Clogged injectors, how to care for an engine while training, avoiding costly altimeter checks, and engine design considerations are on tap for this episode. Email [email protected] for a chance to be on the show.

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Full notes below:

Marko’s engine had a strong revving sound on takeoff. He saw that he had an EGT above 1,800 degrees and one that was below baseline. A run-up after landing made it seem like it one cylinder wasn’t firing. A borescope inspection revealed nothing unusual. A subsequent check of the injectors found that there was debris in one. His mechanic suggested it was a blocked injector. He’s wondering what would cause that. It turns out this event was soon after the annual when the injectors were cleaned. The hosts agree that the maintenance is clearly what caused the clogged injector. Mike said this is such a delicate operation that he thinks it’s almost as if the fuel system should only be cleaned under sterile conditions. Colleen said she used to clean hers, but now doesn’t because she knows the risks. Paul colorfully describes the problem of cross-contamination.

Dylan teaches in a carbureted Seminole and he wants to treat the engines well, and is looking for best practices. He mentions shock cooling, which the hosts quickly debunk. The school’s engines are over TBO and they’ve never had to replace a cylinder. Obviously whatever the school is doing is working. He’s also wondering about failing the engines. Lycoming recommends failing the engine with mixture, but many people like to shut off the fuel. Mike said he wouldn’t worry about shutting the engine down from the fuel selector, and that it shouldn’t introduce air or other issues.

Mike worked in the auto industry for many years, and he works on his own airplanes as much as possible. He’s wondering why aircraft engines don’t have ventilated crankcases. Mike said crankcase ventilation is primarily for environmental reasons. And piston aircraft engines have significantly more blowby. You don’t want to keep it in the crankcase. He said air/oil separators return a lot of junk back with the oil. You want the filth to leave as much as possible.

Doug has three altimeters in his airplane, and he’s wondering how to save money on the checks. Mike thinks he shouldn’t be charged three times for three checks because you hook up the equipment once, and adding on a second or third altimeter doesn’t take too much additional time. Each check includes about five tests, according to Paul, and each has to be separately documented.