Brazil's Alcohol-Powered Car

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[3] Heating the intake manifold. Again, this change helps alcohol fuel to vaporize efficiently. In water-cooled engines, hot water is routed through chambers in the manifold walls . . . in air-cooled models, the intake "runners" are simply shortened to a minimum to reduce heat loss.

[4] Recalibrating the carburetor. Because the ideal air/fuel mixture for ethanol is 9 to 1 (as opposed to 14 to 1 for gasoline), the main jet, idle circuit, power valve, and — in some cases — the accelerator pump stroke have to be modified to supply more fuel to the engine. (Certain carburetors must also have their internal passageways bored.)

[5] Hardening the valve seats. Since alcohol doesn't contain the lubricating elements that gasoline does (although the presence of water in the fuel does help compensate for this lack), the engine's valve seats are induction-hardened or fitted with stainless steel inserts. [EDITOR'S NOTE: Cars built in the U.S. since the early 1970's are already so equipped, and older cars "weaned" on leaded gasoline have likely absorbed enough lubricant to provide a suitable cushion.]

[6] Modifying the fuel system materials. Ethanol, especially in the presence of water, may cause eventual corrosion in various parts of a conventional fuel system. To forestall that problem, the fuel tank and pump and carburetor bodies are lined with a thin bronze coating in place of the lead/zinc veneer which is normally applied at the factories.

[7] Making ignition changes. Because of the antiknock qualities of hydrated alcohol, initial timing is advanced from 4 to 8° over normal settings. In addition, the distributor advance curve is recalibrated . . . to take advantage of the fuel's high "octane" during times of heavy acceleration. A high-intensity ignition coil is also used — along with "hotter" spark plugs — to help overcome the ethanol vapors' resistance to ignition.

[8] Constructing cold-start systems. Since alcohol's reluctance to vaporize is accentuated in cool weather, the ethanolpowered vehicles are fitted with starting aids for cold engines (which are used at temperatures below 55°F or so). Direct gasoline injection down the throat of the carburetor is common now, but alternative methods (based on increased fuel vaporization and auxiliary heating) are currently being researched so that only one form of liquid energy — alcohol — will be needed to operate the car.

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