Keeping your car in good condition can be carried out at home by most mechanically minded members. A basic set of tools, a service manual is all that’s required, with a little bit of help from your friends if necessary. I maintain and tune my own cars and typically get 25 mpg from both the V8 and Century and have not had a serious on-road breakdown!

The first thing to check is the valve tappet clearance. My recently acquired Consort ran on 5 cylinders due to a tight tappet! Remove the tappet covers and adjust as per the manual. Before refitting the covers, start the engine briefly and observe the oil flow to the rockers and valves. At idle there should be a steady low of oil to all valves. If not, slacken the bolts on the oil fed pipes on each cylinder head to ascertain oil pressure feed. This oil feed is metered by a drilling through the camshaft, giving a spurt of oil for each half revolution of the camshaft and through a hole in the top of the camshaft rear bearing. If the supply is okay, it will be necessary to remove rocker shafts and rockers for cleaning. Note that as the rockers are secured by the head bolts, you may end up having to remove the heads
as well! Also see last magazine for article on V8 tappet lubrication.

Next step, check the compressions of all cylinders. Remove all spark plugs; disable the ignition by disconnecting the L.T. distributor lead. Have an assistant crank the engine on the starter with full throttle. With compression gauge on each cylinder in turn, crank the engine until there is no further increase in pressure and record the readings. Ideally, look for a pressure difference between cylinders of no more than 10 psi. Very low or no pressure on any cylinder/s will necessitate removal of cylinder heads. Without good compressions, the engine won’t tune well. Other quick ways of checking for loss of compression on one cylinder is to disable the ignition and listen to sound of the engine cranking, the revs will rise on the low cylinder. Fit a vacuum gauge to the inlet manifold, a momentary drop in vacuum
indicates a low cylinder.

Next, check the ignition system. Mark the position of the distributor as a guide when reassembling and remove from the engine. Set up in a vise, check for any lateral movement in the shaft. If excessive, it will require new bearings. Refer to the exploded diagram of the distributor, remove the contact breaker using and inspect the centrifugal timing control mechanism. Ensure the cam if free to move on the shaft and that the springs are in the correct positions.

Note that only the lighter spring is anchored to the toggle plate, the heavy spring is secured ACROSS the two weights on the additional post. I have seen these incorrectly assembled. Apply a small amount of oil to the pivots and shaft. Inspect the contact breakers and use a points file to dress the contact faces. Ensure the faces are flat and parallel to give maximum contact area. If excessively pitted or worn, they will need to be replaced. Twin points are used, the first to open “fires” the coil, and the second set holds the primary voltage on the coil for longer giving better magnetic charge. Inspect the insulation on both and on reassembly both sets of points should by set with a feeler gauge to 0.015 in. Apply a small smear of grease to the cam. Check the vacuum advance unit by sucking on the inlet. The
breaker plate should move and, by putting your tongue over the hole, hold that position. (Recommended to clean it first!) If it leaks, replace, or these units can be reconditioned.

The function of the vacuum advance is to provide additional ignition advance under light throttle conditions to enhance fuel consumption.

Inspect the rotor arm and distributor cap for hairline cracks which can cause arcing and tracking of the high voltage, also check the carbon brush and spring on the centre contact. Refit the distributor, noting the correct orientation of the large and small “D” on the drive dog.

Timing can be done with a 12 volt lamp connected between the live battery lead and the contact breaker wire on the distributor or coil (ignition off). Turn the engine by means of a spanner on the front crankshaft nut until the timing marks on the front pulley line up. Put a dab of white paint on the marks (10 degrees before top dead centre) to improve visibility. Adjust the distributor so the light goes out as a rough setting only. Continue to turn the motor CLOCKWISE only for 1 revolution, the distributor must be adjusted so the light goes off exactly as the timing marks align. Adjust as necessary and repeat until correct.

Inspect all H.T. cables for cracks or damage. If copper wired cables only the insulation would be an issue. If radio suppression resistive carbon trace leads, these must be checked with an ohm meter, typically 10,000 ohms per foot of cable. These cables do break down causing misfiring and can be damaged by excessive bending and pulling on leads! Do not run your engine with a plug lead disconnected. The plug gap limits the HT voltage, without it, the spark will take the shortest route to earth be it your fingers (ouch!) or worst case can destroy the coil, rotor or distributor cap by burning a carbon track in the insulation, often invisibly!

Inspect spark plugs, a worn plug will have a rounded off centre electrode and/or earth electrode. Worn plugs can be cleaned and filed, but replacement is recommended. Gap the plugs to specification clean inside and out and refit.

Fuel system next time.