Zebra Mussels: Raw or closed cooling?

Well?

 

Closed cooling, also much better for the engine!

 

Very frw engines built today can be cooled with Sea water.
Most are closed cooling , with the coolant being cxooled either by a sea water heat exchanger , or keel cooling.

Keel cooling is more expensive , but is great for a boat in freezing water (Maine Alaska) as the raw water systen on heat exchanger cooling must be winterized each and every time the boat is used.

Yachts on land for most of the winter dont have this problem , but a boat thats used year round in cold water really has no choice, but keel cooling.

FAST FRED

 

Why would you have to WINTERIZE the OPEN raw water portion of a closed cooling system. The expansion tank should have a radiator cap at the top to allow the raw water to drain in less than 30 seconds. Each component is to be mounted at a slight angle upward to prevent pockets. That also includes the the heat exchanger. The engine mounted raw water pump should be of the type that has a out/inlet that self drains.-- If the heat exchenger is of a flush plate type on the bottom of a displacement hull large enough for idling, I see no reason for winterizing.--- I am unfamiliar with the type you have. Fill me in on the pockets of water that stay behind. Rich

 

No matter how well you think the cooling system drains there is always the chance of having a pocket of water that can freeze. Flushing with antifreeze is quick and cheap way to insure that damage won't occur.

One thing you might not have thought of is the odds are great that the boat won't be sitting completely level in storage, thus the slight angle that would allow a passage to drain when perfectly level may then hold water.


Bill H.

 

Most folks are stuck with rubber impeller sea water pumps that do not drain.

Also the wet exhaust manifolds and most blocks are not made to drain completly , without opening a number if pet cocks.

There is little chance of getting the water out of the sea inlet line , behind a closed seacock , with out pulling a plug .
Any Aqualift or similar exhaust system that contains mufflers will also require draining , or antifreez to stay intact overnight.

The cap on the expansion tank is so the engine coolant can expand & contract with heat, it has no function on the sea water cooled porion of the heat exchanger.

FAST FRED

 

You are right Fred. I am 67 and my mund is starting to roll thins and thoughtstogether. Even after pruff reading. Thanks, Rich---- I am wise enough not to winterize my own boat.

 

I know of many people cooling with raw water on Lake Michigan, and none who have had problems with zebra mussels clogging up their water intake. personally, my boat sits in the lake every year for the last 12 years without any problems with zebra mussels. It's not much of a worry.

 

O.K. so I am going to ask the question which, likely everyone else knows, but I don't!!
If someone had a multihull in the fresh water of the great lakes why would a diesel VW engines not work. Yes the problem of where the rad would need to be mounted, would have to be solved but that shouldn't be to hard to solve. What am I missing? Please be nice.

 

Grrrrrrr.