Salt Water in Engine

Hello everyone. I could use some advice. We own a 2022 IP439. Salt water was introduced into the exhaust system of our Yanmar 4JH80 engine. The oil sample taken at the 50 hour oil change revealed 1175 ppm sodium.The oil was like glue and light grey in color.  We hired a reputable independent marine company to change the oil and examine the engine. 5 oil changes later and the oil is down to 04 ppm sodium. We addressed the issue of how the water entered the exhaust: a vent loop problem.  We pressure tested the cooling system for coolant leaks (head gaskets). The exhaust elbow was removed and the turbo was inspected. After a hard set of sea trials I was given approval to operate the engine normally. 

My concerns are as follows:

1) Some damage may have been done which will compromise the life of the engine. Once corrosion has started the best you can do is slow it down. I am now doing 25 hour changes. 
2) The engine may fail when it is most needed. 
3) The Yanmar warranty specifies that only Yanmar certified technicians work on the motor. They are difficult to find and schedule. When you can find one, they are expensive. 
4) Yanmar may not support the engine via warranty. 

I am considering replacing the Yanmar (a fine brand and highly advanced powerplant) with a marinized Kubota engine from Beta Marine. Here is why:

1) I would know what I have.
2) The  Kubota engine is stone age simple. That means reliable.
3) The warranty is an "anybody can work on it at any time" warranty.
4) Kubota parts cost a fraction of Yanmar parts. The parts are readily available anywhere in the world and almost always in stock. 
5) I can change my own oil.
6) Kubota is not common rail. Therefore no computer control requiring a laptop to work in the engine nor would the engine be susceptible to getting fried by lightening. 

I have not had very many good experiences with the marine industry. I am therefore hesitant to haul the boat and leave ourselves vulnerable to a "less than upright" yard. 

1) Does anyone know of someone on the southeast Atlantic Seaboard who can be trusted to swap the engines? 

Thank you very much for your attention to our questions.
Fair Winds, Following Seas,
Mark, SV Redeemed
 

Thank you Hayden,

I will contact Colin Mack forthwith. Yes, we do plan to make extended ocean passages once we gain more experience. I need to be confident in every system on the boat, especially the only propulsion engine.

Thank you for your response to my post, your advice, and your continued support of the Island Packet community through this forum.

Highest Regards,
Mark
SV Redeemed

Hi Mark. We’re taking delivery on 439-19 soon. Really sorry to hear about your experience.  What did you do to remediate the problem so it would not reoccur?  Sounds like something I’d like to get ahead of…  ‘hope all goes well!  John