Plymouth Road Runner

Plymouth Road Runner
Overview
Manufacturer	Plymouth (Chrysler)
Production	1968–1980
Assembly	Detroit, Michigan (Lynch Road) St. Louis, Missouri
Body and chassis
Class	Mid-size performance
Layout	FR layout

The Plymouth Road Runner is a performance car built by Plymouth in the United States between 1968 and 1980. By 1968, the original muscle cars were moving away from their roots as relatively cheap, fast cars as they gained options. Although Plymouth already had a performance car in the GTX, it wanted to reincarnate the original muscle car concept in a car able to run 14-second quarter mile (402 m) times and sell for less than US$3000. Both goals were met, and the Road Runner would outsell the upscale GTX.

First Generation (1968 to 1970)

First generation
Overview
Production	1968–1970
Body and chassis
Body style	2-door coupe 2-door hardtop 2-door convertible
Platform	B-body
Powertrain
Engine	383 cu in (6.3 L) 335 hp (250 kW) V8 426 cu in (7.0 L) Hemi V8 440 cu in (7.2 L) V8
Transmission	3-speed automatic 4-speed manual
Dimensions
Wheelbase	116.0 in (2,946 mm)
Length	202.7 in (5,149 mm)
Width	76.4 in (1,941 mm)
Height	54.7 in (1,389 mm) (loaded with 5-passengers)

1968 Road Runner rear view

1970 Plymouth Road Runner with Hemi engine and "Air Grabber" retractable hood scoop

1968

Paying $50,000 to Warner Bros.-Seven Arts to use the name and likeness of their Road Runner cartoon character (as well as a "beep, beep" horn, which Plymouth paid $10,000 to develop), and using the Chrysler B platform as a base (the same as the Belvedere), Plymouth set out to build a back-to-basics mid-size performance car. Everything essential to performance and handling was beefed-up and improved; everything nonessential was left out. The interior was spartan with a basic vinyl bench seat, lacking even carpets in early models, and few options were available - just the basics such as power steering and front disc brakes, AM radio, air conditioning (except with the 426 Hemi) and automatic transmission. A floor-mounted shifter (for the four-speed) featured only a rubber boot and no console so that a bench seat could be used. The earliest of the 1968 models were available only as 2-door pillared coupes (with a B-pillar between the front and rear windows), but later in the model year a 2-door "hardtop" model (sans pillar) was offered. The Road Runner of 1968-1970 was based on the Belvedere, while the GTX was based on the Sport Satellite, a car with higher level trim and slight differences in the grilles and taillights.

The standard engine was an exclusive-to-the-Road Runner 383 CID (6.3 L) Roadrunner V8 rated at 335 bhp (250 kW) and 425 lb⋅ft (576 N⋅m) of torque. Its extra 5 hp (4 kW) rating was the result of using the radical cam from the 440 Super Commando and a .25 raise in compression to 10.5:1 (vs. 10.25:1 with the 330 hp (246 kW) 383). When air conditioning was ordered, the cars received the 330 hp (246 kW) version, as the radical cam specs of the 335 bhp (250 kW) version didn't create enough vacuum to accommodate a/c; and there were concerns of overrevving which would destroy the RV-2 York compressor. For an extra $714, Plymouth would install a 426 CID Hemi rated at 425 bhp (317 kW) and 490 lb⋅ft (664 N⋅m) of torque. Combined with low weight, the 6-passenger Road Runner could run the 1/4 mile in 13.5 seconds at 105 mph (169 km/h). It would prove to be one of the best engines of the muscle car era, and the Road Runner one of the best platforms to utilize it.

The standard equipment transmission was a four-speed manual with floor shifter and Chrysler's three-speed TorqueFlite automatic was optional. Early four-speed '68 Road Runners featured Inland shifters, which were replaced by the more precise Hurst shifters during the course of the model year.

Plymouth expected to sell about 20,000 units in 1968; actual sales numbered around 45,000. This placed the Road Runner third in sales among muscle cars with only the Pontiac GTO and Chevy's SS-396 Chevelle outselling it. Dodge debuted the Road Runner's cousin, the Super Bee, as a mid-1968 offering after seeing Plymouth's success with the Road Runner, along with demands from Dodge dealers for their own low-priced muscle car as the Dodge Boys started the model year with the higher-priced Charger R/T and Coronet R/T - both of which were priced similar or higher than the Plymouth GTX.

1969

The 1969 model kept the same basic look but with some slight changes such as tail lights and grille, side marker lights, optional bucket seats, and new Road Runner decals. The Road Runner added a convertible option for 1969 with 2128 droptop models produced that year. All were 383 engine cars, except for ten 426ci Hemi convertible cars. Six of those Hemi convertibles were automatics and four were four-speed manual transmissions. Six are known to exist. No 440 6-bbl convertibles were made in 1969.

