Styled “the inevitable replacement for the sparking plug”, the Autoflash convector is a Swiss product which looks for all the world like an ordinary spark plug until it is removed. Instead of having a conventional earth electrode, it has a special capsule with three lateral openings, designed in such a way to provide a rotating spark. The theory is that a portion of the fuel-air mixture enters the three openings during the compression stroke, cooling the convector and preventing pre-ignition. The ignition of the charge in the cylinder is effectively a two stage operation. First, the small portion of mixture within the capsule of the convector is ignited, giving a very strong rotating flash which then ignites the remaining charge in a much more efficient manner than a conventional spark plug. The claims for Autoflash are high, and if it wasn’t for the quoted evidence from independent organisations, we would be more than sceptical. Improved fuel economy as a result of more efficient ignition, cleaner exhaust as a result of more complete combustion, easier starting, more power and a much longer life than a conventional plug – we are told that these claims are all supported by the National Dutch Testing Institute which tried these convectors in six cars and found significant improvements in fuel economy, power increases of up to 7% at full load and much cleaner engines, due to being able to run with weaker mixtures.
The convectors require careful fitting, as the static ignition setting has to be advanced to counteract the lag in firing caused by the two-stage flash and the convectors do show up incipient engine maladies which might go unnoticed with conventional plugs, such as “soft” valves, poor ignition system, incorrect mixture and so on. This is highlighted by our own experience with the staff 3.0S Capri. We took the 17,000 mile car to Graham Perkins at Pigspeed Motors, the London agents for Autoflash, in Chelsea’s Graham Terrace, to have a set of convectors fitted.
The initial result was a car which ran unevenly and misfired at anything above 2,500 rpm, whereas previously it had given only an occasional hiccup, put down to plugs, after prolonged slow running in traffic. The fault was thought to lie with the fuel system, and a look inside the carburetter revealed some foul sludge. Once cleaned out, the car ran very sweetly in and around London, but out in the country, it became apparent that all was not well, for the engine misfired at the top end of the range, indicating fuel starvation. A complete clean out of the fuel system to remove the traces of a tankful of bad petrol, a new petrol pump (the Ford unit is sealed, so impossible to clean) and new jets in the carburetter have transformed the car. Its 0-60 time has improved from low 9’s to low 8’s and it is possible to wind the speedometer needle some five mph further round the dial.
Initial reactions are that the convectors do produce a performance improvement and we look forward to publishing some fuel consumption figures in due course, although we are sceptical about the 10% improvement figure claimed as a possibility: there has been an improvement, but only of the order of 3%.
Pigspeed’s Mercedes, Porsche and Ferrari owning customers have been having Autoflash fitted as a matter of course when their cars are serviced, Perkins being convinced that the convectors do produce a worthwhile improvement, and none have complained so far. The only sour note is that Ford have condemned Autoflash in an article published in Service Statio,1, a trade magazine, saying that it may cause pre-ignition in Ford engines. But then Ford do make spark plugs themselves. – PHJW.