Mercury Part # 47-24447 for vane type impeller
Mercury Part # 47-24427 for oscillator type (formerly M-50-137)
Reason for brass hub in most impeller is because when rubber is molded by vulcanizing process (heat) it does not stick or bond as well to steel as it does to brass or copper. The core for 47-24447 vane type
impeller is a substantial piece of brass with some machining…both of
which make for high costs compared to molded plastic or nylon core.
Steel can be given a copper flash plating to which rubber will bond
however, plastic has replaced metal in many applications due to improved plastics and cost advantages.of injection molding over processes to form metal.
Several points worth noting in photos
1) C spring is a later replacement…had to get a tool at Sears to remove
2) If you open up water pump and find an incomplete impeller, chances
are some of the rest is still somewhere in cooling water system
3) 1940 propeller does not have the cushion in back of hub and is sheer pin drive. 1941 and later models have the recess in back of hub
for rubber cushion and are adapted for either rubber clutch or sheer pin.
4) NOS oscillator had a tag on 47-24427…Mercury Part # Would you
have reached for your wallet as fast as I did? Sellers of parts often
are only interested in moving the merchandise at a profit. It pays to
know what you are looking at.
5) The seal in 3 slit type water pump is a bugger to remove, but, replacement is often way past due. Seal is a stock item 4923
