I am completing my "lifetime" project of building a Roberts 36 from the ground up. I have reviewed Bruce Roberts site on engine size recommendations. He mentions a HP range from 20 to 35. What Beta engine size do you recommend?
This looks like a fantastic project. Great looking boat for trade wind sailing! I need some more information from you before I can make a proper recommendation as there are many different Bruce Roberts designs.
What is the projected displacement?
What is the water line length?
What diameter propeller shaft are you fitting?
What diameter propeller can you acomodate?
Will you want any extra equipment such as a refrigeration compressor?
Will your engine have a regular transmission or a down angle or a V drive?
What is the projected displacement? 18,000lbs What is the water line length? 28' 9" What diameter propeller shaft are you fitting? 1 1/2" dia. What diameter propeller can you acomodate? 21 1/2" Will you want any extra equipment such as a refrigeration compressor? None planned. Will your engine have a regular transmission or a down angle or a V drive? regular transmission.
My prop calc program comes up with the following:
Beta 38 with 2.83:1 TMC 60 transmission.
Propeller called for is 19"x 12" three blade with 50% BAR.
This combination should provide you with more than enough power in bad conditions and comfortable and relaxed and economical cruise speed in good conditions.
What is the projected displacement? 18,000lbs What is the water line length? 28' 9" What diameter propeller shaft are you fitting? 1 1/2" dia. What diameter propeller can you acomodate? 21 1/2" Will you want any extra equipment such as a refrigeration compressor? None planned. Will your engine have a regular transmission or a down angle or a V drive? regular transmission.
