Harley-Davidson enthusiasts seeking uncompromising performance now have an exhilarating new choice with the debut of the Screamin’ Eagle 135ci Stage IV Performance Crate Engine. This complete Milwaukee-Eight engine, designed for 2021 and later Touring models, sets a new standard for factory-engineered American V-Twin power, boasting the largest displacement and highest power ever produced by H-D for a street-compliant crate engine. Developed in part by the Harley-Davidson Screamin’ Eagle factory racing team competing in the MotoAmerica Mission King of the Baggers road racing series, this engine represents a pinnacle of performance. To streamline the setup of high-performance engines, Harley-Davidson offers the wireless Screamin’ Eagle Pro Street Performance Tuner, the sole tuner designed to optimize performance while complying with emissions regulations and warranties.
Engineered and meticulously tested as a comprehensive collection of high-performance components, assembled from the ground up at Harley-Davidson Powertrain Operations in Menomonee Falls, Wisconsin, this street-tuned 135-cubic-inch (2212cc) Screamin’ Eagle Crate Engine is engineered to excel with wide-open throttle at high engine speeds, delivering instant passing power from cruising speed. Generating 143 lb.-ft. of rear-wheel torque at 3500 RPM and 130 rear-wheel horsepower at 5500 RPM, it offers approximately 28 percent more torque and 41 percent more horsepower at the rear wheel compared to a stock Milwaukee-Eight 117 engine.
This street-ready performance engine showcases premium Screamin’ Eagle components, including a new 68mm throttle body and corresponding CNC-machined intake manifold developed originally for Harley-Davidson Screamin’ Eagle factory racing team engines to optimize airflow. The Screamin’ Eagle Extreme CNC-ported cylinder heads enhance cylinder filling efficiency, resulting in explosive power and increased rear-wheel torque compared to stock. High-performance valve springs maintain stability with the high-lift cam and during high-RPM operation. Additionally, the Screamin’ Eagle Pro Billet Cam Plate and Oil Pump ensure consistent pressure, while the new 10.7:1 high-compression forged pistons, SE8-517 high-lift camshaft, high-performance cam bearing, and high-performance tappets contribute to enhanced performance.
Featuring patent-protected 4.31-inch steel sleeve cylinders and a new 4 5/8-inch flywheel, this engine is complemented by new high-capacity 6.8 gram/second fuel injectors. While the Screamin’ Eagle Ventilator Extreme Air Cleaner and Screamin’ Eagle Street Cannon mufflers (available separately) are not mandatory, they are highly recommended for peak performance.
The Screamin’ Eagle 135ci Stage IV Performance Crate Engine is designed for straightforward installation in an original equipment-style 2021-later H-D Touring chassis, requiring no special fabrication or engine-mount relocation. Backed by up to a two-year manufacturer’s warranty through the Custom Coverage program when dealer-installed, it offers unmatched confidence.