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Harley-Davidson Screamin’ Eagle Engine Sets New Record

“The Most Power Ever Created by Harley-Davidson for a Street-Compliant Crate Engine”

The Screamin' Eagle® 135ci Stage IV Performance Crate Engine. Media sourced from Harley's press release.
The Screamin' Eagle® 135ci Stage IV Performance Crate Engine. Media sourced from Harley's press release.

If you’ve ever wondered how Harley’s doing with their engines, sit down for a bit; we’ve got a press release celebrating that Harley’s just gone and set a new benchmark for performance – and not just their own performance, but all American V-Twin performance. 

Apparently, their newest brainchild – the Screamin’ Eagle® 135ci Stage IV Performance Crate Engine (bit of a mouthful) – is built for 2021-later models, and shows off “the most displacement, and the most power, ever created by Harley-Davidson for a street-compliant crate engine.”

The Screamin' Eagle® 135ci Stage IV Performance Crate Engine. Media sourced from Harley's press release.
The Screamin’ Eagle® 135ci Stage IV Performance Crate Engine. Media sourced from Harley’s press release.

That’s a hefty title – and, as you can see from the curve specs above, it is a title well-earned. Some quick maths on those 135 cubic inches afford a stunning 2212cc with 143lb-ft of rear-wheel torque @ 3500rpm and 130 rear-wheel ponies @ 5500rpm.

That’s around 28% more yank (and 41% more ponies) than the brand’s 1,923cc Milwaukee-Eight® 117 heart.

Yikes.

The Screamin' Eagle® 135ci Stage IV Performance Crate Engine. Media sourced from Harley's press release.
The Screamin’ Eagle® 135ci Stage IV Performance Crate Engine. Media sourced from Harley’s press release.

To top it all off, this engine is also purportedly “the only tuner available to maximize performance while being emissions and warranty compliant” – something we will be eager to try out for ourselves when the engine begins the trickle into production models.

How many cc’s is your comfort zone? Take a look below at the components list if you’re curious, and let us know what you think.

Screamin’ Eagle® 135ci Stage IV Performance Crate Engine Componentry

  • 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.

*Media sourced from Harley’s press release*