FWC Question

[Sundancer]

We're buying a new boat and it's being surveyed as I type this. I'm anxiously awaiting the results. My question is this. It has seacocks for the FWC and it also has Alpha drives (Gen 1, I believe?). I don't know if it is fully FWC or only half. If the seacocks provide the water for the cooling, is there still a pump in the Alpha and if so what does it cool? Our current boat is RWC and the Alpha supplies all the water. I can't get to the boat to check it out and I'm trying to get a feel for it's operation before we take delivery tomorrow or Thursday. I want to be prepared to splash this weekend!!

Thanks in advance!

 

[estebanj]

Not sure what you mean by seacocks for FWC. Where are these seacocks and what water do they keep out or bring in?

Is there a reservoir coolant tank and heat exchanger?

Esteban

 

[Sundancer]

Not sure what you mean by seacocks for FWC. Where are these seacocks and what water do they keep out or bring in?

Is there a reservoir coolant tank and heat exchanger?

Esteban

Yes, I can see the heat exchangers/reservoirs and there is a seacock for each engine. That's why I'm confused!! I just thought the water would be supplied by the Alpha? Unless these are Bravo drives? But I'm certain they are Alpha's just like my current boat. Maybe I just need to get the boat back and trace the lines a little better. These are fairly large seacocks and having two that big seems strange. I'd expect ONE for the toilet, but two? The boat doesn't have A/C either so I don't know what these are for? There is no generator either, but maybe it was plumbed that way from the factory? I guess I'll just have to wait until I get the boat back!

The boat is a 1989 30 DA with twin 350's that are fresh water cooled.

 

[estebanj]

I'm thinking the sea water comes from the seacocks (one for each engine) instead of the Alpha pump. I >think< I heard or read somewhere that this is an option to bypass the outdrive pump and have water flow via a throughull with seacock.

Let's see what others reply.

Remember, on a FWC engine, the elbows and heat exchangers are still sea water cooled.

Esteban

 

[Sundancer]

I'm thinking the sea water comes from the seacocks (one for each engine) instead of the Alpha pump. I >think< I heard or read somewhere that this is an option to bypass the outdrive pump and have water flow via a throughull with seacock.

Let's see what others reply.

Remember, on a FWC engine, the elbows and heat exchangers are still sea water cooled.

Esteban

I think the bypass was probably performed successfully! The heart is still beating! That's why I was confused! I was trying to figure out if the seacocks cooled the heat exchanger and the Alpha then took care of the elbows? That seems like WAY too much complexity! One system, one loop and one pump! I'm guessing the water comes in through the seacock, through the heat exchanger and then exits through the Alpha to cool the elbows, PS and exhaust along the way. That's the only way it would make sense to me. I think that's the way some of the Bravo's are plumbed too? I'm not sure about that though.

I'll keep you posted as this unfolds!!

 

[estebanj]

My B3 (and most/all I believe) has the water pump in the engine and it pulls the water via the outdrive (no pump in the outdrive, just the holes and hose to the engine water pump).

Esteban

 

[Sundancer]

My B3 (and most/all I believe) has the water pump in the engine and it pulls the water via the outdrive (no pump in the outdrive, just the holes and hose to the engine water pump).

Esteban

I guess it would be easy to convert the Bravo's to a thru hull to then? I've never been on a boat new enough or had time to look at how the Bravo's cooled. Like I said, I'm anxious to get the boat back and start attempting to figure this thing out! I suspect you are right, they converted or built this one with thru-hulls to bypass the Alpha water pump.

 

[Sea Ray 300]

I guess it would be easy to convert the Bravo's to a thru hull to then? I've never been on a boat new enough or had time to look at how the Bravo's cooled. Like I said, I'm anxious to get the boat back and start attempting to figure this thing out! I suspect you are right, they converted or built this one with thru-hulls to bypass the Alpha water pump.

My engines are FWC, and draw cooling water through both the Bravo III outdrives, and the thru-hulls.
They are piped to a Y fitting, at the back of the water pump, which is then piped to the heat exchanger. Bravo III's do not have internal water pumps.

This gives more volume of cooling water for the heat exchangers, while still cooling the outdrives.
An added bonus is that should seaweed plug the drive water pick-up, you still have the thru-hull.

I suspect that yours is a similar arrangement.

 

[boatdoc100]

Sundancer,
Your engine cooling is routed as follows: Through bottom to raw water pump to oil cooler to heat exchanger to riser and out. The FWC side of coarse simply recirculates around the heat exchanger.
Brad
Pflieger Marine Services

 

[comsnark]

I am sure it works.

The bigger question is WHY the boat is plumbed this way. It does not sound like an original installation.