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Old 08-26-2021, 08:19 AM
lr172 lr172 is online now
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 6,543

Originally Posted by Rv3Dave View Post
Takes forever to get the oil warm enough for takeoff in the winter..
You may want to re-think your minimum oil temp, especially if using a multi-vis oil. I do not use 100* like many, but instead use a minimum CHT (I do worry about differential expansion rates between piston and cyl wall creating scuffing). From my research, there is simply no rational justification for a 100* minimum OT on a non-radial engine running 20W50 oil. I fly a lot in the Midwest winters and couldn't imagine idling on the ramp for 15-20 minutes like some of my neighbors. My 320 has 800 hours now and oil pressures haven't dropped at idle since overhaul, so unlikely I am trashing the bearings in my engine. I do use oil pan heaters and my OT at take off, after getting the CHTs that I want, is usually between 70-85 in the winter.

If I was running straight 100 oil in the winter, I would think differently. The 100* min OT guideline has been around for many decades and keeps perpetuating eventhough oil technology has vastly improved. You will not find that recommendation in the Lyc Operators Manual. I am guessing it is a hold over from the radial days before multi-vis oil was created, but it is nowhere to be found in the Lyc documenation. The Lyc manual is clear on what oil grades to use based upon ambient temps though and they do not recommend 100 oil in winter temps.

N64LR - RV-6A / IO-320, Flying as of 8/2015
N11LR - RV-10, Flying as of 12/2019

Last edited by lr172 : 08-26-2021 at 08:49 AM.
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