I'll have a look! Thanks Ken.
Bronze Raw Water Pump Elbows
- Thread starter kiwisailor
- Start date
Gline
Member I
I'm stuck in the same boat as everyone here. My old fittings are intact, but don't make a snug fit with the 5/8 hose anymore (maybe years of wear have reduced the metal slightly). I have a consistent leak at the fitting from the raw water pump to HE. I could make a 1/2 hose fit and this would solve the leak. But is 1/2 hose a bad idea? Would this decrease the water flow to the HE?
This picture is old, the leak is more obvious now. The fitting on the right (strainer to pump) looks like a modification from previous owner, would be nice if I had two of these fittings...
This picture is old, the leak is more obvious now. The fitting on the right (strainer to pump) looks like a modification from previous owner, would be nice if I had two of these fittings...
No matter what ID size the hose is, or the ID of most of the fittings, it seems to me that any point in the piping with a smaller ID will perforce restrict the flow to whatever that smaller ID happens to be. Or is my intuition wrong?
Gline
Member I
That makes sense to me. So if the inner diameter of the fitting is smaller than or equal to that of 1/2 hose, it should not change the flow?
Agree, just buy some hose that fits. As Loren says, the fitting sets the diameter.
In the meantime, I'd probably cut an inch or two off the existing hose end and try two hose clamps. Maybe heat with a heat gun to smallenize the hose end while clamping.
In the meantime, I'd probably cut an inch or two off the existing hose end and try two hose clamps. Maybe heat with a heat gun to smallenize the hose end while clamping.
GrandpaSteve
Sustaining Member
Smallenize. New word for 2024, thanks Christian.
Pete the Cat
Member III
What follows is useless if you do not have a 25XP.
After reading this entire thread and recently having some "learnings" while installing a new Oberdorfer pump on the 25 XP. I thought I might share my mistakes.
1. If you are looking for real ID 1/2" bronze elbows or fittings for a pump or the salt system: they do not make them with 5/8" NPT male ends in bronze and 1/2" nipples. My mechanic guru friend says they never made them for some reason. I bought an Oberdorfer 1/2" pump (pumps are sold by ID, not OD) and found that I could not find bronze 5/8" threaded elbows that would fit into the pump (a 1/2" pump must have 5/8" OD NPT ports for 1/2"ID elbows or nipples). Lots of brass are available as has been noted, but no bronze.
2. I did manage to find some Marlon 5/8" male NPT fittings with 1/2" nipples for the pump, but I live a few blocks away from a huge commercial shipyard and warehouse with a selection beyond West Marine or your local hardware.
3. Apparently (and please correct me if someone knows better) Ericson or Universal installed the 3/8" Oberdorfer pump (Not the 1/2" version you would expect) on the 25XP so that the pump ports could accommodate a 1/2 OD piece of red brass pipe (not quite as awful as brass in salt water) and they just mashed the 3/4" engine intake hose to it(mine looks like the one in the picture because the fitting is probably only 5/8" OD). The 5/8" ID hose to the heat exchanger looked better on its 1/2"ID--and probably close to 5/8"OD red brass nipple. Seems like this was their only option with the intake (5/8"ID) and output (1/2"ID) they (or more likely Westerbeke (who were the cobblers of the marinization of the Kubota block). This is the kind of thing that drives me nuts about "marinized" tractor engines; the engines themselves are fine--its the cobbling of raw water system plumbing that fails.
I note in the Oberdorfer pump specs, the 3/8" pump puts out almost as much as the 1/2" so this probably does not make much of a difference in flow. I would think that restrictions after the pump in your cooling system might affect flow more than at the pump--but I am no expert at fluid dynamics.
Learning?
1. There is no such thing as 5/8" OD NPT bronze fittings.
2. Next time order the right pump. I note that Catalina Direct sells the right (3/8") one for their 25XPs.
I have always carried a spare fresh and a spare raw pump and needed both at inconvenient times. I recommend installing the new one (to make sure it works) and keeping your old one as a spare. I think I paid $50 for the freshwater pump on Amazon because the same one is used on many engines. The saltwater pumps seem to be $350 now that Oberdorfer was bought.
