BASIC VEHICLE TECHNOLOGIES 2: ENGINES Exam Questions And Answers

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