Switch to closed cooling

"I have an 86 Four Winns and w

"I have an 86 Four Winns and was wondering if I should go with a closed cooling system (have one in a box). Boat came with a sea pump, and also has a pump in the outdrive. Will the outdrive pump be sufficiant? Or should I use the front sea pump since it's there. Its a 27ft w/260 and uses a jack shaft. Also, boat is in Florida and sees salt water every weekend."

"Too late! The block and head

"Too late! The block and heads are loaded with rust that will flake off and plug the heat exchanger. Some have gotten away with it, but it's Russian Roulette with 5 bullets already in the gun.

Sorry.

Jeff"

"Forgot to mention...the engin

"Forgot to mention...the engine was put in 6 months before I got it, and flushed everytime.(didn't sit in the water)."

"Mike,
I can't see why th

"Mike,
I can't see why the engine would need a sea pump and a pump in the drive.
The 5.7 has more than enough cooling with just the drive pump.
The only think that comes to mind is the boat had a heat exchanger on it at one time.
If the engine was a new engine and not a rebuilt one you should be ok but really flush the heck out of it before you close off the system.

If you have a rebuilt block,old manifolds,etc it could be as Jeff said too late.

If you do close it you should change out the coolant after about ten hours or so to get any salt that may be left.
Good luck."

"According to what I can figur

"According to what I can figure, Four Winns used both pumps on the jack shaft models for some reason. I rebuilt the sea pump, and also rebuilt the outdrive pump. They had the outdrive pump just dump water right back out at the housing. I'd prefer just to use the outdrive pump because it's easier to maintain. This mid engine boat is a real pain when it comes to workin on the front of the engine. They left me about 3 inches of room. Does it make a difference being that the outdrive has to pump the water about ten feet to the engine? I'd hate to get this thing all glued back together just to have it overheat."

"The drive pump can't pump

"The drive pump can't pump the water that far, that's why the engine driven pump. The drive pump is only there because of the seal in the lower water pump housing. If the pump is not installed the drive does not cool well and the seal will leak."

I have 5.7's as well that

I have 5.7's as well that are fresh water cooled. The drive pumps just dump out but are needed to keep the drives cool. The sea water pump is used for the heat exchanger and washes out over the risers and out it goes. Given you have it all I would use the sea pump and the drive pumps. Not a expert on this stuff but this is what I use now and she runs at 155 all the time.

"Guys:
What do you think of

"Guys:
What do you think of Mike T. using Salt-Gone™ to flush the engine before installing the heat exchanger? It claims to remove the corrosive salts and chlorides and add a corrosion inhibitor to the engine. Also states that it is environmentally friendly, non-toxic and is safe to use around waterways.

Salt-Gone™ www.saltgone.com"

"Mike,
How is the system plum

"Mike,
How is the system plumbed using two pumps? The drive pump does not cool the drive and can be removed. Mercruiser and OMC both used to supply a belt driven seawater pump with their FW cooling kit. They suggested you remove the impellor from the drive pump to disable it, block off the line and install a thru-hull pick-up to supply water to the new pump. It does not create an oil leak. The belt driven pump has much more capacity than the drive pump and does a much better job. I have had cases like yours where it was impractical to use the front pump and the owner never experienced a cooling problem, but I would use the engine mounted pump if at all possible.

Regarding the Salt-Gone, Volvo offers their Neutra-Salt system which fills the cooling system with a salt neutralizer every time you shut down the engine. This sounds like a manual version of the same operation. I would have to give it a thumbs up.

Good luck,
Rick

P.S. 155 is too cool for a FWC engine, it should run around 175."

"Very informative, thank you!

"Very informative, thank you! Since I already installed the drive pump, will it be sufficient enough to pump the 10ft to the heat exchanger till it needs replacing in a couple years? Heck, might even have a newer boat by then!"