Mixed vs Axial Flow pumps what is the advantage?

[Little Squirt]

What is the difference between the two pumps in relation to thrust/ speed potential/ et.
I have a 4cyl Nissan engine and I am trying to hit around 50mph or so.
I have read past post to this forum ,and while I can fiquire out how the two different pumps work--- No one has mentioned why one is better than the other.
I feel that my engine is putting out around 120-140 hp,with no clue as to how much torque I am producing.
I do find your forum entertaining and informative.

[beached1]

I found this book called Marine Jet Dive systems buy Seloc from a friend. It has diagrams of just about every jet made. It also has a brief chapter on jet theory, the differences of Mixed and Axial flow etc. I'll tey to find out where my buddy picked this book up and let you know if I can.

[Cas42]

I was in CP Performance yesterday and they have them on the shelf. I'm sure you could order from there.

[Eric]

I bought the Seloc book from amazon.
http://www.amazon.com
Eric

[Eric]

Here's a better link...
http://www.amazon.com/exec/obidos/ASIN/0893300292/qid=996170198/sr=2-2/103-7684208-3401450
Eric

[Eric]

...pesky double post snipped...
[This message has been edited by Eric (edited July 26, 2001).]

[flat broke]

Little Squirt,
I think I saw in an earlier post your hull is 13-14' and you thought you were doing around 30-40 mph. If this is true running with 140hp, you aren't bad at all. Figuring that the Nissan is probably a rev hungry little mill that has a narrow powerband, you will probably be lucky to do a whole lot better. We would need to know what kind of pump and impeller you are runnning before anyone could give much more input on your setup.
Chris

[Little Squirt]

Dear Chris,
My Hull is a 12 1/2 ft "Werks" with a Doen Jet Drive., The front section has DJ 81 / and the Tail Section has DJ 82 imprinted on the side. It has a bronze 4 blade impeller that BoBs Prop Shop in West Palm thinks that they can "Cup" if I want to try.
I am able to achieve 30mph at 4,000rpm( 25mph at 3500/ 20mph at 3000(just holding plane at this speed)
I guess that the Nissan engine had around 60-80 hp prior to the work that I recently completed.
It seems that the pump overloads at 4000 and rpms no longer rise(The little engine feels that it wants to go higher but 4000 is the tops at this time .
I appreciate any assistance since I don't know diddley about Jet boats(sailboats/skiboats/houseboats yes)