John: What you describe is commonly referred to as Fresh Water Cooling (FWC) or more accurately, a closed cooling system. Internally, the engine circulates antifreeze, just as in an automotive engine. Typically, there is a block-off plate between the exhaust manifold and the riser. A hose below the block-off circulates the anti-freeze to a heat exchanger which is in turn cooled by raw water From the heat exchanger the antifreeze goes back into the engine. Above the block- off plate, raw water is introduced which then flow out with the exhaust gases. In many systems, the raw water first cools the transmission, then the heat exchanger and then out through the riser.
The system you describe I believe is a "keel cooler." The copper pipes run along the keel and are cooled by the raw (salt) water. They are filled with antifreeze which circulates back to the engine. Most engines are able to be converted to a full or a partial closed system. In the partial system, the exhaust manifold is still raw water cooled. Converting a salt water cooled engine is generally not a good idea if it has accumulated a lot of hours. Gene --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "UnifliteWorld" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/UnifliteWorld?hl=en -~----------~----~----~----~------~----~------~--~---
