Diesel dewatering pump.

[Manateeman]

We have a 6.8 hp HATZ electric start diesel and a lot of space over our main engine. It has a 1” straight shaft with key. We are thinking about connecting it to a semi trash pump. So the first question is which is the best pump and why.
Next, it would be nice to arrange it to run a large 24 volt alternator and yet be able to switch over to the pump within a reasonable time. The second question is how best to do this. Belts, pulleys, cogged?. Another shaft?
We can easily suspend the works fro the center cockpit beams and have a walk around engine room so space is not an issue. The main engine has a water gas separator on the aft bulkhead so the Hatz exhaust is not a problem.
There are four, three inch cockpit drain standpipes but we could hose the pump discharge right overboard. I’m thinking the suction should be hose rather than fitted pipes. My main question is how best to get the diesel connected to two other units. Any sketches or shafting / connection ideas will be very appreciated.
My manatee crew is more concerned designing a on board brewery hence my desire for substantial dewatering.
Captain Mark

[s/v Jedi]

I have one for sale here: https://www.cruisersforum.com/forums...mp-242255.html

It uses an electric clutch, so belt drive. It was mounted to an extension of an alternator bracket. If you have one alternator, it is recommended to mount this on the opposite side so that crankshaft side loads on its bearing cancel each other out a bit.

[tkeithlu]

A reasonable arrangement would be the generator off the back end and the pump off the front end of the little diesel. Then comes how to mate the pump. Belts have the advantage of allowing you to match RPM, and even use a very cheap idler wheel as a way of clutching the pump. Don't figure on taking full horsepower off the front of the engine - the bearings were not really designed for that.

An "A" section V-belt can transmit 2.2 HP max, so we are talking about double or even triple pulleys, depending on the pump you choose.

Five horsepower allows 230 amps or so at 24v, so you're probably talking about a power end rather than a whopping alternator for the back end of the diesel.

Using large diameter PVC for the suction side has advantages. You don't have to use expensive reinforced hose to keep suction from collapsing it, and you can make a strainer at the input by drilling holes in the last section and then capping it.

[Manateeman]

Jedi...sent you a pm.
Keith. It’s a B30 HATZ and I’ll ask about the bearings but you can only take power off one end. They use them for really tough applications...I’ll post HATZ reply.
OK. So first I have to connect the Diesel and the Jedi pump. Next the alternator. I’ve been looking at the military surplus Leece Neville alternators. We have a 8 kw NL gen set and huge solar but we would use the HATZ only if neither worked. The HATZ is going to make a Lot of Noise and heat. We are never at a dock. The principle reason is for emergency dewatering. Since the pump is electric clutch, maybe we can go without a lay shaft...I was thinking I needed the cog belts like drag race cars have on a supercharger. I’ll post the alternators I’m looking at tomorrow.
As always, thank you for the expertise.
Mark

[Manateeman]

The alternators we have looked at : Leece Neville 140 amp brushless marine J180...175 amp for Volvo Penta, 110-258A.
We love the big Leece Neville.
But...other suggestions?
Got to be 24 volts. $500 max.
Hose for the suction idea is that we can drag it forward or aft as needed. We also might in the future buy some lesser quality stuff so we could pump out another boat in an emergency. Maybe a tee and two valves in the engine room. One way direct, the other side a cam fittings for the hose.
I’ll have to hide the fire fighting nozzle or the manatees will be using it for water fights with the bad orcas.
Happy trails.
Mark

[s/v Jedi]

Originally Posted by Manateeman

The alternators we have looked at : Leece Neville 140 amp brushless marine J180...175 amp for Volvo Penta, 110-258A.
We love the big Leece Neville.
But...other suggestions?
Got to be 24 volts. $500 max.
Hose for the suction idea is that we can drag it forward or aft as needed. We also might in the future buy some lesser quality stuff so we could pump out another boat in an emergency. Maybe a tee and two valves in the engine room. One way direct, the other side a cam fittings for the hose.
I’ll have to hide the fire fighting nozzle or the manatees will be using it for water fights with the bad orcas.
Happy trails.
Mark

That’s a shame, I have a bunch of really nice Lestec Brute 225A alternators but they are 12V

[Lepke]

Air cooled engine is going to put a lot of heat in your engineroom if you don't have great ventilation.

[Manateeman]

Yes it will get warm very quickly even though we have a good continuous duty blower. I should have clarified the application.
Emergency de watering...as in we are sinking.
Or someone else is sinking or on fire.
If our gen set stops and it’s very cloudy for solar, we could use the alternator to charge our batteries but adding the alternator is secondary to pumping a lot of water quickly.
On a lot of commercial vessels, they have a big dewatering pump and it’s tested frequently. I think the HATZ diesel coupled to the big Jabsco pump will be a good combo...no gasoline, electric start, proven engine and pump.
All I need to do is prevent the manatee crew from joining fire boat parades.
Mark