Mercury Racing 400R Specifications
| Engine Model: Mercury Racing 400R |
| Engine Type: 4-stroke 10-cylinder DOHC 40-valve gasoline outboard engine |
| Total Displacement: 349 cu.in (5.7 L) |
| Rated Engine Power: 400 Hp (298 kW) at 6600 rpm |
| Fuel System: Electronic Fuel Injection (EFI) |
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The Mercury Racing 400R represents the apex of
high-performance outboard engineering, delivering 400 Hp from an all-new
naturally aspirated V10 powerplant. This engine replaces the previous
supercharged inline-six 400R with a larger-displacement architecture
that produces more low-end torque, increased peak Hp, and superior fuel
economy while delivering full power on readily available 87 octane fuel.
The 64-degree V10 configuration maintains the compact width required for
26-inch center-to-center mounting on multi-engine transoms, enabling
seamless installations on performance catamarans and high-speed center
consoles. The 400R features the exclusive Mercury Racing Quad Cam Four
Valve (QC4) cylinder head design with a proprietary 92mm throttle body,
producing instant throttle response and a broad 6000-6600 RPM power
band.
The engine is available in four shaft lengths and offers a choice
between the surface-piercing Sport Master gearcase for boats exceeding
85 mph or the 5.44-inch HD gearcase for heavy offshore applications.
With a 150-amp alternator, Advanced Range Optimization, and the robust
Racing Advanced MidSection, the Mercury Racing 400R delivers race-proven
performance and exceptional drivability for the most demanding
high-performance boating enthusiasts.
Power: 400 HP (298 kW).
Full Throttle Operating Range: 6000-6600 RPM.
Displacement: 5.7 Liters, 349 Cubic Inches (CID).
Engine Type: 64-degree V-10, Four-Stroke.
Valvetrain: 40-valve, Dual Overhead Camshaft (DOHC) with Quad Cam Four
Valve (QC4) design.
Bore and Stroke: 3.23 inches x 3.23 inches (82 mm x 82 mm).
Induction System: Naturally aspirated.
Fuel System: Electronic Fuel Injection (EFI) with Advanced Range
Optimization utilizing electronic sensors to precisely adjust the fuel
mixture for optimal efficiency at all speeds.
Throttle Body: Proprietary 92mm throttle body with heavy-duty servo
motor for instant throttle response; Mercury Racing fuel pressure sensor
provides precise fueling under acceleration.
Ignition System: SmartCraft digital inductive with Transient Spark
Technology for digitally adjusted spark timing to optimize low-end
hole-shot torque without sacrificing top-end Hp.
Alternator Output: 150 A (1,890 W) with Idle Charge battery management.
Control System: Digital Throttle and Shift (DTS) standard; compatible
with Mercury Racing Digital Zero Effort controls.
Steering: Available electro-hydraulic power steering; new electric
steering system option for Joystick Piloting for Outboards (JPO)
equipped boats; optional rear tie-bar bracket integral to Racing AMS for
ultra-high-speed applications.
Engine Protection: SmartCraft Engine Guardian monitor system with
over-rev, overheat, and low oil pressure protection.
Starting System: Electric start with SmartStart Protection.
Gearcase Ratios: 1.60:1 for both Sport Master and 5.44-inch HD gearcase
options.
Shaft Lengths: 20 inches (508 mm), 25 inches (635 mm), 30 inches (762
mm), and 35 inches (889 mm) available.
Midsection: Racing Advanced Midsection (AMS) with precision-fitted
heavy-duty guide plates and stiffened engine mounts.
Recommended Fuel: Unleaded Regular 87 Octane Minimum (R+M/2) or 91 RON.
Recommended Oil: Mercury Racing lubricants formulated for
high-performance applications.
Dry Weight: 695 lbs (315 kg).
The foundation of the Mercury Racing 400R is an all-new 64-degree V-10
cylinder block displacing 5.7 liters, engineered from the proven design
architecture of the V8 4.6-liter Mercury Racing 300R model. This
deep-skirt block configuration delivers exceptional structural rigidity
while maintaining the compact width required for multi-engine
installations with 26-inch center-to-center spacing.
