1987 454 mercrusier water pump

J

Jamie 10017

Member
Joined
Nov 13, 2011
RO Number
32751
Messages
45
Does anyone know if the engine water pump on bbc the cw rotation and the ccw engines are the same. I know some of the sbc are the same the don't have a directional impeller. Im not sure on the bbc. Thanks Jamie
 
Never heard of a directional impeller.
Also, bbc & sbc ???????
 
If it's marine, it has to be bi-directional.

bbc-big block chev

sbc-small block chev
 
The impellers that are directional are curved for the direction of coolant flow. The non directional are straight they will move coolant either way. I built 2. 305 cursader engines one was reverse rotating and the pumps were the same each one had straight impellers in the engine water pumps.
 
quote:
Originally posted by jtybt15

If it's marine, it has to be bi-directional.

bbc-big block chev

sbc-small block chev

Click to expand...


Thanks, can't imagine how I would know that! My impellers are straight but every year during winterizing, I manually reverse them so they don't take a set. Been doing this for 30+ years!
 
The directional issue really became an issue in the automotive world with the advent of serpentine belts. V-Belts ran the water pump same rotation as the crankshaft, but Serp belts reversed it. Leading to "I put a new pump on it and it overheats." Since a marine engine can have V- or Serp belts AND reverse crank rotation, those Bi-Directional pumps are really a blessing.
 
If this is the raw water intake pump. The pumps are the same. The intake hoses get switched on the pump hook ups. This takes care of the cw or ccw issues.

Ron
 
hey guys this tread is on the Water pump for the exchanger...not the raw water pump...
 
Yes!

The Circulating Pump, not the Raw Water Pump.

It's possible if the engine is old enough that the circulating pump being replaced could be directional but the replacement be universal (bi-directional).

The only bbc circ pump I could find was on Catalog Page 1073 and it replaces two MerC part numbers and specifies "composite timing cover" meaning "plastic". The one for our sbc is called out the same "composite" but it's in fact bi-directional. And our cover IS composite. Yet I think the pump replaces older pumps as well.

BoatFix Help Ticket might get you an explanation.
 
you can also call Sierra Monday with serial of your engines and they give you the part # you need then order it from boatfix... :)
 
You must log in or register to reply here.
Back
Top