Mike wrote: <<When I got it from him, Steve was using NAPA synthetic 10-30 in the 2180 he put on the KR-1½. I have continued with that oil, >>
You might want to reconsider using synthetic in a air cooled motor. One of the big selling points of synthetic oil is "reduced oil tempreature". Unfortunately, this is not a good thing for us because the oil temperature is reduced by the oil's inability to accept heat. Therefore, the synthetic oil cannot carry the heat to the cooler as well as petrolium oil. This results in an engine that is running hotter even though the oil temperature is cooler. When you think about it, friction is a small part of the total engine heat compared to heat of combustion. So even if synthetic oil reduces friction, it does not significantly reduce the overall engine heat load. Synthetic oils are great for jets or water cooled engines. In an air cooled engine the oil system provides a significant amount of the cooling and pertolium oil is better at transfering heat to the cooler. Regards, Bob Lee N52BL KR2 Suwanee, GA USA 92% done only 67% to go!
