1972 Dodge Challenger Rallye Engine Options and Specs
In 1972 the Dodge Challenger Rallye could be ordered with two different engines.
For the 1972 Dodge Challenger Rallye, the 318 2 barrel was the standard engine and the 340 4 barrel was an optional engine. There were no other engine options available for the Rallye.
1972 was the first year a big block engine, like the 383, 440 4 barrel, 440 Six Pack or 426 Hemi wasn’t available for the Challenger model.
This article will include the 1972 Challenger Rallye 340 4 barrel and 318 2 barrel engine specifications. This includes the engine code, cost, displacement, horsepower, torque, compression ratio, camshaft, lifter type, valve sizes, bore, stroke, air cleaner, exhaust, fuel and carburetion.
1972 Dodge Challenger Rallye Engine Options and Specifications
The 1972 Challenger Rallye was available with the following engines.
- 318 2-barrel (Standard)
- 340 4-barrel (Optional)
In 1972 the 383 4 barrel, 440 Six Pack and the 426 Hemi were dropped from the Challenger engine lineup and wasn’t offered as an option.
The Dodge Challenger Rallye replaced the Challenger R/T for the 1972 model year.
All Engine Horsepower and Torque Ratings Change
Prior to 1971 an engine’s gross horsepower and torque were used for the factory power ratings. In 1971, the manufacturers reported both gross and net horsepower and torque. Starting in 1972 SAE gross horsepower was no longer used and the SAE net horsepower became the new rating.
Gross and net horsepower are both measured at the crank. The difference is the use of engine accessories, air cleaner and factory exhaust to calculate net horsepower which is not used for gross horsepower.
Therefore, in addition to horsepower robbing internal engine changes, the net rating lowered the power numbers for 1972.
1972 Challenger Rallye With a 318 2-barrel
In 1972 the 318 2-barrel was the standard engine for the Challenger Rallye.
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 | 150 @ 4,000 RPM |
| Torque | 260 @ 1,600 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 |
1972 Challenger Rallye With a 340 4-barrel
The 340 4-barrel was the optional engine.
The rated horsepower was drastically reduced and the compression was lowered from the previous year.
The 1.88″ intake valves were smaller than the 2.02″ valves the year before.
As of April 11, 1972 a cast crankshaft replaced the forged crankshaft starting with 340 engine serial number HM340R-3911-8000. In addition, a different damper and a torque converter and/or flywheel with special balance was used.
The engine code was E55. Let’s take a look at the specifications.
| Specifications | 340 4-barrel |
| Displacement | 340 |
| Bore and Stroke | 4.04″ x 3.31″ |
| Horsepower | 240 @ 4,800 RPM |
| Torque | 290 @ 3,600 RPM |
| Compression Ratio | 8.5:1 |
| 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 | Unsilenced |
| Exhaust System | Dual, low restriction |
| Fuel Recommended | Regular |
That’s the complete list of engines available for the 1972 Dodge Challenger Rallye. If you have any questions to ask me about the engine options or specifications for the 1972 Challenger Rallye 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.
Read More E-body Challenger R/T and Rallye Articles
1970 Dodge Challenger R/T Engine Options and Specifications
1971 Dodge Challenger R/T Engine Options and Specifications
1973 Dodge Challenger Rallye Engine Options and Specifications
1974 Dodge Challenger Rallye Engine Options and Specifications
Article Resources
- 1972 Dodge Service Manual
- Google Books: Chrysler Engines 1922-1998
- The Definitive Barracuda & Challenger Guide 1970-1974 by Scott E. Ross
