Tech & Auto
This Is Harley-Davidson’s Most Powerful Motorcycle Engine
By DANIEL MEAGHER
A big part of why Harley-Davidson has built a reputation for extremely powerful motorcycles is its Screamin’ Eagle line of engines.
In 2003, Harley Davidson announced the release of the newest edition to the Screamin’ Eagle line of engines, the Screamin' Eagle Stage IV Performance Crate Engine.
Harley-Davidson dubbed it, “the biggest, most powerful street-compliant crate performance engine Harley-Davidson has ever created.”
The Stage IV is a V-Twin engine, meaning it has two pistons arranged at a 45-degree angle. This is the standard for Harley V-Twins, and it's what gives them their distinct sound.
Adding to the high performance are 6.8g/sec fuel injectors, which are more than fast enough to reach high speeds in seconds. It also has 4.31” steel sleeve cylinders.
Those fancy cylinders are topped with the Screamin’ Eagle Extreme CNC-ported cylinder heads, designed for a “wide open throttle,” so you can crank it to accelerate in a flash.