fuel consumption

Question
QUESTION: Hello Ron,
I recently acquiered a Criss Craft 1996, concept 23 openbow. It is powered by a 1993 OMC King Cobra 7.4 L.  Could I know at what RPM it is mostly fuel effecient. Furthermore I plan to replace by a deisel engine, what do you recommand me to consider ? and where should I browse for used engine?

ANSWER: Elias...Thank you for selecting the undersigned to reply to your question.

I suspect that your '96 boat may have taken a beating since its original '96 engine has already been replaced with one 3 yrs. older. Fuel efficiency is dependent upon weight distribution of people, equipment, fuel, etc. within the vessel, combined with sea considitions, but right now its not important, because you're contemplating purchase of a preowned diesel engine. Its age, weight, horsepower, and whatever modifications are required to the hull, will affect fuel efficiency. In the final analysis, most engine manufacturers offer insight in their owners manuals as to the most effective rpm. Check it out.

Safe Boating
Ron

---------- FOLLOW-UP ----------

QUESTION: I plan to replace by a deisel engine, what do you recommand me to consider (weight and diemnsions..) ? and where should I browse for used engine?

Answer
Hello Elias

Regardless of where you're located, I suggest consulting local marinas, marine restoration facilities, as well as marine mechanics and surveyors for guidance as to where you might make a purchase. In all probability, you'll have to accommodate the new engine mounts, which may mean some alterations to the stringers in the engine room. Weight influences balance and how the vessel will sit level in the water. Also consider whether exhaust port(s) will need modification.

Safe Boating
Ron