can anyone think of any reasons why I can't use ethanol in my 68 300In. six? It has an rv cam, headers, clifford intake and a 500cfm 2bbl. carb. Can the ethanol be mixed, say 50/50 with reg. gas? thanks

 

The fuel system will not take that mix. Use 5% max ethanol to be on the safe side. Congress allows 10% but that will eat up seals at elevated temps like under the hood. Only use ethanol if you are going to burn thru it fast. The ethanol will draw moisture from the air and it will rust your tank and lines if you do not burn it up fast. It will also corrode the carb and erode the rubber fuel lines. The new vehicles have special coatings and materials to resist alcohol fuel's corrosive and solvent properties. You can convert your engine to run on pure alcohol or E85 tho. See the alternative fuels forum for info on the conversion.

 

the main thing you need for ethanol is the alcohol seals for your carb. The natural rubber seals will dry out and crack, causing them to not do their job properly and overfuel. Ethanol is not as corrosive as methanol, which will eat up the fuel lines and tanks as described, it takes a long time in relation for ethanol to cause the same damage. Most new carb kits come with ethanol seals, as they will fail under 10% the same as they do for higher rates. If you were to run the fuel through in a bout a week, you wouldn't notice any problems with corrosion. If the vehicle were driven less, and the ethanol allowed to evaporate, then you would eventually see the problems described. Many guys are running it in South Dakota on the Wissota dirt tracks, and they do not experience the problems of corrosion with the standard galvanized tanks. The carbs also are cleaner than you will see with regular gasoline, no varnish. I have run it (E85)through a multitude of vehicles and had no corrosive problems, actually, no problems other than what you would have running normal gasoline. I did not run it through non alcohol seals, as that will dry them out. Everything I have run it through was 82 and later, because they have the alcohol seals to counteract the 10%. If the carb kit has the blue seals, those are neoprene and are alcohol tolerant.
Methanol, on the other hand, is derived from wood pulp, and has the acid in it that is highly corrosive, and requires special tanks and fuel lines. The high end racers use methanol for race fuel, (NHRA) and have to run the special equipment. There was one racer in the late madel class in South Dakota that was running 100% ethanol, and I had talked to him about it, and he stated that there was nothing special about his setup, it was the same that was mandated, fuel cell, the like, but he did not run anything out of the ordinary to be able to accept the ethanol. Of course, that was in regards to the rest of the class running methanol, but he said the equipment lasted longer because ethanol is a bit more stable. It does have an affinity for water, but there is almost always some water in the fuel you buy at the pump, just not in large amounts. It will separate out and gather at the bottom of the tank, causing the same damage that is blamed on ethanol. Water is used to push the oil products through the pipeline, since it is heavier and can be used to divide the different product formulation. Otherwise, how could they tell the difference? It depends on the operators to shut the valve and drain off the water in time. Condensation also occurs in the pump tanks, so there is always some water getting into your tank. Ethanol will absorb it and take it into the fuel system and out of the tank on regular use. Why else would products like HEET and other fuel deicers use alcohol? If left for a long time, they too will evaporate leaving the water in the tank again.

 

Good information! I noticed the water in relation to Ethanol years ago and studied the problem after it destroyed a mower. You are correct that Methanol is even more corrosive. The fuel lines and tanks on our old trucks have a very thin zinc plating if any at all which ads to the problem. Newer replacement tanks and lines are coated better.

One correction to make tho. The alcohol in the fuel does not "dry" the elastomer seals out. It actually swells the material causing it to split. It does look like it has "dried" them out after they have are out and dry tho. The elastomeric surfaces dust and crumble due to the solvent swelling which clogs fuel filters and carb orifices. The splits also form leaks. The splits look a lot like tire checking, little fissures in a square pattern. The float needle usually is not a problem because it is made of a very expensive elastomer.

The pipeline operators also use "pigs" to separate the products in pipelines.