Hi Stanley, I purchased a new 722 Beta engine with heat exchanger cooling. I am going to install it with keel cooling. I will use the water pump to cool the waterlock exhaust. What do I need to change in the engine to do this? Tom

The above post was on my whiteboard and as this very seldom get's looked at, the reply is later than usual. A quicker response will always be made when your post is written in the normal posting area. This way the post can also be read by others who may also be able to answer you. Here is my reply to Tom.

Welcome to the forum Tom. To convert a heat exchanger cooled engine to a keel cooled engine is quite easy. First the tube stack must be removed and the ends of the tank sealed up so that there are no leaks. Then the lower hose (from the circulating water pump to the manifold) must be removed. The two hose barbs where that hose was connected are then connected to the keel cooler or skin tank and you have your complete system. As you are going to use a waterlock muffler system, the tube from the raw water pump must be connected direct to the water inlet on the exhaust elbow. You must be very careful with how the exhaust is routed and you want to make sure that salt water does not come back into the engine when sailing. Keel cooled engines normally use a dry lagged exhaust system.  

Stanley