JARRETT BAY 70 AN IDEAL TEST BED FOR NEW HIGH HORSEPOWER ENGINES THE NEW CATS ON THE BLOCK Powering large sportfish vessels to higher speeds has long been a balancing act between horsepower and weight. Put simply, when adding more horsepower via increasing the number or size of combustion cylinders, the size and weight of the engine increase too. Thus, one of the many challenges of engine development for this segment is to endeavor in packing more power into smaller packages. Caterpillar Marine has been working to deliver on just that with the development of their new “B” series of recreational marine engines. “The C32B is a major evolution of the venerable C32, which has been in the industry for quite some time, especially around yachting. Through a number of modifications and improvements, such as the air system, strengthening of the block, modified pistons and more, we’ve now got 2400 horsepower,” explains Caterpillar’s Charlson Smith. Formerly, Cat’s highest rated pleasurecraft engine was 1925 mhp—a V12 going up against competitors’ larger (and heavier) 16-cylinder products for the bragging rights of powering sportfishing’s largest yachts. To follow through on the years of development of the B series power systems back at Cat headquarters in Germany, the company invested heavily into testing and demonstrating their new C32B engines to the U.S. marine market. Jarrett Bay custom hull number 48, a 70-footer, was one of the first boats in North America to be chosen for this demo program, and was the first repowered boat to hit the water with the new power plants in 2021. A PERFECT PLATFORM “What’s unique about hull 48 is it was originally built [launched in 2006] as a test platform for another engine manufacturer,” explains Jarrett Bay Engineer Peyton Lanier. In fact, it was the first boat and hull form the company was able to send overseas to the MARIN laboratory in the Netherlands to be tank tested. “This is really awesome because we get to take the data from the original engine manufacturer’s test platform, and compare it with the C32Bs,” says Lanier. Smith and his colleagues at Caterpillar wholeheartedly agree, “We found it fitting when the C32B was ready for tests, that we would have this particular 70-foot Jarrett Bay to test out our own 2400 horsepower engines.” Caterpillar’s documentation states that these engines are more powerful, quieter, and feature new long-life filter technologies, all while fitting into the same general footprint as the prior C32 models. Despite the C32Bs being designed to be a drop-in replacement and ideal repower solution, there is still a lot of work that goes into these repower projects. When considering a repower, especially one that adds more horsepower, there are a plethora of items to be considered, including everything connected to the engine. In a nutshell, more horsepower likely means different back-pressures and thus exhaust, plus stronger shafts, struts, tubes, and bearings. Basically, most of the running gear, including propellers and rudders, are going to be beefed up or Going from 16- to 12-Cylinder engines allowed for space to install twin gyro stabilizers Photos by Luke Pearson 48 BLUEWATER
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