Arty Facts by PETER BOOTH Click here to comment on this article

ADJUSTING VALVES: Adjusting engine valves was never my favourite pastime. Having done so on many different cars, from sitting on the mudguards of International Trucks with legs inside the engine compartment, to fiddling through a trap-door in the valance of Anne's Morris 8-40 with the front right hand wheel off, and hanging upside down over the mudguard of the Chummy, the job was plagued for a long time by Murphy's 3rd law:- "No matter how patient you are, the damn tappet will always, finish being too light or too loose". With the advent of hydraulic tappets this aggravation has largely been eliminated.

The point of this preamble is to tell those who do not already know that help is at hand, all is not lost, and the frustration is at an end!!! The good book advises A-7 valves be set at .006 inch. I go for .005 inch inlet and .007 inch exhaust. I use .004, .006 and .008 inch feelers.

Whatever you choose, say .005 inch, use 2 feeler gauges, a .004 inch and a .006 inch as GO and NO GO gauges. The .004 inch should go easily and the .006 inch should not go at all.

By using a .005 inch feeler and trying to get it just right you are actually playing with 10ths of a thousand of an inch, which is far more precise than necessary and, with worn parts virtually impossible.

Remember, two feeler gauges, one a thou. over and one a thou. under will make the job much easier.



Sometimes called cotter pins. In my book cotter pins are round with a flat on one side and a male thread on one end, so I intend to call split pins 'SPLIT PINS'.

When I started work in the test division of International Harvester Trucks I had need to remove some SPLIT PINS. I sallied forth with the mandatory screwdriver and pliers, where-upon a young mechanic named Jimmy Bence sidled up to me and handed me his wire cutting SIDE CUTTERS and said out of the side of his mouth behind the back of his hand, "Here use these". This proved to be valuable advice which I have heeded for the past 45 years. Buy an 'el-cheepo' pair ($2.00 at the $2.00 shop, or $2.50 at the Reject Shop) and keep them for that purpose. I even use mine occasionally to cut wire!

The only place I have found they are not effective is the A 7 front axle nut split pin. If anyone knows of a simple clean way to get them out, 'PLEASE TELL ME!

Chummy Wiring

For anyone with, or who has recently, acquired an Austin Seven with the scuttle mounted fuel tank, the prospect of access to the ‘behind the instrument panel’ wiring is not a happy one, you need fingers at least two inches longer and half as thick just to get at the screws, nuts etc. to remove the switch panel.

Faced with this state of affairs to install parking lights on Tootle, it occurred to me it wasn’t much trouble to remove the fuel tank when I de-leaked it recently, in fact I had taken a three frame panarama photograph from the engine compartment of the wiring at the time, just for the record.

The rest goes without saying. When you need access to the above mentioned wiring, whip out the tank. While I was at it I checked the grub screws on the back of the switch panel and was surprised how many needed a tweek up.


"THERMO-WHAT?" As motor cars go our wee beasties are about as simple as they get, mainly because of all the components they don't have. Not the least of these is a water pump. Sir Herbert, (or was it Stanley Edge?) opted for the ancient principal of THERMO-SYPHON. Which in England's less than warm climate was adequate, but in warmer places barely coped. What may you ask is a Thermo-syphon?

For those who did not pay attention in physics class, it is a means (also known as convection) by which a fluid (in this case water) circulates by heating and cooling in appropriate places.

The basic fact is when water is heated it expands and becomes less dense: A litre of water at 20 degrees centigrade weighs 1,000 grams and it's specific gravity (density) is 1.0. A litre of water at 100 degrees centigrade weighs 900 grams and it's specific gravity is 0.9. This means hot water is lighter than cold water and, believe it or not, will float on top of cold water. This is called layering or stratification. How does all this almost keep our treasures cool? Because petrol engines are pretty inefficient at converting heat into mechanical energy, about half the heat produced is wasted and must be got rid of, water is cheap, can absorb heat, and can carry it from one place to another as required. Enter the THERMO-SYPHON.

You stir your 10 or so horses into action. The cylinder head gets hot, followed by the cylinder block. This heats the water therein. This water is then lighter than that in the radiator so it floats up the top radiator hose into the top radiator tank and pushes (displaces) the cool water, causing it to sink down through the radiator core into the bottom radiator tank, then up the lower radiator hose back into the cylinder block. Because of the huge surface area of metal in the radiator core, with water on one side and air on the other, the air picks up heat and, as the car moves forward carries the heat into the engine compartment where it mixes with the stink of hot oil, and makes its way through gaps, holes and cracks into the driver's compartment. This warms his feet and knees, and induces a chronic state of near nausea.

It didn't take Sir Herbert long to discover, when the car was stationery with the engine running, no air passed through the radiator and very quickly the whole system reached 100 degrees C and boiled. Drivers couldn't see traffic policemen for steam!

Enter the FAN . . . . another item he had omitted in the cause of simplicity. Fitted with this device large quantities of air were drawn through the radiator core at all times, the water ceased to boil, and drivers stopped being quite so bilious and running over (or is it under?) traffic policemen.