Part 3: Boaters want to go faster and farther.
By Capt. Patrick Sciacca — June 2002
All told, about five months of the C-12 project were taken up by engineering the aforementioned modifications. The rest of the 18 months (a typical upgrade takes 18 to 30 months) were spent on durability and reliability testing, which included installing prototype engines in charter and commercial boats and logging as many hours on them as possible to discover what might fail. Caterpillar even put out a few 800-hp "probe" engines. "By overrating the engine we shake out the weakest link," Tow explains, adding jokingly that a boat owner with a probe engine "usually calls sooner [about a problem]."
The ability to significantly increase the output of a diesel engine without significantly altering its size, weight, or appearance is pretty impressive. Why do manufacturers go though all this design and testing for what may seem to some a relatively modest horsepower gain? The answer is demand. Boaters want to go faster and farther, and engineers are put to task like mice on a treadmill to satisfy them. Indeed, Tow says that boatbuilders demand more performance, and if one engine manufacturer can't satisfy that demand, another one will.
(One interesting characteristic about increasing horsepower is that often fuel consumption does not increase proportionately to the horsepower increase. In fact, Tow notes that cruising-speed fuel burn will often remain the same as it was at the lower horsepower rating, although cruising speed might actually go up.)
And they want that extra horsepower without giving up engine room space. "We're always pressed to increase power without increasing size," Tow says, explaining that's why "we don't want to change a block on a regular basis."
It seems safe to say that as long the technology develops to upgrade the output of an engine safely and efficiently, engineers like Tow and the Caterpillar marine group will continue to find more performance somewhere. They'd better, because if my friends ever get into boating, I can only imagine that they'll find some way to strap that nitrous tank onto the tuna tower.
Caterpillar Phone: (309) 578-9073. Fax: (309) 578-4400. www.cat-marine.com.
This article originally appeared in the February 2003 issue of Power & Motoryacht magazine.