My Sea Scout 90 has been working fine the last 23 years that I have been using it, however it runs a bit cold. The engine runs at a consistent 104 degrees. I have recently reread the original manual and realize the boat engine plumbing is not as it may have been designed. There were several ways to cool the engine but the system that may have been designed for my boat has yet to be tried. I am wondering if any other users have experience with the plumbing system the manual describes. Currently the water pump connected to the generator pumps water through the motor and a thermostat opens to release water from the motor once the motor is up to the thermostat temperature. In this system, the thermostat rarely opens and a trickle of water comes out of the boat from time to time.
The manual describes..."
"On small 4 cylinder models, water is circulated from the sea water pump directly to the exhaust manifold jacket, where it acquires heat, and from there it is piped to the rear end of the cylinder block. From the block it rises by convection and pressure through passages at the gasket surface into the cylinder head. The outlet overboard is taken from the high end of the cylinder head."
Has anyone used the exhaust manifold jacket to preheat lake water before it enters the engine?
Also, what forces the water to flow through the engine? Am I to increase pressure in the exhaust manifold jacket by closing the outlet so the water makes it way back to the motor?
If anyone has experience with this set up, let me know how it has been working, thanks!
Christian Gould
Rhodes Chesapeake 1961
The manual describes..."
"On small 4 cylinder models, water is circulated from the sea water pump directly to the exhaust manifold jacket, where it acquires heat, and from there it is piped to the rear end of the cylinder block. From the block it rises by convection and pressure through passages at the gasket surface into the cylinder head. The outlet overboard is taken from the high end of the cylinder head."
Has anyone used the exhaust manifold jacket to preheat lake water before it enters the engine?
Also, what forces the water to flow through the engine? Am I to increase pressure in the exhaust manifold jacket by closing the outlet so the water makes it way back to the motor?
If anyone has experience with this set up, let me know how it has been working, thanks!
Christian Gould
Rhodes Chesapeake 1961