I'm having trouble figuring something out.
How do I get from 3/4 npt on the raw water
intake to 3/8" npt-female on the oberdorfer water
pump, then from 3/8" npt female out of the raw water pump
to 5/8" barb on the heat exchanger
without using brass reducers or nipples (i.e. bronze only)? Currently, whole setup is pieced together using bronze and brass nipples and reducers plus a few brass 90 degree elbows.
Both Moyer Marine's oberdorfer replacement pump (MMI 502 flange pump ) and an oberdorfer N202M-7 only have 3/8" npt female input/output
Here's the problem.
intake is 3/4", goes from thru hull
3/4" barb off the thru hull
to perko bronze strainer (3/4" input and output), to the V-drive (in 3/4" pipe thread and out 3/4" pipe tread). From V drive with 3/4" hose for 10' to the raw water pump, were the input port is only 3/8" npt female. Then out from the raw water pump's 3/8" npt female to 5/8 barb on the heat exchanger
. I'm having a hell of a time finding the necessary parts
in bronze. to make all these connections with a 3/4" hose to the raw water pump, then 5/8"hose from pump to Hx.
I'm trying to redo the PO's work and get rid of the brass fittings and minimize the number of connections/fittings.
is Universal M-50/5444 (that's the 4 cyl, V1902 Kubota block) with a Walter RV26 v drive. Engine
freshwater cooled, v drive raw water cooled.
If the raw water pump is only 3/8" npt, do I really need the 3/4" hose from v drive to the input of raw water pump? If not, I can bush the output of the walter V drive from 3/4 npt female to 3/8" barb and run 3/8 ID hose to the raw water pump. I haven't figured out how to deal with the 3/8 output form the pump to the 5/8" barb on the Hx. PO used brass reducer.
If the pump ports
were 1/2", problem would be solved
. I just don't understand why 3/8" npt is used; there are no fittings for that size in bronze. Well, ther are fittings, but not the ones I need go step up to 3/4 and 5/8" hose.
I redrilled and tapped 1/2" npt on an old spare oberdorfer and it worked, but the I realized that every replacement pump will have to be drilled and tapped for 1/2".
There is probably a simple solution that I just can't see right now.
If anyone can help me figure this one out, let me know.