This may help you with your decision: MOJO is a 50' (49'-10") all steel trawler, Beebe Design #112. She displaces about 75,000 lbs and carries 1,500 gal of fuel. She is powered with a 1989 Cummins 5.9BTA-M1 engine coupled to a ZF BW-61 transmission with a 4.67:1 ratio. She swings a 40x34 4-blade prop on a 3" ss shaft. The Cummins engine does a fine job of moving her along. At 1,600 rpm she makes 7.5 kts and burns 2.7 gph. Max speed is ~9.3 kts at about 2,100 or so. She's probably a little over-propped since the Cummins is a 2,500 rpm max engine, but I don't run her wide open so it's not an issue. I've owned her since 2000 and put about 1,000 nm per year on her.
New to me 50, Steel full displacement, engine questions
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"This may help you with your decision: MOJO is a 50' (49'-10") all steel trawler, Beebe Design #112. She displaces about 75,000 lbs and carries 1,500 gal of fuel. She is powered with a 1989 Cummins 5.9BTA-M1 engine coupled to a ZF BW-61 transmission with a 4.67:1 ratio. She swings a 40x34 4-blade prop on a 3" ss shaft. The Cummins engine does a fine job of moving her along. At 1,600 rpm she makes 7.5 kts and burns 2.7 gph. Max speed is ~9.3 kts at about 2,100 or so. She's probably a little over-propped since the Cummins is a 2,500 rpm max engine, but I don't run her wide open so it's not an issue. I've owned her since 2000 and put about 1,000 nm per year on her."
This is an excellent match up of engine/trannt and vessel.
Only in a custom build will a right sized engineered power train be found.
Happily the designer and owner selected the package , not an advertising dept!
This is an excellent match up of engine/trannt and vessel.
Only in a custom build will a right sized engineered power train be found.
Happily the designer and owner selected the package , not an advertising dept!
Actually it was a custom build, designed and supervised by Robert Beebe. However, the original engine was a massive (in size) Cat D-13000. 150 hp at 1,200 rpm max. Was coupled to a 3:1 Twin Disc gear, same shaft & prop. But, it was an air start engine and the previous owner said it was a royal pain to get started. So, he removed it and put in the Cummins with the ZF tranny. He and his wife did all the work themselves... During the pre-purchase sea trial I hired a Cummins factory service rep come along. He hooked up a bunch of instruments/gauges to the engine before we got underway. All his measurements were spot on, he couldn't find any fault with the installation or operation of the engine. I have to say, the Cummins has been essentially flawless (knock wood) over the 17 years we've cruised the boat!
