What Are the Specifications for a Harley 1340 Torque?

by Jillian O'Keeffe
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The Harley-Davidson Evolution engine comes with 1340 cubic centimeters or 80 cubic inches and is used to power the Touring, Dyna and Softail ranges of cruiser motorcycles. The torque produced by the engine depends on which bike it is fitted to and the bike's type of fuel induction.


The Evolution engine of 1340-cc displacement has a bore and stroke of 3.5 inches by 4.3 inches, where bore is the diameter of the engine cylinder opening, and stroke is the total distance the piston travels up and down. The compression ratio is 8.5 to one, where the compression ratio is the ratio of the volume between the piston and cylinder head before and after a compression stroke.

The engine is a V-twin with the two cylinders at a 45-degree angle to each other. It is four-stroke, which means the pistons take four strokes to complete an engine cycle.


Torque is measured in foot-pounds in the U.S. and Newton meters in countries using the metric system. The torque produced by an engine is a turning force around an axis measured in foot-pounds. For example, if a force of 100 pounds is applied one foot from an axis of rotation, the resultant torque would be 100 foot-pounds.

Torque is related to horsepower, and one horsepower is actually equivalent to 550 foot-pounds a second. Torque is also related to work, which is measured in foot-pounds also. However, torque is distinct from work, as work involves the movement of an object over distance, whereas torque acts on an axis where distance is not necessary.

Torque also changes with engine revolutions, which is why it is usually specified at a particular rpm when it is at its maximum.

Torque of the 1340-cc Evolution

The torque of an Evolution 1340-cc engine depends on the motorcycle it is fitted to. For the Dyna group, the maximum torque produced is 79 foot-pounds at 3,500 engine revolutions per minute. At the same rpm, the engine produces 76 foot-pounds in the Softail group of bikes.

The Touring bikes can have either carburetor fuel induction or Electronic Sequential Port Fuel Injection (ESPFI). In the bikes with a carburetion system, the Evolution produces 77 foot-pounds of torque at 4,000 rpm, and in the ESPFI touring bikes, maximum torque of 83 foot-pounds is developed at 3,500 rpm.

Metric Torque

The equivalent torque in Newton meters is 107 Nm for the Dyna group and 103 Nm for the Softail bikes. The carbureted Touring bikes produce 104 Nm and the fuel-injected models 113 Nm.

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