Do I need fresh water cooling

[fmeiere]

I almost bought a Stingray 240CR for use in brackish water. (Waccamaw River and Winyah Bay near Georgetown, SC.) I worried about using sea water cooling for the engine; a Mercruiser with a Bravo 1 stern drive. My only experience is with fresh water cooled inboard engines. Anyone have experience with a similar situation? If so, do you flush you engine after every boat trip? If not, has your engine corroded away? Thanks.

 

[snapperbait]

Re: Do I need fresh water cooling

I would say your OK without freshwater cooling as long as you flush the engine after you use it... FWC would be better but only if you feel it's worth the extra cost involved.. You should also factor in the amount of time you will be using the boat... The more useage then the more the FWC will pay for itself in the end..

 

[VMAX]

Re: Do I need fresh water cooling

I was considering freshwater cooling also, and was wondering; doesn't freshwater cooling still need to have the seawater part flushed anyway?

 

[Walter]

Re: Do I need fresh water cooling

Let's get our terminology straight...<br /><br />Freshwater cooling generally refers to cooling systems that circulate raw, sea, fresh...(whatever type of water your boat happens to be floating in) throughout the engine and exhaust manifolds.<br /><br />Closed cooling systems circulate antifreeze through the engine. Cooling takes place via a heat exchanger and the exhaust manifolds that have raw, sea, fresh...whatever...water flowing through them. The heat exchanger works much like an automotive radiator that uses the air flowing through it to cool the antifreeze.<br /><br />If it were me...I'd opt for a closed cooling system if my boat were to be used the majority of the time in brackish or salt water. <br /><br />Although it would be wise to flush the raw water components of a closed cooling system after the boat was used in salty water...it's not critical. Nevertheless...doing so will add more life to those components. Flushing is a simple process...and well worth the minor effort.<br /><br />Walt

 

[Capt Ken]

Re: Do I need fresh water cooling

Sorry Walter, RWC'ing (raw water cooling) refers to cooling that uses whatever water the boat is sitting in to cool the engine. FWC'ing (fresh water cooling) refers to the closed cooling system that uses a coolant other than the water the boat is in. There is two ways to FWC an engine. One way is to use a heat exchanger which a raw water pump, pumps the water from outside the boat to cool the water in the cooling system and exits the water via the exhaust risers. The second way is thru keel cooling. The coolant in the closed system is pumped thru tubes located on the keel or bottom of the boat and the outside water cools the coolant. These vessels either has dry exhaust or uses a small raw water pump to cool the exhaust gas flow. Over the years I've found that there wasn't a big advantage to FWC a gasoline engine running in salt water. The salt water still flowed thru the risers and that's where the main damage is done to the exhaust system. The perfect system would be to use FWC'ing and install some of those Mercruiser SS risers. That way the system would almost be bulletproof.

 

[vinney]

Re: Do I need fresh water cooling

Fresh water cooling helps the next owner of the boat. Mercruiser doesn't recommend adding fresh water cooling after 30 hrs. of service if the engines raw water cooled. The only up of fresh water cooling is the engine temp. runs higher that a raw water cooled engine. the engine runs a little better. You will hang the rods out the side of the block befor the block rots out. Vinney