There are two important problems of VP elbows, which are produced by casting technique from iron casting material. The first is that they oxidize in a very short time. Oxidation makes the flow of the exhaust
gas and seawater mixture discharged through the elbow
unstable, and as a result of advanced oxidation, the sea coolant
splashes back towards the engine exhaust
When used in this way for a few years, the manifold made of aluminum
is exposed to corrosion
by the effect of seawater splashing back and can be punctured. In this case, the fresh coolant
flows into the engine
and the engine is damaged greatly. The second problem with the elbow
is that they are short in length, and this short design is one reason why the sea coolant splashes back.
I have been using the 50 mm longer elbow, which was manufactured by welding method from 3 mm thickness 316L Stainless Steel
in my own boat
, for four years without any problems. Upon the request of fellow sailors, we manufactured the same elbows for approximately 20 boats and replaced them with cast iron ones. There has been no problem for a long time. Engine performance is always at maximum level. Clogging, oxidation is left behind.