This is exclusive to all the other LE pilots who are as enthusiastic (aka stupid) as I am and fly their legal eagle in cold weather, for me that is Northern Michigan in November. This is the first winter I have decided to bundle up and fly her under 40 degrees. Contrary to expectations, I have been experiencing poor climbout performance in cold weather. When I say poor, I have better performance on a 85 degree day, which is grossly opposite to what it should be! My theory is that since my oil temp is barely getting over 100 with the uncowled 1/2 vw getting blasted with frigid air, I am not getting warm enough to expand and get a sufficient head to cylinder seal, therefore having low compression. Note I do not have a copper head gasket/shim, I lapped the head into the cylinder per original VW design, therefore it really needs that expansion to create a good seal.
Next time I am in the hangar I planned on doing a compression test cold vs warmed up (if I can even achieve that), and that should be a good tell if that is the culprit or not. Has anyone with an uncowled 1/2VW ever experienced this in cold weather operations? If so did you have a remedy? If you fly in the cold and don't have this issue do you have a copper head gasket/shim installed? I was thinking about installing one and removing a steel under barrel shim when I go to double check the head stud torques.
Anybody have any other theories? Thought it would be interesting to open this topic up and hear everyone's experiences. Note I don't really see any rpm loss, 10-20rpm maybe?? Only thing I notice is oil temp is barely over 100 F even after a mind numbing LE climb to 3000'.