1970 Plymouth Road Runner Superbird Engine Options and Specs
In 1970 the Plymouth Road Runner Superbird could be ordered with three different high performance engine options.
For the 1970 Plymouth Superbird, the 440 High Performance 4 barrel engine was the standard engine. Two engine options were available including the 440 Six Barrel and the 426 Hemi.
This article will include the 1970 Superbird 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.
1970 Plymouth Superbird Engine Options and Specifications
1970 was the first year for the Plymouth Road Runner Superbird. It was available with the following three engines.
- 440 High Performance 4-barrel (Standard)
- 440 Six Barrel (Optional)
- 426 Hemi (Optional)
1970 Superbird With a 440 High Performance 4-barrel
The 440 High Performance 4-barrel was available as the standard engine for the 1970 Superbird. The compression ratio of the 440 engine decreased from 10.1:1 to 9.7:1 from the previous year when it was available in other Chrysler car models.
Another change was the introduction of the heavier “Six Pack” connecting rods.
The engine code was E86. Let’s take a look at the specifications.
| Specifications | 440 4-barrel |
| Displacement | 440 |
| Bore and Stroke | 4.32″ x 3.75″ |
| Horsepower | 375 @ 4,600 RPM |
| Torque | 480 @ 3,200 RPM |
| Compression Ratio | 9.7:1 |
| Camshaft | High lift, long duration, high overlap |
| Cam Duration/Overlap | 268°/284°/46° |
| Cam Lift | .450″/.458″ |
| 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 | Premium |
1970 Superbird With a 440 6-barrel
The 440 Six Barrel was available for the first time the previous year in the 1969 A12 Road Runner. It was an optional engine for the Superbird in 1970.
The engine’s compression ratio increased from 10.1:1 to 10.5:1. Another change was the introduction of the heavier “Six Pack” connecting rods. The aluminum Edelbrock intake manifold was replaced by a cast iron Chrysler manifold which had the same exact design.
The engine code was E87. Let’s take a look at the specifications.
| Specifications | 440 Six Barrel |
| Displacement | 440 |
| Bore and Stroke | 4.32″ x 3.75″ |
| Horsepower | 390 @ 4,700 RPM |
| Torque | 490 @ 3,200 RPM |
| Compression Ratio | 10.5:1 |
| Camshaft | High lift, long duration, high overlap |
| Cam Duration/Overlap | 268°/284°/46° |
| Cam Lift | .450″/.458″ |
| Lifter Type | Hydraulic |
| Valve Diameter, Intake | 2.08″ |
| Valve Diameter, Exhaust | 1.74″ |
| Carburetion | Triple Holley 2-bbl |
| Air Cleaner | Unsilenced |
| Exhaust System | Dual, low restriction |
| Fuel Recommended | Premium |
1970 Superbird With a 426 Hemi
The 426 Hemi was available as an option for the 1970 Superbird. The Street Hemi engine was produced in previous years on other car models starting in 1966. The camshaft was changed from the previous year using hydraulic tappets instead of mechanical. The lift and duration remained the same.
The engine code was E74. Let’s take a look at the specifications.
| Specifications | 426 Hemi |
| Displacement | 426 |
| Bore and Stroke | 4.25″ x 3.75″ |
| Horsepower | 425 @ 5,000 RPM |
| Torque | 490 @ 4,000 RPM |
| Compression Ratio | 10.25:1 |
| Camshaft | High lift, long duration, high overlap |
| Cam Duration/Overlap | 284°/284°/60° |
| Cam Lift | .490″/.481″ |
| Lifter Type | Hydraulic |
| Valve Diameter, Intake | 2.25″ |
| Valve Diameter, Exhaust | 1.94″ |
| Carburetion | Dual Carter 4-bbl |
| Air Cleaner | Unsilenced |
| Exhaust System | Dual, low restriction |
| Fuel Recommended | Premium |
That’s the complete list of engines available for the 1970 Plymouth Road Runner Superbird. If you have any questions to ask me about the engine options or specifications for the 1970 Superbird 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
- 1970 Plymouth Service Manual
- Google Books: Chrysler Engines 1922-1998
- Wikipedia: Plymouth Superbird
