At 05:45 AM 12/25/2012, you wrote: >Why do I need to preheat here in the south? Roy says to not take off with >the OT less than 120 degrees. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Why so hot? That seems overly cautious to me. On the 0-200 I gauge it by when adding power does not peg the oil pressure meter. I'm assuming that at that point the oil is flowing well. A cheap and very effective engine pre-heater can be made using 1/2" foil wrapped foam insulating board and a 1500 watt ceramic heater. A single 4 X 8 foot panel is more than adequate. Fabricate a square or rectangular tube sized to accept the heater placed inside the tube. The tube should be in the shape of an "L" with the heater part that sets on the floor made approximately 3 feet long. Make the transition to vertical a double 45 degree corner for more efficient airflow. Make the vertical run whatever height necessary to just fit under the opening in the back bottom of the cowl and shape it to best fit the opening. Place a blanket over the cowl and plug in the heater. This will heat the entire engine, oil, cylinders, and battery too if located in the engine compartment. I made my first heater for the TriPacer and could preheat the engine from 30 degrees in the hangar to an oil temp reading on the panel of 80 degrees in just under one hour. I've made several of these over the years, each modified to a particular aircraft, Cessna 170, 150, Cherokee's, TriPacer, KR, etc. I suppose you could plug the heater into a remote thermostat located inside the cowl and keep the engine at a constant temp if you wanted. Don't put it on a timer that lets the engine warm and then cool in cycles. That will cause the engine to "breath" air in and out with each cycle and probably induce more moisture in to the case, not good. Merry Christmas to all.......... Larry Flesnre
