Exam 38: Natural Gas, Propane, and Biodiesel Fuels

Technician A says that the Westport CNG-DI Mono injector is designed to inject liquefied fuel. Technician B says that the Westport CNG-DI Mono injector is designed to inject gaseous fuel. Who is correct?

In which geographical area does biodiesel have the most acceptance?

Technician A says that natural gas (NG) is lighter than air. Technician B says that NG quickly disperses when released to atmosphere making it relatively safe. Who is correct?

What is used to ignite the gas charge in a Westport LNG engine using HPDI injectors?

Technician A says that engines fueled with NG require special crankcase lubes. Technician B says that NG fueled engines require more frequent service intervals than equivalent diesel fueled engines. Who is correct?

Which of the following companies specializes in converting diesel fueled engines to NG fueling?

When biodiesel is used to fuel commercial vehicles which US federal standard must the fuel comply with?

If the same volume-sized container of each of the following fuels was to be used, which would allow you to travel furthest using today's technologies?

Technician A says that when biodiesel is used in place of petroleum base diesel fuel engine power is increased by approximately 10%. Technician B says that HC emissions are reduced when biodiesel is used as an alternative to diesel fuel. Who is correct?

What pressure must compressed natural gas (CNG) be stored at in vehicle fuel tanks?

What is the time period required for electrically charging the coil in a CNG spark-ignited (SI) engine known as?

Technician A says that B100 standard biodiesel has better cold climate handling properties than B20. Technician B says that B20 standard biodiesel produces generally lower emissions than current petroleum stock diesel fuels. Who is correct?

?When waste spark ignition is used on an engine, when is the waste spark delivered to the engine cylinder?

Technician A says that when compressed natural gas (CNG) is used to fuel a modified diesel engine, a means of igniting the fuel charge must be provided. Technician B says that propane does not auto-ignite in a compression-ignition engine. Who is correct?

Which of the following best describes the type of vehicle fuel tank required to store LNG?

Technician A says that biodiesel burns more cleanly with zero sulfur emissions than equivalent petroleum base diesel fuels. Technician B says that biodiesel has higher calorific value producing better fuel economy than petroleum base diesel fuel. Who is correct?

Technician A says that when a diesel engine is adapted for LNG fueling using Westport HPDI injectors, a special camshaft is required. Technician B says that Westport HPDI injectors are capable of multipulse fueling events. Who is correct?

Which OEM has optioned dimethyl ether (DME) fuel engines ?

What is the primary input reference signal to the ECM responsible for triggering spark delivery to a CPI system on a commercial vehicle NG engine?

What temperature is LNG stored at in vehicle cryogenic fuel tanks?