ASVAB Automotive Information Practice Test 223952

Questions 5
Topics Coolant, Cylinder Arrangement, Master Cylinder, Spark Plugs, Wheel Hub

Study Guide

Coolant

Modern car engines are cooled by liquid which circulates through the engine block and cylinder heads absorbing excess heat. This liquid is made up of half water and half antifreeze (commonly, ethylene glycol) which both keeps the water from freezing at low temperatures and raises its boiling point making heat transfer more efficient.

Cylinder Arrangement

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.

Master Cylinder

The master (brake) cylinder converts pressure on the brake pedal to hydraulic pressure in the brake lines.

Spark Plugs

Spark plugs receive current from the distributor and use it to spark combustion in the combustion chamber of a cylinder.

Wheel Hub

The wheel hub is the mounting point for the wheel and tire assembly. The wheel hub can rotate while being held stable by the steering knuckle which applies the motion of the control arms to the wheels.