Raw water flow path reversal?

I am trying to improve and simplify the raw water cooled log/snail exhaust manifold plumbing on the boat. The previous owner had installed a bunch of tee's to drain raw water from the system. Looking at it I think if I reverse the flow through the heat exchanger and the logs I can eliminate low water collecting hose runs, eliminate (2) drain locations, and provide better draining of both the heat exchanger and the logs. See attached file (note: only raw water side of heat exchanger is shown for clarity).

Does it matter which direction the raw water flows through either the heat exchanger of the logs? Am I going to cause cooling issues by reversing the flow in either? I can't see a reason why it wouldn't work but I am not very familiar with this older style of exhaust manifold. Thanks!


Attachment 57068


Attachment 57069

It is possible to have air trapped inside the manifold and have a hot spot. if you feed from the bottom all the air is pushed out the top . Very similar to a heater core in a car .