macd
Well-Known Member
Your memory's just fine, Gladys: the ingredient that gave the oil its name was castor bean oil, although this was only a small percentage of the mix: most was mineral oil. The castor oil element improved film strength and helped the mix cling to working surfaces in a way that was difficult with pure mineral oil in the early days of oil technology.
The corrupton of 'Castor' and 'oil' also gave the company its name: Castrol was previously Wakefields. Interesting article on 'R' here: http://www.motorsportmagazine.com/archive/article/july-2000/55/castrol-r
Seajet: I doubt your enjoyment of the smell of RD400s had anything to do with Castrol 'R'. It was really a one-use competition oil, the entire fuel system, carbs included, needing to be cleaned thoroughly after use. The alternative was truly crippling gumming of everything between tank and venturi. It was truly horrible stuff, and synthetic replacements couldn't come quickly enough. Several other 2-stroke oils had an aroma broadly similar, but less sweet, than 'R'.
It's possible that the RD400's owner had put a tiny drop of 'R' in with his regular 2-stroke oil, just for aromatic effect. I once met an elderly ex-racer, by then suffering severe angina, who did exactly that with his sit-on lawnmower, just to relive old times.
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