I received an interesting note from Patrick Puckett who is considering replacing the 100LL engine on his aircraft with a new aviation diesel engine. He had several questions concerning the performance of Jet A vs. #2 diesel fuel.
I received an interesting letter from Karl Sieg concerning my article on synthetic oil in the March 11 issue (Synthetic oil: Is it right for your plane?). Several years ago, Karl’s cousin had run synthetic oil in his 1946 T-craft and “”the engine ran so well he had to retune it.”" Karl then tried some synthetic oil in his car and the mileage improved. He then went on to ask about the problems, litigation and FAA rulings regarding the use of full synthetic oils in aircraft engines.
Phil Smith from Iowa wrote to ask about leaded vs. unleaded octane. He heard at a seminar that “”?when the octane is maintained, lead is NOT necessary in an aircraft engine.”"
One of the big questions in aviation is, “”What is synthetic oil and should I use it in my airplane?”" As always, my answer is a definite maybe.
I’ve received several questions about the future availability of avgas. One reader noted that AOPA President Phil Boyer has warned that oil companies will stop producing avgas in five years or so. The reader went on to ask if he would be able to use auto gas in his aircraft or would he need to replace his engine.
That was the question from Bryan Gore, who flies a Citabria with an IO-320 engine equipped with an oil inverted system. It does not have an oil filter.
I received an interesting letter from Kurt Wegge, who flies a VariEze with a TCM O-200 engine, and has experienced numerous incidents of exhaust valve sticking. He was wondering if Marvel Mystery Oil would help reduce this. Kurt also noted documents from the FAA (Special Airworthiness Information Bulletin No. NE 03-45, dated June 27, 2003) and TCM (SIL 99-1 and SIL 99-2A) that give a lot of information on this subject. I strongly recommend that you get a copy of these documents if you have an O-200 with this problem. The information is also applicable to other engines and aircraft that have experienced this problem.
For the past 20 years, an older gentleman has sought me out at Oshkosh to ask me the same question: “”Which is better in an aviation piston engine: single grade (SG) or multi-grade (MG) oil?”" Every year I feel that he wants a quick one-or-the-other answer, but every year I gave him a long, qualified answer that depended on what he is flying and where he lives. The main difference between most sales people and most engineers is that the engineers have very few black and white answers. To an engineer, the answer to just about every question depends on a lot of variables.
It’s the number one oil-related question of all time: “”How often should I change my airplane’s oil?”"
A few issues back, my good friend Paul McBride was asked what was the best oil temperature for an aircraft engine (Just what is normal? Oct. 15 issue). Since then, I have received a few questions about the same subject, but from the lubricant perspective.