The cylinder heads represent the pinnacle of Mercury Racing's
engineering, featuring the Quad Cam Four Valve (QC4) design with dual
overhead camshafts and four valves per cylinder for a total of 40
valves. This advanced four-valve architecture enables optimum breathing
efficiency, maximizing volumetric throughput across the entire RPM
range. The combustion chambers are meticulously engineered to complement
the high-flow intake system and promote complete fuel combustion.
The QC4 design works in concert with the proprietary 92mm throttle body
and tuned intake manifold to maximize airflow and power delivery,
creating the deep-breathing character that defines this engine.
Transient Spark Technology digitally adjusts spark timing to optimize
low-end torque for exceptional hole-shot performance without
compromising the 6600 RPM peak Hp capability.
The Mercury Racing 400R employs a sophisticated naturally aspirated
Electronic Fuel Injection system with proprietary racing enhancements.
The centerpiece of this system is the exclusive 92mm throttle body,
engineered specifically for this engine and featuring a heavy-duty servo
motor designed to produce instantaneous throttle response. A Mercury
Racing fuel pressure sensor provides precise fueling under acceleration,
further enhancing throttle response and ensuring optimal air-fuel ratios
during rapid throttle openings.
The Advanced Range Optimization system utilizes electronic sensors to
continuously monitor operating conditions and precisely adjust the fuel
mixture for optimal efficiency at all speeds, contributing to the
engine's superior fuel economy compared to its supercharged predecessor.
A remarkable achievement of this fuel system is its ability to deliver
full 400 Hp output on readily available 87 octane (91 RON) fuel,
eliminating the need for premium gasoline and reducing operating costs.
The tuned intake manifold is specifically designed to maximize airflow
and work in harmony with the QC4 cylinder head architecture.
The Mercury Racing 400R utilizes an integrated wet sump lubrication
system engineered to withstand the extreme demands of high-performance
operation. A high-efficiency oil pump circulates lubricant under
pressure to all critical components including the crankshaft main
bearings, connecting rod bearings, camshaft journals, and the 40-valve
valvetrain.
This positive pressure system maintains a protective film between moving
surfaces even under sustained high-RPM operation. The use of Mercury
Racing lubricants, specifically formulated for high-intensity marine
applications, is recommended to ensure proper protection and cooling of
internal components.
The industry-exclusive Top Cowl Service Door provides convenient access
to the oil dipstick and fill cap without removing the engine cowl,
simplifying routine oil level checks and maintenance procedures. This
feature is particularly valuable for multi-engine installations where
cowl removal can be cumbersome.
The cooling system on the Mercury Racing 400R is designed to manage the
thermal load of 400 Hp under sustained high-speed operation. The system
utilizes a high-capacity water pump drawing water through
gearcase-mounted pickups, with the configuration depending on the chosen
gearcase option.
Sport Master gearcase models feature low water pickups designed for
surface-piercing operation, while 5.44-inch HD models utilize
conventional water intake locations. A thermostat regulates coolant flow
to maintain optimal operating temperatures for combustion efficiency and
component longevity. The system includes pressure regulation to maintain
adequate cooling flow across all engine speeds and operating conditions.
Overheat sensors interface with the SmartCraft Engine Guardian system to
provide operator warnings and automatic power reduction if cooling
system anomalies occur. The system is engineered to provide consistent
cooling performance whether idling in harbors or running at wide-open
throttle in offshore conditions.
| Mid Section and Lower Unit |
The Mercury Racing 400R features the exclusive Racing Advanced
Midsection (AMS), specifically engineered to meet the demands of
high-performance boat operation. This midsection incorporates
precision-fitted heavy-duty guide plates and stiffened engine mounts
tuned to stabilize the powerhead for enhanced high-speed handling while
still isolating vibration to ensure smooth and quiet operation.
An optional rear tie-bar bracket integrated into the Racing AMS provides
a strong, ultra-light mounting point for rock-solid precision steering
on catamaran and other ultra-high-speed applications requiring precise
control. The exhaust system is tuned to produce an authoritative growl
at startup and idle, providing the auditory experience expected from a
Mercury Racing powerplant.
Two gearcase options are offered for the V10 400R. The race-proven Sport
Master gearcase is a surface-piercing design intended for boats capable
of exceeding 85 mph, featuring low water pickups and a crescent leading
edge to maximize speed and efficiency.
