1974 Plymouth Road Runner Engine Options and Specifications
In 1974 the Plymouth Road Runner could be ordered with four different engines.
For the 1974 Road Runner, the 318 2 barrel was the standard engine. Optional engines included the 360 4 barrel, 400 4-barrel and the 440 4-barrel. If the 440 was ordered, the GTX name was added to the Road Runner calling it the Plymouth Road Runner GTX.
This article will include the 1974 Road Runner engine options and their specifications. This includes the engine code, displacement, horsepower, torque, compression ratio, camshaft, lifter type, valve sizes, bore, stroke, air cleaner, exhaust, fuel and carburetion.
1974 Plymouth Road Runner Engine Options and Specifications
The 1974 Road Runner was available with the following engines.
- 318 2-barrel (Standard)
- 360 4-barrel (Optional)
- 400 High Performance 4-barrel (Optional)
- 440 High Performance 4-barrel (Optional)
The 360 engine was available for the first time in a Road Runner. It replaced the 340 engine which was no longer available in any Chrysler car.
1974 Road Runner With a 318 2-barrel
The 318 2-barrel was the standard engine for the Road Runner in 1974. It was the second year the 318 was available for the Road Runner model.
The engine is little changed from 1973 with similar horsepower and compression.
The Road Runner came with a dual exhaust allowing 20 more horsepower (170 H.P.) than a 318 with a single exhaust available in other models.
The engine code was E44. Let’s take a look at the specifications.
| Specifications | 318 2-barrel |
| Displacement | 318 |
| Bore and Stroke | 3.91″ x 3.31″ |
| Horsepower | 170 @ 3,600 RPM |
| Torque | 270 @ 2,000 RPM |
| Compression Ratio | 8.6:1 |
| Cam Duration/Overlap | 240°/248°/26° |
| Cam Lift | .373″/.399″ |
| Lifter Type | Hydraulic |
| Valve Diameter, Intake | 1.78″ |
| Valve Diameter, Exhaust | 1.50″ |
| Carburetion | Single Ball and Ball 2-bbl |
| Air Cleaner | Single Snorkel |
| Exhaust System | Single |
| Fuel Recommended | Regular |
1974 Road Runner With a 360 4-barrel
The 360 4-barrel was available as an optional engine for the Road Runner in 1974. This is the first time it was available for the Road Runner. The 360 replaced the 340 engine.
The rated horsepower, 245 @ 4,800, was five more than the 340 from the previous year. The rated torque, 320 @ 3,600 rpm was also more than the 340 engine. The 360 shared the same camshaft as the 340 engine.
The engine code was E58. Let’s take a look at the specifications.
| Specifications | 360 4-barrel |
| Displacement | 360 |
| Bore and Stroke | 4.00″ x 3.58″ |
| Horsepower | 245 @ 4,800 RPM |
| Torque | 320 @ 3,600 RPM |
| Compression Ratio | 8.4:1 |
| Camshaft | High lift, high performance |
| Cam Duration/Overlap | 268°/276°/44° |
| Cam Lift | .429″/.444″ |
| Lifter Type | Hydraulic |
| Valve Diameter, Intake | 1.88″ |
| Valve Diameter, Exhaust | 1.60″ |
| Carburetion | Single Carter 4-bbl |
| Air Cleaner | Single snorkel, low restriction |
| Exhaust System | Dual, low restriction |
| Fuel Recommended | Regular |
1974 Road Runner With a 400 4-barrel
The 400 4-barrel engine was available as an option for the Road Runner in 1974. The engine’s horsepower and torque slightly decreased. The compression ratio remained the same.
The engine code was E68. Let’s take a close look at the specifications.
| Specifications | 400 4-barrel |
| Displacement | 400 |
| Bore and Stroke | 4.342″ x 3.375″ |
| Horsepower (Net) | 250 @ 4,800 RPM |
| Torque (Net) | 330 @ 3,400 RPM |
| Compression Ratio | 8.2:1 |
| Camshaft | High lift, high performance |
| Cam Duration/Overlap | 268°/284°/46° |
| Cam Lift | .450″/.464″ |
| Lifter Type | Hydraulic |
| Valve Diameter, Intake | 2.08″ |
| Valve Diameter, Exhaust | 1.74″ |
| Carburetion | Single 4-bbl |
| Air Cleaner | Dual Snorkel |
| Exhaust System | Dual, low restriction |
| Fuel Recommended | Regular |
1974 Plymouth Road Runner GTX With a 440 High Performance 4-barrel
The 440 High Performance 4-barrel was available for the 1974 Road Runner GTX. The engine’s horsepower and torque slightly decreased from the previous year. The compression ratio remained the same.
The engine code was 86. Let’s take a look at the specifications.
| Specifications | 440 4-barrel |
| Displacement | 440 |
| Bore and Stroke | 4.32″ x 3.75″ |
| Horsepower (Net) | 275 @ 4,400 RPM |
| Torque (Net) | 375 @ 3,200 RPM |
| Compression Ratio | 8.2:1 |
| Camshaft | High lift, long duration, high overlap |
| Cam Duration/Overlap | 268°/284°/46° |
| Cam Lift | .450″/.464″ |
| Lifter Type | Hydraulic |
| Valve Diameter, Intake | 2.08″ |
| Valve Diameter, Exhaust | 1.74″ |
| Carburetion | Single Carter 4-bbl |
| Air Cleaner | Dual Snorkel |
| Exhaust System | Dual, low restriction |
| Fuel Recommended | Regular |
That’s the complete list of engines available for the 1974 Plymouth Road Runner. If you have any questions to ask me about the engine options or specifications for the 1974 Road Runner car model, send us an email found specifically on my contact page or comment below.
About 38 years ago I assembled my first Mopar engine, it was for a 1970 ‘Cuda. It’s at that time my hands on experience with Mopar cars and engines, including the 440, started. Although my research of the engines started years earlier.
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Article Resources
- 1974 Plymouth Service Manual
- Google Books: Chrysler Engines 1922-1998
- Wikipedia: Plymouth Road Runner