An Air Grabber option (N96 code) was introduced this year; it consisted of a fiberglass air duct assembly bolted to the underside of the hood that connected to twin rectangular upward-facing vents in the hood with orange vent screens. The fiberglass hood box had an "Air Grabber" sticker on the front. When the hood was closed, a rubber seal fit over the large-oval unsilenced air cleaner. A decal with Wile E. Coyote saying "Coyote Duster" was on the air cleaner lid. The assembly ducted air directly into the engine. The vents in the hood could be opened and closed via a lever under the dashboard labeled "Carb Air."

In 1969 the 383ci engine was the standard powerplant, and the 426 cubic inch Hemi was the only engine option available for the Road Runner until mid year production. The standard 383ci V8 had 335 horsepower, and was marketed as the "383 Roadrunner" engine, which is also what the air cleaner read. The 383 Roadrunner had 5 more horsepower than the usual 383 Commando or Super Commando, thanks to a more radical cam. In addition to its higher horsepower rating, the 383 also had 425 pound-feet of torque, which was the second-largest torque rating offered by Plymouth. However, if you were to order your Roadrunner with optional A/C, your standard 383 would be bumped down to the ordinary 330 horsepower. This is because the radical cam in the 335 didn't create enough vacuum to accommodate a/c; and there were concerns of overrevving which would grenade the RV-2 York compressor.

The (A12) 440 cubic inch engine option with three Holley 2 barrel carburetors was added to the lineup at mid-year. Several of the cars were ran in Super Stock Eliminator drag race competitions. As denoted on its fiberglass hood, Dodge marketed its three two-barrel setup as the "440 Six Pack" for the 1969 Super Bee. 440 6-bbl Road Runners had no wheel covers or hubcaps, sporting only the 15x6" "H" stamped steel black wheels with chrome lug nuts. It featured an organosol black fiberglass lift-off hood with 4 hood pins and a large functional hood scoop with a red sticker on each side saying "440 6BBL". The scoop sealed to the large air breather. All cars had a Dana 60 rear axle with a 4.10 gear ratio. Production of the 440 6-bbl A12 option Road Runner was approximately 1432. The A12 option had an "M" as the fifth character in the VIN. The 440 engine was rated at 390 hp (291 kW) @ 4700 rpm, and 490 pound-feet of torque @ 3200 rpm, the same torque as the Hemi but at a lower engine speed. This meant the stock 440 6bbl was about as fast as the stock 426 Hemi in the 1/4 mile, with its lighter engine and hood. This option, along with the standard 383 and the Hemi made Plymouth and Dodge fierce competitors at the dragstrip. The Plymouth Road Runner was named Motor Trend "Car of the Year" for 1969. Sales topped 84,000 that year.

1970

1970 brought new front and rear end looks to the basic 1968 body, and it would prove to be another success. Updates included a new grille, a cloth & vinyl bench seat, hood, front fenders, quarter panels, single-piston Kelsey-Hayes disc brakes (improved from the rather small-rotor Bendix 4 piston calipers of '68 - '69 ), and even non-functional scoops in the rear quarters. The design and functionality of the Air Grabber option was changed this year to increase both efficiency and the "intimidation factor". A switch below the dash actuated a vacuum servo to slowly raise the forward-facing scoop, exposing shark-like teeth on either side. "High Impact" colors, with names like In-Violet, Moulin Rouge, and Vitamin C, were options available for that year. The 1970 Road Runner and GTX continued to be attractive and popular cars. The engine lineup was left unchanged although a heavy-duty three-speed manual became the standard transmission, relegating the four-speed to the option list along with the TorqueFlite automatic. This was to be the second and last year of the Road Runner convertible, with only 834 made. These cars are considered more valuable than the 1969 version (save for 1970's 440-6 cars vs. 1969's A12s) due to a better dash, high impact colors and more options including the new high-back bucket seats shared with other Chrysler products which featured built-in headrests.

The relatively popular 440 Six Barrel was relegated to option status for 1970. The 1969 "M" Code Edelbrock aluminum intake was replaced by a factory-produced cast iron piece; however there were some early cars built prior to January 1, 1970 that were equipped with the left over aluminum Edelbrock intake from the year prior.

