LA series small-block V-8 to the B and RB big-blocks (the 383s and 440s) and the 426 Hemi.
The extra structural strength came from large structural subframes and crossmembers at the front and rear. One large crossmember is installed at the rear, just ahead of the rear axle and connects the two frame rails, essentially “boxing” the rails. On hardtop and coupe models, thick roof bows deliver added strength and rigidity to the roof panel. Up front, cowl panels, radiator support, and fender wells are tied together for improved strength. In addition, 426 Hemi-equipped cars received their own unique engine crossmember (the K-member), specially engineered for the Hemi’s weight and to prevent its massive torque output from twisting the car’s Unibody into a pretzel at full throttle.
The Unibody had been proven in thousands of Plymouths, Dodges, Chryslers, and 1967 and later Imperials that preceded the third-year Road Runner into production.
A totally new B-Body body design was in the works for 1971; 1970 marked the final year of the generation of midsize Plymouths and Dodges that had debuted for 1966.
Beyond the styling and comfort improvements, the Air Grabber cold-air induction featured a revised design and operation for the 1970 model year. The Road Runner’s steel hood was changed from the parallel-twin-scoop design that was used in 1968 and 1969 to one with a large center bulge that accommodated the vacuum-operated Air Grabber scoop and the big carburetors that resided on top of the engine. A dash-mounted switch activated a servo, which raised and lowered the scoop. Once it was deployed, the shark teeth graphics (that resembled the nose art on the legendary Flying Tiger fighter planes of World War II) were clearly visible on each side, adding to the car’s street credibility and increasing its intimidation factor over other car brands’ attempts at cold-air induction.
The standard Road Runner engine was a high-output version of Chrysler’s venerable 383-ci B-engine big-block V-8. Its cylinder heads, camshaft, and other components were borrowed from the 440 Magnum. Here, Coyote Duster artwork graces the air cleaner that was included with the optional Air Grabber hood (Code N96).
The coupe was still the most affordable Road Runner in 1970. Its sticker started at just under $3,100 and included potent high-performance hardware such as its standard 383 and heavy-duty suspension. The Dust Trail stripe along the side was a $15.55 option. Bright trim on the B-pillar denotes this car as having the Code A87 Decor Package, which added Satellite-level bright trim inside and out for an extra $81.50.
Although the Road Runner’s available engine lineup remained the same for 1970, a high-performance floor-shifted 3-speed manual gearbox became the standard transmission; the A-833 4-speed and TorqueFlite automatic were offered as options. The A-833 was one of strongest as well as heaviest 4-speed manual transmissions built during the muscle car era. Through the 1960s, the A-833 was continually developed and improved upon, and by 1970 it was offered in two versions. One was known as the 23-spline version so named for the number of splines on its input shaft that was used on all but the highest-output V-8s including the 426 Hemi and 440 Six Barrel. For those applications, the so-called “Hemi 4speed” (also known as the 18-spline version) was specified for 426 Hemi duty, and installed on the assembly line. That gearbox’s strength was evident in its input shaft because the splines (and shaft itself) were thicker than those used with the 23-spline unit. Regardless of which 4-speed your Road Runner was built with, a Hurst 4-speed shifter was standard equipment from the factory, and did not need to be retrofitted immediately after the car was purchased.
Once again for 1970, the A-727 version of Chrysler’s rugged TorqueFlite automatic was optional on all Road Runner engines, even the 426 Hemi. In service since 1964, and noted for its smooth shifting and reliability even under severe-service conditions, this heavy-duty automatic did not require the frequent band adjustment or other service procedures that rival automatics from Ford or General Motors required.
Similar to 1969 models, the base engine for 1970 was the special Road Runner 383, and there were just two engines on the option list: the 440 Six Barrel and the 426 Hemi. (The four-barrel-equipped 440 Magnum was GTX-only for 1970; it was not offered on the Road Runner until 1971.)
The base Road Runner 383 engine was no pedestrian station-wagon “grocery getter” 383. In fact, it shared many of its internals with the 440 Super Commando. These included high-flow cylinder heads, aggressive high-lift/long-duration camshaft and accompanying high-performance valvetrain, and improved exhaust manifolds that scavenged exhaust gases away from the engine in a way that rivaled many expensive aftermarket exhaust headers. As Chrysler’s best rendition of the 383, the engine package produced 335 hp, and that’s despite the fact that the compression ratio dropped from 10.0 to 9.5:1 for 1970.
The Road Runner convertible returned to the lineup for a second year in 1970. It’s seen here with the Code V21 Performance Hood Paint option atop the new domed hood (the Air Grabber scoop is shown closed). The F60-15 Goodyear Polyglas tires were introduced in 1970; it was the largest tire size offered on a Plymouth up to that point. (Photo Courtesy Mecum Auctions)
A view under the hood of a Code N96 Road Runner shows the rubber seal that goes around the Coyote Duster air cleaner, sealing off hot, undressed air from the colder, denser outside air that the scoop directs into the engine for more power. The front of the seal sits where an optional air conditioning compressor would have been installed, making the Code H51 Airtemp air-conditioning option unavailable with the Air Grabber option.
