Hello All!
I am super happy. I just bought a 1999 Sundancer 310 with 350 MAG MPI (Bluewater Inboard) With V -drives . I love the wider beam of the older models.
It is raw water cooled. I understand the differences between the RWC and FWC.
The boat lived in lakes in AZ all of its life and dry stored during winter. Engines have 400 HOURS.
I tested it for 3 days in a Lake before buying it. The engine runs like a charm. Compression is 165 on all cyls.
It will be kept in the San Francisco Bay in Salt water.
My old boat was a 2005 Glastron 279 with a volvo penta 5.7 RWC and inboard/outboard. I replaced the manifolds and risers right away by myself for $900 bucks (the old ones were close the 90% clogged after the boat sat on a dock for 3 years). The engine had 150 hours when I bought it. I never had a problem with the engine in the 18 months I owned it. Temp stays locked at 155 even after a 6 hour ride non stop to Sacramento.... The local Volvo shop told me that the engine was solid and as long as I used it regularly a couple of times a week, I didn't even need a flush system. He said that my radio would rust faster than the engine... But I spent the cost of the boat on issues with the stern drive...
Since then I learned my lesson... SALT WATER = INBOARD ONLY FOR ME
I do acknowledge that a lot of fisherman use RWC engines in salt water with no problems as long as they maintain them well.
Now, back to my question:
I considered installing a FWC system kit on my Sea Ray 310 with 350 MAG MPI (Bluewater Inboard). Part number 710-860427a 5. Each kit is about $2000 and the mechanics would charge $1500 on each engine.
One of the top shops in the bay questioned my choice... he said that a 20 year old engine is not worth the money of the FWC system investment. He said that I could just install a good flushing system and leave it alone. At some point, I should change manifolds and risers and that would be it. He said that on a boat that old, the resale value of FWC vs RWC is not worth the investment in the FWC conversion...
I read a number of forums about FWC vs RWC. There are pros and cons of each and many well fundamented beliefs of do's and don't do's.
I literally considered launching the boat in the river, installing the the FWC kit and ONLY THEN going to the bay.... but the logistics of my transport are leading to getting the boat on the Bay's salty water next week...
My Kid is really into this boating thing so we'll definitely go out a few times a month and probably run the engine for 2-3 hours each time.
I would appreciate some guidance on what you would do if it was your boat.
1. Would you just install a flush kit , make sure i flush it after each use and leave it alone?
2. Would you run it on the bay in salty water till the end of the season and spend the $7K upgrading to FWC after doing a good flush of the cooling system?
3. Should I just run it and inspect manifold and risers at the end of the season?
4. Other ideas?
I found it cool that a reputable Merc mechanic shop told me to leave it alone instead of selling me a huge project...
Any comments, ideas and food for thought are appreciated.
Thanks
Fer
My opinion...
A RWC boat that lives in saltwater should be flushed after every use (when feasible) so as to prolong the life of the exhaust manifolds, risers and elbows. With a flushing system and a salt removing product (I use "Salt Away), you can can greatly extend the time frame of replacing these items.
If money is not an issue, then dont flush and just plan on automatically replacing those items every 2-3 years like clockwork.
On my system (that I installed), you close the raw water intake seacocks and open an inline valve that is between the seacock and the strainer. The valve is connected to a short piece of reinforced hose that you drop in a 5-gallon bucket kept full of fresh water by a running garden hose from the dock. Crank the motor and let the engine pull the fresh water from the bucket for 5 mins or so....when you are ready to shut down, turn off the garden hose in the bucket and quickly dump 4oz of Salt Away to the bucket. Shut down the engine when the bucket is empty (but dont let your impeller run dry!!).
With the Salt Away product you should see some suds/foam come out of your exhaust water outside the hull. Then turn off your flushing valve and leave the fresh water/Salt Away mixture inside the engine.
You have now rinsed out any salt water from your cooling system and greatly reduced internal corrosion.
Anything cooled by seawater needs to be inspected at around 100 hours regardless of flushing in my opinion. I installed new OEM elbows and manifolds 3 years ago and have been flushing after every use. I know my flushing process is working as I dont have any rust stains on the hull by the exhaust ports and when I crank it before going out, the water comes out clear with the Salt Away mixture (no rust in water). My first inspection will be this winter before our trip to the Dry Tortugas off of Key West.
