It’s not every day that one of the world's largest motorcycle makers, Harley-Davidson, releases a new crate engine into the wild. In fact, if you look back in time, you’ll see such a thing occurs at most once per year, often even rarer than that. But one thing you can always be sure of is that when it does release such an engine, the technology is something to remember.
In 2023, that something to remember comes as the Screamin' Eagle 135 Stage IV crate engine. It was presented by the Milwaukee motorcycle maker at the beginning of March with grand fanfare, and for good reason. It is, after all, the crate engine with the largest displacement Harley ever made, and also the most powerful street-compliant powerplant.
To put that in numbers, because they are always easier to understand, that would be a displacement of 135ci (it’s in the name, really) and a power output of 130 horsepower at 5,500 rpm and 143 lb.-ft. at 3,500 rpm. For reference, that’s 41 percent more hp and 28 percent more torque than the star of the Harley engine lineup, the Milwaukee-Eight 117.
Somewhat developed with inspiration drawn from the King of the Baggers racing series, which Harley is a major part of, the engine has loads of new parts, elements, and design ideas fitted into it.
For instance, for this unit, in a bid to get the most out of the airflow coming into the engine, Harley devised a 68 mm throttle body complete with a CNC-machined intake manifold. CNC-ported cylinder heads, new 10.7:1 high-compression forged pistons, but also a new flywheel are just a few of the things that went into the project to make the engine the monster that it is.
Photo: Harley-Davidson
The 135 was designed with Touring motorcycles in mind, more precisely those produced after 2021. It’s a type of bolt-on engine that requires no modification to the bike’s frame, but does need a few extra parts, like the head pipes and oil coolers. And at $7,999.95, it is not prohibitively expensive either. Oh, and you can also get it in either black or chrome, depending on your needs and desires.
Many of the details listed above have been known ever since Harley announced the engine, and we’ve already even had a bunch of photos showing what the Screamin' Eagle 135 is all about.
But this week, Harley decided to give us a more intimate presentation of the engine and released a short, two minutes video not only to praise it, but also to give the world a glimpse at the powerplant's entrails and its inner workings.
You can enjoy all that below, but if you were hoping to see this thing being fired up and screaming, you’re in for a disappointment.
Daniel loves writing (or so he claims), and he uses this skill to offer readers a "behind the scenes" look at the automotive industry. He also enjoys talking about space exploration and robots, because in his view the only way forward for humanity is away from this planet, in metal bodies. Full profile
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