Ballast suction off raw water intake?

[dtb]

I need some advice from this great group of do-it-yourselfers.

I installed upgraded rear ballast on my 2000 VLX a couple seasons ago at which time I simply connected my suction point for the new fill pumps at the threaded drain plug hole beneath the transmission in the center of the hull. This has been a PITA because I have to pull the fittings out each time I need drain the oil, or drain water out of the hull - plus I can't get as much water through the 3/4" hole as I'd like for two 1,000 GPH pumps. I've been contemplating better solutions for the ballast pump suction point. I know the simple answer is just to cut a new hole in the hull, which I'm comfortable doing and have done in the past for PerfectPass install and ballast discharge. My problem is there really just is not another good location to cut a new hole in the hull below the waterline. I'm out of room in all accessible locations.

So here's my question: I'm thinking of teeing off of the raw water intake to draw suction for the ballast pumps. I would put a bronze threaded tee at the scoop intake before the hose connection to the v-drive cooling jacket. The straight through tee connection would be to the v-drive/raw water pump. The tee branch would go to the ballast pump suction through a ball valve. I would not intend to fill ballast while the engine is running for fear of starving the cooling system for water, and there would be check valves on the ballast fill before the bags to prevent the raw water pump from pulling water back out of the ballast bags.

It works in my mind. Is there any reason not to plumb the system this way? What did I not think of? I'm mostly concerned if there is something I'm overlooking that might affect the performance of the engine cooling system and its ability to get the water it needs.

Thanks for all thougts and opinions.

[barefootpaul]

I have thought of doing something similar as well but I have been to scared to mess with the raw water intake. Interested to see what others have to say.

[Wake My Day]

I recently added rear ballast in my 23 lsv. I was also going to utilize the 3/4 threaded drain hole in my boat as well. After talking with Jason at Wakemakers several times he felt this opening would work, however a 1inch would be much better. I read several posts on drilling the hull and installing new through hull fittings. After getting sick to my stomach I mapped out the location for two new holes, charged up the drill and put a 1 3/8 hole saw bit into the drill and went at it. Following all the rules of drilling backwards first for the gel coat, and beveling the gel as well. Piece of cake. Holes drilled in 5 mins. A little more time spent mapping out the holes and applying masking tape but really no problems at all. So to make a long story even longer, DONT use the existing holes if you have space on your hull or around you bilge. Drill in one or two holes and install new through hull fittings. It really isn't that hard. Just my opinion.

[Ndawg12]

I need some advice from this great group of do-it-yourselfers.

I installed upgraded rear ballast on my 2000 VLX a couple seasons ago at which time I simply connected my suction point for the new fill pumps at the threaded drain plug hole beneath the transmission in the center of the hull. This has been a PITA because I have to pull the fittings out each time I need drain the oil, or drain water out of the hull - plus I can't get as much water through the 3/4" hole as I'd like for two 1,000 GPH pumps. I've been contemplating better solutions for the ballast pump suction point. I know the simple answer is just to cut a new hole in the hull, which I'm comfortable doing and have done in the past for PerfectPass install and ballast discharge. My problem is there really just is not another good location to cut a new hole in the hull below the waterline. I'm out of room in all accessible locations.

So here's my question: I'm thinking of teeing off of the raw water intake to draw suction for the ballast pumps. I would put a bronze threaded tee at the scoop intake before the hose connection to the v-drive cooling jacket. The straight through tee connection would be to the v-drive/raw water pump. The tee branch would go to the ballast pump suction through a ball valve. I would not intend to fill ballast while the engine is running for fear of starving the cooling system for water, and there would be check valves on the ballast fill before the bags to prevent the raw water pump from pulling water back out of the ballast bags.

It works in my mind. Is there any reason not to plumb the system this way? What did I not think of? I'm mostly concerned if there is something I'm overlooking that might affect the performance of the engine cooling system and its ability to get the water it needs.

Thanks for all thougts and opinions.

Someone did the math on here a while ago and found that a 3/4" will pass well over 2k gallons per hour (like 2300 or something). I suggest 1 3/4" hole and a "T" to 2 pumps like the factory does for our rear hard tanks.

[martinarcher]

Someone did the math on here a while ago and found that a 3/4" will pass well over 2k gallons per hour (like 2300 or something). I suggest 1 3/4" hole and a "T" to 2 pumps like the factory does for our rear hard tanks.

