[rotorwrench]

The 1949 Mercury pump was a one year only deal. First off it had the odd engine mount set up and then there was the difference in bearings. It has a ball bearing on the forward part of the impeller shaft and a bushing on the rear portion. An oiler cap was placed on the upper pump area to be able to service the bushing with oil on a regular basis. I figure this design was made in a time when all of the Ford V8 engines still used a bushing type pump at the beginning of WWII while the Mercury design was being completed. The pumps changed for 1950 to be able to use the same bearing set up that the 8BA pumps used. The 0CM pump was used through the 1951 model year but these pumps required the engine mount spacer to make up for the casting design which was carried over from the 8CM pumps. This allowed the large engine mount biscuits to be used. The holes on the frame were deleted and a larger round hole was opened up for the large type mounts as well. The 1949 mounts had two 5/8" studs on the bottom to mount to the frame with two nuts. The 50 & 51 mounts with the one big shoulder bolt through the large type biscuits above & below the frame.