Raw water cooled engines in salt water

M

majoma

Member
Oct 10, 2008
284
San Francisco
Boat Info
2000 340, V drive
Engines
Twin 7.4
I am looking at a 2004 Sea Ray 320 with the 350 engines and V drive. The engines are not fresh water cooled and the boat will be kept in salt water.
Does anybody have any experience with this configuration?
Thanks
 
I re powered my old 300 Sundancer in 2012 when it was 25 years old. Both motors were raw water cooled and used in saltwater their entire lives.
I did however replace them with fresh water cooled motors.
 
One of my good friends has an 03 320 with the 5.7s (350) and another buddy has an 05' with the 6.2s. Both are RWC and have had minimal issues. I will say that the 5.7s definitely are a little sluggish compared to the 6.2s but at the end of the day we all do the same trips and nobody ever complains. The 320 is a great boat. Take care of your maintanece items like the exhaust etc and you will be fine. Only issue i didnt like for myself personally was the bed up front was a little short so I ended up going with the 340. Im also 6.3'.
 
You may consider adding fresh water cooling BEFORE you run the boat in salt. It will allow the engines to run more efficiently at a higher temp and add resale value as well.
 
I'll offer a dissenting opinion: I think it's crazy to pump saltwater through an iron engine block.

Sure, it can and is done. That doesn't mean it's a good idea. BTW, does anyone want to buy a giant 5.7L paperweight, aka my 280's starboard engine? Aside from holding down paper, it has low hours and can also be used a planter in your backyard. It'll go cheap. (port was replaced before 200 hours because of someones's bad flushing habits, so I can't offer a matching pair of giant balls of rust)
 
I was afraid I would get those comments about salt water running through the engines. I better look for a boat with fresh water cooled engines.
Unfortunately, there are several 320s for sale in my area; they are all in salt water and they are all raw water cooled.
Thank you all.
 
I have over 1000 hrs on my motor which is rwc. When I bought the boat I installed a flushing system so when I get to the dock I connect the freshwater and run the motor so I leave it with freshwater while it sits.
Would I like to have fresh water cooling, sure. I believe a retrofit kit is probably in the 1000-1500 dollar range for the parts alone. I opted for the flush system which I made myself which is better than nothing.

Just providing you you more fuel for thought.

Mark
 
boatrboy said:
I have over 1000 hrs on my motor which is rwc. When I bought the boat I installed a flushing system so when I get to the dock I connect the freshwater and run the motor so I leave it with freshwater while it sits.
Would I like to have fresh water cooling, sure. I believe a retrofit kit is probably in the 1000-1500 dollar range for the parts alone. I opted for the flush system which I made myself which is better than nothing.

Just providing you you more fuel for thought.

Mark
Click to expand...

I'm surprised there's not more closed loop cooling on boats. Obviously it would still make sense to use a raw water heat exchanger, but that could be easier to harden against salt water corrosion than a zillion little passages through an engine block.

I would think that fresh water environmentalists would be driving this, too, even though I don't think that raw water cooling is the source of very much pollution.
 
majoma said:
I was afraid I would get those comments about salt water running through the engines. I better look for a boat with fresh water cooled engines.
Unfortunately, there are several 320s for sale in my area; they are all in salt water and they are all raw water cooled.
Thank you all.
Click to expand...
Raw water just means you need to inspect the engines annually. Inspect the exhaust system annually. The fresh water cooled guys do this too. RIGHT?
 
boatrboy said:
I have over 1000 hrs on my motor which is rwc. When I bought the boat I installed a flushing system so when I get to the dock I connect the freshwater and run the motor so I leave it with freshwater while it sits.
Would I like to have fresh water cooling, sure. I believe a retrofit kit is probably in the 1000-1500 dollar range for the parts alone. I opted for the flush system which I made myself which is better than nothing.

Just providing you you more fuel for thought.

Mark
Click to expand...
Where do you connect the fresh water flushing system?
 
I think you will be fine if a tech thoroughly inspects the engines, your oil analysis is good, and everything else checks out.


Brown Eyed Girl - 2007 Sea Ray 320 Sundancer, 350 MAG MPI V-drive
 
I have an '03 320, 5.7L and V-drives with fresh water flush and cruise in the Puget Sound. After a cruise I flush with water and salt away. No issues with RWC.
 
Just make sure it has a fresh water flush system... and buy it. There are millions out there and if properly maintained are fine
 
majoma said:
I am looking at a 2004 Sea Ray 320 with the 350 engines and V drive. The engines are not fresh water cooled and the boat will be kept in salt water.
Does anybody have any experience with this configuration?
Thanks
Click to expand...

Take a nail and soak it in sea water for a couple days.
Then decide if you're comfortable purchasing 13 year old engines from salt water use.
 
El Capitan said:
Take a nail and soak it in sea water for a couple days.
Then decide if you're comfortable purchasing 13 year old engines from salt water use.
Click to expand...

Utter nonsense! I've got 20 year old 7.4's and they run like the way they did brand new.
 
Boater420 said:
Utter nonsense! I've got 20 year old 7.4's and they run like the way they did brand new.
Click to expand...

But... But... You must be mistaken! El Capitan knows everything! Just ask him, he will tell you!
 
El Capitan said:
Take a nail and soak it in sea water for a couple days.
Then decide if you're comfortable purchasing 13 year old engines from salt water use.
Click to expand...

majoma said:
I am looking at a 2004 Sea Ray 320 with the 350 engines and V drive. The engines are not fresh water cooled and the boat will be kept in salt water.
Does anybody have any experience with this configuration?
Thanks
Click to expand...

No mention of current berthing sutuation.
 
boatrboy said:
I have over 1000 hrs on my motor which is rwc. When I bought the boat I installed a flushing system so when I get to the dock I connect the freshwater and run the motor so I leave it with freshwater while it sits.
Would I like to have fresh water cooling, sure. I believe a retrofit kit is probably in the 1000-1500 dollar range for the parts alone. I opted for the flush system which I made myself which is better than nothing.

Just providing you you more fuel for thought.

Mark
Click to expand...

I would love to see pix of that. Frankly, I would not allow RWC to throw a sale for me one way or another. IMO, the plus is one less system to maintain and less to go wrong.
 
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