This pump came to me as junk. It may have fallen off a truck...it was badly damaged. The engine now runs fine. Originally it appears this was a self-priming water pump, but all of the outer housing was missing. I welded up a rotor shell and sealed all the obvious holes. First test it leaked like a seive. I used some water resistant house floor leveler (left over from my house building days) to seal the whole machenworken. I have tried it without a priming port and with a priming port. It does help the prime to be able to run a hose directly before the pump...but it still barely pumps. There is a little pressure, but nothing like I expect. It is designed for 2" feed hose, but all I have is PVC pipe in 2" and can't get it into water properly so I switched to small garden hose. Would this pump, with 2" designed feed and 3/4" outlet actually require a 2" feed hose?
Pumpless water pump
- Thread starter Gary66
- Start date
Gary, that's not the prettiest thing I've ever seen. 
I don't know a whole lot about small water pumps having never owned one but I am familiar with larger pumps and I'm hoping that the principle is the same. My understanding is that they are mini centrifugal pumps. Assuming that the engine and pump is working good, it should put out a certain head of pressure and that's all it will put out and I don't think that these pumps put out a great deal of pressure (psi). They may have a fairly high throughput volume wide open but not a whole lot of pressure. With that 2" outlet choked down to a 3/4" hose right at the outlet it's probably creating enough back pressure on the pump for it greatly restrict it's throughput. There's also probably pressure losses associated with the 3/4" hose itself. The higher the backpressure, the lower the throughput volume will be.
I'd start by taking off the hose and that 3/4" swage and seeing how much water it puts out straight from the 2" PVC.
Wait a minute. I think that I misread your post. That hose is on your feed. From the reply section I can't go back and see the photos. If that pump is working properly it should collapse that water hose flat and I mean flat. Is the water hose connected to a domestic tap or is it sucking from a body of water? Either way, it's probably not getting enough feed volume and is cavitating badly. It's designed with a 2" feed for a reason and if it has a 3/4 outlet it's possibly a relatively high pressure pump, say around 100 psi or so outlet pressure, maybe higher. Be careful that thing could go "pop". It might also be designed to supply water from a pond and boost it to water hose/domestic supply pressures around 40 or so psi.
Honestly, if that engine is good you can probably buy a new pump for just over a $100. It may not be worth messing with.
I don't know a whole lot about small water pumps having never owned one but I am familiar with larger pumps and I'm hoping that the principle is the same. My understanding is that they are mini centrifugal pumps. Assuming that the engine and pump is working good, it should put out a certain head of pressure and that's all it will put out and I don't think that these pumps put out a great deal of pressure (psi). They may have a fairly high throughput volume wide open but not a whole lot of pressure. With that 2" outlet choked down to a 3/4" hose right at the outlet it's probably creating enough back pressure on the pump for it greatly restrict it's throughput. There's also probably pressure losses associated with the 3/4" hose itself. The higher the backpressure, the lower the throughput volume will be.
I'd start by taking off the hose and that 3/4" swage and seeing how much water it puts out straight from the 2" PVC.
Wait a minute. I think that I misread your post. That hose is on your feed. From the reply section I can't go back and see the photos. If that pump is working properly it should collapse that water hose flat and I mean flat. Is the water hose connected to a domestic tap or is it sucking from a body of water? Either way, it's probably not getting enough feed volume and is cavitating badly. It's designed with a 2" feed for a reason and if it has a 3/4 outlet it's possibly a relatively high pressure pump, say around 100 psi or so outlet pressure, maybe higher. Be careful that thing could go "pop". It might also be designed to supply water from a pond and boost it to water hose/domestic supply pressures around 40 or so psi.
Honestly, if that engine is good you can probably buy a new pump for just over a $100. It may not be worth messing with.
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Ugly non-pump
Thanks for your reply information, Frank. I worked for Chevron Chemical about 45 years ago as an operator and thought I remembered enough still about pumps...but I guess I don't. I don't have a need for the pump, I just wanted to fix it. I tried to use the 2" feed as a first effort, but couldn't hold the prime. I even made a foot valve. I was surprised at the narrowness of the rotor, or vane. Perhaps there was more to the pump that is necessary for a small vane surface to perform...or, I'm expecting too much. I would guess the vane is 3/4" wide. Oh well, mayhaps I'll find a use for the engine. Thanks again.
Thanks for your reply information, Frank. I worked for Chevron Chemical about 45 years ago as an operator and thought I remembered enough still about pumps...but I guess I don't. I don't have a need for the pump, I just wanted to fix it. I tried to use the 2" feed as a first effort, but couldn't hold the prime. I even made a foot valve. I was surprised at the narrowness of the rotor, or vane. Perhaps there was more to the pump that is necessary for a small vane surface to perform...or, I'm expecting too much. I would guess the vane is 3/4" wide. Oh well, mayhaps I'll find a use for the engine. Thanks again.
