Austin Healy 100

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Healeys is essentially simple in design, and the cars are not difficult to maintain at home. The ignition system (Lucas) is conventional and relatively easy set up, as is the fuel system, which employs twin SU carburetors. These can be time-consuming to tune properly, but the work is not difficult. All lubrication operations can be carried out at home.

How easy are they to work on?

The overhead valve (pushrod) Austin A90-derived engine used in the four-cylinder Healeys is essentially simple in design, and the cars are not difficult to maintain at home. The ignition system (Lucas) is conventional and relatively easy set up, as is the fuel system, which employs twin SU carburetors. These can be time-consuming to tune properly, but the work is not difficult. All lubrication operations can be carried out at home.
Note 1: Mileage/time intervals shown are suggested for typical use; frequency will need to be increased under harsh operating conditions.
Note 2: The information in this feature is intended to be helpful, but is necessarily abbreviated (and some specifications changed as the models developed). Please consult manufacturer’s literature for full details of each aspect of maintenance, as it relates to your version.
Note 3: The specifications given apply to the 2660cc four-cylinder models (BN1 and BN2).

Engine

Overhead valve (pushrod) in-line four-cylinder. 2660cc, 90bhp.

Valve Clearances

It is wise to check/re-adjust the clearances approximately every 12,000 miles. Conventional screw and locknut adjusters are employed. The clearances for both inlet and exhaust valves should be 0.012in (‘cold’). The ‘Rule of Nine’ is applied, i.e. check/adjust valve No. 1 with valve No. 8 fully open, check/adjust valve No. 2 with valve No. 7 fully open, check/adjust valve No. 3 with valve No. 6 fully open - and so on; in each case the sum of the valve numbers is nine.

Brakes

At every service: Check the master cylinder and reservoir for leaks (investigate if the fluid level is low), also assess the level and condition of the fluid. Examine all fixed and flexible brake fluid pipework; renew if damaged/corroded. Remove all brake drums and check for lining wear and fluid leaks; renew worn linings and weeping cylinders (immediately!) in axle sets. On re-assembly, check/re-adjust the lining to drum clearance (please consult manufacturer’s literature). Ensure that the handbrake mechanism moves freely, and make sure that the rear brakes are locked with the handbrake fully applied, also that the rear wheels are free to rotate with the brake lever in the ‘off’ position (please consult manufacturer’s literature). At least every 24,000 miles/two years whichever comes first), renew the brake fluid.

Ignition

Firing order: 1-3-4-2 (No. 1 at front of engine) Spark plugs: Long-reach Champion NA8 or equivalent; gap 0.024in to 0.026in. Check/clean plugs every 6000 miles (ideally using brassbristled wire brush); renew plugs regardless every 12,000 miles. Every 6000 miles: Examine the high tension leads, distributor cap and rotor arm. Sparingly re-lubricate the mechanical components within the distributor (and apply a small amount of high melting point grease to the distributor cam). Renew the contact points (check condition every 3,000 miles and re-gap if necessary); gap 0.014in to 0.016in. Check ignition timing; static setting at flywheel - 1/4in before 1/4 mark.

Fuel System

Oil-wetted gauze type air filters: Every 6000 miles, rinse gauze in clean paraffin, dry thoroughly then lightly moisten gauze with fresh engine oil. Paper element type air filters (where fitted): Every 3000 miles or annually (whichever comes first), examine the air filter element and renew if visibly dirty; renew regardless every 12,000 miles. Every 6000 miles/annually, check all fuel system pipes and connections. Renew any failing pipes/securing clips. Every 6000 miles, check/clean the fuel pump filter. At each service: Check/top up the oil level in the carburetor dashpots; if necessary, top up the piston spindles with SAE20 oil. Check/re-lubricate the accelerator linkages. Check carburettor synchronisation and mixture settings; use proprietary carburetor balancing equipment. Re-set idle speed. Every 20,000 miles (approximately), remove carburetor suction chambers and pistons, clean (DO NOT use abrasive substances) and re-assemble. On completion, top up the dashpots with oil.

Cooling System

Always use high quality anti-freeze mixture containing corrosion inhibitors; this should be used in the system all year round to protect against corrosion. Every 1000 miles, where a lubrication point is fitted, remove the sealing plug and re-lubricate the water pump with SAE140EP oil or water pump grease; re-fit the plug on completion. Every 3000 miles/annually (whichever comes first), scrutinise the radiator and its cap, the fan, the and all hoses plus their connections. At least every two years/20,000 miles (whichever comes first), drain the system, reverse-flush and re-fill with fresh anti-freeze solution (observe the dilution recommendations of the anti-freeze manufacturer). Capacity: Approx. 20 pints (11.37 litres).