Fitting an Oil Catch Tank to an Austin Healey 3000

Big Austin Healeys have always been notorious for heavy oil consumption – even the manual says they may consume 1 pint of oil per 250 miles. While this was probably normal in the 1940s and 1950s it is not the case on modern cars. Some of this oil goes past the valves and mixes with the exhaust gases that are ‘blown-by’ the piston rings into the crankcase. Our Healey is fitted as standard with a Positive Crankcase Ventilation (PCV) system which links the crankcase to the rocker cover and then via a T-piece across to the rear of one of the carburettor air filter canisters. This is designed to reduce the gas pressure built up in the crankcase and rocker cover, rather than reduce the oil consumption.

The PCV system means that the oil fumes are sucked into the carburettors by the inlet manifold vacuum and burnt along with the fuel. When I accelerated hard in our Austin Healey 3000 I could see exhaust fumes in the rear view mirror, so it seemed the system was burning some oil as well as the crankcase fumes.

A coupe of years ago I decided to fit an oil catch tank in line with the PCV breather system to see if it would make any difference. I found a suitable one in polished aluminium with an inlet and outlet pipe and a small clear plastic tube showing oil level. The fumes and oil mist are drawn in, the oil and any un-burnt fuel condense out and the remaining gases are then sucked out into the back of the air cleaner and burnt as before. I fitted this using normal rubber tubing to/from the catch tank.

It did its job well as over the course of a year, covering about 6,000 miles, it accumulated about 1/2 pint of oil. This is released through a drain plug in the base of the tank which I then poured back into the engine for re-use. This meant that I had prevented the engine burning about 1/2 pint of oil a year, reducing both the emissions and the likelihood of the plugs becoming fouled by burnt oil.

This year I decided it was time to tidy up the engine compartment a bit and bought chrome finish air cleaners to replace the grey painted ones and thought it time to replace the rubber tubing. The engine has a chrome heater pipe running the full length so I bought some chrome plated, standard plumbing type, copper piping and using a plumbers pipe bending machine made up a pair of chrome pipes.

These now run along the engine, above the heater pipe, connected using short lengths of rubber tubing and jubilee clips and provide for a much tidier engine bay. The oil catch tank continues to operate as when first installed.

The fact that I have prevented at least 1/2 pint of oil a year being burnt by the engine makes fitting a catch tank well worthwhile, and using chrome plated copper piping makes for a much tidier engine bay than just using rubber tubing.

The Importance of Painting Brake Calipers and Brake Drums on Classic Cars

On a guided tour of a Bentley dealer, the service manager took great pride in emphasising their attention to detail by showing me one of the mechanics painting the brake calipers on a modern Bentley that was in for a service. I’ve been doing this for years on our fleet of classic cars for a number of reasons.

Anyone who has bought a classic car that hasn’t had much use knows that rust on the brake calipers can cause problems. It is unsightly when viewed through nice gleaming chrome wire wheels or period alloy wheels. But most importantly rust can actually cause problems with the braking system when servicing.

The calipers are normally made out of cast iron and while some cars have nickel plated or, better still, copper brake pipes, virtually all of them have steel fittings on the brake pipes and steel brake bleed nipples which can rust. If the rust isn’t kept under control then the bleed nipples can rust into the calipers making it virtually impossible to bleed the brakes. I have seen too many cars where the flats on the bleed nipples have been rounded off so that they can no longer be undone with a spanner. In severe cases I have known of bleed nipples that have snapped off, meaning the caliper has to be removed, brake pipes removed (if they will come undone, and then the bleed nipple very carefully drilled out and replaced.

If the bleed nipple has reached this stage then it is quite possible that the brake pistons have started to rust in the calipers as well – but that is a separate issue.

When I do my main winter service on all my classic cars I remove any rust from the calipers with a wire brush, particularly around the brake pipe ends and the bleed nipples. I treat these items with a rust preventer, normally Kurust, and I then give the calipers a thin coat of Smoothrite paint, normally in silver. Some brake calipers were cadmium plated when new (which has now been banned) which has a yellow / gold colour. In this case I use the gold Smoothrite which dries to a similar colour to cadmium.

