Veg fuel risks when greater than 20% volume

[PalmspringsSCal]

Over 30 different vegetable oils have been used to operate compression engines since the 1900’s (Quick, 1980). Initial engine performance suggests that these oil-based fuels have great potential as fuel substitutes. Extended operation indicated that carbonization of critical engine components resulted from the use of raw vegetable oil fuels, which can lead to premature engine failure. Blending vegetable oil with diesel fuel was found to be a method to reduce coking and extend engine life. Pryde (1982) reviewed the reported successes and shortcomings for alternative fuel research. This article stated that short-term engine tests using vegetable oils as a fuel source was very promising. However, long-term engine test results showed that durability problems were encountered with vegetable oils because of carbon buildup and lubricating oil contamination. Thus, it was concluded that vegetable oils must either be chemically altered or blended with diesel fuel to prevent premature engine failure. Studies involving the use of raw vegetable oils as a replacement fuel for diesel fuel indicate that a diesel engine can be successfully fuel with 100% vegetable oil on a short-term basis. However, long-term engine durability studies show that fueling diesel engines with 100% vegetable oil causes engine failure due to engine oil contamination, stuck piston rings, and excessive carbon build-up on internal engine components. Therefore 100% unmodified vegetable oils are not reasonable diesel fuel replacements. Vegetable Oil, Diesel Blends as Potential Fuel Sources Engelman et al. (1978) presented data for 10% to 50% soybean oil fuel blends used in diesel engines. ( Vegetable oil fuel blends of varying percentages refer to fuels of which raw vegetable oils have been mixed at the indicated percentage with #2 diesel on a volume basis.) The initial results were encouraging. They reported at the conclusion of a 50-hour test that carbon build-up in the combustion chamber was minimal. For the fuel blends studied, it was generally observed that vegetable oils could be used as a fuel source in low concentrations. The BSFC and power measurements for the fuel blends only differed slightly from 100% diesel fuel. Fuel blends containing 60% or higher concentrations of vegetable oil caused the engine to sputter. Engine sputtering was attributed to fuel filter plugging. They concluded that waste soybean oil could be used as a diesel fuel extender with no engine modifications. Studies in New Zealand by Sims et al. (1981) indicated that vegetable oils, particularly rapeseed oil, could be used as a replacement for diesel fuel. Their initial short-term engine tests showed that a 50% vegetable oil fuel blend had no adverse effects. While in long-term tests they encountered injector pump failure and cold starting problems. Carbon deposits on combustion chamber components was found to be approximately the same as that found in engines operated on 100% diesel fuel. These researchers concluded that rapeseed oil had great potential as a fuel substitute, but that further testing was required. Caterpillar (Bartholomew, 1981) reported that vegetable oils mixed with diesel fuel in small amounts did not cause engine failure. Short-term research showed that blends using 50/50 were successful, but that 20% vegetable oil fuel blends were better. Dupl Conclusions Many studies involving use of un-modifed vegetable oils in blend ratios with diesel fuel exceeding 20 percent were conducted in the early 1980’s. Short-term engine testing indicates that vegetable oils can readily be used as a fuel source when the vegetable oils are used alone or are blended with diesel fuel. Long-term engine research shows that engine durability is questionable when fuel blends contain more than 20% vegetable oil by volume. More work is needed to determine if fuel blends containing less than 20% vegetable oil can be used successfully as diesel fuel extenders TommyGunn

[AndysFords]

I don't know what you consider "long-term", but I just rebuilt the engine in my 88 Ford, the last 30,000 miles it ran almost nothing but vegetable oil, there was absolutely no sign of contamination. I know thats really not a lot of miles, but if there was long term effects you should be able to see the start of it after 30,000 miles. I still believe that the money you save greatly outweighs the added costs. Lets say the average 7.3 IDI has at least 300,000 miles in it if properly cared for. If you only get 200,000 miles out of it, you still have saved a lot of money. The average person never puts over 200,000 on a truck. Any way you look at it the benefits outweight the costs by far.

[thymekiller]

I have to agree with Andysfords. Also, I think wvo is cleaner at the tailpipe. Thats worth something. Some guys mix alittle tranny fluid in and they claim that helps stop cokeing. I dont know for certain about that.
Its a good disscussion.
Anytime you buck the system, theres a report that says you cant do that.
At some point in time, it was a proven fact that the world was flat and tomatoes were poisionus.
My 2 cents, for what its worth.....

thyekiller