Mercury Racing’s Director of Engineering, Jeff Broman, gives a technical walk-through of the 360 APX competition outboard.
This powerhouse V8 four-stroke outboard is designed specifically for the UIM F1H2O World Championship.
The 360 APX outboard is the first model in a new Mercury Racing Apex Series of outboards designed for closed-course competition.
The engine is normally aspirated and retains its double overhead cam/four-valve architecture.
The compression ratio is increased from 10:1 to 11:1 and peak rpm is boosted from 6400 RPM to 7000 RPM. The engine calibration is modified to take full advantage of the powerhead modifications.
The 360 APX uses a 24-volt starter for faster dock-side starting in competition.
A digital control offers smooth and precise throttle application. Additionally, this engine offers 90% lower emissions than current two-stroke racing engines.
An evolved version of the Mercury Racing Super Speed Master (IV SSM) outboard gearcase is direct-drive with no neutral or reverse shifting.
Above-water exhaust offers unrestricted flow and produces an exciting tone for racing fans.
The motor is equipped with integrated, light-weight steering arms for tunnel boat cable steering. The top cowl and driveshaft housing covers are lightweight carbon-fiber composite.