I emphasise here a ‘thin’ coat of paint. Just enough to give a good covering and brushed out thinly. DO NOT paint the brake pipe ends or the bleed nipples or the part of the caliper that the nipple screws into, otherwise this can seize up with paint which is as bad as it rusting in situ. If you remember, it is also worthwhile adding one drop of thin oil or a squirt of WD40 (or equivalent) to the base of the nipple to allow it to seep into the top couple of threads.

Some of our cars have drum brakes on the rear, so here I remove the drums, de-rust, Kurust and paint them, normally in silver Smoothrite. The brake pipes and bleed nipples don’t fit into the drums but through the drum back plate, so while the wheel and drums are removed, I wire brush the pipe ending and nipples and Kurust these as well.

You now have a set of rust free, very tidy looking, calipers and drums with fittings that hopefully will undo when needed. Nice to know that Bentley in Cheltenham come up to my standards.

At this point it is also worth adding a reminder that brake fluid absorbs moisture from the air and therefore should be flushed out and changed every three years, hence the need to be able to undo the bleed nipples.

The Importance Of Tightening Spokes On Wire Wheels On Classic Cars

I own a number of classic cars and have never really been a fan of wire wheels for a variety of reason. Firstly they take a lot of cleaning and it is very difficult to get between all the spokes and to clean the hub properly. Secondly and more importantly, spokes can work loose, or worse still they can actually crack or break under hard driving. I have never had a spoke snap on me, you really need to be doing some spirited rallying for them to fail, but I have had them work loose.

Over the years I have replaced the wire wheels on some of our cars (MGB Roadster, Triumph TR4a and Austin Healey) with Minilite alloy wheels and have D-Type alloy wheels on our Jaguar E-Type. These are easier to clean, no spokes to mess about with and they are actually easier for tyre companies to balance properly so normally make for a smoother, better ride. One of my latest acquisitions is a 1961 Jaguar Mk2 saloon which arrived with chrome wire wheels. Minilites would look out of place on a Jaguar and changing to standard steel wheels would involve replacing the hubs, and would look a bit plain and boring. So for now I am sticking with the wire wheels.

Cleaning the wheels recently, I noticed that a couple of the spokes were loose, and much credit to my local garage they also spotted this on the car’s annual MOT test, so I decided I needed to check all the spokes on all five wheels (including the spare).

This is a non-trivial task and can’t be done with the wheels on the car as you need to be able to get to both sides of the wheels to tighten the outer and inner spokes. First you need a spoke spanner, or at least a spanner the same size as the spoke nipples. The spokes themselves don’t tighten, they are held in place by the nipples and it is the nipples than need tightening. These are fitted though the steel wheel rim onto the spokes and the head of the nipple is therefore inside the wheel, touching the inflated inner tube. If you tighten the nipples with the tyre inflated it is quite likely they will pinch the tube and could puncture it.

The first thing to do is therefore to deflate the tyre almost fully. Then find the loose spoke(s) and tighten the nipple until the spoke no longer actually feels loose. Once the loose spoke(s) are tightened, you should then work round the whole wheel tightening up all the spoke nipples a little. Start at the valve and work round the outer spokes, and then turn the wheel over and work round the inner spokes. So you don’t overtighten any spokes, just tighten them a little and then work all the way round the wheel again giving them another little tweak.

Once all the spokes have been tightened you can re-inflate the wheel to the correct pressure, then refit to the car and move onto the next wheel. Completing all five wheels will probably take a couple of hours. Particularly if like me, you use the opportunity, of having the wheels off the car, to clean and polish them properly.

Job done. All spokes tightened and unlikely to work loose for at least another year. An afternoon of my life I’ll never get back.

Now I remember why I replaced the wire wheels on the other cars with alloy ones!