Sales of the '70 Road Runner dropped by more than 50 percent over the previous year to around 41,000 units (about 1,000 ahead of Pontiac's GTO but still about 13,000 units behind Chevy's Chevelle SS-396/454). This would also be the last year of the Road Runner convertible with 834 total production. Only 3 Hemi (R) code Road Runner convertibles were built (plus 1 to CANADA). The declining sales of Road Runner and other muscle cars were the result of a move by insurance companies to add surcharges for muscle car policies - making insurance premiums for high-performance vehicles a very expensive proposition. Also, Plymouth introduced another bargain-basement muscle car for 1970, the compact Duster 340 which was powered by a 275 hp (205 kW) 340 4BBL V8 which in the lighter-weight compact A-body could perform as well if not better than a 383 Road Runner. Furthermore, the Duster 340 was priced even lower than the Road Runner and its smaller engine qualified it for much lower insurance rates.

Plymouth Duster I

The Plymouth Duster I was a high-performance concept car version of the Road Runner produced in the late 1960s. It featured the usual low-curved racing-type of windshield and had airplane-type flaps on the top and sides. A set of adjustable spoilers on the side of the rear fender (near the gas tank filler cap) helped prevent side-to-side yaw when slipstreaming in a race, with two more of them on top behind the driver, plus spoilers in the front as rock shields to reduce frontal lift. It was powered by a 383 4BBL V-8.

1970 Superbird

Plymouth Superbird

Main article: Plymouth Superbird

In the tough competition of the 1969 NASCAR "aero wars", Chrysler first fielded the Dodge Charger 500 that featured aerodynamic improvements to a standard 1969 Charger. Later in the season Chrysler and Dodge debuted the Dodge Charger Daytona. The Daytona featured an elevated spoiler raised 23 inches off of the trunk deck by upright pylons and an aerodynamic nose cone. The Charger 500, especially, and the Daytona to a lesser degree struggled to equal the fastback Ford Torino Talladega and Mercury Cyclone Spoiler II in 1969. Dissatisfied with the performance of the 1968 Road Runner, Petty Engineering had asked the Chrysler managers for 1969 Dodge Charger 500s and Charger Daytonas for the 1969 season. The Chrysler managers told the Pettys that they were "a Plymouth team." The Pettys signed with Ford in days and Richard Petty and Petty Engineering won 10 races in 1969 and finished second in the NASCAR points championship.

To meet NASCAR homologation rules and also to bring Petty Engineering back to Chrysler, it was decided that Plymouth would get its own version of Dodge's winged wonder for the 1970 NASCAR season. While spectacular on the track, consumer response was luke-warm, leading a few dealers to remove the wing and nose, making them appear more like normal Road Runners. Significantly all public sold Superbirds had vinyl tops, while the Charger Daytonas did not. Production was 1,935 for the US market. 135 Hemi's (58 4Spd and 77 Automatics), 1,084 - 440 4BBL Super Commando's (458 4Spd and 626 Automatics) and 716 - 440 Six Barrel's (308 4Spd and 408 Automatics).

According to Road Test magazine, performance was around 0 to 60 mph (97 km/h) in 5.5 seconds, 1/4 mile in 14.3 seconds at 104 mph with the Hemi. Although similar in appearance, the Superbird was actually quite different from the Daytona. The Superbird was based on the Plymouth Road Runner and the nose, airfoil, and basic sheet metal was different between the Daytona and Superbird. The Superbird actually used the front fenders and a modified hood from the '70 Dodge Coronet that lent themselves better to the nose design. It was an easy fix due to the fact that the mounting points for fenders on both cars were identical. The special nose added 19-inches (483 mm) to the overall length (the Daytona's was 18-inches or 457 mm), and the trunk spoiler was more angled and higher than the Daytonas. On both models, the spoiler was two feet high. Although it created quite an impression on the street, the wing was not needed at normal highway speeds; it was designed for speedways, to keep the rear wheels to the ground at 150 mph (240 km/h) and higher speeds.

NASCAR only required 500 copies to be built in 1969, but in 1970, NASCAR required a manufacturer to build one unit per dealer. In the end, Plymouth built a total of 1,935 Super Birds. Super Birds were available with three different engines. The most popular was the basic Super Commando 440 V8 with a single four barrel carburetor rated at 375 bhp (280 kW). Next up was the 440 Six Barrel rated at 390 bhp (291 kW). At the top, and ordered by just 135 buyers, was the mighty 426 Hemi, rated at 425 bhp (317 kW). Despite the success of the Super Bird on the tracks, 1970 would be the only year it was made.

The reason for using such a tall spoiler was so on the production version the trunk could open. In test the spoiler didn't need to be so tall. The tallest the spoiler had to be was the same height as the roof.

