Automech Paper 2, May-June 2015

(a) (i) Identify the unit shown in the sketch below.

(ii) Name the parts labeled V, W, X, Y and Z..

(b) (i) State one function of the parts labeled W, X and Y

(ii) State the function of a thermostat.

The expected responses are given below:

(a) (i) The unit is cylinder head assembly

(ii) V: thermostat housing

W: valve spring
X: valve cover
Y: rocker shaft
Z: pushrod

(b) (i) W: It keeps the valve properly seated in its position.

Y: It holds the rocker arm in position.
X: It protects the upper part of the cylinder head.

(ii) The thermostat allows for quick warm-up of the engine