No way....not at the pressure those little pumps generate. He's on the intake side of the pumps too so it's actually having to draw a vacuum. Under vacuum you'll never get 2000 GPH through a 3/4" pipe.

Here's a little reference chart on PVC pipe water flow ratings at the different pressures....

http://flexpvc.com/WaterFlowBasedOnPipeSize.shtml

That's why I ran all 1" in my boat.

[Chia]

No way....not at the pressure those little pumps generate. He's on the intake side of the pumps too so it's actually having to draw a vacuum. Under vacuum you'll never get 2000 GPH through a 3/4" pipe.

Here's a little reference chart on PVC pipe water flow ratings at the different pressures....

http://flexpvc.com/WaterFlowBasedOnPipeSize.shtml

That's why I ran all 1" in my boat.

i think he is saying, and your chart shows that a 3/4 inch pipe will handle 2000gph. So shouldn't those pumps (800 or 1200gph) be able to push as much water thru a 3/4" line as a 1" line?

[Chia]

wouldn't it be nice if there were 2 water intakes attached to the engine. one for the engine to use and one for us to use for filling ballast.

Wouldn't need any extra pumps, just some valves to divert the flow to the bags of choice.

[martinarcher]

i think he is saying, and your chart shows that a 3/4 inch pipe will handle 2000gph. So shouldn't those pumps (800 or 1200gph) be able to push as much water thru a 3/4" line as a 1" line?

Your looking at a different chart than I am. It shows 2000gph going through a 3/4" PVC pipe at burst pressure. That's well over 100psi.

It shows 660gph on a 3/4" pipe on the suction side which is what he will have at the thru-hull fitting on the bottom of his boat.

Edited May 17, 2011 by martinarcher

[dtb]

Thanks for the replies guys. Let me re-state my question: Regardless of how much water I can get through the existing 3/4" drain plug hole, I don't want to continue using it because I have to pull the ballast connection fittings out for every oil change so I can drain the oil through the oil pan drain hose out the bottom of the hull. It doesn't sound like a big deal but it is a pain to pull everything out even if it is just once or twice a season. Plus, I'd prefer use that hole to drain water from the hull when it builds up in there from wet riders, packing nut drip, etc.

So back to the original question - teeing off the raw water intake for ballast fill, good idea or bad? See OP.

Thanks.

[Levi900RR]

I have my ballast T'd off the raw water intake. It works great. I know MartinArchers set up is like that too. Check out this thread.

[martinarcher]

Thanks for the replies guys. Let me re-state my question: Regardless of how much water I can get through the existing 3/4" drain plug hole, I don't want to continue using it because I have to pull the ballast connection fittings out for every oil change so I can drain the oil through the oil pan drain hose out the bottom of the hull. It doesn't sound like a big deal but it is a pain to pull everything out even if it is just once or twice a season. Plus, I'd prefer use that hole to drain water from the hull when it builds up in there from wet riders, packing nut drip, etc.

So back to the original question - teeing off the raw water intake for ballast fill, good idea or bad? See OP.

Thanks.

As Levi posted, that's how I set-up my ballast system. I T'ed into the 1 1/4" raw water feed and then built a little manifold to feed the two 1200GPH pumps. Works like a champ.

[dtb]

Thanks martinarcher - that's what I'm planning to do. Great video link above too. Just curious - do you fill ballast with the engine running with your setup?

[Levi900RR]

I know your question was directed towards MA, but I fill my bags while my engine is running. (I have the same set up as MA) I usually run the fill pumps as Im idling away from the ramp. I have a clear raw water intake line so the first few times I monitored the water to make sure everything was getting enough. I have never had a problem.

Hope this helps.

[dtb]

Awesome, thanks for the advice guys. I think my plan is complete - now to find the parts I need....

[Brad B]

That's why I ran all 1" in my boat.

Well and its a lot easier to stretch a 1" id hose on the Tsunami fitting

[martinarcher]

Awesome, thanks for the advice guys. I think my plan is complete - now to find the parts I need....

Cool! Glad my video helped! I hoped it would come in handy for others!

[martinarcher]

Well and its a lot easier to stretch a 1" id hose on the Tsunami fitting

No doubt! Add a little heat and disk soap and it goes right on.

[Brad B]

I changed all of my fill hosing to 1" i.d. years ago when I upgraded to 1200 gph pumps and very happy with it.