Installation Instructions
12.8.20
Kapitel/Chapter 6: Installation Instructions - Seite/Page 59
If the waterlock is arranged in an unfavourable position, the cooling water flowing back in the exhaust hose can rise
so high, that it reaches the exhaust stack. Since at least one discharge valve is always open when the engine is shut
off, the sea water has free access to the combustion chamber. By capillary action, this sea water then flows past the
cocks and even reaches the engine oil in that way. (In fact, a surprisingly high oil level is a first indication of an
upcoming catastrophe).
If an usual high oil level can be detected and/or the oil is of a greyish colour, the engine must not be used
anymore. This is a certain sign for cooling water that got into the oil pan. If the engine is started under these
conditions, the water and the oil are mixed into an emulsion. The oil will quickly become so viscous that one
will have to call it a paste. In this phase the fine oil hoses are blocked and a few moments later the machine
gets destroyed because of insufficient lubrication. Before this happens, an immediate oil change should be
made. Since the water can only reach the engine via the combustion chamber, it can be assumed that the
compression rings will start to corrode. These effects have to be discussed with an engine expert. It will
certainly be reasonable to immediately inject plenty penetrating oil through the intake stack and to slowly
turn the engine with the starter motor.
The cooling water can reach the exhaust area via the exhaust hose as well as via the cooling water feed.
6.6.1 Possible cause for water in the exhaust hose
6.6.1.1 Possible cause: exhaust hose
If the cause is the exhaust hose itself, the following points are to be checked at the hose:
a) Position of the waterlock is too high. The water reaches the exhaust hose.
b) Position of the waterlock is too far away from the middle of the generator. The water reaches the exhaust hose in
tilted position.
c) The waterlock is too small relating to the length of the exhaust hose.
6.6.1.2 Possible cause: cooling water hose
If the generator is not clearly installed 600 mm over the water line, the cooling water feed must be equipped with a
„venting valve“ which is at least led out 600 mm over the water line. (This position must also be assured in every
tilted position. Therefore, the venting valve should be located in the ships’ center line, so that it cannot move in tilted
position).
a) Position of the venting valve is too low. The water flows into the exhaust area when the ship is tilted.
b) Position of the venting valve is too far from the ships’ center line. The water reaches the exhaust area when the
ship is tilted.
c) The venting valve does not work, because it jams or it is clotted. (The venting valve’s function needs to be
checked regularly.)
As it consistently happens that functioning risks are not realised during the laying of the exhaust hose, the following
explanations refer explicitly to the exhaust hose. Here, the location, the size and the position of the „waterlock“ play
a very decisive role:
6.6.2 Installation area of the waterlock
Concerning a water-cooled exhaust system, it must be regarded that - under no circumstances - cooling water from
the exhaust hose can get into the exhaust elbow area at the engine. If this happens, the cooling water can get into
the combustion chamber via an open discharge valve. This would lead to irreparable damage at the engine.
In addition to that, one has to reckon with possible tilted positions of sailing yachts, which makes the position of the
waterlock even more important. In general one could say that:
The deeper the waterlock is located underneath the generator, the better the protection from entering water into the
combustion chamber.
