Mixed Flow vs Axial Flow vs Multi-Stage...

[WheelerDealer]

Okay pump gurus, walk us through the differences of each style of pump please. What are the pros and cons of each and what is each style best suited for. I was cruising the internet and found a New Zealand site where they were all running multi-stage double and triple impeller pumps that I have never even heard of before.

[1978 Rogers]

I believe some of those are used for commercial applications. i.e. there is a high speed catamarn ferry that runs between Seattle & Vancover B.C. It's nozzle must be 12" inches across.

[bottom feeder]

I have no clue what are you talking about? differant types of pump?
Just my view I am no expert and have made no such claim.
Mixed flow: By far the most popular pump here in the states. Often refered to as a pressure pump. As far as pumps go it will net you the best MPH if this is what you are looking for. Takes the most power compared to the other designs to achive it's speed. Has the slowest hole shot. More up keep in abrasive inviroment. The object is to push the water out under considerable force. This generates the high velocity jet stream. Fairly small intake face. (probably the smallest) Cost is fair, parts can be had anyware. (Berk, At, Dom and Agressor)
Axil Flow: Less popular here in the states. Good hole shot gives up a bit on the top end. Takes less power to turn as it makes little pressure after the impeller. Damage from debris is slight. I do not know if any are still being produced. Parts are common most upgrade kits are designed to convert them to the more popular Pressure style. (jacuz, early hamilton) Just dont have much experiance with these critters.
Multi stage: least popular here in the states.(gaining though) While they are still a axil flow the are head and shoulders above the prior models. The concept is to accelerate the water through the pump in stages. One note It can be run as one ,two ,three or more stages. The more stages the more power it takes to run and the higher exit velocity can be. They build some pressure after the impellers but agin the PSI is low compared to the pressure style. Moves huge volumes of water at high velocity, Has a huge intake face to match. Un matched in holeshot. Agin top end is given up to the mixed flow. (not sure for how much longer) Low wear. Still takes less power to the pump at given speeds than the mixed. Hamilton, Scott, twin disks.
All out racing deep water = mixed
All out racing shallow water = Axil multi stage, mixed
All out fun boat Any :)

[UBFJ #454]

Wheeler Dealer -
Which New Zealand Site are you referring to? There are several I've come across.

[WheelerDealer]

Hey Jak, it wasn't any one site in particular, I checked out several of them as well. Most of the ones I was looking at were sprint boat racing, and I must say that it looks like an absolute blast!! :) :)

[HotRod Sprint]

Hey Jak, it wasn't any one site in particular, I checked out several of them as well. Most of the ones I was looking at were sprint boat racing, and I must say that it looks like an absolute blast!! :) :)
How about posting some links to those sites. Would like to check them out.
Thanks,
Rod

[Rampager]

Lots of valuable info to get from the NZ sites. I'm sure we could all learn a thing or two by seeing what a different "style" of boater does.
Check out www.NZjetboating.com and their forum. Lots of great pics and a cool "projects" section. The section dedicated to organising events is a great place to see scenery of the outings and what antics the guys get up to in skinny water. They also have a pretty good sense of humour over there ;)
The reason sprintboating you see on TV evolved is because its not that far off how they boat for recreation!
That site will link you to most jetboating stuff over there.
By all means ask them about their pumps. Interestingly enough it seems that several of them have projects on the go with "american" style pumps. Big blocks are rare there but then again would you want to push one when(not if, when) you get stuck??? lol
Cheers
(this is my fav pic of extreme boating in NZ, you gotta ask what were they thinking? lol)