Exam 6: Cylinder Heads and Valve Train Mechanisms

While installing a cylinder head, technician A says the threads in cylinder head bolts must be lubricated before installation. Technician B says that only the underside of the bolt head requires lubrication and that the threads only need be clean. Who is correct?

Excessively worn valve train components are more commonly found on which valve actuation mechanism?

The maximum allowable warpage for a cylinder head is approximately ___________.

What color is the diesel exhaust when the valve guides are worn?

The most common valve angle for poppet valves is ______.

The purpose of a variable intake swirl mechanism is to __________.

Technician A says that some OEMs (original equipment manufacturers) require that diesel engine cylinder head bolts be loosened in a specified pattern. Technician B says that some cylinder head bolts must be discarded after use. Who is right?

Technician A says that overhead cam engines with unit injectors can provide the greatest actuation force for the highest injection pressures. Technician B says that pushrod engines that use a low-mounted camshaft can provide the same force as an overhead camshaft engine to its unit injectors. Who is correct?

The most common valve angle for poppet valves is ______.

Technician A says that continual pounding of the valve faces and seats can take place whenever valves are out of adjustment. Technician B says that maintenance of cylinder heads is often required when coolant or combustion leaks occur. Who is right?

What can be eliminated through the use of direct acting finger-type cam followers?

Which valve guide in a turbocharged diesel engine will more likely not have valve stem seals?

Which of the following is the most common method for achieving consistent head gasket clamping force on today's diesel engines?

What ensures that more of the twisting force used to tighten a bolt turns the bolt and is not lost to friction on the bolt threads instead?

_____ is a comparison of the distance between the rocker shaft or fulcrum point of the rocker arm and the distance to each end of the rocker arm.

Technician A says that overhead camshaft engines will often use two camshafts to optimally locate valves and ports on either side of the cylinder head. Technician B says that two camshafts eliminate the need for long rocker levers and rocker shafts. Who is right?

Technician A says that there are two varieties of crossheads: guideless nonadjustable and adjustable crossheads. Technician B says that crossheads are also called yokes or bridges. Who is right?

A valve adjustment is being discussed. Technician A says that you must first locate original equipment manufacturer (OEM) service literature for valve adjustment procedures. Technician B says that lash should be adjusted on a warm engine. Who is right?

Technician A says that integral valve guides cast into the cylinder head are removable. Technician B says that the condition of a valve guide is critical to oil consumption control. Who is right?

Which of the following transmits the cam actuation force from the followers to the rocker levers?