Brackish water/closed loop retrofit questions. First boat!

[j-rob]

Hello, we are currently in the process of purchasing our first wake boat, a 2001 Super Air Nautique. I have been around sail boats, and outboards, growing up, but very inexperienced when it comes to inboards. We live on a canal in Tx with access to Clear lake/Clear creek so our intended use will be brackish water.
Through a ton of research here and other places I have learned about closed loop cooling and flush kits. After quite a few searches here and other places, I am not seeing any documented retrofits of closed cooling onto the PCM GT-40.
A local boat dealer said running open loop around our local brackish water is no big deal...though I have little regard for the word of salesmen.


Does anyone know a good source for a retrofit cooling kit for the PCM GT-40?
Fundamentally it would seem possible to piece one together from a heat exchanger, reservoir, and some hose. Has anyone built their own?

Further, is it entirely necessary for brackish water if one were to be diligent in their flushing and servicing?

Thanks for any input or advice.

We are super stoked!

[DW SD]

I've had several Nautiques and my latest is a 2001 SAN with GT40 PCM, too and used my last two Nautiques in salt water (lagoon directly connected to the ocean). I'd say the determining factor about whether I'd suggest closed cooling is your ability to flush the engine with fresh water after use. I am confident that no appreciable build up will take place in a few hours (or more) of running at a time. I believe when build up occurs within the engine and cooling system is if salt water is left to stagnate and then chemically react.

Even if you have a closed loop cooling system and are unable to flush, you'll develop issues with the heat exchanger failing prematurely where the salt / brackish water attacks chemically the heat exchanger.
So either with closed or open cooling system, you'll need a way to flush if you want to maintain parts longevity.

The one tip I'd give is to flush for a long period of time. With my old boat, I used to monitor heat coming from the heater to know when the flush was making its way through those hoses. It took several minutes (2 to 3) to feel heat at the heater core, which indicated it takes quite a while. I usually run mine for a good 5 to 8 minutes while I'm cleaning.

I generally don't use salt a way or similar product, but I'd see no harm in that. On the boat itself, I rinse then hand wash everything down, including upholstery and even try to soak up residual salt in the carpet, compartment latches, etc. I also do my best to flush brakes, fenders, and other parts. My trailer frame is mild steel and closed tube (Ram Lin), which I'll be treating very soon to some rust conversion and paint application. I expect that to fail and will start keeping an eye out for aluminum or galvanized.

Note, I found a great production called CRC Heavy Duty Corrosion Inhibitor 06026 and buy it on amazon.
It is an aerosol wax, which leaves behind a coat of wax very similar to cosmoline often used by German auto manufactures to protect exposed metal. I use it on fasteners, hose clamps, bolt heads, any exposed brass or other metal like engine mounts, etc. in the engine bay. I also use it on the trailer parts like fasteners, chains, chrome wheels, etc.
Multiple coats can be applied. The product works great. It can be removed with some type of thinners, though I haven't had a desire yet to remove it


Hope this helps!

Doug

[j-rob]

Nice, thanks for the thorough reply Doug. Between this post, your post in the cooling thread, and the hydrophase review, you have provided a ton of useful info. The boat I am looking at doesn't have Perfect Pass and I was unaware of an alternative. Austin, Tx made is a selling point for me.

I am familiar with CRC, we use it offshore in my profession, so I know that's good stuff.
For now I think I will build a similar flush system out of brass fittings and run that for awhile. Diligent flushing of 10 minutes or so after each use will be very easy, as the boat will be kept in a lift in my back yard. Because of this, the trailer should also see minimal exposure to the brackish water, and can easily be pressure washed in my driveway after putting the boat in, and before storing it for my rotations home.


Looks like we might end up with identical boats by the way...The one I am looking at isn't quite in the immaculate shape that yours is. Hopefully I can get it whipped into similar shape over the winter though. Having a mechanical/marine survey done on Wednesday to ensure everything is legit. The suspense is killing me.