Ted Connolly

Ted talks tappets.

THE world of radio fascinates me, even more so than television or the cinema. Perhaps it’s because I grew up in an era when it was a luxury, rather than a given, to have a telly. They were expensive items and most families, including my tribe of peasants, used to crowd round the wireless we got from Radio Rentals for, I think, 10 bob a month (work it out, junior, I’m not here to do conversion charts).

It was a Bakelite set with knobs for the Light programme, Home programme and Radio Luxembourg. The Light and Home stations broadcast news, middle-of-the-road music and, at night, stuff like Journey into Space

with Dan Dare. That sure was a long time ago, but I remember listening to it and being frightened silly by tales of outer-space travel and the terrifying creatures encountered. As for Radio Luxembourg, the reception sounded like the station was being broadcast from the cockpit of a passing Tiger Moth.

Nevertheless, I enjoyed listening to the radio. It did, and still does, occur to me that it must be an almost surreal experience being a dee-jay, because you don’t know who you are broadcasting to nor, indeed, if you are actually broadcasting to anybody at all. The audience is invisible.

In much the same (but tinier) way that I write this column. I could be thrashing away at the word processor for absolutely no other reason than to bore the production team at Car

Maniacs and make a few beer vouchers in the process.

Thus it is always good to get reader feedback. I don’t actually mind if it’s slagging me off, I just like to know that somebody out there reads my drivel.

Reader Greg Piwowarski writes: “I read that you have been contributing to this fine magazine for 35 years. I wish you to do it for at least another 35. It is my pleasure to tell you that every time I take a new issue, I start to read it from the back. Thanks for your nononsense approach.”

I am genuinely pleased to hear that, Greg.

I also wrote a piece about adjusting tappets and asked why there needed to be a gap, explaining that adjusting the clearance fine-tuned the valve timing and had nothing to do with expansion. Jeremy Haworth says: “OK, no total experience, but I have never known of valve clearances being set when hot, although I have heard of setting them with the engine running, leading to many a mangled feeler gauge, I suspect.”

Mr G N Harris of Caterham, Surrey, wrote in on the same subject, saying: “I don’t know if Ted was having one of his off days or just joking. I am sure that tappets are set with the engine cold. I have always left my engine to cool overnight before setting tappets. I hope Ted hasn’t been on too much of the intoxicating stuff.”

OK, let’s sort this out. The notion that you set tappets with a clearance to take expansion into account is a myth. Think about it: if you got it wrong and set them a little too tight, the valves wouldn’t seat and then they’d burn out. Also, what exactly is cold? Nobody knows for sure – is it three degrees above or two below? However, you do know when an engine has reached its correct running temperature, so that is definite, rather than a guess.

As I said, the real reason for setting a gap is to fine-tune the valve timing. Camshafts are expensive to produce and they would be a whole sight more expensive if machined to precise tolerances, so the clearance takes care of that, in the same way that setting the points (remember them?) fine-tunes the ignition timing. Close the gap and it is advanced, open the gap and it is retarded. Also, as I explained, if there is a gap then you know for sure that there is a working clearance and that the valve has closed.

Mr Harris wonders whether I’ve been on the intoxicating stuff too much. Yes, of course I have. And as for having an off day, I rarely have an on day.

As for setting the clearances with the engine running, referred to by Jeremy, that was the procedure on the Vauxhall Viva and Chevette motors, with those daft, pressed-steel tappets that always ended up with holes worn through them by the pushrods.

And finally, reader Chris Snow – who is often in touch – recalls: “My wife remembers, with some annoyance, me having the cylinder-head from my Leyland Princess with the 2.0-litre O-series engine on the kitchen table, measuring the gaps to work out what size shims I required. However, she knew when she married me in 1965 that I was a petrolhead, because in our early years as teenage sweethearts, she had helped me clean and service my BSA 650 and, in return, I maintained her Vespa.”

Thanks to all four of you for getting in touch. As for Bakelite radios and tappets, such things will be totally alien to the young fellow-me-lad readers. Ah, those were the days. Actually they weren’t – the radio played lousy music and I adjusted so many tappets that I grew to hate the things. My glasses are scratched and grubby, but they have no sign of the tint of roses.