Maybe the distance between the impeller/vane and the housing(s) is too large.
un-pump
I copied this GIF picture from Northern Tools. It looks like what this pump probably was. As I understand it, that entire shroud normally contains water and it's purpose is for self priming. I now suspect that when it broke not only did that shroud terminate but the entire impeller chamber cracked all the way around near the outside radius. The part that I made covered the last stage of the impeller chamber and I had to shape it as it seemed right. I musta seemed it wrong! I've already shelved that basket and moved on to several new projects to screw up. I'm trying to get that Craftsman modified riding mower painted and back together. The modifications were major and lots of 'em, so final assembly is always a booger. I'm also working a lot of hours on my DC motor drive system for tractors. Today I took an old Makita 12V drill driver that had a destroyed chuck and junk batterys/charger and cut the front off just leaving a shaft stub to connect to. After cutting the pistol grip off (leaving the trigger) I could connect it to a 12V tractor battery. It seems to run well. I sprung it apart enough to inspect the gear box and was very impressed. It is very well geared down and should be able to operate a rear lift mechanism or some such. When I get my 6V tractor battery charged, and it stops hailing and raining for an hour, I will connect it with the 12V for another test of that 18V DC drive on Ol' Yeller. I'm still pretty confident the additional amp/hrs of power from those two batterys will enable that little DC motor to lift 200lbs net. without slowing down (as in the first test with the little drill battery). I can't imagine you or anyone else cares a rip about any of this, so I'll continue - it helps me focus project prioritys. I've been experimenting with small electric element water heaters. They range from 750watts to 1,800watts generally BUT I collared a spa heater that indicates 6 or 7,000 watts (240V) and if I can figure it out and fix it, I see the makins of a steam cleaner for my tractors and parts. I really want to get further into that one! Sometimes the connection between my projects and tractors gets pretty thin I suppose. If I catch flack I'll post about the manifold I made for my '36 Case model C or the "Gary66" method for timing my '37 Case RC, or my tricked-out 17.5hp (former) riding mower that now pulls big wheelies from a rolling start. I took the battery out to save my life after the last exhibition for pictures. Or about my interest in hydrostatic transaxles, such as my White with a BIG Wisconsin engine. Nuff
I copied this GIF picture from Northern Tools. It looks like what this pump probably was. As I understand it, that entire shroud normally contains water and it's purpose is for self priming. I now suspect that when it broke not only did that shroud terminate but the entire impeller chamber cracked all the way around near the outside radius. The part that I made covered the last stage of the impeller chamber and I had to shape it as it seemed right. I musta seemed it wrong! I've already shelved that basket and moved on to several new projects to screw up. I'm trying to get that Craftsman modified riding mower painted and back together. The modifications were major and lots of 'em, so final assembly is always a booger. I'm also working a lot of hours on my DC motor drive system for tractors. Today I took an old Makita 12V drill driver that had a destroyed chuck and junk batterys/charger and cut the front off just leaving a shaft stub to connect to. After cutting the pistol grip off (leaving the trigger) I could connect it to a 12V tractor battery. It seems to run well. I sprung it apart enough to inspect the gear box and was very impressed. It is very well geared down and should be able to operate a rear lift mechanism or some such. When I get my 6V tractor battery charged, and it stops hailing and raining for an hour, I will connect it with the 12V for another test of that 18V DC drive on Ol' Yeller. I'm still pretty confident the additional amp/hrs of power from those two batterys will enable that little DC motor to lift 200lbs net. without slowing down (as in the first test with the little drill battery). I can't imagine you or anyone else cares a rip about any of this, so I'll continue - it helps me focus project prioritys. I've been experimenting with small electric element water heaters. They range from 750watts to 1,800watts generally BUT I collared a spa heater that indicates 6 or 7,000 watts (240V) and if I can figure it out and fix it, I see the makins of a steam cleaner for my tractors and parts. I really want to get further into that one! Sometimes the connection between my projects and tractors gets pretty thin I suppose. If I catch flack I'll post about the manifold I made for my '36 Case model C or the "Gary66" method for timing my '37 Case RC, or my tricked-out 17.5hp (former) riding mower that now pulls big wheelies from a rolling start. I took the battery out to save my life after the last exhibition for pictures. Or about my interest in hydrostatic transaxles, such as my White with a BIG Wisconsin engine. Nuff