Underneath the hood of this 1970 Road Runner resides the 426 Hemi, the most exclusive, valuable, and powerful engine installed in this model. As you can see, it’s equipped with the N96 Air Grabber hood, Rallye Wheels, and the optional “Dust Trail” side stripes adorn the quarter panel, door, and fender. (Photo Courtesy David Newhardt)
The high-output 383-ci engine that was standard in 1968 remained for the 1970 Road Runner. This one wears aftermarket chrome valvecovers and an orange Mopar Electronic Ignition System control box on its firewall. Note the bottom of the Coyote Duster air cleaner, which fits flush with the air-scoop mechanism on the underside of the hood when the hood is closed.
The 426 Hemi was rated at 425 hp with 490 ft-lbs of torque; it was an $841.05 option. It’s seen here covered with unrestored patina and an aftermarket battery next to it. This car is equipped with an Air Grabber scoop (Code N96) as well as with non-power-assisted brakes. (Photo Courtesy David Newhardt)
Redesigned for 1970, the Road Runner’s all-vinyl bench seat incorporated the federally required headrests into the seatback. The taper toward the top allowed easier rearward viewing by the driver, something that Ford’s also-new-for-1970 high-back bucket seats didn’t have. (Photo Courtesy David Newhardt)
Another new feature for 1970 was the Rallye dash, borrowed from the Dodge Charger and featuring a standard 0-150–mph speedometer. The “Tick-Tock Tach” tachometer, which featured an electric clock at its center, was a $68.45 option (Code N85). (Photo Courtesy David Newhardt).
For an additional $14.05, the Bird’s plumage included optional High Impact colors such as Lime Light (seen here), Tor Red, Vitamin C Orange, In Violet, and Lemon Twist. Another vivid shade of green, Sassy Grass Green, joined the High Impact color selection in February 1970, as did the shocking-pink hue Moulin Rouge.
In 1969, the Road Runner hardtop was the top-selling two-door Plymouth, and the nation’s Chrysler-Plymouth dealers were optimistic that the 1970 version would sell strongly again. This one wears the optional paint color In Violet atop its freshened-for-1970 sheet metal, one of eight vivid colors available for an additional $14.05. (Photo Courtesy Mecum Auctions)
For many performance-car buyers, that was plenty. For others, the optional 440 Six Barrel offered more in the way of features and performance. Using the 440 Magnum as a base, the 440 Six Barrel used the same new-for-1970 thicker forged-steel connecting rods, molybdenum-filled top piston rings, and revised camshaft lift and duration that the 440 Magnum used, along with the 906 cylinder heads (so nicknamed from the last three digits of its factory casting number), which flanked a new intake manifold that was topped by three big Holley 2-barrel carburetors with mechanical linkage.
The new intake manifold was cast iron, instead of the cast-aluminum part sourced from aftermarket specialty company Edelbrock for 1969. Cost issues (namely involving the much-lower cost of cast iron compared to cast aluminum) and concerns that Edelbrock’s foundry didn’t have the capacity to support this option over a full model year led Chrysler to take it in-house for 1970. (Some early 1970 440 Six Barrels were built with leftover 1969 aluminum intake manifolds to use up the parts stock on hand.)
Using the simulated scoops pressed into the 1970 Road Runner’s rear quarter panels, the optional Dust Trail side stripes extended forward to the decal of the running bird on the front fender. The stripe appears to be dusty brown until light shines on it, which then reveals the stripe’s reflective gold-colored material. (Photo Courtesy David Newhardt)
Add a slight bump in compression from 10.1 to 10.5:1 (meaning that the best available pump premium gasoline was your only fuel choice, lest your engine “knock” from lack of octane and tear itself apart inside) and the 440 Six Barrel was good for a peak of 390 hp and 490 ft-lbs of torque. It was a great performance value if you look at how much extra it cost, compared to the 426 Hemi.
The horsepower and torque numbers for the 440 Six Barrel were reached at lower engine speeds than the Hemi’s, adding to the dual street/strip capability of the triple-carbed RB engine.
The 426 Hemi was Plymouth’s top performer since its 1-2-3 finish in its debut at the 1964 Daytona 500, and being put on the B-Body Plymouth option list in 1966. For 1970, its camshaft was switched from a solid-lifter one to a hydraulic-lifter stick, while not losing any performance as evidenced by its 425-hp rating, the same as for 1969.
The voice of the Road Runner was the “Beep Beep!” horn that simulated the cartoon bird’s voice. The purple color helped assembly-line workers tell it apart from the regular horns used on other B-Body Plymouths. The 1970 sticker still said “Warner Bros. – Seven Arts, Inc.” on it, even though a 1969 studio-ownership change had shortened the name back to Warner Bros.
The 1970 Road Runner convertible shows the same vertical-pattern grille that was used on the base Belvedere and Satellite series in 1970. Also seen here is the grille’s “dog bone” shape that the 1971 B-Body Plymouths wore. (Photo Courtesy David Newhardt)
The 426 Hemi resided at the top of the Road Runner’s engine list and was conservatively rated at 425 hp. It carried the Bird to 60 mph in just 5.6 seconds, running the quarter-mile in 13.49 seconds.