The Mercury Racing 5.44-inch HD gearcase option is ideal for heavy bay
boats and multi-engine performance center console boats requiring a more
submerged gearcase that provides added stern lift. Both gearcase options
feature a 1.60:1 gear ratio, optimized for high-performance
applications.
The Power Trim and Tilt system on the Mercury Racing 400R provides
complete control over engine angle for optimal performance across
varying conditions. The trim function allows precise adjustment of
engine attitude while underway, enabling the operator to optimize boat
trim for maximum speed, fuel efficiency, or ride quality. The system
provides the full range of motion necessary for surface-piercing
operation with Sport Master gearcases, allowing the engine to be raised
for reduced drag at high speeds.
The tilt function raises the engine completely clear of the water for
trailering, launching, beaching, and maintenance access. Adaptive Speed
Control maintains engine RPM as load changes due to sea conditions or
turning maneuvers, maintaining boat authority with reduced control
input. Performance Active Trim technology available through SmartCraft
integration further enhances operational convenience.
The Mercury Racing 400R is designed to work with a comprehensive range
of performance propellers tailored to specific gearcase and application
requirements. The new Mercury Racing Ventera propeller series features a
15-inch diameter, four-blade design engineered specifically to handle
the 400R's power output on fast center consoles, day cruisers, and bay
boats, carrying more load with greater efficiency at high speeds and in
semi-surfacing installations.
For Sport Master gearcase applications, Mercury Racing offers various
propeller options including the Clever-style and other performance
profiles designed for surface-piercing operation. The 5.44-inch HD
gearcase accommodates a range of propeller options suitable for
submerged operation.
The broad 6000-6600 RPM full-throttle operating range provides a
generous window for propping any performance hull type, allowing precise
matching of propeller pitch to achieve optimal engine RPM at wide-open
throttle. A selection of performance-proven Mercury Racing propellers is
available for either gearcase to allow customers to realize the full
potential of specific boat-and-engine combinations.
Dry Weight: 695 lbs (315 kg)
Shaft Length Options: 20 inches (508 mm), 25 inches (635 mm), 30 inches
(762 mm), and 35 inches (889 mm) available to accommodate any single or
multi-engine performance application
Mounting Center-to-Center: The compact 64-degree V-angle allows for
26-inch center-to-center mounting on multi-engine transoms, enabling
seamless installations on new boats and repower applications
The Mercury Racing 400R is designed for straightforward maintenance
despite its high-performance nature. The industry-exclusive Top Cowl
Service Door provides tool-free access to the oil dipstick and fill cap
without removing the entire cowl, simplifying routine oil level checks.
Key maintenance requirements include regular engine oil and filter
changes using Mercury Racing lubricants at intervals specified in the
owner's manual.
Gearcase lubricant requires regular inspection and replacement, with the
interval depending on operating conditions and usage intensity. The
water pump impeller should receive annual inspection with replacement as
needed, particularly important for high-performance applications where
cooling system demand is elevated. Sacrificial anodes on gearcase and
transom brackets require regular inspection and replacement when
significantly eroded to maintain galvanic corrosion protection.
Freshwater flushing after operation in salt water is essential,
facilitated by flushing attachment points. The SmartCraft Engine
Guardian system monitors critical engine parameters and provides
operator alerts through VesselView displays, helping prevent damage
before it occurs. The Mercury Racing QC4 Factory Refresh Program offers
an opportunity to have the original engine builders restore the
powerplant to factory-fresh condition after extended service.
The Mercury Racing 400R is designed for a wide range of high-performance
boating applications. Performance center console boats benefit from the
engine's power density and torque characteristics, enabling speeds well
beyond 75 mph while maintaining excellent drivability. Catamarans and
other ultra-high-speed applications utilize the optional rear tie-bar
bracket integrated into the Racing AMS for rock-solid precision
steering.
Multi-engine installations on offshore performance boats realize the
full potential of the compact 64-degree V-angle allowing 26-inch
center-to-center spacing. Heavy bay boats and multi-engine performance
center console boats requiring added stern lift are ideal candidates for
the 5.44-inch HD gearcase option. Vessels capable of exceeding 85 mph
benefit from the surface-piercing Sport Master gearcase with low water
pickups and crescent leading edge design maximizing speed and
efficiency.
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