What Is the Most Reliable Harley Davidson Engine?


The Evolution (Evo) line of Harley engines is arguably the most reliable among them all. These engines first began manufacturing in 1984 and are not as powerful as the twin-cam models. However, their design is considered reliable and dependable by many motorcycle owners. Read on to learn more about these engines. And if you have one of these bikes, make sure to check out these tips to ensure its performance.


The two motorcycles have very similar engines. The Honda CR-Z750 was the first Japanese motorcycle to feature the new engine and was based loosely on the H-D Nova Project. The CR-Z750 sold for over a decade and was the first motorcycle to use an OHC V-Twin engine. Yamaha and Harley Davidson were a year apart in the production line, but they were able to build similar engines in the same timeframe.


The Knucklehead engine is one of three primary types of Harley-Davidson motorcycle engines. This overhead valve V-Twin features two cylinders and a 45 degree angle, and was introduced in 1936. The Knucklehead engine was Harley’s best-selling model, and for many years reigned supreme on motorcycles. But it wasn’t without its problems. In this article, we’ll explore the history of the Knucklehead and its role in Harley-Davidson motorcycles.

Overhead-valve design

The overhead-valve V-twin was first used in the Harley 61ci Knucklehead. The name “Knucklehead” came from the shape of the cylinder heads and the rocker boxes that surrounded the valves. In 1937, Joe Petrali set the Daytona Beach speed record on one of these motorcycles. During the early 1930s, Fred Ham conducted durability testing on the motorcycle at Muroc Dry Lake in California. As soon as the new powerplant hit the market, consumers forgot about the side-valve engines and rushed to the dealerships for their first chance to purchase a Harley.

ORCA pistons

ORCA pistons are forged to provide lightweight strength and a high degree of performance. One inch of forged aluminum is lighter than one of its competitors. Hp is a measure of torque times RPM, and one horsepower equals the acceleration of a motorcycle at 6400 RPM and seven hundred and twenty five RPM. A typical Harley Evo 80 inch piston and pin combination weighs 12,251 pounds at 6400 RPM, while a 113-inch normally-aspirated high-compression piston and pin combination weighs just 856 grams and 16949 pounds at the same speed.

Revolution Max

At EICMA 2018, Harley-Davidson teased two models. One is a pan-American adventure tourer, and the other is a Bronx streetfighter. Both models will be powered by the brand’s new liquid-cooled 60-degree V-twin engine platform. The Pan America will have 1,250cc, while the Bronx will feature a 975cc engine. According to Harley-Davidson, both models will be available in late 2020.

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