it's should . my 103 with cams and ported heads makes 120

 

The 120R has the highest lift and overlap cam that H-D offers. The compression ratio is 10.5 with an optional piston of 12:1. Then an intake manifold of 58, 62 or 64 mm can be done. Injectors to 6.7 grams are available.

Of Course other pistons in the aftermarket have a range of ratios.

Most in the past used the now defunct H-D race tuner for strip or track. Again the aftermarket still has race tuners like TTS.

The 10.5:1 with the right combo of intake, injectors and tune have repeatedly seen 138. The H-D 12:1 pistons have hit 150.

The 120R in the picture is 138 hp and is in my 13 Dyna Street Bob platform.

The 120ST which is identical to the R except with a milder cam but the correct intake manifold, injectors and race tune it does 122 hp.

That is what is in the Freewheeler pictured on the lift being installed. It runs amazingly.




Collectively they have 15,000 miles between them. No issues. And so far no tickets.

 

2012 CVO Roadglide with 120r. Six gears are not enough. Added a Baker 7 then changed front sprocket from 31 to 33 teeth. Sixth gear is now about same ratio to rear wheel and 7 is a great "overdrive" so now I'm not constantly looking for another gear. Problem is that Harley only lets you set cruise control to 95. As soon as you go over it shuts off the cruise. I can cruise for hours between 115 and 120 mph. I just wish I didn't have to hold the throttle. By the way it beats my SE 110 for fuel efficiency!

 

 

This thread started many years ago, since when S&S has introduced their 143" twincam engine, so scope for yet more performance! They also have their new 124" and 128" M8 kits. So much to do, so little time....