12-21-2015, 05:32 AM
Maybe the rule of warming the engine goes back to times when oil was really thick and not as we know it today. I bought a Vintage speedway bike earlier this year and the engine is a 1947 J.A.P 500cc single which is designed to run on Castrol R (smells great). When I disconnected the pipe from the oil tank to the engine to drain the tank nothing came out for ages and finally it flowed as a tiny line, almost breaking into single drips. I checked with Castrol to find a more modern oil to use but they said this engine was designed to run on Castrol R and warned me to warm the engine quickly to heat and thin the oil otherwise the head would not get lubricated properly. So, I think your friend is probably correct and modern oils do not require old fashioned drainage rules.