Harley-Davidson riders craving no-compromise performance have a thrilling new option with the introduction of the Screamin’ Eagle 135ci Stage IV Performance Crate Engine. This complete Milwaukee-Eight engine for 2021-later Touring models is the new benchmark for factory-engineered American V-Twin performance, offering the most displacement, and the most power, ever created by H-D for a street-compliant crate engine. Its development was fueled in part by the efforts of the Harley-Davidson Screamin’ Eagle factory racing team competing in the MotoAmerica Mission King of the Baggers roadracing series. To simplify set up of high-performance engines Harley-Davidson offers the new wireless Screamin’ Eagle Pro Street Performance Tuner, the only tuner available to maximize performance while being emissions and warranty compliant.
![harley-davidson se 135 studio shot](https://vtwinvisionary.com/wp-content/uploads/2023/03/135-studio.jpg)
Engineered and tested as a complete collection of high-performance components and assembled from the bottom up at Harley-Davidson Powertrain Operations in Menomonee Falls, Wisconsin, this street-tuned 135-cubic-inch (2212cc) Screamin’ Eagle Crate Engine is designed to run with a wide-open throttle at high engine speeds and provide instant passing power from cruising speed. The engine delivers 143 lb.-ft. of rear-wheel torque at 3500 RPM and 130 rear-wheel horsepower at 5500 RPM – approximately 28 percent more torque and 41 percent more horsepower at the rear wheel than a production Milwaukee-Eight 117 engine.
![harley-davidson se 135 studio shot](https://vtwinvisionary.com/wp-content/uploads/2023/03/135-cam-chest--683x1024.jpg)
This street-ready performance engine features premium Screamin’ Eagle components:
- New 68mm throttle body and matching CNC-machined intake manifold, originally developed for Harley-Davidson Screamin’ Eagle factory racing team engines, to maximize airflow to the engine.
- Screamin’ Eagle Extreme CNC-ported cylinder heads provide significantly improved efficiency of cylinder filling, leading to more explosive power and increased rear-wheel torque when compared to stock. High-performance valve springs remain stable with the high-lift cam and in high-RPM operation.
- Screamin’ Eagle Pro Billet Cam Plate and Oil Pump provides higher pressure when the oil is hot to keep pressure drops to a minimum.
- New 10.7:1 high-compression forged pistons.
- SE8-517 high-lift camshaft, high-performance cam bearing and high-performance tappets.
- Patent-protected 4.31-inch steel sleeve cylinders and new 4 5/8-inch flywheel (bore x stroke is 4.31 x 4.625).
- New high-capacity 6.8 gram/second fuel injectors.
- Screamin’ Eagle Ventilator Extreme Air Cleaner and Screamin’ Eagle Street Cannon mufflers (each sold separately) are not required but are highly recommended for peak performance.
![](https://vtwinvisionary.com/wp-content/uploads/2023/03/135-on-bike-683x1024.jpg)
The Screamin’ Eagle 135ci Stage IV Performance Crate Engine is intended for bolt-in installation in an original equipment-style 2021-later H-D Touring chassis. No special fabrication or engine-mount relocation is required. The engine is backed by up to two-year manufacturer’s warranty for unmatched confidence when dealer-installed through the Custom Coverage program.
With an MSRP of $7,999.95 the Screamin’ Eagle 135ci Stage IV Performance Crate Engine is offered in Black or Chrome finish with 135 Stage IV badging on the cylinder heads and timer cover.
![](https://vtwinvisionary.com/wp-content/uploads/2023/03/Hp-v-Torque.jpg)
Two versions of the engine will be offered: For 2021-later Touring models equipped with Air/Oil-Cooled Milwaukee-Eight engine, and for 2021-later Touring models equipped with a Twin-Cooled Milwaukee-Eight engine. The engine does not fit Trike models. Installation requires the separate purchase of Head Pipe P/N 65600177. Air-Cooled models require Oil Cooler Fan Assist P/N 62700204 or Fan for Factory Oil Cooler P/N 26800195. All models require ECM recalibration with Screamin’ Eagle Pro Street Tuner for proper installation. Does not fit California models. Find out more on the MoCo’s website.