p90 with 3" Suction nozzle, would this work?

[Sean C]

Wanting to use a p90 pump (2.5hp honda) to run a 3 inch suction nozzle but I'm not sure if it would work. Problem is a p90 is 1.5 x 1.25 inlet/outlet and a 3 inch nozzle is 1.5 inlet so I would have to neck up making the pump 1.5 x 1.5. Not sure if this would cause problems with cavitation or give me enough pressure to create suction. Working depth is very shallow, less than 2 ft, so I don't need much lift. Any opinions?

[russau]

marginally if at all.

[DJR]

Don't think so.I have a 2.5" nozzle and it has problems with that if you have any kind of lift to do.

[russau]

on your 3 inch nozzel, what is the orfice size in the highpressure water pipe reduced to??

[Sean C]

I don't currently have a 3 inch nozzle but all the ones available are 1.5" inlet. Before I went and wasted money on something that might not work I wanted to get some feedback. My 2.5" nozzle is a 1.25" pressure inlet and work great at half throttle or less but I need to move more material. I've had one person tell me that if I neck up at the nozzle inlet instead of the pump that it will work. I'm working a tiny shallow creek that I need about a max lift of 1.5 ft when I hit bedrock and the sluice sits down hill. The values are good, 1/4 - 1/2 oz a yard, but its in patches so every yard or two of gravel you have to move the whole rig 20-40 yards which is why I want to use the 2.5 honda p90 combo. I'm basically sniping, thats how often I move. Water will be to low to work by August which is another reason for wanting to step up to a 3" now while I can.

[Hoser John]

Gonna have wimpy suction BUT adding in the factor your box is DEFINATELY downhill---then your sucking up gravels in less than 2feet of water makes it's a crapshoot. Throw in a suction nozzle and wow really makes it a tougher problem. If engine was bigger-or pump ez but????? Your not running any air either as that costs much off the hp also. What are you using for a box as almost 75% more water--what kind of header as 2.5 won't accept a 3 ?? Very close call and plugups will happen with that little suction. How long is the suction hose and water to jet hose?? John

[libertydave]

You are getting some good advice from the above...to NOT consider using a HondaGX50/P90 pump with a 3" suction nozzle. Here are the specs.

1. Max output on HondaGX50/P90 pump is around 100 GPM (optimum). This is also not considering head pressure requirements in your operations.
2. 3" suction nozzle requires MINIMUM volume of at least 130-140 GPM (recommend 150+ GPM) to begin to adequately function in variety of mining operations.

Simple math will give you your answer. If you use the P90 stay with a 2" suction nozzle because that (design-wise) is what will work best with your smaller engine/pump combo. Good luck.

Liberty Dave