283 cooling problem

[birrellsa]

Looking for advice on CC 283 cooling problem.

I have a 1963 24' CC Sea Skiff with a 283 185 HP. The engine is rebuilt, including the water pump and manifolds. The exhaust setup is flexible pipe to CC mufflers to flexible pipe out the transom. When the engine is idling the water coming out of both exhaust ports is equal. Once the engine revolutions go up the water all but stops on the ports side exhaust at the transom exit. I have checked the water flow at every point and it is all good and even right back to the entry point to the exhaust elbow. At idle both banks stay cool, at speed the port side heats up immediately and only cools down when brought back to idle. I suspect that the port side muffler is partially blocked as it has a very strange sound compared to the starboard side which is clear and crisp versus a chocking sound on the port side. The water pump and manifolds were rebuilt and tested by Miller Potter boat works in Ottawa. I would like to remove the mufflers and go to a straight pipe setup to see if this solves the problem. When is install the straight pipe, do I need a drop or can I go from the engine to the transom with the roughly 6 inch curve that exists?

The only other thing that I can think of would be a hose collapsing at speed. Is this possible? Any advice would be greatly appreciated as I have just completed a 2 year restoration and now have a very expensive floating raft!!!

Thanks in advance.

Steve

[evansjw44]

If your 283 have the two chamber water pump that would be standard for a '62 then you problem is very likely the inlet hose collapsing. These hoses collapse on the inner layers and that's not detectable. The engine heat warms them up enough to let thie happen. I had that problem years ago and it drove me nuts.

[drrot]

Also check the exhaust hose. It will delaminate and plug up too. Like the intake it can not be seen from the outside. If one side is bad replace them both as the other side could go soon.