Second Generation (1971–1974)

Second generation
Overview
Production	1971–1974
Body and chassis
Body style	2-door coupe
Platform	B-body
Related	Plymouth Belvedere Plymouth Satellite Dodge Coronet Dodge Charger Plymouth GTX Plymouth Fury Chrysler Cordoba
Powertrain
Engine	318 cu in (5.2 L) V8 400 cu in (6.6 L) V8 340 cu in (5.6 L) V8 440 cu in (7.2 L) V8 V8 426 cu in (7.0 L) Hemi V8 383 cu in (6.3 L) V8
Transmission	4-speed manual 3-speed Torqueflite automatic
Dimensions
Wheelbase	115 in (2,921 mm)
Length	203.2 in (5,161 mm)
Width	79.1 in (2,009 mm)
Height	52.9 in (1,344 mm)
Curb weight	3,640 lb (1,651 kg)

1971

In 1971, the coupe bodywork was completely changed to a more rounded "fuselage" design in keeping with then-current Chrysler styling trends, including a steeply raked windshield, hidden cowl, and deeply inset grille and headlights. In a departure from previous thinking, the B-Body two-door bodies shared little if any sheet metal, glass, or trim with the four-door bodies. The convertible was canceled. The interiors could be ordered with 6-way power leather seats, thick deep-pile carpeting, and additional sound-proofing was installed. A/C, and power steering could be had, except on the Hemi. 1971 was a high-water year for ride and handling for the Road Runner. The overall length was increased, but the wheelbase was shortened an inch. It also saw the introduction of the 340-4bbl option, and a detuned 383 "Road Runner" engine with 8.7 compression, hardened exhaust valve seats, and power dropping to 300 hp (224 kW). In return, Road Runners with the 340 and 383 engine received a standard insurance rating without the costly premiums normally tacked onto muscle cars. The 383 would now run on regular gas. The 370 hp 440 4-barrel returned to the option list, and the 440+6 and 426 Hemi were available, though this would be the last year for them. The tall axle ratios with the 8 3/4" Dana rear ends, as well as the wide and close ratio 4-speed transmissions could be had with any of the engine choices, though few cars were built with the six-pack or Hemi engines. Aerodynamics were much improved over the first generation Road Runners, resulting in much-improved high-speed handling.

1972

1972 saw new emission regulations drive power down and 1/4 mile times up.

1972 Plymouth Road Runner

The 1972 model was nearly identical to the 1971 with a few minor changes. The grille design was cleaned up, and the tail lights were changed to match the new aerodynamic look of the grille. Side marker lights changed from the flush mounted side markers to the surface-mounted units that were adopted across the entire Chrysler line-up for the 1972 model year. The optional bumper guards for 1972 included a rubber strip surrounding the tail lights and a rubber strip below the grille. The big differences came in the cutting back of performance options for the car. The suspension, rear axle ratios (a 3:55 ratio was the tallest available), and most noticeably the engines changed, with the big-block 383 being replaced by a larger-bore (and lower performance) 400 CID version as the standard engine. The small-block 340 CID as well as the performance version of the 440 CID engine (with a 4-barrel carburetor, performance camshaft, and dual exhausts) were also available, and for the last time a 4-speed manual transmission could be paired with any of the three engines. All of the engines suffered a drop in compression ratios to allow use of low-lead/no-lead gas and to meet the first round of emissions regulations. The 280 hp (209 kW) 440 engine was the basis for the "GTX" package (the GTX was no longer a separate model) available on Road Runners from 1972 to 1974. The 1971-72 Road Runner sheetmetal was used by several NASCAR racing teams for their racecars and ran well on the circuit during the 1971-74 seasons. Richard Petty won the championship both in 1971 and 1972 using the Road Runner-based cars, winning 30 races over the two seasons.

For 1972 power ratings on all engines looked much lower on paper due to the new SAE net measurement system. The famed 426 Hemi was discontinued for 1972, and only five 440 Six Barrel equipped cars were produced before this engine option was dropped (it was determined the 440 six-pack could not meet the stricter 1972 emissions regulations) in the fall of 1971.

1973-74

The 1973-74 models received completely new sheet metal and had more conventional squared-up front-end styling and changes to the rear that more closely resembled the four-door models than the 71-72s. The restyling helped sales which were up 40% over the 1972 models. In testing 1/4 mile times were getting close to the 16s, top speeds had dropped to barely over 125 mph (201 km/h), and the car moved further away from "musclecar" status. The base engine for the 1973-74 models had dropped down to Chrysler's workaday 318 CID V8 but equipped with dual exhausts which bumped the power up to 170 hp (127 kW). After 1972, no 440 with four-speed manual cars were built. The 400 was the biggest engine Plymouth offered with the four-speed, which could also be had with the 340 (1973), and 360 (1974) engines. The 318 was equipped with a three speed manual transmission as standard (though very few were built), and the TorqueFlite as an option, though at least one 318 engine 1974 car was built with the 4-speed manual Hurst shifter transmission. The 440 was still available for 1973 and 1974, but only mated to the 727 TorqueFlite automatic.

