Vintage BMW Motorcycle Owners

A friend gave this to me. It's a dipstick oil cooler. He had it in an R75 he used to own. The only information I can find on it is that it was (supposedly) made by a company called Redwing, and it fits the R60 and R75 models. It certainly fits an old R75 engine I have in the shop. I can find no information about this online, but I'll bet some of you guys know something!

Have never heard/seen that before. Seems to me that the surface area involved is pretty small to get any great oil cooling. Only about 1-2 inches of the bottom is dipped in the oil. The oil would have a high heat transfer, but the rest of the rod is in air and likely wouldn't transfer much heat. I guess there is oil splash that has to get up to the holes that drain down to the valves...so maybe some of that oil gets cooled and drains back. Clearly it didn't catch on!!

If memory serves - and that's not a given these days that unit uses a thermosiphon mechanism to cool the oil. Basically, there's a liquid (low boiling point?) in the tube that gets heated to boiling at the end submersed in the oil pan. The hot gas rises to the top and gets cooled by the end with the fins in the breeze. No clue how well they worked, but they were available new for quite a few years a some decades ago. Given it's age, curious if there is any liquid left inside it.

Hope that helps,
Chuck S.

If you google "red wing oil cooler" you can actually see what appears to be new items, at least NOS. Here's one for a Harley:

https://picclick.com/NOS-Red-Wing-Isocy ... 87830.html

Thank you, gentlemen, for your responses. Using the info you provided, I was able to find out exactly what this is.