is high alcohol content (in fuel) damaging to a stock aircooled engine?

I doubt it.

Brazil's fuel is more than 40% ethanol, and air-cooled VWs run perfectly well over there. Their jetting is richened up to allow for the weaker fuel, but I'm not aware of any other changes. I don't think VW changed the compression ratio, for example. Nor, as far as I know, did they make any special changes to the fuel lines. Normal good quality VW rubber fuel hoses seem to work prefectly OK. Aftermarket hoses - who knows?

I've heard that some cheap outlets in Australia are putting up to 20% ethanol in their mix, and this will cause your VW to run lean. With an ethanol mix in your tank, try readjusting (richening) the idle mixture a little. The next trick would be to enlarge your main jet, but it may not be necessary.

It would be nice to see the govt legislate a maximum of 10% ethanol in Australia - we can live with that.

Hi

I work for a large motoring organisation. A workmate went to a Gemini that had just filled up at the local cheapy petrol place, the car just stopped, it ran proplerly when fresh fuel was put in. When the filled his car he spilled fuel on the body it bubbled the paint.

The biggest problem with ethanol is the eratic mix. The south american VW motors that use higher mixes can only run on those higher mixes. We need things to be standardised.

1302Steve

If your paint bubbled, it wasn't ethanol. And, these things are standardised - we need the gov to approve alcohol more than remove it. Berg reckons 10-15% alcohol works sweet and in my younger years I ran up to 25% alcohol in various engines (admitedly, the RON of the original fuel was higher in those days) without any problems. The reason I stopped at 25% was because my calculations predicted problems - I ran a moped on 100% ethanol for a while (well, only a tankful, but I didn't hear any ping - and it did run.) I did these experiments because at the time Queensland had a large excess of sugar and the price of ethanol was lower than petrol before tax (I later discovered the ethanol I was buying was extracted from petroleum.)

The reasoning behind adding 10-20% alcohol (as the governement is considering legalising) is that the lowering of combustion temperatures and raising of RON will couteract the leaner mixture produced. This might be more of an advantage for a VW, I'd love to see some results of proper scientific experiments.

this article claims that a special coating is used inside vw fuel tanks in brazil, i guess to stop corrosion.

www.mg-tri-jag.net/alcohol_fuel.htm

aside from that seems that jetting and timing require tweeking. so, yes a bit of work would appear to be in order. all futile though until regulation states the baseline figures for us to work with.

I work for BP at their oil refinery in WA. To my knowledge the only ethanol that should be in fuel is in Ultimate in QLD, where a trial has been run on 5% ethanol mix. You are right - it is because QLD can make cheap ethanol from the sugar cane, which is the reason you will only see it in QLD currently.

The reason you might see more corrosion in a fuel tank with ethanol mix is that the ethanol is hygroscopic (ie attracts water). Sit water in any fuel tank and it will corrode.

I agree though - its alternative fuels that are the future, so the more trials in this area the better, but like has already been mentioned, the mix needs limits and standards as you need to know what you are running to ensure your engine is tuned safely.

Doug