lml@lancaironline.net Mailing List Archive

<<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> First Union Securities, Inc. Mike Dehate came to Charlotte last weekend for the second test flight of my 360. The first flight was terminated after the governor failed to keep the propeller under 2700 RPM. I had the governor overhauled - it had been set to 3200 RPM, so it seemed to be the likely culprit. Mike arrived on another cold weekend in NC - about 40 degrees, but the hangar always seems to feel colder. Saturday morning he took off, and... When the oil temperatures got over about 215 degrees, the prop RPM began to increase. Mike landed the plane before an overspeed occurred. We hacked a new hole in the cowl and installed the "sharks gills" to try to keep the oil temperature down, and he took off for another test. Unfortunately, the RPM started to increase again with oil temps over about 215 degrees and Mike had to reduce power to avert another overspeed. So... what's the problem? 1. I know 225 degrees isn't a good oil temperature - but is it TOO hot to allow the governor to control the prop? My prop shop thinks so, but Lycoming doesn't. 2. Should I adjust the "static RPM" (course pitch adjustment) on the MT -12B to 2400 RPM (currently set to 2600 RPM) to make it "easier" for the governor? Lancair's Orin indicated he typically sets up the MT prop and governor so that static RPM is around this range and I have spoken with another mechanic who said he has set them to 2200 RPM static... 3. Do I have an internal engine problem (i.e. thrust bearing...)? Any thoughts appreciated. Matt >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML website: http://www.olsusa.com/Users/Mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>