CPIGUY

Hey Brian:

I'm amazed at what your suggesting. I've owned 5 ocean boats from a 32' w/twin big blocks to a 59' Marquis that I just sold, and I've never flushed anything on any of them without a single problem, ever. I do however flush my Seadoo's and Dingy's outboard.

I'm sure you know a hell of a lot more than I do about this. I just find it interesting. I've even been told that the new 302 Cobalt I just ordered with 496 HO's will not need to be flushed. Crazy

Arnie

Sydwayz

iTrader: (1)

The advantage to closed cooling is that you have pure and clean antifreeze actually touching the block and the majority of the cooling system.

However, the sea water (salt) has to enter somewhere to do the cooling (of the antifreeze) and exit somewhere out the back of the boat. Hence, these two places are where you can and will have salt water issues if you do not flush. I guess its a matter of personal preference if you do not want to flush, and would rather replace parts after a while.

As for the 525s, the CMIs are notorious for being delicate, when it comes to salt water. For many (not all) boats/engines, its not if your headers leak, its when. If you have/get a leaky header, its not going to be pretty or cheap.

As for the 496s, (I have them in my boat) with cast iron exhaust, you have a little bit more robustness to the exhaust, but the cast iron is actually more susceptible to salt/rust corrosion than the SS of the CMI headers. Even worse is that the salt water actually drains off from the majority of the exhaust system, just by gravity. This leaves the metal that has been exposed to salt water, with the salt deposits, sitting on the metal, exposed to AIR. This is basically a petri dish encouraging salt/rust corrosion.

As for the heat exchanger, virtually the same on the both the 525 and 496, there are many tiny tubes inside the heat exchanger that the sea/salt water run through. If/when these tubes become salt/rust corroded, the cooling capabilty of your closed cooling system is going to diminish. Hence, you are going to run hotter. Eventually, the salt/rust corrosion can and will eat its way between the passages of the heat exchanger and will allow AF to enter the sea water side, and the worst... sea water to enter the AF side. Now, the benefits of your fresh water cooling system are out the window.

So, bottom line, YES, you do need to flush a boat used in salt water if you have a closed cooling system. You don't need to flush it as long as with a open cooling system, as there is no thermostat in the sea water side of the closed cooling system. However, you must get the salt out.

(BTW, it you use the little air pump on the 496 motors, to push out the salt water, you are pushing out the water, and replacing it with air, leaving the salt deposits to sit on the interior surfaces of the cooling system. Whalaaa... petri dish.)

PhantomChaos

Brian......you don't need to flush the AC or the genset. Why would you?

Sydwayz

iTrader: (1)

If they are predominately plastic hoses, and internals, you have less to worry about. I'll admit that I am overly anal about this kind of stuff, but I would never want to have an issue with salt scale or rust buildup. With the way your big boat is stored in the water, you are right, its basically nil need on having to flush. Its not like you are going to get the salt completely out of the system.

However, if I stored my boat on a lift or trailer, I'd have something setup to rinse the salt out of their systems.

H20 Toie

Well i just got a quote on a new hydro hoist $27k

So much for that idea.

Nice used on the the classifieds but it is on the wrong coast

Might be time for bottom paint.

Michael1

H2O Toie, I see you are from Channel Islands. I was just down there last weekend, and one guy said he has a diver clean his boat every two weeks. I don't think it is super expensive though.

I also saw a recent article on the different types of bottom paints. Pretty interesting. I'll see if I can find it.

Michael

PhantomChaos

Dan

They also have have white bottom paint now too........

thisistank

Michael, Dan bought the house were we were tied up the weekend you rode with Al....Nice place!

C_Spray

iTrader: (2)

Most of the heat exchangers and power steering/oil/fuel coolers I've seen are of copper and bronze, which should survive almost indefinitely without flushing. Most of the larger coolers also have sacrificial zinc anodes in them, usually the pencil-type ones that screw into pipe plugs. The problem is, indeed, the exhaust systems. Volvo Penta and a couple of other companies offer a post-run salt neutralizer system that pumps a protective solution into the raw water side of the cooing system at the touch of a button. (Black Pearl may have this system on his boat.) You can reduce the outdrive corrosion issues to an extent with a Mercathode active corrosion system, which I would bet that Formula includes as standard equipment on a 400SS. There were some major corrosion issues with Bravo III drives early on, but I believe they were addressed by Mercury adding tons of zinc anodes throughout the drive. It's essential that you keep these zincs in good shape at all times.

34Mach1

Call the folks at econolift. I have 10K lift with them lifting an 11 K boat and it is outstanding. They can advise you on the correct setup and I'm certain it will be substantially less than 27K. Besides, Hydrohoists are inferior. The fiberglass cracks and they seem to break down often. Econolifts are made of Polypropelene and will last practically forever. http://www.econolift.com/