| Mazda Motor Corporation
has unveiled a new direct injection 2 litre turbo
diesel engine which the company considers to be
one of the most effective technologies for
helping to solve global environmental problems. Designed for clean combustion and
high economy operation, the new compact diesel
engine uses a highly fuel-efficient direct
injection system.
The result is a smaller
engine size, reduced combustion noise and NOx
emissions similar to the level of indirect
(pre-chamber) fuel injection diesels, making it
an ideal diesel engine for passenger cars.
This compact, 1,998 cc
mrbocharged diesel generates a maximum output of
100 ps at 3,500 rpm (target), and a maximum
torque of 220 Nm at 2,000 rpm (target). This is a
14 percent and 18 percent increase, respectively,
over the conventional engine on which it is
based. This new diesel engine scores an
impressive 5.2 litre/100kin fuel consumption rate
at 120 km/hour (target).
The advanced diesel also
has a new combustion system that employs
innovative centre fuel injection technology, a
four-valve-per cylinder design and an electronic
fuel injection system which places the fuel
injection nozzle at the centre of the combustion
chamber to inject fuel uniformly
These features give this
engine the quick ignition of indirect injection
engines at the start of combustion and the high
pressure fuel-air combustion of direct injection
engines during the main propagation period.
The system also improves
fuel atomization for better ignition, inhibits
rapid combustion at the start of the combustion
cycle, and reduces noise and NOx emission. Fuel
is also distributed more uniformly promoting even
combustion and improving output.
Each cylinder has two
intake and two exhaust valves to increase the air
intake to the engine and decrease resistance to
exhaust flow. This design improves the
intake-exhaust resistance coefficient by
approximately 50 percent compared with
conventional two-valve technology. Output is
improved and black smoke and particulate are also
reduced because the fuel is burned with more air.
The electronic fuel
injection system constantly monitors changes in
vehicle operation, including the accelerator
position and vehicle speed, to optimally control
the amount and timing of fuel injected.
Noise and Nox emissions are
reduced under partial engine load conditions
because the fuel injection timing is delayed
according to the load, thereby improving
combustion.
From outside a vehicle, the
new engine is "seen" to be cleaner
because under full load conditions, the amount of
fuel injected is maximized without increasing
black smoke.
The new direct injection
diesel engine will be fitted to Mazda 626
vehicles in Japan and Europe from mid 1998.
Major Specifications
- Type: In-line
4-cylinder, 16-valve, water cooled, with
turbocharger
- Displacement (cc):
1,998
- Bore x stroke (mm):
86.0 x 86.0
- Max. output (ps/rpm):
100/3,500 (target)
- Max. torque (Nm/rpm):
220/2,000 (target)
- Fuel supply system:
Electronically-controlled fuel injection
|
