Reply With QuoteI was told that unless you have more the 600 HP a stainless is not needed.
With a nomally aspirated engine, at what point is it advisable to use a stainless impeller? I'm refering to BIG inches in the 540-572 range making upwards of 625 hp and gobs of torque.
Thanks,
Steve
I was told that unless you have more the 600 HP a stainless is not needed.
I've always found interesting the Berkeley chart does not recommend aluminum above 325@4700 and SS above 500@6000. Seems conservative to me. I don't know what pump you have, but if you wish to follow their recommendations, then SS is certainly advisable.
But with this sorta question, you'll find plenty of opinions to choose from http://free.***boat.net/ubb/smile.gif
I've also wondered if Berkeley's recommendations factor shock loading from say, jumping a wave, or are they just based on steady-state stresses with a healthy safety factor.
In any case, with your 625 hp, I'd go with SS. SS is also very durable. I just took my pump apart, and after 10 years of eating occasional rocks, sticks, and bear cans, it looks nearly new.
jer
[This message has been edited by LVjetboy (edited March 30, 2002).]
in addition to that question. how many types of impeller material are there? if i am knowing correctly there is: aluminum, ss, and mag-bronze. i dunno what m-b is. but i always see badass boats in dragboats.com classifieds advertising MAG-BRONZE impeller.
but i went to a jet site the other day, and i think m-b impellers were cheaper than ss. if this is the case, and m-b is better then why does ss exist.
i propably sound stupid right now, but please clear my mind.
i would say that 600 is the staring point for stainless.
I may be a little out of my league on this topic but J4F hear is an answer to your question. There are three types of material commonly used to make impellers: Aluminum, Magnesium Bronze, and Stainless Steel. Mag bronze is just another alloy created by blending two or more materials. As a machinist Ive work with aluminum bronze on several occasions but never mag bronze. Since magnesium machines similar to aluminum I would take a guess that mag bronze machines similar to aluminum bronze, which is pretty tuff stuff. As far as strength for a jet boat impeller goes, S.S. is the king, mag bronze is next, and aluminum is the least strong out of the three. Hope that helps.
Why don't you try one of Aggressors Mag-Bronz!? I understand they should save you a couple of $$.
There are a couple of Aggressor dealers that I know about, Jett Performance (in Phoenix), Cyclone Marine in (CA), a couple in the East, CBM Jet and of course Dwayne Oblander......
PS:
Let us know how you like it, if and when you decide.
Give it a shot!
MikeC
Was your motor dyno'd at 625hp or are you assuming that it will make close to 625hp? If you are currently using an aluminum impeller and it is in great shape, a true 625hp motor won't hurt your impeller. If you decide to bump up the power much over that with a blower, or a big nitrous system, you might want to consider running a stainless. If you need another impeller because the current one is in bad shape, and your not going to upgrade the engine to produce more power, then save a few bucks and stick with the aluminum. Some people here love Mag Bronze over life itself, but from the majority of pump builders I've spoken to recomend aluminum or stainless, depending on the power your using. You might want to ask the builder who did your pump an see what they say. I've actaully had good luck with the advice from my builder since they know this stuff for a living. Good Luck and let us know what you decide to go with.
HBjet
I got Mag Bronze A Agressor. Works fine Lowered R.P.M. A little but after talking to what seems everyone in the country I think it is equally important to have the suction,Grate, and the rest in proper tune.
Any one know where to get a spare shoe? I would like to try a deep one to grab up a little more water and slow R.P.M. a little more as I wanna run more H.P. without to much rpm. What about choking the nozel? Who does the machining?
Hey Sleek, how about just shimming the shoe down instead of installing a deeper one? Just go a little at a time and remember to also shim the ride plate to keep the same angle relative to the hull.
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