Date: 04 Jul 2006 17:19:44 GMT
From: John B <>
Subject: ethanol conversion query

Hi, I've been reading up lately on the technical aspects of converting gasoline vehicles (e.g. a Saab c900 turbo) to run on ethanol or ethanol/gasoline blends. I'd appreciate any input on the ideas, and of course any experience anyone might have doing such a project. I've been considering the following facts: 1. gasoline is now rather expensive (and is likely to stay that way); 2. ethanol is likely to become increasingly available; and 3. c900 turbos are relatively inexpensive these days. Also, I understand that turbo engines are particularly suited to running on ethanol because they can take full advantage of high octane fuels. It looks like there are two primary obstacles to running a gasoline engine on ethanol: compatibility of the fuel delivery system with ethanol, and the need to inject more fuel per mass of air. 1. Fuel storage/delivery a. Compatibility of fuel tank and fuel lines with ethanol. I'm not really sure what the c900's fuel tank is made of. Is it stainless steel? Also, not sure about fuel line compatibility. Does anyone have any idea? b. Fuel pump The fuel pump may contain internal seals or other parts that dissolve in ethanol. Probably not an impossible obstacle though. c. Fuel injector O-rings ... must verify that injector o-rings are not ethanol-soluble. Probably not a big obstacle to overcome. 2. Air/fuel mixture My understanding is that the c900 can tolerate 10% or maybe even 20% ethanol/gasoline mixtures, as the ECU can detect and compensate for lean/rich mixtures via the oxygen sensor. But running on > 20% ethanol probably screws up the air/fuel mixture by a greater degree than the ECU can compensate for. The solution to this problem must be to inject more fuel. One way to do that is to enlarge the injector ports, but that introduces assorted other problems (i.e. spray pattern and mixture-too-rich when running on gasoline). So another solution is to change the injection pulse length. There seems to be an aftermarket product designed to do just this (see - not affiliated, etc). It apparently intercepts the signal from the ECU to the injectors and lengthens the pulse, and you can still switch it off to run on gasoline. They claim to be compatible with Bosch fuel injection. The same people also sell some sort of engine treatment, which they claim coats certain engine parts to protect them from ethanol/water induced corrosion. That's probably the scariest part of this whole thing as far as I'm concerned. Oh, and they also warn that the ethanol will clean out lots of gunk from the fuel tank, necessitating a couple of fuel filter changes. So, does this sound like it would be a worthwhile experiment? The total cost would likely be $2000 - $3000, including the car... John -- Posted via a free Usenet account from

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