New to the site.  Been looking for a good jet boat forum like I have with my Supra boat and looks like this is the place.

Jet Boat newbie.  Rebuilding a 1973 CeeBee Avenger Mach III. 

Question:  I have rebuilt my Berkeley JC-A pump and just bought another pump.  The one I just bought very cheap has a stainless impeller in it.  Previous owner said his engine didnt have the torque to turn the stainless impeller to the proper RPM.  I was going to continue my build with the aluminum A cut impeller I have but now I am wondering if I should use the stainless impeller to complete it instead. 

I am building a 468 BBC for the boat which will be built to have some high torque at lower RPM and HP of around 500 at about 5400-5500 rpm.  Am I better off with the aluminum A or should I go with stainless?  Or run them both?  Does the stainless require a different wear ring? Some said that I have to get it balanced, is that the case?  I think the HP rating is right on the line for when to switch over to stainless.  Over time I will probably build on the motor.

Thought I was just going to part out the pump and sell the impeller but now thinking I should hang on to it.  Again, pretty new to jet boats so I appreciate any insight you can provide.

thanks
Dan

New to the site.  Been looking for a good jet boat forum like I have with my Supra boat and looks like this is the place.

Jet Boat newbie.  Rebuilding a 1973 CeeBee Avenger Mach III. 

Question:  I have rebuilt my Berkeley JC-A pump and just bought another pump.  The one I just bought very cheap has a stainless impeller in it.  Previous owner said his engine didnt have the torque to turn the stainless impeller to the proper RPM.  I was going to continue my build with the aluminum A cut impeller I have but now I am wondering if I should use the stainless impeller to complete it instead. 

I am building a 468 BBC for the boat which will be built to have some high torque at lower RPM and HP of around 500 at about 5400-5500 rpm.  Am I better off with the aluminum A or should I go with stainless?  Or run them both?  Does the stainless require a different wear ring? Some said that I have to get it balanced, is that the case?  I think the HP rating is right on the line for when to switch over to stainless.  Over time I will probably build on the motor.

Thought I was just going to part out the pump and sell the impeller but now thinking I should hang on to it.  Again, pretty new to jet boats so I appreciate any insight you can provide.

thanks
Dan

Welcome to SCJB. You should be good with the aluminum. Once you get close to 600 hp is when you might want to consider moving up to a stronger impeller. As long as the impeller lets the motor run to peak HP, you should be good.
I’m not sure about a different wear ring or the balancing. But the balancing would make sense.

Where are you located? Do you have any reputable jet shops in your area? You can get the impeller and bowl vanes detailed to make your pump more efficient. This can make a noticeable difference. A lot of reputable shops have pumps shipped to them. Just an option to keep in mind.


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Hey Tollerdave,

Thanks you for the welcome and for the advice.  I am in Pittsburgh but have a place up on Chautauqua Lake in New York.  Jet boats are not necessarily a big thing here anymore so trying to find people to ask questions is difficult.  I have joined a few sites but none of them seem to be up to date and I didnt get any advice.  i have a buddy in NC who rebuilds jet boats but he is tough to track down...so a big thank you for getting back to me.   Eventually maybe I will get to over 600 hp but my first build I am just hoping for 500.  From there I will experiment.  I did try to detail the bowl vanes a bit.  There were some nicks on the vanes I took a dremel tool and cleaned them up a bit.  The aluminum impeller is in good shape.  My understanding is that the previous owner had the pump rebuilt and then blew up his motor with nitrous. 

I guess maybe I will just go with the aluminum and maybe sell the stainless for cash for the build.  I am sure there are a lot of upgrades I would need to make to make the stainless impeller worth using.  Or maybe I just hang on to it.  I will continue the pump rebuild with the aluminum.

Thanks!
Dan

Yeah, I fell in love with the windshield on these.  I know most jet boat guys don't want the windshields.  My buddy thinks I am crazy wanting to put the engine hatch back on.  He says all jet boats need over the transom headers with engine exposed.  I want to dial this back a bit and make it look like a bit of a sleeper with through transom exhaust and engine hatch/cover.  Still going to be loud as hell.

