Mercury Racing 200 APX Specifications
| Engine Model: Mercury Racing 200 APX |
| Engine Type: 4-stroke 6-cylinder DOHC 24-valve gasoline outboard engine |
| Total Displacement: 209 cu.in (3.4 L) |
| Rated Engine Power: 200 Hp (149 kW) at 6800 rpm |
| Fuel System: Electronic Fuel Injection (EFI) |
____________________________________________________________________________________
The Mercury Racing 200 APX is a purpose-built
competition outboard engineered exclusively for UIM F2 and APBA OPC
tunnel boat racing. Rated at more than 200 Hp, this 3.4-liter V6
four-stroke represents Mercury Racing's first V6 four-stroke outboard
and a significant technological leap for circuit racing. Its defining
characteristic is the combination of a potent, high-rpm powerhead with a
specialized overdrive gearset and the evolved Super Speed Master IV SSM
gearcase, creating a system that delivers the power and propeller speeds
required for competition while achieving a 90 percent reduction in
exhaust emissions compared to legacy two-stroke racing engines.
The engine produces approximately 20 percent more torque than its
two-stroke predecessor, but at lower RPM, allowing teams to utilize
existing propeller inventories - a substantial cost saving. With a
lightweight carbon fiber cowl, forced cold air induction, and a robust
12-inch circuit-specific midsection, the 200 APX is engineered for the
extreme demands of tunnel boat competition, where boats accelerate from
zero to 100 km per hour in just over five seconds and reach speeds
approaching 190 km per hour.
Engine Type: 64-degree V6, Four-Stroke with Dual Overhead Cam (DOHC) and
24 valves
Power: More than 200 HP (149 kW) at the propshaft
Displacement: 3.4 Liters (209 cubic inches)
Compression Ratio: 11:1, increased from the base engine's 10:1
compression for competition performance
Full Throttle RPM: 6800 RPM
Idle RPM: 750 RPM
Induction System: Long-runner intake manifold with forced cold air
induction integrated into the carbon fiber cowl
Fuel System: Competition-tuned Electronic Fuel Injection managed by
SmartCraft PCM 112
Fuel Requirement: Unleaded 91 Octane minimum (R+M/2) or 98 RON with E10
maximum ethanol content
Ignition System: Competition Spec SmartCraft PCM 112 Digital Inductive
Alternator Output: 85 A / 1071 W
Starting System: 24-volt electric starting system for rapid and reliable
ignition
Throttle Control: Digital throttle control (DTC) for precise,
instantaneous response
Engine Management System: Competition Spec SmartCraft PCM 112 with
specialized racing calibration
Engine Protection System: SmartCraft Engine Guardian with Competition
Calibration, monitoring critical sensors and adjusting power delivery to
prevent damage under extreme conditions
Emissions Reduction: 50 percent reduction compared to Mercury Racing 200
XS OptiMax, 90 percent reduction compared to legacy SST 120 two-stroke.
Steering Angle: +/- 30 deg steering range for precise control in
competition.
The foundation of the 200 APX is its advanced 64-degree V6 powerhead,
derived from the Mercury Marine 3.4-liter production engine but
extensively modified for racing duty. The 64-degree cylinder angle
provides inherent balance while maintaining a compact profile essential
for tunnel boat applications where space is at a premium. The cylinder
heads incorporate dual overhead camshafts (DOHC) operating four valves
per cylinder, a 24-valve architecture that optimizes airflow and
combustion efficiency for maximum power output at elevated engine
speeds.
To prepare the engine for competition, Mercury Racing elevates the
compression ratio from the stock 10:1 to 11:1, increasing cylinder
pressures and thermal efficiency for greater power production. A
lightweight flywheel allows the engine to accelerate more rapidly than
the stock motor, a critical attribute for the explosive acceleration
demands of circuit racing. The carbon fiber cowl incorporates forced
cold air induction, ducting dense, cool air directly to the intake to
maximize volumetric efficiency and power output. The entire powerhead is
engineered to withstand the sustained high-RPM operation and extreme
thermal loads encountered during competition.
The heart of the 200 APX is its competition-tuned Electronic Fuel
Injection system, managed by the SmartCraft PCM 112 engine control
module. This advanced fuel delivery architecture utilizes the 24-valve
DOHC configuration to optimize cylinder filling and combustion
efficiency across the 6800 RPM operating range. The system is calibrated
specifically for racing applications, delivering precise fuel metering
under the extreme acceleration and high-RPM conditions encountered on
the race course.
The fuel system is designed to operate on readily available 91-octane
pump gasoline with up to 10 percent ethanol content, reducing logistical
complexity for race teams while maintaining competitive power output.
This represents a significant advancement over racing engines requiring
specialized, hard-to-source fuels.
The 200 APX employs a structural wet sump lubrication system with an
integrated baffle system designed specifically for the high lateral and
longitudinal accelerations experienced in tunnel boat racing. The oil
capacity is 6.6 liters (approximately 7.0 quarts). Mercury Racing
engineered a new high-performance full-synthetic lubricant specifically
for this engine: Mercury Racing 10W-30 MRX engine oil.
This oil is formulated to withstand the extreme heat and stress the
engine encounters during tunnel boat competition, maintaining viscosity
and protective properties under sustained high-RPM, high-load operation.
The structural wet sump design integrates the oil reservoir within the
driveshaft housing, contributing to the engine's compact overall package
while ensuring reliable oil delivery under all racing conditions.
