What part of ‘no’ don’t they understand?

One of the joys of being retired is that I get to read more of the newspaper each evening. Now the front page has all of the big stories that are of worldwide importance, like the Kim Kardashian marriage that lasted only 72 days. But if you read the inside pages, you can find some very interesting information. On page 5 of our local daily paper here in the agriculture heartland was an article that caught my eye. The headline read: “Study: E15 damages boat engines.”

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Why lead reduces knock

In the Sept. 23, issue of General Aviation News, there was a letter to the editor from Jack Thompson, who wrote: “Re: Visser’s Voice: Knock free, Aug 26 issue: It is a sad commentary given that the IC engine is such an integral part of aviation that the user community is so ignorant of its operation and engineering issues. What percentage of the users understand the impact of fuel detonation resistance and the if-then relationships of fuel suitability for a given service?”

The actual truth is that no one really completely understands the interaction, especially how lead additives work in a fuel to reduce knock.

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Winterizing your plane

A couple of days ago when I went out for my morning walk I noticed something had changed. Instead of warm and sunny, there was a chill in the air. I then realized that fall is approaching and I needed a jacket.

The same kind of thing happens to many pilots each year. They are enjoying the nice flying weather when all of a sudden, winter is upon them, so they put their plane away and figure they will just change the oil in the spring before they do any more flying. There is a big problem with this plan.

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Knock free

In one of my recent columns I stated that if an engine runs knock free on an 87 octane fuel, using a higher octane fuel will not benefit you in any way. I received several inquiries about whether this was for automobiles or airplanes. Basically it applies to both.

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Flawed logic

Ben Visser is an aviation fuels and lubricants expert who spent 33 years with Shell Oil.

I recently received a question from reader Bill Blank asking whether there was more BTUs in higher octane fuels and if there was any reason to use a higher octane fuel if a vehicle ran knock free on a lower octane fuel. The simple answer is no.

I have received this question many times and the concept of more is always better is very ingrained in our minds. [Read more...]

Good science

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Ben Visser is an aviation fuels and lubricants expert who spent 33 years with Shell Oil.

In one of my past columns, I criticized the ethanol industry and others for using “bad science” to promote their products. I received several emails from readers who felt that I was off base because, they said, the Wright brothers were just bicycle mechanics — not scientists — who discovered controlled flight. Let me share with you a little history about Orville and Wilbur. The Wright brothers were two of the top aeronautical scientists of their day who just happened to run a bicycle shop to pay for their research. [Read more...]

How long can fuel be safely stored?

Ben Visser is an aviation fuels and lubricants expert who spent 33 years with Shell Oil. He has been a private pilot since 1985.

Reader Jerry Johnson recently wrote in with a question about fuel storage: “Rotax indicates that octane ratings degrade rapidly and significantly with storage. If so, wouldn’t storage for a matter of weeks render the fuel dangerous to use in aircraft?”

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Testing for ethanol

Ben Visser is an aviation fuels and lubricants expert who spent 33 years with Shell Oil. He has been a private pilot since 1985.

How do you test for ethanol in auto gas?

Recently, I’ve received a lot of e-mails from people who want to know exactly how much the water phase volume will change in the test, and whether they can mix water with the bulk fuel and remove the ethanol to make the auto gas safe for their aircraft.

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The fuel of the future: Is it already here?

Ben Visser is an aviation fuels and lubricants expert who spent 33 years with Shell Oil. He has been a private pilot since 1985.

I recently received a note from reader Scott Shroyer, who is looking to buy a used Cessna 182 with an auto gas STC. He wants to know if it is worth his time to buy the 182 “in hopes of finding auto gas at an airport to fill it up?”

A lot depends on which state Scott lives in as to the availability of auto gas without ethanol. I then forwarded his question to Todd Petersen of Petersen Aviation, who has sold more than 34,000 mogas STCs worldwide since 1983.

Scott’s question raised several questions in my mind. First, is it worth considering the fuel requirement of an engine in the purchase of an aircraft? I would say that it does at this time.

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