The Mercury Racing 360 APX is a potent competition outboard designed specifically to power Formula 1 tunnel boats in the premier class of the UIM F1H2O World Championship. The 360 APX is tuned to deliver amazing torque from a durable, low-emissions four-stroke V8 powerhead that sets a new benchmark for circuit-racing performance.
A 4.6-liter V8 powerhead is naturally aspirated and features deep-breathing dual overhead cam/four-valve architecture with a short-runner intake manifold mated to a cold-air induction system. An 11:1 compression ratio boosts torque output while the 7000 RPM redline extends the power curve. A dynamic oil pickup system is designed to maintain critical engine oil pressure under high-G loads. A cut-down flywheel, deleted balance shaft and carbon fiber top cowl optimize weight.
To align with the sustainability initiatives of the UIM and F1H2O organizations, this engine offers 90% lower exhaust emissions than current two-stroke racing engines.

MODEL DETAILS
The Mercury Racing 360 APX is a potent competition outboard designed specifically to power Formula 1 tunnel boats in the premier class of the UIM F1H2O World Championship. The 360 APX is tuned to deliver amazing torque from a durable, low-emissions four-stroke V8 powerhead that sets a new benchmark for circuit-racing performance.
A 4.6-liter V8 powerhead is naturally aspirated and features deep-breathing dual overhead cam/four-valve architecture with a short-runner intake manifold mated to a cold-air induction system. An 11:1 compression ratio boosts torque output while the 7000 RPM redline extends the power curve. A dynamic oil pickup system is designed to maintain critical engine oil pressure under high-G loads. A cut-down flywheel, deleted balance shaft and carbon fiber top cowl optimize weight.
To align with the sustainability initiatives of the UIM and F1H2O organizations, this engine offers 90% lower exhaust emissions than current two-stroke racing engines.
Specifications
- Rated Horsepower (HP/kW) 360 / 268
- Measured Propshaft Horsepower360
- Idle RPM750
- Max RPM at Full Throttle 7000
- Cylinders/Engine Configuration V8 [64 degree] with Racing-Specific Dual Overhead Cam [DOHC] and 32-valves
- Displacement (cc)4573
- Displacement (Cubic Inch, CID)279
- Bore & Stroke (mm)92 x 86
- Bore & Stroke (in.)3.62 x 3.39
- Induction System Short-Runner Intake Manifold with Forced Cold Air Induction
- Midsection DesignCircuit Racing Specific 12" Mid Section Direct Mounted with Integral Trim and Lift
- Fuel SystemElectronic Fuel Injection (EFI) Computer Controlled with O2 and Pressure Feedback
- Fuel Requirements Unleaded Premium 91 Octane Minimum (R+M/2) or 98 RON 10% Ethanol Maximum
- Ignition System SmartCraft PCM 112 Digital Inductive
- Charging System 85-amp (1071 Watt)
- Starting 24V Electric Start with SmartStart Protection
- Exhaust SystemAbove Water
- Cooling SystemWater-cooled with Thermostat Control and Integrated Pressure Relief
- Lubrication system Structural Wet Sump with Integrated Baffle System and Oil Cooler
- Oil Requirement Mercury Racing High-Performance Synthetic SAE 10W-30
- Oil Capacity (qts)7
- Oil Capacity (L)6.6
- Engine Management SystemCompetition Spec SmartCraft PCM 112
- Throttle and Shift Controls Digital Throttle
- Engine Protection SystemSmartCraft Engine Guardian with Competition Calibration
- Trim/Tilt SystemPower Trim and Lift with Remote Pumps
- Tilt RangeNA
- Trim Range13°
- Lift Range26 mm [1 in]
- Troll ControlNA
- Gearcase OB IV SSM
- Gearcase Ratio1.13 (15:17)
- Overdrive Ratio0.714 (35:25) | 0.739 (23:17)
- Overall Drive Ratio0.809 | 0.837
- Gear ShiftNA
- Dry Weight (lbs./kg)*430 lbs / 195 kgs *Dry weight refers to base engine without liquids, battery cables, throttle/shift cables, bolt-on steering components, mounting hardware, or propeller/hub kits.
- Steering Angle+/- 30 degrees
- SteeringCable with Wing Plates
- Emissions LevelCARB/EPA 3-Star, EU RCD II
The Mercury Racing 360 APX is a potent competition outboard designed specifically to power Formula 1 tunnel boats in the premier class of the UIM F1H2O World Championship. The 360 APX is tuned to deliver amazing torque from a durable, low-emissions four-stroke V8 powerhead that sets a new benchmark for circuit-racing performance.
A 4.6-liter V8 powerhead is naturally aspirated and features deep-breathing dual overhead cam/four-valve architecture with a short-runner intake manifold mated to a cold-air induction system. An 11:1 compression ratio boosts torque output while the 7000 RPM redline extends the power curve. A dynamic oil pickup system is designed to maintain critical engine oil pressure under high-G loads. A cut-down flywheel, deleted balance shaft and carbon fiber top cowl optimize weight.
To align with the sustainability initiatives of the UIM and F1H2O organizations, this engine offers 90% lower exhaust emissions than current two-stroke racing engines.
Specifications
- Rated Horsepower (HP/kW)360 / 268
- Measured Propshaft Horsepower360
- Idle RPM750
- Max RPM at Full Throttle7000
- Cylinders/Engine ConfigurationV8 [64 degree] with Racing-Specific Dual Overhead Cam [DOHC] and 32-valves
- Displacement (cc)4573
- Displacement (Cubic Inch, CID)279
- Bore & Stroke (mm)92 x 86
- Bore & Stroke (in.)3.62 x 3.39
- Induction SystemShort-Runner Intake Manifold with Forced Cold Air Induction
- Midsection DesignCircuit Racing Specific 12" Mid Section Direct Mounted with Integral Trim and Lift
- Fuel SystemElectronic Fuel Injection (EFI) Computer Controlled with O2 and Pressure Feedback
- Fuel RequirementsUnleaded Premium 91 Octane Minimum (R+M/2) or 98 RON 10% Ethanol Maximum
- Ignition SystemSmartCraft PCM 112 Digital Inductive
- Charging System85-amp (1071 Watt)
- Starting24V Electric Start with SmartStart Protection
- Exhaust SystemAbove Water
- Cooling SystemWater-cooled with Thermostat Control and Integrated Pressure Relief
- Lubrication systemStructural Wet Sump with Integrated Baffle System and Oil Cooler
- Oil RequirementMercury Racing High-Performance Synthetic SAE 10W-30
- Oil Capacity (qts)7
- Oil Capacity (L)6.6
- Engine Management SystemCompetition Spec SmartCraft PCM 112
- Throttle and Shift ControlsDigital Throttle
- Engine Protection SystemSmartCraft Engine Guardian with Competition Calibration
- Trim/Tilt SystemPower Trim and Lift with Remote Pumps
- Tilt RangeNA
- Trim Range13°
- Lift Range26 mm [1 in]
- Troll ControlNA
- GearcaseOB IV SSM
- Gearcase Ratio1.13 (15:17)
- Overdrive Ratio0.714 (35:25) | 0.739 (23:17)
- Overall Drive Ratio0.809 | 0.837
- Gear ShiftNA
- Dry Weight (lbs./kg)*430 lbs / 195 kgs *Dry weight refers to base engine without liquids, battery cables, throttle/shift cables, bolt-on steering components, mounting hardware, or propeller/hub kits.
- Steering Angle+/- 30 degrees
- SteeringCable with Wing Plates
- Emissions LevelCARB/EPA 3-Star, EU RCD II