Clay Blair in his book
Silent Victory spends a lot of ink on the infamous HOR engines. Since, H.O.R. (Hooven-Owens-Rentschler) was the US licensee for M.A.N. which made the German diesel engines a rumour went around that the designs had been sabotaged on the drawing board by the German parent company.
Given their temperamental reputation the crews called them 'wHORes.'
