SoCal Jet Boats
Tech Talk => Jet Pumps => Topic started by: hallett1974 on February 24, 2014, 04:49:13 PM
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After i got the engine (455 olds) finished, the engine builder told me that i need to run a A cut or B cut impeller. Is there anyway to tell just by looking at the impeller what cut it is?
Thanks for the help again.
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If its a berk, it will be stamped on the back side facing bowl. If its been modified this link might help.http://www.b1racing.net/blog/2013/02/03/Impeller-sizing.aspx (http://www.b1racing.net/blog/2013/02/03/Impeller-sizing.aspx)
A is standard and will work well with a stock olds. Most who run olds know they dont like high rpm so A is a good choice and try to keep most runs under 4000. Going to a B would allow more rpm and in a stocker olds...no good. Make sure your builder knows as well you, the mods needed to run an olds in a boat. My olds would puke shit tons of oil out the breathers on just a quick pass....that was when my heads were swapped (stolen) out at mechanics shop years back. The B's on it before had the drains opened up.
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Well the 455 is not stock. The motor has 550 horsepower bored 20 over with a roller cam. The engine builder told me to buy a ignition with a rev limiter and set it to 5500 rpm's. So should I go with a B cut impeller?
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Well the 455 is not stock. The motor has 550 horsepower bored 20 over with a roller cam. The engine builder told me to buy a ignition with a rev limiter and set it to 5500 rpm's. So should I go with a B cut impeller?
Sent from my SGH-T999 using SoCal Jet Boats mobile app
In all honesty this is somewhat impossible to answer.
At what point (rpm wise) does it make the mentioned 550 hp? More importantly, how much torque does she develop at that RPM?
I would go with an A impeller, if you have the pump apart already, it is really easy to tell, that being said, your 550 HP is pretty much at the limits of an aluminum impeller anyway, you might consider picking up a mag bronze or stainless A, you may even be able to get away with a AA which is why it is somewhat critical to know what you will be doing with the boat and what you have for actual power.
There is an impeller cut chart here, that is the ONLY way to tell what you have, make sure and verify the wear ring clearances and bowl face to impeller shimming to ensure your pump is nice and tight before going through all the headaches of putting it all together...
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Hope this helps you out.
GT
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Well the 455 is not stock. The motor has 550 horsepower bored 20 over with a roller cam. The engine builder told me to buy a ignition with a rev limiter and set it to 5500 rpm's. So should I go with a B cut impeller?
Sent from my SGH-T999 using SoCal Jet Boats mobile app
With the 550hp, what oiling mods were done to this motor? I don't mean to jack the thread, but te OLDS is a picky B!tch when it comes to RPM over 4500ish... Also who built it?
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Well I have a giant oil pan and I'm sure some other things but I would have to look at the motor specs. The builders name is terry and he works at graves automotive in Ontario, ca.
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Stock type regular flow oil pump, oil restrictors, open up oil return in heads/block, puke tank, 10qt oil pan ect... just a few things you must do to an olds. What heads do you have B,C,G,K... Big valve? If your engine builder built it for a car than you need to rebuild it for marine/jet use.
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I have the 10qt pan I will have to find out about the heads and look at tge specs. I told terry that it was for a marine/ jet boat.
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