what is the maximum rpm that a berekly drive can be turned?
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what is the maximum rpm that a berekly drive can be turned?

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    Default what is the maximum rpm that a berekly drive can be turned?

    I am wondering and cant find any info on, how many rpms you can turn a berekly jet at. i know what the norms are, but i want to know the true maximum. thanks guys

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    i'm back!! 1QuickCP's Avatar
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    lets see if you cut the impeller to a "d" and hooked it to a 3:1 gear box with a nice blown fuel motor i'd say a bunch....until the bearing exploded..


    on a serious note u need to give a lot more info on what ur doing

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    Quote Originally Posted by 1QuickCP View Post
    lets see if you cut the impeller to a "d" and hooked it to a 3:1 gear box with a nice blown fuel motor i'd say a bunch....until the bearing exploded..


    on a serious note u need to give a lot more info on what ur doing
    How fast can you turn the bearings and still be safe?
    How fast can you turn an a cut impeller before it 1. explodes and 2. doesnt gain you any more?

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    come on people, i know some one knows this stuff, or some wild man has experimented with this stuff.

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    Quote Originally Posted by millwrightlong View Post
    come on people, i know some one knows this stuff, or some wild man has experimented with this stuff.
    I've "heard" that after 7500rpm they lose most of their efficiency. The impeller cut in the pump is what determines how many RPM you can turn with "X" amount of horsepower (alot more factors than that, but in general). Top Fuel Jets can turn a pump around 8000rpm, but that is "top fuel". With difference impeller choices, cuts, brands, etc you have pretty much an endless amount of choices to effectively "gear" your pump to your motor.

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    it depends on the impellor material. alum impellors are good to about 500hp and ss/bronze are rated for 1000hp+. i've exploded a alum impellor before layin 1200+hp to it the pump can be turned as fast and hard as you'd like, as long as the parts inside were meant to handle it.most pumps don't do much better at 7500 as they do at 7krpms. to many factors to just say "the pump will explode when"

    Dare to be different, if it turns out great you can claim you planned it that way.

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    Im thinking you just want to know, just to know right?
    Well you might want to check out this thread. Alot of good info here.
    I noticed that there isn't to many people running high rpm's (above 7K).
    A good source of info right here!

    http://www.performanceboats.com//showthread.php?t=21529

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    Quote Originally Posted by n8dawg View Post
    Im thinking you just want to know, just to know right?
    Well you might want to check out this thread. Alot of good info here.
    I noticed that there isn't to many people running high rpm's (above 7K).
    A good source of info right here!

    http://www.performanceboats.com//showthread.php?t=21529
    Thanks. well, first i need to research all the data, then i can see what i can do within those perameters.

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    As far as the maximum speed of the front bearing we use this formula


    dN = d (bearing bore, mm) x N (RPM). ... for standard type radial ball bearing dN should be no greater than 850,000 or about 11,000 rpm assuming a 3" bore

    if u use a hybred bearing ($$$$$$) dN can be as high as 9,000,000 or 118,000+ rpm.....lol.. ie turbocharger bearings

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    Senior Member Robert Jonsson's Avatar
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    i am not an expert, but i have been told a couple of times that a pump will start to lose efficency around the mid 7k range. may or may not be true.

    i think the other problem is that most motors dont make the power to spin the pump faster than that unless they cut the impeller way down, which can cause issues with hole shot and efficency because of the smaller bite.

    i know of some racers out there that are running high rpm pro-stock type motors that have installed gear reduction boxes allowing them to buzz the motor without having the pump need to spin that fast and allowing for a bigger impeller. but you will add weight and resistance from the gearbox. for most applications i dont think it is worth the cost and effort

    i have never really heard a discussion about the max rpm of the bearing, but maybe thats because nobody is operating near it's limit. if i read 1quickcp's post correctly then it looks like about 11,000

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    yes but u could go crazy ceramic bearings in that size and the skys the limit....who knows how many rpms the tail shaft bearings would turn...I do work for a friend on turbine engines in unlimiteds and those turn crazy numbers for speed and cost like 4k EACH.....spendy bearings....

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    Quote Originally Posted by Robert Jonsson View Post
    i am not an expert, but i have been told a couple of times that a pump will start to lose efficency around the mid 7k range. may or may not be true.

    i think the other problem is that most motors dont make the power to spin the pump faster than that unless they cut the impeller way down, which can cause issues with hole shot and efficency because of the smaller bite.

    i know of some racers out there that are running high rpm pro-stock type motors that have installed gear reduction boxes allowing them to buzz the motor without having the pump need to spin that fast and allowing for a bigger impeller. but you will add weight and resistance from the gearbox. for most applications i dont think it is worth the cost and effort

    i have never really heard a discussion about the max rpm of the bearing, but maybe thats because nobody is operating near it's limit. if i read 1quickcp's post correctly then it looks like about 11,000

    so if you had enough power and you spin your motor up to 5500 thoreticaly you could have a two speed gear box, with 1 to 1 for first and say 1to 2 for second and run the pump up to 11000, but what would the gain be spinning that fast or even 9 or 10, if you start loosing at 7g

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    Quote Originally Posted by millwrightlong View Post
    so if you had enough power and you spin your motor up to 5500 thoreticaly you could have a two speed gear box, with 1 to 1 for first and say 1to 2 for second and run the pump up to 11000, but what would the gain be spinning that fast or even 9 or 10, if you start loosing at 7g
    None.

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