I've leave a 60 watt light bulb inside an aluminum reflector (home depot) going all winter. I have it right under the
oil pan. Any advantage I can give to an engine that does not run on a daily basis is worth it to me.
When the ambient temperatures are below 65 degrees or so I also block the
oil cooler with a piece of plexi (you can't even see it - thanks Art G.). If I don't, the
oil never gets above 150. Even with the cooler blocked I usually run around 180. During really cold rides (anything under 50) I block the bottom third of the radiator so as to return the coolant at a little bit higher temperature.
I always wonder how many distributor gear problems are caused by owners running heavy, cold oil through all that plumbing and the oil cooler. How much of that oil do you think just goes out the pressure relief valve?
Bob