ロールスロイスのエンジンの伝統から川の名前をつけることになってシナノになった

Rolls-Royce acquired Bristol Siddeley in 1966 and all the Bristol engines
come under the Rolls-Royce banner but the way to remember which is which is simple.
If its a river, its a Derby engine, if its mythical, its a Bristol developed engine.