Underfloor Ballast Tank Dump Pump

[Primal 98]

Hey Guys I am starting to think about rigging up the 3 underfloor Ballast tanks I have in my boat. These run for the first 6ft or so between my stringers up in the nose and either side on the outside of my stringers. The nose tank is probably around 35 Gallons and each side is around 10 Gallons. They will all be filled through a single retractable fill pipe at the transom through 1 1/4" fill and 1 1/2" Vent lines in the top of the floor. They will all dump through 1 1/2" hoses at the rear of each tank into a single large flow pump which will then pump back up to an outlet in front of the helm so that I can visibly see outlet flow. The question is, what would be a recommended pump for this set up. I have seen the Rule 3700 GPH General Purpose pump used, however I am wondering if there are better options. The only requirements I have is that it needs to have 1 1/2" inlets and outlets, be 12 volt, be of good quality and have the highest flow possible.

[Aaronhl]

What blue boat is that?

[AZMIDLYF]

Looks like an Australian Force 21

[Primal 98]

Nah guys, it's something I knocked up in the shed in my spare time. I call it a 'Primal X-21' :

Scratch built 21ft Ski Race Prototype

Its got a fair way to go in regards to final fairing and bottom tuning, but so far its performing way beyond expectations.

[AZMIDLYF]

That is impressive Primal. Are you a boat builder by trade and wanted to create your own at home? I thought it was a Force because of the body line running down the side.

[Primal 98]

G'day AZMIDLYF,
Nah mate, not a boat builder, just a guy who raced boats back in the day and always had an interest in boat design. I am an aircraft engineer by trade and thought that I could build a slightly larger hull to maximise aero lift across the deck and also carry the larger, heavy Verado motors better than the current offering. I have no real plans for the boat. I am just enjoying testing and tuning it at the moment with multiple changes happening to the running surface at this point, while playing with a matrix of standard rigging combinations (setback/height/prop) with each hull surface change. If it ever becomes better than what is currently out there I may mold it however there is currently an over supply of similar boats available in Oz. Force/Connelly/Bullet/Cyclone/Lab Sports etc are the benchmark at the moment and I see no point in going commercial unless I have a better mouse trap. Your right in the silhouette and mold line been similar to a Force, however the silhouette is all about the upper 'wing' surface and out of respect to all original boat builders there are absolutely zero copied surfaces. The bottom is 100% unique. Basically, I am just a guy who wanted to build an original design to see if my theory was correct. Time will tell.....

[Aaronhl]

Very nice I really like that hull

[AZMIDLYF]

Again, very impressed with what you have been able to accomplish.

The ballast pump question seems like one that you should be asking of all those OZ manufacturers though. They equip every ski hull with them.

[Primal 98]

Thanks guy's, yeah I'm pretty happy with how it has come out and as the testing is progressing the results seem to be quite good. A long way to go at this point and I don't get much access to good water so it is a slow process. Either way I am enjoying it.

As for the Ballast pump question, I am a little 'out of touch' with the Oz race scene and live about 3000 miles from that action, so I am hoping that someone from the States/International members of S&F may have experience either from ballast systems or maybe from the bass boating scene for their live bait tanks.
Thanks again

[NICE PAIR]

Attachment 365807I don't care who you are ... "Awesome build"

[home made tunnel]

I remember your build thread in that shed !!! Great build. Once you painted it, it really came together.
Surprised you're not finished yet !!! Didn't you tow it half way across Australia when you moved or something?

Wish I had more info to help you, but I do know the company Shurflo makes some damn good pumps. All kinds too. 12v, mainly made for RV motor homes, but can be used for so many applications. Check out there site to get the pump you desire, then shop on Google for a supplier? Tractor Supply stores also have agricultural pumps you could use.

[XstreamVking]

A pump type that will pump from above the water level in the tank with no airlock, would be a good one IMO. The bilge type require that the pump is always below the water level. And they tend to airlock easily....

[Primal 98]

Thanks again HMT and XV, I'll check out the Shurflo, and good input regarding the airlock/need to keep a bilge style below the water, I'll keep that in mind during the hunt for the right pump.

As for the boat, it's 'kind of finished' however 'evolving' with each test session. Since it hit the water in November it has had the steps underneath tweaked, tuned and finally tapered out, Hook removed from the chine extensions and a pair of lifting strakes are going onto it this weekend. Engine setback has incrementally been changed with engine height adjustment, and a number of props trialled for each change to the bottom. I'm currently chasing more lift from the hull (hence the strakes), which will start the process all over again. It's currently at 1 inch below and
12 1/2" setback however expect to be back into maybe 10" with the strakes once its all done. Once happy with the lift at the rear I will move onto the foot of the bow to assess the way it spans waves. I'll be looking to create enough lift to hold the hull up on the crests without bouncing and launching in about 2-3ft waves that are getting towards a boat length apart. Any mods will need to be considered for their impact on turning ability however. That's where the tenability for the ballast tanks will provide a level flexibility in what I come up with.
We are currently not that focused on top end speeds . So far we have only pushed out to around 54MPH (stock 225hp Optimax) at 5500 (would have no problem pulling to redline, but no need at this point) with a 21" Trophy. Go fast testing will come later but I'll need to drop this thing onto a 20" leg first.

[gtflash76]

If you put a pump in a tank, you will need a substantial inspection port for when the pump fails. A lot of pressure when fillling. Why not go old school and have a combined fill and dump. Then all that is needed is a 33c three position lever to control pickup and a breather on tank

[Primal 98]

Thanks gtflash76 I definitely will be picking up with a pickup like you have shown. The tanks are currently plumbed with a 50mm outlet pipe at the back of each tank to feed a pump. The pump is planned to draw from the pipes and be mounted external to the tanks. There are fill and vent fittings in the top of the tanks. I like the idea of a basic setup, however would prefer to be able to visually see when the tanks are empty, hence needing the pump to pump to an outlet in front of the drivers seat.
Thanks again