Which port on oberdorfer pump is intake?

Sep 22, 2013
24
Catalina 30 NOB Norfolk W5CDR
I have just installed a new oberdorfer n202m-908 pump on my M3-20B engine. I need to know which port on the pump should be the water-in port. The pump is oriented similarly to the original Sherwood so the ports are facing down. I did not keep track of the water hookup on the Sherwood, hence my question.

Along the same lines does the pump, off the end of the camshaft, rotate clockwise or counter clockwise looking straight on from the pump front plate.
 
Last edited:
Feb 26, 2004
22,759
Catalina 34 224 Maple Bay, BC, Canada
As you said, ports facing down, right (port side) is intake, left goes to the HX. At least on my boat, M25 engine.
 

Ward H

.
Nov 7, 2011
3,645
Catalina 30 Mk II Barnegat, NJ
Along the same lines does the pump, off the end of the camshaft, rotate clockwise or counter clockwise looking straight on from the pump front plate.
If you need to know to bend the vanes in the correct direction, they bend the correct way on start up.
 
Sep 22, 2013
24
Catalina 30 NOB Norfolk W5CDR
Thanks Stu got the connections on now correctly. Now to replace the suction side with proper reinforced suction hose. I had good hose but not suction rated and the hose finally collapsed at a mild bend. Live and learn.

Again thanks,

Sean
 
Feb 8, 2014
1,300
Columbia 36 Muskegon
It can go either way based on engine rotation. Hit the starter and note which way the engine turns. Then look at the pump, the water enters and goes the LONG way around the pump body.