Bio-fuels and classic cars
Jul 18, 2008
New bio-fuels may be damaging to classic car engines, so Kettering professors are studying the effects of ethanol-blended gas on the treasured classics.
The rumor mill among classic car enthusiasts is that modern gasoline is ruining classic car parts, specifically engines and fuels systems. “The concern is that modern fuels may have a negative effect on classic car engines,” according to Dr. Craig Hoff, professor of Mechanical Engineering at Kettering University.
He and Dr. Greg Davis, professor of Mechanical Engineering, are studying the effects of ethanol-blended fuels on the engines and fuel systems of classic cars to determine if they accelerate corrosion and cause component failure at the request of Hagerty Insurance Agency in Traverse City, Mich. Also working on the project is Dr. Chuck White, from Kettering's Industrial and Manufacturing Engineering Department, who is serving as the team's materials expert and is helping evaluate damage to parts.
Hagerty insures more than 600,000 collector cars and a number of vintage boats, and they have funded a $50,000 study with Kettering’s Advanced Engine Research laboratory (AERL) to explore the effects of bio-fuels on older engines.
“We serve the hobby in many ways, so we felt it was important to ascertain the impact of ethanol-blended fuel on collector cars and boats,” Hagerty CEO McKeel Hagerty was quoted as saying in the on-line edition of AutoWeek.
Currently, most automotive fuel (gas) has at least 10 percent ethanol content. (Not all marine gas is ethanol-blended, and some vintage boats have had problems with ethanol blended fuel.)
Ethanol is an organic solvent known to be corrosive that, according to Hoff, in high concentrations may result in corrosion in older gas tanks. Specifically, in older tanks that may have a sludge build up. The ethanol breaks up the sludge, varnish and dirt that commonly accumulates in older gas tanks and sends it through the engine causing blockages to fuel lines and carburetor jets.
In lower concentrations, ethanol may soften materials such as seals and gaskets, which get brittle and fail, Hoff said.
“We had to decide which issue we wanted to tackle first,” said Hoff, “and we decided to focus on the low blend fuels first.” The team plans to test classic car components to determine the effects of fuel from a commercial gas station, which is about 10 percent ethanol, and compare it to results when using pure gasoline with no ethanol.
The project will be conducted on two levels: general material compatibility and ethanol compatibility testing on specific material and parts which are likely to be used in the classic automobile community.
In the ethanol compatibility testing, researchers will test two sets of parts in simulations of an automotive fuel system complete with carburetor and fuel pump. They will test both fuel systems in a closed loop on the Engine Test Cell on campus. One is currently on the test stand.
Because ethanol is hydrophilic it will absorb water from the ambient air. In a sealed fuel system, such as those on modern vehicles, the ethanol will remain mostly anhydrous. However, in a classic car lacking a sealed fuel system, the fuel can potentially absorb a significant amount of water from the ambient air. It is believed that this water content can increase the corrosion in fuel system components.
Ethanol will be aged in open wet air for one month to allow the fuel to pick up water. For control purposes the un-blended gasoline used in the testing will also be aged this way. Additionally, some of the ethanol will be aged in wet salt-air to simulate conditions in locations with salt-water.
“We will run 12 different tests on 12 common components from six classic cars,” said Hoff. Following modifications to the fuel room they have created, testing of all 12 components will get underway, he said.
Hoff said the study represents approximately 3,000 hours of testing, with every 1,000 hours representing the effects of 50,000 miles at 50 mile per hour on the components.
Plans also include cutting up a third and fourth set of parts, such as sections of the fuel tank and gaskets, immersing them in ethanol-blended fuel and pure gasoline and repeatedly exposing them to air to accelerate corrosion. In addition, control chips made of materials known to be sensitive to ethanol, like aluminum, will be placed in the testing tank.
“We can’t cut up the parts we are using in the simulator,” said Hoff, “so this allows us to see 'inside' the components during testing,” said Hoff.
The corrosion testing has proven to be the most problematic part of the process. “We have to be very careful because fuel is highly flammable,” said Hoff. He and Davis had to create a special room for the test. The room has to have a high rate of exchange of fresh air requiring them to use compressed air and special fans. “We want to perform safe tests,” said Hoff.
According to Hoff, there is a lot of interest in this research project outside of the insurance company. The Environmental Protection Agency (EPA) has contacted them about the project and colleges as far away as Germany are interested in their results.
“There is a lot of opportunity to pursue this line of inquiry because there are many people who want to know more about this subject,” Hoff said. "It’s amazing the amount of interest there is in this study.”
Despite the comprehensive testing they are performing, Hoff and Davis do not anticipate sludge and corrosion to be the most critical issue related to using ethanol-blended fuels in classic cars. “Most likely the biggest problem will be with gaskets made of rubber,” explained Hoff.
Until the study is complete, classic car owners might want to take a few precautions, such as: drain and clean their car’s fuel tank; use a fuel tank sealer that is impervious to ethanol; keep all screens clear; and use a fuel tank stabilizer if the car is to be stored for long periods of time.
Information from the Jan. 14 edition of AutoWeek Magazine was included in this story.
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Written by Dawn Hibbard