Tech Wizard

Octagon Newsletter

By Mike (The Wizard) Owen


þ A close match in colour to the original maroon engine paint is dark carmine.

þ To secure the bonnet in an entirely raised position, use a long nylon cord, one end looped over the bonnet safety catch and the other end securely tied around the trunk lock or gas cap.

þ To avoid the congealing of grease in your kingpins and handbrake cable use 90 weight. oil in your grease gun instead of grease (occasionally).

þ To avoid corrosion on battery terminals, coat them with Vaseline after cleaning.

þ Austin 1100 door handles, window winders and door seals are the same as those of an early MGB.

þ When relining your brakes, it is a good idea to have your rotors or drums resurfaced as this provides a new surface for your linings to work on.

þ If, after using your hazard lights your traficators stop working, operate your hazard switch a few times this can sometimes correct the problem.

þ Later MGBs retarded their camshafts by changing the position of the keyway in the cam gear.

þ A newly rebuilt engine tends to run at a hotter than normal temperature. To counteract this have your radiator reconditioned.

þ Use only the original fluted radiator hoses, not the wire reinforced type as they can crack the radiator outlets.

þ To maintain correct oil temperature, especially during summer, consider installing an oil cooler.

þ MGB fuel pump problems can sometimes be caused by the ground wires being left off the rear license plate bracket.

þ To prevent bearing damage when starting a new engine or one that has been sitting for a while, remove the sparkplugs and operate the starter till oil pressure is shown on the gauge.

þ To reduce stress on the camshaft lifters and rockershaft, single valve springs of a lighter tension can be used in place of doubles.

þ Oil leaks from tappet cover bolts can be cured by using Subaru valve cover washers that have a rubber insert built-in.

þ Felt timing cover seals on MGAs often leak, but MGB covers use a neoprene seal this cover will bolt right on if an MGB oil thrower is also used.

þ Machined surfaces often have small nicks that prevent a good seal use a flat file to remove them.

þ An excellent sealing compound is Hylamar which is used by Rolls Royce now available from McOrd Gaskets.

þ Your intake manifold gasket can easily be checked for leaks by lifting up the air filters while the engine is running. If the engine speed changes, the gasket is leaking and needs to be replaced.

þ Later style MGs have crankcase breather hoses connected to each carb. Make sure these are not plugged or have not fallen off.

þ When replacing a valve cover gasket, clean off all traces of gasket and oil from the cover and then contact cement the gasket to the cover. Do not use contact cement or gasket sealer between the head and gasket.

þ To lubricate cables such as heater, bonnet or handbrake (that don't have a plastic covering), apply a thin oil, such as 10 weight or 3-in-1, along the outer surface and this will penetrate throughout the cable.

þ When installing your air filters and gaskets, make sure all the holes line up with the carb faces.

þ When installing your air filters and gaskets, make sure all the holes line up with the carb faces.

þ Be cautious when adding oil to your engine, as the distance between the dipstick minimum and maximum marks is only one pint of oil.

þ The correct ignition timing is very important, as just a small variation can ruin your motor. Ensure that you have the correct distributor for your engine and that the initial timing, mechanical advance and vacuum advance are to factory specs.

þ Thin dashpot oil will allow the dashpot piston to open sooner than thicker oil. If the piston rises slightly slower it will give more accelerator pump action.

þ To remove your choke cable retaining nut from the tight spot behind your dash, a modified wrench (as shown) can usually be made to do the job.


þ Check the three Phillips screws on your MGB door locks for tightness as they often come loose causing stress on the door skin.

þ When installing brake shoes apply masking tape to the lining to prevent finger prints.

þ Rubber caps used for plugging vacuum lines work well to cap brake lines so fluid is not lost.

þ Carbon core spark plug wires should be replaced every five years as the carbon core can break causing a high resistance with little or no spark at the plug.

þ Check your ignition coil turret on every tune-up as it can get burned, corroded and cracked, giving a poor spark.

þ SU carb dashpots should be cleaned out on every tune-up. Before removing them wash the outside with solvent to prevent any dirt entering the carb.

þ Be sure your choke 'fast' idle speed is set correctly, as too low a speed can cause stalling, too high can be damaging when first starting.

þ Correct valve clearance is very important as too little clearance can cause valve burning: Too much clearance can be harmful to cam lifters and valve train.

þ Next time you have your valve cover off check that the rocker shaft locating screw is not missing.

þ With summer here it's a good idea to give the cooling system a good check over. This should include checking all hoses, radiator and cap, thermostat and coolant

þ Since summer is here many of us are taking our MG's on trips, so I thought a list of spares to take along would be a good idea. These parts need not be new, as good used ones will work fine.

þ Fuel pump, points, condenser, rotor, cap, HT wires, plugs, fan belt, fuel filter, top and bottom radiator hoses, 2' of 1/2" heater hose, 2' of 1 /4" gas hose, spare tyre (with air), thermostat and gasket, frost plug, clutch and brake seal kits, carb needle and seat, Universal joint, throttle cable and return spring and spare keys. If you know some or all of these parts have been replaced recently then, good luck and happy motoring.

þ To prevent dirt and moisture from accumulating in your brake and clutch systems, bleed them thoroughly once a year replacing the entire contents with new fluid.

þ A spin-on oil filter wrench can be used to remove a stubborn tandem brake cylinder cap.

þ When replacing your brake shoes, also overhaul the wheel cylinders. Don't try to service them on the car as a thorough cleaning, honing, inspection and rebuild is done much easier on the bench. After re‑assembly a coat of clear lacquer will prevent surface rust.

þ When overhauling tandem master cylinders with nylon spacer washers, instead of drilling to remove them, heat a 1/8 rod until it is red hot and melt through. This prevents accidental scoring of the piston.

þ Inspect all hydraulic cylinder bores for pits or scratches as the surface must be absolutely perfect for correct seal operation

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