2,212cc Harley-Davidson Screamin' Eagle 135 Stage IVCrate motorcycle engines may not be as common as those for cars, but don't tell that to Harley-Davidson. The iconic American brand makes two Screamin' Eagle crate engines, the Milwaukee Eight 131 and the larger, burlier Screamin' Eagle 135 Stage IV, the latter of which we'll look at here.Harley-Davidson offers the 135 cubic inch (2,212cc) Screamin' Eagle 135 Stage IV as a bolt-in replacement for the Milwaukee Eight engines in 2021 and newer Harley-Davidson Touring bikes, both air/oil and twin-cooled. As the name may suggest, the Screamin' Eagle 135 comes with a range of Harley-Davidson's Screamin' Eagle performance parts, including CNC-ported cylinder heads, a high-lift camshaft, high-compression forged pistons, high-flow fuel injectors, and a new 68-mm throttle body.Combine all of these parts with the Screamin' Eagle 135 Stage IV's massive displacement and you get the largest and most powerful street-legal crate engine Harley-Davidson has ever built. The Stage IV makes 130 horsepower and 143 lb-ft of torque at the rear wheel, a significant chunk more than the 115 horsepower Milwaukee Eight 121 VVT engine in bikes like the 2024 CVO Street Glide. The best part? You won't even need to spend all that much to get your hands on one. The air/oil and twin-cooled versions of the Screamin' Eagle 135 Stage IV can be had for just under $8,000. Even better, Harley's crate offering is 49-state EPA compliant, so most Harley owners in the U.S. will be able to enjoy one if they so desire — unless you live in California.