With the launch of the Screamin’ Eagle 135 Stage IV Performance Crate Engine, Harley-Davidson has delivered the thickest and most extreme V-twin ever. The figures: 130 hp and 194 Nm from a displacement of 2,212 cc.
Where Suzuki has completely withdrawn from motorsport, to concentrate fully on zero-emission drives and there is no longer a link between motorsport and production motorcycles, they have done exactly the opposite at Harley-Davidson.
The Bagger race on the other side of the Atlantic once started as a joke as a side program of the MotoAmerica road race championship has now grown into a serious racing class. Because it doesn’t matter what you race with, as long as you make sure you start with similar engines.
The MotoAmerica Mission King of the Baggers road racing series has led Harley-Davidson to revamp its Milwaukee-Eight V-twin to once again beat arch-rival Indian, who took home the title last year.
Developed and tested by Harley-Davidson Powertrain Operations in Menomonee Falls, Wisconsin, the Screamin’ Eagle 135 Stage IV Performance Crate Engine is essentially a high-performance Milwaukee-Eight V-twin.
In addition to the engine, Harley also offers the new wireless Screamin’ Eagle Pro Street Performance Tuner, the only kit available that gets the most out of the 135ci V-twin while meeting US emission standards and under warranty. .
The block has been developed to run at full throttle at high speed and to deliver instant power from revs to overtake. The numbers don’t lie: Harley claims a maximum torque of no less than 194 Nm at 3,500 rpm and a top power of 130 hp at 5,500 rpm. That’s about 28% more torque and 41% more power than the Milwaukee-Eight 117.
What exactly did they change to the block? For starters, both the bore and stroke have been increased from 103.5 x 114.3mm to now 109.5 x 117.5mm, with proprietary coated cylinder liners and a new flywheel. To get more air into the cylinders, a 68mm throttle body with matching CNC-machined intake manifold is mounted.
Of course, the intake and exhaust ports in the cylinder head have also been machined for more efficient filling, high-performance valve springs have been used and a sportier camshaft with a more aggressive profile has been fitted. A Screamin’ Eagle Pro Billet Cam Plate and oil pump provides increased oil pressure to minimize oil pressure drop caused by hot oil.
Not enough yet? In addition to the high-lift camshaft with high-performance bearings and high-performance tappet bushings, the block is fitted with new 10.7 high-compression forged pistons and Harley has fitted new high-capacity injectors capable of injecting 6.8 grams of fuel per second.
Finally, a Screamin’ Eagle Ventilator Extreme Air Cleaner air filter and Screamin’ Eagle Street Cannon rear mufflers can also be mounted, but that is not strictly necessary.
The block retails in the United States from $7,995.95, excluding assembly, of course. Available in two different versions, for 2021 Touring models with oil/air-cooled Milwaukee-Eight V-twin and for 2021 Touring models with Twin-Cooled Milwaukee-Eight V-twin.
Whether the block will also be available in Europe is unknown, but since it is not suitable for California models in the US, we strongly believe that the 135ci V-twin will not meet the emission requirements in Europe either.
– Thanks for information from Motorfreaks.