There is one of these for sale in Ohio.  It looks really nice.  Silver flake.  Cant remember what he wants for it.  I think it is in the 8-10 range.  probably would have been better to find one in decent condition to buy but like you said, I wasn't seeing any like this one and now I am deep into this project.    Its been fun and learning a lot.  So all good.

would love to stay in touch. 

Another question for you regarding the exhaust.  What are you running on yours.  Logs and snails or regular manifolds and risers.  My old Supra inboard has the manifolds and risers and familar with them.  But been looking at running logs and snails.  will either work?  seems logs and snails are less expensive.  I like the look of the logs and snails too.  Any thoughts?   I plan to run 4 inch tips with internal flapper.  From what I am reading the I will have to adapt the hose from the smaller snail to the larger tip but I maybe be completely wrong on that.  Any insight would be greatly appreciated.

New to the site.  Been looking for a good jet boat forum like I have with my Supra boat and looks like this is the place.

Jet Boat newbie.  Rebuilding a 1973 CeeBee Avenger Mach III. 

Question:  I have rebuilt my Berkeley JC-A pump and just bought another pump.  The one I just bought very cheap has a stainless impeller in it.  Previous owner said his engine didnt have the torque to turn the stainless impeller to the proper RPM.  I was going to continue my build with the aluminum A cut impeller I have but now I am wondering if I should use the stainless impeller to complete it instead. 

I am building a 468 BBC for the boat which will be built to have some high torque at lower RPM and HP of around 500 at about 5400-5500 rpm.  Am I better off with the aluminum A or should I go with stainless?  Or run them both?  Does the stainless require a different wear ring? Some said that I have to get it balanced, is that the case?  I think the HP rating is right on the line for when to switch over to stainless.  Over time I will probably build on the motor.

Thought I was just going to part out the pump and sell the impeller but now thinking I should hang on to it.  Again, pretty new to jet boats so I appreciate any insight you can provide.

thanks
Dan

Hi Dan,

The RPM that an impeller will turn, in any given combination, is based on the cut size.  The material that the impeller is made from has no impact on RPM, at least not directly.  I will say that there are some stainless impellers that are of a poorer design than some aluminum and bronze.  The inverse is true also.

If you can post up pictures of both impellers, we can help you make a better educated decision.

Without being able to measure the impeller wear surface, there is no way to tell how much life is left in it.

As far as the cut size, I can usually tell if the impeller is an AA or large A (30-degree)  cut from a picture of the trailing edges.  A small A (33-degrees) impeller or smaller, can only be identified by measuring.

It is most likely worth it to keep the stainless impeller.  Stainless will have better wear characteristics and it will have better edge retention.

Be advised that Berkeley made some extra heavy duty stainless impellers.  These would not be my first choice for performance applications.

Cheers,

Joe

Joe,

Here are some pics of my aluminum A cut and my stainless A cut.  there are some major differences.  When I pulled the stainless impeller today I found that it was shimmed.   The lip on the stainless impeller is much shorter than the aluminum and the you will see difference in the hub are.  There is slight indentation on the stainless impeller looks like it was ground.  The vanes on the stainless are definitely bigger than the aluminum.  What is also a little confusing is the pump I bought is a 12JB which I didn't know existed but think the 12JB is identical to the 12JC but came with a split bowl...but it looks like the split bowl is gone as I the bowl that came with it is not split.

I rebuilt the JC pump I have and replaced the wear ring with the one that came in the rebuild kit.  Can I use this wear ring with the stainless impeller?  I definitely think it will need shimmed based on the look of the stainless but I have no idea. 

the stainless is heavier than the aluminum but not by much.  I didn't weigh them just holding them in my hand. 

Let me know you thoughts on these two impellers.  Like I said i am very new to all of this so I appreciate your help very much.

Thanks
Dan

The green is zinc chromate primer and that one is almost definitely aluminum.  The other one looks aluminum also, because of the corrosion.  Both look like large 30-degree A cut aluminum Berkeley impellers.

Stainless steel should feel twice as heavy as aluminum.

Both of those impellers should turn the exact same RPM.

Can't see the wear ring surface from your pictures.  Per your description, some older pumps have a narrow wear ring.  The short wear ring step on the impeller can be turned back to use a modern wear ring.