Water in Engine

[old bradders]

I have found that water has been seeping into the engine from the exhaust valves once the engine has been stopped. The perkins 4108 is low in the boat (Claymore 30 motor sailor) and I have fitted a non return box in the lowest part of the engine space for the top half of the exhaust water but the water from the manifold to the non return box runs with a limited gradient. This means that when the engine is stopped the last blow of water and exhaust almost fills the low level pipe and has slopped back up the manifold and into the engine. Does anyone know of a fitting that would easily allow me to drain off this water when I stop the engine which would make sure that I dont have a repeat of the problem.
Any slight continued flow of cooloing water from the outside seacock, through the impellor and across the heat exchanger will soon fill up the pipe to the non return valve. This means I already have to rremember to turn off the sea cock immediately I stop the engine to prevent the flow back of water. Another jog of puliing some king of drain plug would not be an extra burden.
Any ideas.

[daddle]

Ouch! That is bad. Even the steam from the last water can be bad. How about shutting off the water a few seconds before you kill the engine? Otherwise you'll need to move the water injection further downhill from the manifold.

[James S]

We've got some good diagrams of some exhaust system dimension parameters in previous threads.
I've looked and so far haven't found them but I'll keep looking.
This is a serious problem that could have catastrophic consequences if not dealt with properly.

[osirissail]

Originally Posted by old bradders

. . .
Any slight continued flow of cooloing water from the outside seacock, through the impellor and across the heat exchanger will soon fill up the pipe to the non return valve. This means I already have to rremember to turn off the sea cock immediately I stop the engine to prevent the flow back of water. Another jog of puliing some king of drain plug would not be an extra burden.
Any ideas.

You have several serious problems. But I don't understand how you are getting any water flow past the engine raw water pump. The impeller system is a positive displacement pump and will not pass any water when it is not rotating. If it does then you are missing an awful lot of vanes from the impeller - or - the impeller is the wrong size - or - the body of the raw water pump is worn out.

- - As to the exhaust installation you seem to be missing some important parts like a water-lock muffler. For a simple example of the exhaust on a low mounted engine see: EXHAUST INSTALLATION
Here is a larger size diagram of the parts and measurements (250mm = 10 inches) -

[James S]

Thats the drawing I was looking for....thanks osirissail.