Exam 12: Upper End Theory and Service

Technician A says VVT [variable valve timing] engines use a cam phaser that advances or retards the camshaft as the engine is running. Technician B says VVT engines use a third cam lobe with increased lift and duration, operating a third rocker arm that is coupled to the two primary rocker arms by a hydraulically controlled pin, while the engine is running. Who is correct?

A single hole in the cylinder head that divides into two branches is called a _____ port.

Installed valve spring height can be adjusted with ____________________.

Hemispherical combustion chambers are being discussed. Technician A says the flame path from the spark plug to the piston head is short, which provides efficient burning. Technician B says cross-flow arrangement of the inlet and exhaust valves allows for a relatively free flow of gases in and out of the chamber. Who is correct?

To ensure proper seating of the valve, the valve seat must _____.

The distance between the valve face and the head of the valve is called the ____________________.

Which of the following is NOT true of knurling?

____________________ support the valve in the head and prevent the valve from moving in any direction other than up and down.

Technician A uses a 30-degree stone for topping a 45-degree valve seat. Technician B uses a 60-degree stone to lower a 45-degree valve seat. Who is correct?

A cylinder head that has the intake manifold and all the intake valves on one side and the exhaust manifold and exhaust valves on the opposite side is called a ____________________type cylinder head.

The hemispherical combustion chamber provides excellent turbulence to the air and fuel mixture.

What is typically the maximum amount of warpage that is acceptable on a cast-iron cylinder head?

To protect against scuffing and wear, some valves have coatings of black nitride applied to the valve stem.

Technician A resurfaces valve seats using a grinding stone. Technician B resurfaces valve seats using a cutting blade. Who is correct?

Valve springs should be checked for all of the following EXCEPT:

Technician A says the end of the valve spring that is wound the tightest should face toward the spring retainer. Technician B says the O-ring seal should be installed in the lowest of the keeper grooves on the valve stem.

_____type valve stem seals move up and down with the valve stems to deflect oil away from the guides.

Installed spring height [the distance between the spring seat and the bottom of the retainer] can be measured with a spring height gauge or ____________________.

Cylinder head warpage can be measured with _____.

Stainless steel is nonmagnetic.