Engine tuning. Correctly adjusted, but still running poorly

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).

Also read_
- Gasoline. And the stuff called E10
- The difficult gasoline story
- Ethanol and gasoline hose
- Ignition and modern gasoline

Didn't learn to drink modern gasoline
E10 vs Aspen


In the past, gasoline didn't do this kind of thing with gasoline line


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  1. In the early 70s (what is that a long time ago) someone came to me with his BMW R-60/2 (the one with that swing arm).
    He had taken the engine to a local engine garage for maintenance and adjustment.
    When he came to pick it up, the engine was in a corner; we don't get any more life in it. He could go with that (he was brought on foot !!!)
    After some research it turned out that the key had disappeared from the cone of the camshaft so that the rotor could be mounted in any position ……………… ..

  2. For all its worth, my old Diesel definitely rides badly on the new, and of course "improved"
    low sulfur Diesel. Fortunately, we have a Bio-Diesel station in Squamish, where my elderly person Citroen CX 2500 (non turbo) Diesel drives superbly. The car has lived in West Vancouver its entire life, and for the last 7 years in the West end of Vancouver.
    If there is no Bio-Diesel nearby, I will try to refuel Petro-Can normally. About 900 kilometers
    from a long-range tank. Trips of approximately 4 to 7 hundred kilometers. Especially through the mountains, the car still runs exemplary. It is a five-speed gearbox and you don't really have to switch back often. Today, gasoline here is $ 1.29 per gallon and Bio-Diesel is $ 0.99.

  3. Ton Rossewij reports that his engine of his Alvis was later improved with new settings
    and wiring this can be seen in AMK and on sleuths and AutoScout24
    the engine is lead-free with chain drive very reliable block,
    more than a 6 cylinder it can easily drive 100 km you can
    to perform on the block with two comedians, but that is not necessary at all
    He is very economical 1/10, which is nice for such a classic car.

    • Ton Rossewij wants to report that the engine is lead-free, but the use
      E5 petrol is recommended because of the rubbers etc.

  4. I found out that this also applies to older diesels, those with pre-heating special! Super diesel with additives necessary, not much is written about it yet.

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