Still a dry sump, oil is now filtered before it is routed to the engine, ensuring that cleaner oil gets to key areas. As temperature and oil pressure increase, oil jets in the crank case spray oil under the pistons, reducing piston temperatures by up to 50 degrees, an innovation for Harley, although not for the rest of the motorized world. A strengthened and redesigned vertical, four-bolt rear interface connects the engine to the transmission. The result is a more rigid connection between the powertrain and chassis, reducing stress to the inner primary and is very good news to customizers that have had to brace the primary to prevent cracking due to the increased stresses of Evo horsepower hop-ups. A redesigned tappet guide is machined into the crankcase, adding structural strength, improving airflow and facilitating the evacuation of oil from the top of the engine.
Tappets are now steel rather than cast iron.
Enough is enough. Well, it feels good, really good. Customizers should be very excited about this engine. Although there, the difference seemed subtler than might have been thought. The Twin Cam-equipped Dyna Wide Glide, the Evo version of which was recently familiar in our minds, was all the more fun and felt great through the winding roads of Zion National Park.