Rather more important than these nice points is the question of safety. In the last couple of years, I’ve experienced front hub breakages on three occasions

A small crowd gathered behind one man as he walked round the paddock at the Silverstone Classic. He was an eligibility scrutineer, carrying out spot checks, and he had a new toy. This gadget comprised a flexible fibre-optic lead with an inspection light plus 8mm camera lens on one end and a TV-type screen on the other.

Every eligibility scrutineer should have one. This chap works for Duncan Wiltshire’s Motor Racing Legends organisation, Duncan being extremely keen to keep all his races straight. Without stripping engines down, our man could look inside all sorts of otherwise inaccessible areas in a matter of seconds. This time, his lead was probing into the oil fillers on rocker covers and, er, ho hum, he started finding things which should not have been there.

Three cars had illegal lightweight roller rockers. Well, you might think, that’s no big deal. You would be wrong. An engine fitted with such non-standard stuff can rev higher in safety, producing more power in the process. It is unfair on those who have stuck to the rules to turn a blind eye to such little details.
What was to be done?

On this occasion a good old British compromise was reached. Those concerned were given a choice: they could either pack up and leave or they could start the race at the back of the field, from the pit road. They were also told to get their engines legal before the next race meeting.

The little crowd then began to whisper certain allegations about other irregularities. It was time for a bit of straight talking, during which it turned out that a couple of cars were suspected by fellow competitors of having illegal limited-slip differentials. No problem for our man: he simply removed the oil plugs, stuck that lead inside the differential casings and, hey presto, both were very obviously completely legal.

Checks like this are invaluable, especially once any category of racing has become well-established. Without them, naughty things creep in over time. It will be interesting to see what happens if the very promising Pre-1963 GT race, introduced at the Silverstone Classic by Ben Cussons, goes on to become a regular series. Everybody felt that this was a huge success, bringing out a full field of apparently straight cars and producing a great race with no nonsense.

That was probably fair comment but the eligibility scrutineers will have to keep on top of it. Whenever word gets around that the old blind eye is being turned to cheating, the whole field starts doing it just to keep up. I have ranted on about such things before but I have no doubt that despite everybody’s best efforts there are still some very funny historic cars around.

At one race late last year, I wondered why an Aston Martin DB4GT was so much quicker than our car which, on paper, should have been faster. The preparer of our car told me that our opponents’ machine, prepared by someone else, had a very large engine and a five-speed gearbox. He should know and I am sure he was right but nobody, including me, did anything about it. Looking back on that, I’m feeling rather less polite, shy and retiring than I used to be.

In fact, if I’m up against that car again and it hasn’t been made legal, I think shall blow a gasket myself. I’m determined not to suffer in silence next time. Engine capacity is easy to check and you don’t need any high-tech gadgets to find out whether a five-speed gearbox has been put into a car that should have only four forward gears.

Rather more important than these nice points is the question of safety. In the last couple of years, I’ve experienced front hub breakages on three occasions. The most irritating one was in a Ford Zodiac when I was leading a race and the front left wheel fell off. More alarming was an identical failure in a DB4 when I was doing 120mph on the old Nürburgring – a hair-raising escape.

It happened to me again more recently in a D-type.

All three cars were extremely well prepared but any of those incidents could have led to the total loss of a car. It’s easy to overlook proper crack testing, which is expensive but well worth the money. It’s the owners’ decision.