| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.33 |
| Score | 0% | 67% |
Ignition timing is measured in number of degrees:
before top dead center |
|
after bottom dead center |
|
after top dead center |
|
before bottom dead center |
Ignition timing defines the point in time at the end of the compression stroke that the spark plug fires. Measured in number of degrees before top dead center (BTDC), the exact point that the spark plugs initiate combustion varies depending on the speed of the engine. The timing is advanced (the spark plugs fire a few more degrees BTDC) when the engine is running faster and retarded when it's running slower.
Engine oil viscosity is rated using the format XW-XX with the number preceding the W indicating viscosity at __________ ℉ and the XX indicating viscosity at __________ ℃.
0, 0 |
|
100, 0 |
|
100, 100 |
|
0, 100 |
The primary component of the lubrication system is engine oil. Engines require oil blends with different thickness (viscosity) and additives depending on their operating conditions. Viscosity is rated using the format XW-XX with the number preceding the W (winter) rating the oil’s viscosity at 0 ℉ (-17.8 ℃) and the XX indicating viscosity at 100 ℃.
What function does a two-stroke cycle engine perform on the second stroke?
compression and combustion |
|
fuel intake and exhaust |
|
combustion and exhaust |
|
fuel intake and compression |
The two strokes of a two-stroke cycle engine are fuel intake and compression then combustion and exhaust.
The primary purpose of the muffler is to:
reclaim unburned fuel |
|
quiet exhaust |
|
cool the exhaust |
|
remove harmful gases from the exhaust |
The muffler follows the catalytic converter and absorbs sound to help quiet load exhaust. It is followed by the exhaust pipe which is the final exit point for exhaust gas from the vehicle.
Which of the following cylinder arrangement would be most common in an eight cylinder engine?
inline |
|
V-type |
|
opposed |
|
vertical |
Cylinder number and arrangement depends on the purpose of the engine. Smaller (four and six cylinder) engines in front-wheel drive vehicles often use an inline design which orients cylinders vertically over the crankshaft and aligns them in a row. Other common orientations are a horizontal/opposed design which places cylinders flat facing each other with the crankshaft between them and a V-type design common in six and eight cylinder engines that features one cylinder head per block of cylinders oriented at a 60 to 90 degree angle to each other with the crankshaft at the bottom of the V.