cooling system flow direction

[RDT]

Hey guys,

I have a 1978 Searay mercruiser 898 305 engine that Ive been having high speed overheat issues with for 2 years now.

I have replaced everything at least once, new raw water pump impeller a few times, new exhaust manifolds and risers, new thermostat 143 degrees, new hose from the raw water pump to the thru hull fitting which is also clear, no impeller parts in the power steering cooler.

Now im wondering in what direction the water is supposed to flow through the log style manifolds with the restrictor plates, and engine block.

The distribution block and thermostat housing have 6 1" hoses plus the raw water supply hose and the supply hose for the engine water pump, which has also been replaced.

I think if I know how the water should flow I might be able to narrow the problem down closer.

 

[mkast]

Re: cooling system flow direction

Coolant flow will be in the maintenance manual.
Have you checked for blockage, like the water shutter plates the the y pipe?

 

[RDT]

Re: cooling system flow direction

Yes, I removed the engine and took out the y pipe and it was clear and the water shutters were fine.

I tried to download the manual for this engine from the adult only section but I couldnt get it downloaded.

The only thing that seems to be left is the heads or engine block clogged but water seems to flow through the block when i spin the water pump with the stat housing off.

 

[mkast]

Re: cooling system flow direction

Find the manual, right click, "save to desktop", quite large, take's some time.