BASIC VEHICLE TECHNOLOGIES 2: ENGINES
For vehicles with a Cummins® V8 diesel engine, how will a driver know if the Diesel Exhaust Fluid (DEF) level is low?
-A gauge in the instrument cluster shows the DEF level -A warning light illuminates when the level is low
How does Nissan's Dual Injector System compare to single injector systems?
-Delivers a finer spray -Creates a wider fuel injector spray pattern
What does a variable-flow exhaust system do?
-Gives the engine more exhaust back pressure to help with low-end torque -Uses a special internal valve that opens and closes according to exhaust pressure -Allows more air to exit the muffler to improve high-speed performance
What technologies does Nissan use to reduce friction inside various engines?
-Hydrogen-free diamond-like carbon coating is used on valve lifters -Microfinishing puts ultra-smooth finish on rotating surfaces of components
What is the reason for reducing friction in an engine?
-Improves efficiency, power, and reliability -Results in less heat and vibration
What are the advantages of the compacted graphite iron (CGI) cylinder block in the Cummins® V8 diesel engine compared to traditional iron?
-Lighter -Stronger
What are the benefits of Nissan's Dual Injector System?
-More fuel-efficient than single injector systems -Helps increase horsepower and torque
What's the benefit of timing chains?
-No maintenance inspections or replacement for service life of engine -More precise and reliable actuation of the camshafts
What are the benefits of lightweight engine components?
-Reduce vibrations -Make engine more responsive -Reduce overall engine weight
What are the advantages of supercharging?
-Relatively small fuel economy penalty -Increased horsepower and torque across the complete engine operating range -Immediate throttle response
What does a cylinder head do?
-Seals the top of the cylinders -Contains intake and exhaust valves
How does the vehicle immobilizer system guard against car theft?
-Verifies key code from microchip ID -Will not allow the engine to start without a special key
What is the compression ratio range in the Variable-Compression Turbo (VC-Turbo) engine?
8:1 to 14:1
What drives a supercharger?
A compressor driven by an accessory belt
What is the advantage of turbocharging in small-displacement engines?
Can enhance on-demand performance without sacrificing fuel efficiency
What does an intake manifold do?
Channels fresh air into the cylinders
What does a crankshaft do?
Converts linear motion from the pistons into rotating motion
What helps to give the MR16DDT 4-cylinder engine the power of a larger engine?
Direct Injection Gasoline and turbocharging
What feature of the HR16DE 4-cylinder engine helps to enhance fuel efficiency and reduce emissions?
Dual Injector System
What is the benefit of the Active Torque Rod in the Variable-Compression Turbo (VC-Turbo) engine?
Helps reduce engine noise and vibration by producing counterbalancing vibrations
How long does it take for the ceramic glow plugs in the Cummins® V8 diesel engine to warm each cylinder in cold weather?
Less than 4 seconds
How does variable valve timing improve performance?
Opens and closes the intake or exhaust valves at different times depending on engine load
How does a turbocharger improve performance?
Puts more oxygen into the combustion chamber
A low-friction piston coating helps ________ caused by the pistons sliding up and down the cylinder wall.
Reduce energy losses
What is turbo lag?
The delay between accelerator pedal application and turbo boost reaching the cylinder
The Cummins® V8 diesel engine uses a two-stage turbocharger system which helps reduce ____.
Turbo lag
How does a variable-flow intake manifold help promote low-end torque at low to mid engine speeds?
Uses a longer airflow path, forcing a larger amount of air into the engine
What drives a turbocharger?
exhaust gases
