Exam 7: Cylinder Head: Parts and Service

List two methods of head resurfacing.

What is the maximum amount of warpage allowed on an aluminum head before it must be resurfaced?

When repairing a crack, what should be done to both ends of the crack to prevent it from growing larger?

Why are valve guides reamed without lubricant?

Before using a valve spring compressor, what part of the valve and spring assembly should be struck with a short piece of pipe and a hammer?

Would smoke during deceleration most likely be traced to the seal for the intake or exhaust guide?

An engine has excessively worn exhaust guides. Technician A says to look for weak or short exhaust valve springs. Technician B says that this can cause excessive crankcase pressure. Who is right?

What caution is necessary when setting an OHC head on a bench?

Which cylinder heads should not be cleaned by glass beading?

When repairing valve guides, what are two reasons that integral guides are used with iron heads?

Briefly distinguish between a head called a stock replacement and a bolt-on head.

Technician A says that Magnaflux is a crack detection method that is commonly used on aluminum heads. Technician B says that bead blasting is the preferred method for cleaning OHC heads. Who is right?

An engine has excessive valve guide wear. Technician A says to ream the guide and install a new valve with an oversized stem. Technician B says to knurl the valve stem and reinstall it in the guide. Who is right?

Technician A says that valve stem-to-guide clearance can be measured using a dial indicator. Technician B says that valve stem-to-guide clearance can be measured using a feeler gauge. Who is right?

A cylinder head has required substantial metal removal to make it flat. Technician A says that a shim can be installed under the head gasket to compensate. Technician B says that on OHC engines, the valve timing will be retarded. Who is right?

An engine has a warped cylinder head. Technician A says that this could be caused by running the engine with a faulty thermostat. Technician B says that this could be because the engine was overheated. Who is right?

Valve guides can be driven in using an air chisel or hammer.

Technician A says in case of extremely hard carbon deposits, an old valve can be used to break off carbon before cleaning. Technician B says some valve spring compressors can be used on or off the car. Who is correct?

Technician A says knurling is a metal displacement process not a cutting process. Technician B says that guides worn as much as 0.012" can be successfully knurled. Who is correct?

Aluminum melts at 750 degrees Fahrenheit.