When looking at the flow diagram for an 888 Mercruiser it just does not seem right to me.
-The water pump in the outdrive supports water to the lower section (sump) of the thermostat house, there it splits, cold water flows down into the circulation pump for the engine to cool and the remaining flows on both sides to the back of both the exhausts.
The water then flows to the front of the exhausts and mixes on the top of the thermostat house with the water comming out the engine. Now here is the issue. The thermostat reacts on the mixed water temperature comming from the exhaust on both sides and the water comming out the engine.
If the exhausts run hot increasing the water temp in it the thermostat opens due to the exhaust water temp and not the engine water temp, making the engine to cool when not nessesary. On the other hand when the exhaust does not heat up the water sufficient and it mixes, the thermostat wont open (enough) so the engine runs hot.
It all hangs somekind on the water flow speed of the exhausts, Poor design?
Im working on a cover now that seperates them, making the exhaust waste water to flow over the thermostat instead of mixing it with the engine water and then run thru the thermostat (when lucky) or the bypass hole.
It then mixes with the engine water after the thermostat and out thru the elbows.
Now the thermostat only reacts on the water comming out the engine making it more stable and efficient.
Anny thoughts?
A- Cold water comming from outdrive
B- Cold water to circ pump for cooling engine
C- Cold water to Starboard exhaust
D- Cold water to port side exhaust
1- Hot water comming from port side exhaust
2- Hot water comming from starboard side exhaust
3- Hot water comming from engine
4- Mixed water thru bypass hole
5- Mixed water to run thru thermostat (when hot from either)
-The water pump in the outdrive supports water to the lower section (sump) of the thermostat house, there it splits, cold water flows down into the circulation pump for the engine to cool and the remaining flows on both sides to the back of both the exhausts.
The water then flows to the front of the exhausts and mixes on the top of the thermostat house with the water comming out the engine. Now here is the issue. The thermostat reacts on the mixed water temperature comming from the exhaust on both sides and the water comming out the engine.
If the exhausts run hot increasing the water temp in it the thermostat opens due to the exhaust water temp and not the engine water temp, making the engine to cool when not nessesary. On the other hand when the exhaust does not heat up the water sufficient and it mixes, the thermostat wont open (enough) so the engine runs hot.
It all hangs somekind on the water flow speed of the exhausts, Poor design?
Im working on a cover now that seperates them, making the exhaust waste water to flow over the thermostat instead of mixing it with the engine water and then run thru the thermostat (when lucky) or the bypass hole.
It then mixes with the engine water after the thermostat and out thru the elbows.
Now the thermostat only reacts on the water comming out the engine making it more stable and efficient.
Anny thoughts?
A- Cold water comming from outdrive
B- Cold water to circ pump for cooling engine
C- Cold water to Starboard exhaust
D- Cold water to port side exhaust
1- Hot water comming from port side exhaust
2- Hot water comming from starboard side exhaust
3- Hot water comming from engine
4- Mixed water thru bypass hole
5- Mixed water to run thru thermostat (when hot from either)
