How to tell the difference between greases? Mike, Paul, and Collen break it down, plus high lean of peak temps, breaking in an engine on an experimental, and composite airframe cracks.

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Full episode notes below:

Mark wants to make sure he’s clear on which grease to use for which application. The manuals call for specific greases, but there are allowances for those with equivalent specs. But Mark wonders how to determine

Grease Options March 24 2022, David Prizio, Kitplanes: 

https://www.kitplanes.com/grease-options/#:~:text=If%20your%20plane%20lives%20on,05%20and%20GN%2015%2C%20respectively

For a full grease cross reference chart: EMTC

https://emtc.aero/wp-content/uploads/2021/01/Mappe2.GREASE-XREF-1.pdf

From the LPS product application guide: https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://pdf.directindustry.com/pdf/lps-laboratories/application-guide/11942-89226.html&ved=2ahUKEwjYgbmQiIiOAxVHHTQIHS21OzQQFnoECB4QAQ&usg=AOvVaw0KD4UOmbKMMo-0_4cGPymS

Todd has a 2008 Cessna 400 that he just took delivery of. The airframe around the windscreen has a few little cracks that look like spider cracks. He’s read that there’s been an issue with this area and he’s wondering how much it matters. Paul said Todd is seeing cracks in the filler, and the expansion and contraction rate of it is different than the structure, which causes the cracks. Cessna apparently said back when it was built that they were working on a warranty repair for this area, but never did so.  

David is wondering how to break in a new engine on a new experimental airplane he’s building. He has the engine now pickled, waiting for the airplane to be finished. Colleen did some research and on the Van’s forum

Jason is worried about his lean of peak temps on his B55 Baron. With the cowl flaps closed and a relatively warm day outside, he can’t keep one of his cylinders below 400 degrees. He’s done the Savvy flight test profile, and Savvy told him that the GAMI spread is acceptable and suggested checking the baffling. The first thing the hosts tell Jason to do is not compare the two engines. It’s irrelevant data. They focus on the baffling, even though Jason’s mechanic said it looks good. Paul said he’s seen cases where the baffling is wavy, which requires a slit be cut so that it lays flat and incoming air flow pushes it against the surface next to it (usually the cowling). After taking a deeper look, the hosts also suggest swapping probes to see what happens.