The cooling system on the 200 APX is a water-cooled design with
thermostat control and integrated pressure relief, engineered to
maintain consistent operating temperatures under the extreme thermal
loads of competition. The system incorporates features to ensure
adequate cooling capacity during sustained high-RPM operation, including
integrated pressure relief to manage flow rates.
The above-water exhaust system not only provides unrestricted flow for
maximum performance but also produces an exciting tone appreciated by
racing fans. The exhaust exits above the water surface, reducing back
pressure and enhancing power output while contributing to the
distinctive sound of racing outboards.
| Mid Section and Lower Unit |
The mid section of the 200 APX is a 12-inch, circuit-racing-specific
assembly shared with the Mercury Racing 360 APX V8 competition outboard.
This robust housing incorporates a structural wet sump driveshaft
housing with integrated power trim and lift operated by remote pumps.
The lift range is 26 mm, allowing precise vertical adjustment of engine
height for optimal performance. The midsection is designed to
accommodate the extreme loads of tunnel boat racing while providing the
adjustability required for fine-tuning race setup.
The lower unit features an evolved Mercury Racing Super Speed Master (IV
SSM) outboard gearcase, a direct-drive unit with no neutral or reverse
shifting, reflecting its pure competition purpose. This gearcase is
engineered for minimum drag and maximum strength at high speeds. To
achieve the propeller speeds required for competition - matching the
8000 RPM propeller speeds of the two-stroke racing outboards presently
used in F2 and OPC - the 200 APX incorporates an overdrive spur gearset.
This overdrive ratio is 0.818 (22:18), with an overall drive ratio of
0.927, increasing input shaft speed to the gearcase and producing the
desired left-hand propeller rotation. This engineering solution allows
the engine's higher torque at lower RPM to be converted into the
propeller speeds necessary for competition, enabling most teams to
continue using their existing propeller inventories.
Mid section Length: 12 inches (305 mm), circuit racing specific
Gearcase: Mercury Racing Super Speed Master (IV SSM), direct-drive, no
neutral or reverse
Overdrive Ratio: 0.818 (22:18)
Overall Drive Ratio: 0.927
Lift Range: 26 mm
Propeller Rotation: Left-hand
The 200 APX incorporates a race-specific power trim and lift system with
integrated hydraulics and remote pumps. The maximum trim range is 13
deg, providing the adjustment range necessary for optimizing boat
attitude and performance under varying race conditions. Unlike
recreational outboards, the 200 APX has no tilt range specification, as
the system is designed specifically for competition setup rather than
trailering or shallow-water operation.
The trim and lift system is integrated into the structural midsection,
providing the adjustability required for fine-tuning race boat setup
while maintaining the rigidity essential for high-speed stability.
Remote pumps operate the hydraulic system, allowing precise control of
engine height and trim angle during race setup and, where rules permit,
during competition.
Propeller selection for the 200 APX is a critical performance
consideration, and Mercury Racing engineered the powertrain specifically
to accommodate existing race propeller inventories. The 200 APX produces
approximately 20 percent more torque than the two-stroke racing outboard
it replaces, but at a lower engine speed.
The overdrive gearset (0.818 ratio) converts some of this torque to
increase propeller RPM, matching the 8000 RPM propeller speeds of the
two-stroke engines previously used in F2 and OPC competition. This
engineering approach allows most race teams the opportunity to use the
same propellers they have been fitting to their two-stroke motors,
representing a significant cost savings. The IV SSM gearcase is designed
for left-hand propeller rotation, matching the requirements of tunnel
boat racing applications.
Specific propeller pitch and diameter recommendations depend on boat
setup, race course conditions, and team preferences, with the gearcase
and overdrive system providing the flexibility to optimize performance
across a range of propeller options.
Dry Weight: 395 lbs (179 kg).
Shaft Length: The engine utilizes a 12" (305 mm) midsection specifically
designed for racing.
Overall Dimensions: Compact V6 packaging optimized for tunnel boat
installations.
Engine Oil: Mercury Racing 10W-30 MRX high-performance full-synthetic
oil, specifically formulated for this engine. Oil Capacity: 6.6 liters
7.0 quarts). Cooling System: Water-cooled with thermostat control and
integrated pressure relief requiring regular inspection and maintenance.
Fuel System: Designed for 91-octane pump fuel, simplifying logistics
compared to specialized racing fuels. Engine Guardian System: SmartCraft
Engine Guardian with Competition Calibration monitors sensors and can
reduce power to protect the engine if faults are detected.
Warning System: Audible alert horn integrated into helm harness,
providing continuous tone for critical faults requiring immediate
attention. Break-In Requirements: Specific break-in procedures must be
followed for new engines, including operating within prescribed RPM
ranges and monitoring critical temperatures before full-throttle
operation.
The Mercury Racing 200 APX is designed for a singular, highly specific
application: UIM F2 and APBA OPC tunnel boat racing. These are carbon
fiber tunnel boats weighing just over 510 kg (approximately 1,124 lbs)
including the engine and driver. The boats measure approximately 16 feet
(4.8 meters) in length and are capable of accelerating from zero to 100
km per hour (62 mph) in just over five seconds, with top speeds
approaching 190 km per hour (118 mph). Up to 20 boats compete
simultaneously on race courses, navigating spray and wakes in high-speed
competition.
____________________________________________________________________________________
| Outboard Engines Technical Specifications |
| Small Engines Technical Specifications |
| Car Engines Technical Specifications |
| Industrial Engines Technical Specifications |
