Best Diesel Inboard

I am building a new boat and need an inboard diesel engine with around 300hp and want to know which engines people thought were better in terms of lifespan and problems. I have previously owned an Iveco and a Cummins so ideally looking for info on others.

I know there is a vast amount of divide over which is the best but wondered if people could tell me why and what common problems you get with some brands.

Any info would be great.

 

I would use a Detroit Diesel series 60 if the 300 hp was almost always needed , or the smaller Series 50 if the requirement was closer to 250 hp, forever.

These are available used or fully rebuilt , but the local air police might obstruct the installation , depending.

 

The answer to your question is it depends. There are many variables weight-physical size of motor-RPM range-available parts and support-reman or new-how boat will travel planning-SD-full displacement. Do you want to deal with teir 3 common rail or do you want sloppy old school or somewhere between. Is price a big factor? As for Quality of engines you are going to get a lot of opinion. You might want to monitor the boatdiesel site for a month or so to get a feel for layman and pro opinions. Also be aware that any given brand has multiple models with different hp ranges over many year spans some better or worse than others. My personal custom boat was speced with 300 hp range Cummins or JD and I ended up with JD because of better local support.

 

I work with diesel engines every day, although they are land based. I'd STRONGLY urge you to get a pre-2006 engine whatever one you choose. The 2006 and later enironmental regulations have resulted in much more fragile. much less reliable and durable engines. In this I am assuming that the decline in road diesels will contaminate marine diesels as well due to common manufacturing practice. If I were looking for a large diesel engine I would, without any doubt look for a Cummins N-14 plus, freshly rebuilt from a reputable shop. (Assuming I had a big budget) That was probably the best engine I've ever used in the last 22 years. My opinion, plus $1.50 will get you a cup of coffee, but there it is.

 

Some specs on the boat might help choose an appropriate engine & always take maintenance & parts into consideration.