I do not key for others. First of all, I'm no more than a well-meaning amateur - with half a century of key and improvisation experience, that's for sure - but you shouldn't get in the way of professionals. And then an acquaintance arrived who had his classic car given a major overhaul at his local village garage. His car was not running smoothly ...
Craftsmanship is mastery
'Village garages' or 'universal', non-branded garages are usually a good and affordable alternative to official brand dealers after the warranty period of a car. From my own experience, I dare to say that the mechanics of universals are often just a bit - or much - sharper than brand mechanics of recent cars. They often think more technically without directly focusing on their diagnostic equipment.
But all over the garage world, the real old-fashioned craftsmanship is disappearing. The company where my acquaintance had had his car 'done' was neat. And everything was set by the book. However, those adjustment data were all 'ex works' when petrol was just petrol instead of excise duty diluted with alcohol. And that made the story clear, because it has been known in classic circles for a long time: That stuff you now throw in your tank has long been no more tiger. but a fat, cut tomcat, struggling in the windowsill above the central heating radiator. And you get that hangover from bio ethanol.
Well, bioethanol is actually not a bad motor fuel at all
Every sprinter or drag racer knows that. If you used a modified engine block for it, you could compress higher. That would give more power and / or a lower fuel consumption. Nice is not it? Little feasible in our classics.
Ethanol contains less energy than petrol. If you were driving on 100% ethanol, you would have to add 1,5 times as much for the same energy value as petrol. With 'only' 10% admixture the problem is of course smaller. And a modern, smart injection engine can adjust that. But if you inject more, the fuel consumption just goes up.
The problem is bigger with carburettor engines: they have to make do with what they swallow. As a result, they can get a mixture that is too lean. Especially with the latest generation of carburettors, which are already very poorly adjusted due to emission requirements. As a result, they generate more heat, they lose power, so that you give more gas and therefore they use even more. Because you have to try everything, I refueled E10 in classics. Measured over the wet finger, this resulted in a 15-20% higher consumption. While the engines also ran noticeably rougher.
Ethanol is also quite aggressive and corrosive
It attacks some rubbers, polyester, fiberglass and certain aluminum alloys. This therefore causes problems if the fuel system is made of these types of materials. The flame or explosion character is also different, so that with E10 refueling your ignition will be 'wrong' if the block has been adjusted according to the booklet.
An old-fashioned mechanic has adjusted the classic of my knowledge not by the book, but by feeling. This also meant that the nozzle occupation was adjusted. Setting the ignition on time happened in the way I learned it myself in service: 'Set the ignition to' pinging ', and then back a bit'.
And when the owner then once refueled 102 octane in Germany, he thought he had a completely different engine.
Workshop manuals and the like including youtube are indispensable for people who tinker. But some of the things in it have become obsolete over time. And then you just need old-fashioned craftsmanship (and a multi-gas meter).