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WINTER 2015 | MARINE TECHNICIANTODAY
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THE
PERFORMANCE
CORNER
Y
es that is
c o r r e c t ,
M e r c u r y
Racing has entered
into the automotive
crate engine sales
business. This really
all began back in
2010 with their
release of the quad cam four valve 1100 and 1350
sterndrive marine engine packages, commonly
called the QC4v. Following that in 2013 Mercury
Racing released the QC4v 1650 Race engine for
the offshore powerboat racing circuits. The 1650
with closed cooling provides more consistent
temperature distribution throughout the engine,
providing optimal running quality and longer
engine life. Along with closed cooling they added
a ball bearing supported turbocharger compressor
shaft to enhance the 1650 turbo’s performance
and durability. Also Mercury Racing’s proprietary
pulse separated exhaust tuning keeps the turbos
spooled up eliminating throttle lag and maintains
high torque levels.
The Mercury Racing 1650 V-8 engine block has
a 9.0 L (552 cubic inches) displacement with a
90 degree DOHC (Double Over Head Cam). The
block and heads are aluminum, achieving a
big reduction in weight compared to cast iron.
Durable NiCom coated aluminum cylinder bores
improve heat transfer and durability. Quad cam
with 4 valves per cylinder optimizes power
and torque throughout all rpm ranges and the
overhead cam design extends the operating rpm
range. Specific specifications are:
• Rated horsepower at the transmission is 1650 hp
• Bore 4.57 inches / 116 mm
• Stroke 4.21 inches / 107 mm
• Compression Ratio 7.8:1
• Full Throttle RPM 6500 - 6800
• Alternator output 105 amp /1481 watt
• Fuel System is Sequential Injection with
fuel octane requirements of 112 AKI Octane
Sunoco Race Fuel or an equivalent.
• Transmission Mercury racing dry sump hydraulic
• Outdrive is the M8 dry sump
• Gear ratio is dependent on specific application
The 1650 can be ordered in a long block form
and includes the timing cover and dry sump
oil pan. The total weight is 640 lbs. A full
long block can be ordered that comes with
intake manifold, throttles, crank damper and
oil pump with a weight of 699 lbs. A turn-
key key 1650 engine package for supercar
applications can be ordered with harnesses,
alternator, starter, twin turbocharges, water
to air charge air cooler with a copper nickel
core, and exhaust headers, weighing in at 935
lbs. These new QC4v engines are all designed
and manufactured at Mercury Racing located
in Fond Du Lac, Wisconsin. Mercury Racing
has installed a complete turn-key 1650 QC4v
engine package in an Ultima GTR Super Kit
car that has been displayed and run in various
markets including the SEMA show.
When Mercury racing developed these QC4v
engines they realized that for the marine
applications a new larger stronger outdrive
and transmission was needed to handle
the massive torque and horsepower. The
new drive is called the M8 and it is mated
to a newly designed hydraulic transmission
strong enough to handle the tough marine
offshore requirements. This all is linked with
a Smartcraft DTS (digital throttle & shift)
system that features one touch smart start
and automatic throttle synchronization, as well
as a shadow mode for triple or quad engine
applications. The engines are controlled with
Mercury zero off digital controls.
The surface piercing M8 gear case is a dry
sump outdrive and is 2 inches shorter than
the dry sump Number Six drive, allowing the
engine to be mounted lower in the engine
compartment. The benefit of this is a lower
center of gravity, improving boat handling and
overall performance. The M8 outdrive features
a race inspired twin pinion gear shaft design
and forged gears. This designed was first
patented by Mercury for the outboard racing
back in the 1950’s. The innovative design splits
Mercury Racing and the Performance Automotive Engine
By John Mosetti
q
Mercury Racing
1650 Automotive
complete engine
package
t
Mercury Racing
1650 complete
marine package
u
Mercury Racing
1650 intake
cut away
q
Mercury Racing key fob system for
changing horsepower levels 1350 to 1550