(Some info from the Dodge and Plymouth Muscle Car Red Book,, by Motorbooks International.)

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  1974 Plymouth Road Runner
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  1971 Road Runner engine
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  Plymouth Road Runner
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  Plymouth Road Runner

Third Generation (1975)

Third generation
Overview
Production	1975
Body and chassis
Body style	2-door coupe
Platform	B-body
Related	Plymouth Fury Dodge Coronet Dodge Charger Chrysler Cordoba
Powertrain
Engine	318 cu in (5.2 L) V8 360 cu in (5.9 L) V8 400 cu in (6.6 L) V8 440 cu in (7.2 L) V8
Transmission	3-speed manual 3-speed Torqueflite automatic
Dimensions
Wheelbase	115 in (2,921 mm)
Length	213.8 in (5,431 mm)
Width	77.4 in (1,966 mm)
Height	52.6 in (1,336 mm)
Curb weight	3,500 lb (1,588 kg)

1975

The 1975 model was based on the newly restyled, more formal-looking B-body which was now called the Fury (the former full-sized Fury being called "Gran Fury"). The Road Runner came with a blacked out grille and a special stripe treatment to distinguish it from the Fury, as well as a heavy duty suspension. As before the 318 was the standard engine, but it was now just with a single exhaust and 145 hp. The engine options were extensive; with a two-barrel/single exhaust 170 hp 360, a high performance four barrel/dual exhaust (Code E58) 360 (220 hp (164 kW)), and three 400 cu in offerings; a two-barrel/single exhaust/160 hp, a 185 hp four-barrel/single exhaust, and a high performance four barrel/dual exhausts/moderate cam 235 hp {172 kW}) were also available. In Car and Driver magazine testing of a 1975 car with the top line 400 engine; 0-60 happened in 8.1 seconds, the quarter-mile times were solidly in the 16-second range, and the top observed speed was 121 mph. While just a shadow of the 1970 figures, this performance was at least respectable for the times. All engine choices were limited to the 3-speed Torqueflite automatic, with the E58 360 and the 400 engines being available with the 3.21 axle ratio gearing. Plymouth's most powerful engine; the 440, was restricted to police models, though it has been rumored that a few 1975 Road Runners were built (via special factory order) with the 255 hp (190 kW) police spec 440, along with the police spec suspension and wider (7") rims. Only 7,183 Road Runners were built in 1975, and most (just over 50%) had just the 318 engine.

Though the name of the car the Road Runner was based on changed from Belvedere to Satellite to Fury, the Road Runner remained a B-body through 1975. While the Road Runner name was planned to be on a B-body in Plymouth's published literature for the 1976 model year, the name was transferred to an optional appearance package for the all-new Volare.

1976–1980: F-body Trim Package

A Volare-based Plymouth Road Runner.

In 1976 the Road Runner name was switched to the 2-door model of the replacement for the compact A-body Valiant/Duster series. This car, based on the new F platform, would be known as "Volaré". The new Road Runner was little more than a trim and graphics package; however, many suspension parts were borrowed from the police packages. A 360 CID engine was offered as an option (but only with a two barrel carb for 1976-'77 and single exhaust) to the standard 318 V8, but only paired with the 3-speed automatic transmission. Rated at 160 hp (119 kW), the F platform's best 1/4 mile times would be just inside 16-seconds at 88 mph (142 km/h). Although no comparison to the earlier stormers, the 360 powered models were respectable performers in their time. By 1978 and thru to 1979 the 360 was offered with a four-barrel carb and, for 1979, dual exhaust, bringing power up to 195 hp (145 kW). However, performance continued to suffer, and by 1979 the 225 CID "Slant 6" six-cylinder became standard. The Road Runner continued as part of the Volaré line until its discontinuation in 1980. However, in 1980 the 360 was no longer offered. The 318 was the top engine offered for the 1980 model year.

Concepts

The now-defunct Mopar Enthusiast magazine released a concept rendering of a potential 2010 Road Runner, with design cues based on the 1971-72 model.

See also

• Muscle car
• Dodge Super Bee
• Wile E. Coyote and The Road Runner

External links

• Plymouth Road Runner
• 1969 Roadrunner Forum
• Road Runner
• Decode This! Plymouth VIN Decoder