2021 Road Glide vs. '13 F6B

[taxfree4]

The Milwaukee 8 is not and never was a racing motor. It is an evolution of the traditional Harley V-twin. The Twin Cam it replaces was a evolution from the Evo and so on all the way back to the Knucklehead. As a result of more efficient combustion and relocation of the catalytic converter the exhaust temps were lowered by 100 degrees.
The last Harley motor with 4 valves per cylinder was the V-Rod, before that the only 8 valve motor Harley produced was the 1916 Model 17 racing motorcycle.

Somebody better tell Harley because they're using it for King of the Baggers racing series. And as far as efficient combustion take a look at a engine tear down after just 500 miles of this engine, they're on YouTube. Every engine Harley ever made is an "evolution" of the previous engine so I don't see the point.