FWIW.
After reading this entire thread and recently having some "learnings" while installing a new Oberdorfer pump on the 25 XP. I thought I might share my mistakes.
1. If you are looking for real ID 1/2" bronze elbows or fittings for a pump or the salt system: they do not make them with 5/8" NPT male ends in bronze and 1/2" nipples. My mechanic guru friend says they never made them for some reason. I bought an Oberdorfer 1/2" pump (pumps are sold by ID, not OD) and found that I could not find bronze 5/8" threaded elbows that would fit into the pump (a 1/2" pump must have 5/8" OD NPT ports for 1/2"ID elbows or nipples). Lots of brass are available as has been noted, but no bronze.
2. I did manage to find some Marlon 5/8" male NPT fittings with 1/2" nipples for the pump, but I live a few blocks away from a huge commercial shipyard and warehouse with a selection beyond West Marine or your local hardware.
3. Apparently (and please correct me if someone knows better) Ericson or Universal installed the 3/8" Oberdorfer pump (Not the 1/2" version you would expect) on the 25XP so that the pump ports could accommodate a 1/2 OD piece of red brass pipe (not quite as awful as brass in salt water) and they just mashed the 3/4" engine intake hose to it(mine looks like the one in the picture because the fitting is probably only 5/8" OD). The 5/8" ID hose to the heat exchanger looked better on its 1/2"ID--and probably close to 5/8"OD red brass nipple. Seems like this was their only option with the intake (5/8"ID) and output (1/2"ID) they (or more likely Westerbeke (who were the cobblers of the marinization of the Kubota block). This is the kind of thing that drives me nuts about "marinized" tractor engines; the engines themselves are fine--its the cobbling of raw water system plumbing that fails.
I note in the Oberdorfer pump specs, the 3/8" pump puts out almost as much as the 1/2" so this probably does not make much of a difference in flow. I would think that restrictions after the pump in your cooling system might affect flow more than at the pump--but I am no expert at fluid dynamics.
Learning?
1. There is no such thing as 5/8" OD NPT bronze fittings.
2. Next time order the right pump. I note that Catalina Direct sells the right (3/8") one for their 25XPs.
I have always carried a spare fresh and a spare raw pump and needed both at inconvenient times. I recommend installing the new one (to make sure it works) and keeping your old one as a spare. I think I paid $50 for the freshwater pump on Amazon because the same one is used on many engines. The saltwater pumps seem to be $350 now that Oberdorfer was bought.
FWIW.
Pete the Cat
Member III
Not sure where to post this, but if you have a 25XP with Oberdorfer pump,you want the M202-15 (3/8") rather than the M202-16 (1/2")--even though that may not seem logical given the inside diameter of your hoses (3/4" and 5/8")
The Oberdorfer Repair kit for both includes carbon bearing, seals (which is what usually wears out after the impellers), and impeller. But includes an O ring, not the paper gasket of the older models of this pump. You can make this gasket from regular paper if you have the older pump. There are Youtube videos of rebuilding the pump.
Apparently the new corporate owners of Oberdorfer have discontinued some of the repair kits and the carbon bearing type model of the pump.
Arcane information, perhaps. But maybe useful. This is the kind of info I keep in my maintenance log.
The Oberdorfer Repair kit for both includes carbon bearing, seals (which is what usually wears out after the impellers), and impeller. But includes an O ring, not the paper gasket of the older models of this pump. You can make this gasket from regular paper if you have the older pump. There are Youtube videos of rebuilding the pump.
Apparently the new corporate owners of Oberdorfer have discontinued some of the repair kits and the carbon bearing type model of the pump.
Arcane information, perhaps. But maybe useful. This is the kind of info I keep in my maintenance log.