Return-Path: Received: from imo20.mx.aol.com ([198.81.17.10]) by truman.olsusa.com (Post.Office MTA v3.5.1 release 219 ID# 0-52269U2500L250S0V35) with ESMTP id com for ; Thu, 4 Mar 1999 13:42:23 -0500 Received: from Fredmoreno@aol.com by imo20.mx.aol.com (IMOv19.3) id kBNDa16741 for ; Thu, 4 Mar 1999 13:43:30 -0500 (EST) From: Fredmoreno@aol.com Message-ID: Date: Thu, 4 Mar 1999 13:43:30 EST To: lancair.list@olsusa.com Subject: Ref: David Jones, Oil temperature rise X-Mailing-List: lancair.list@olsusa.com Mime-Version: 1.0 <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> David: You did not mention the outside air temperature or oil type which may suggest the solution. I had a similar problem years ago in my old 182. Departed Salt Lake City on a cold winter day, and oil temperature went high on climb. Back to the airport, to the FBO, and I learned about congealing oil in oil coolers. Oil gets so cold it turns to molasses and oil flow slows dramatically, hence high oil temperature. Cessna makes a kit for this that blocks much of the oil cooler. No kit available, so the fix for us was to put duct tape across half the oil cooler to restrict cooling (tape perpendicular to the tubing direction, sized to approximate the picture showing the Cessna kit), and it worked fine getting us back to the Bay Area where we removed the tape upon landing. So, my guess is that your oil temperature was being controlled by the vernatherm until you opened the door, increased the air flow, over-chilled the oil in the cooler which then caused it to slow to a dribble of molasses, temperature goes up, then you shut the oil door causing the oil cooler to get warmer, the oil to start flowing, and oil temperature drops. My guess is you were using straight 50 weight instead of multigrade. You were also flying low in thick air and going fast, so cooling was very good, unlike high altitudes where the air is thin. If you provide the rest of the data (oil weight, OAT) maybe we can solve the mystery. Fred [Fred, and everyone... David was kind enough to write back with the real explanation, that being that the oil cooler door was closed when he thought it was open and vice versa. I had originally thought that that was what his symptoms were suggesting, but I didn't say anything because I thought that there was no possibility of it being something that simple. I guess I was wrong. This would appear to be one of those instances where we can all be reminded of a very basic engineering tenet, that being when something is wrong the first place to look is to the obvious. Granted, many times we may be searching for a real gremlin, but if we don't eliminate the first things that come to our minds before going on to find the more mysterious explanations, we may very well spend a lot of time in chasing our tails, only to find out there was a simpler explanation all along. That being said, just keep those posts coming!!