More than a biker is curios to know how a Stage II performs on the latest of Harley-Davidson Big Twin. Stage II means an engine in which new cam was installed in addition to the canonical air cleaner, exhaust and mapping of the Stage I. No displacement increases, no high-compression pistons or oversized throttle bodies. Straightforward Stage II without frills.
In this case I am talking about a Low Rider S 114″ equipped as follows:
- Screamin’ Eagle air filter
- 2-in-1 Thunderheader exhaust system
- Andrews M8 464 cam
The new Milwaukee Eight engine was introduced in 2017 and since that time a wide range of cams suited to almost all riding styles and biker’s preferences has been produced by many manufacturers of performing parts.
In this case the cam installed is an Andrews M8 464 that gives its best at medium/high rpm and this could be the worst case. In fact almost all of us love to ride our light-like-dragonflies Harleys pushed by the powerful torque already delivered from 1600 rpm.
At the end of the tuning process made with Power Vision on a DynoJet dyno I obtained the dyno graph published below. At a quick look of the graph the bike could appear too weak under 3000 rpm but focusing on the graph it is clear that starting from 1600 rpm the engine delivers 135 N-m of torque. Numbers similar to those of a John Deere.
The final numbers are 112 hp of peak power and 168 N-m of peak torque measured at the rear wheel.
Not bad at all for a basic cam upgrade.