Out With the Old)
CONTEMPLATING A NEW POWERPLANT FOR YOUR BOAT? JOIN US AS WE BEGIN REPOWERING THE 1996 GRAND BANKS MOTORYACHT WE’RE TOTALLY REHABILITATING—AND WE MEAN TOTALLY—WAY DOWN SOUTH IN THE VIRGIN ISLANDS.
Our charterboat guy Tommy McCoy’s got a practical, salty streak to him. And his decision to repower Arawak, a 1996 Grand Banks motoryacht that’s been in his fleet for quite some time now, was a practical one. “In a nutshell,” he says, “the financial side of going with new engines outweighs the option of rebuilding the old ones. And I gotta also add that the conversion from Caterpillar V-8s to a narrower Yanmar inline-6 configuration is rather exciting to me. The amount of space I’m going to gain in Arawak’s engine room, both inboard and outboard, is gonna be pretty grand the way I got it figured.”
McCoy’s approach to the not insignificant
BY CAPT. BILL PIKE task he’s just embarked upon, especially in terms of the first point he makes, pretty much jibes with the advice he’s getting from the folks that are giving him significant support, both at Yanmar USA and, for the repower itself, at Mastry Engine Center in St. Petersburg, Florida, a Yanmar company as well as Yanmar’s primary repower specialist in the southeastern United States, the Bahamas, and the Caribbean.
“While rebuilding a couple of existing engines does often pose fewer challenges,” argues Mastry’s general manager Kevin Carlan, “installing new products on a boat of this type will often provide long-term economic as well as other advantages. Think about it. There are a whole lot of older parts on older engines, including alternators, starters, and water pumps, and they’ll most likely be retained after a rebuild is completed. And hey, older parts are going to have an uncertain life expectancy when compared to new powerplants. And what’s more, remember that new engines are going to have a very valuable, very inclusive manufacturer’s warranty that the rebuilds are not going to have.”
Of course, there are any number of things to think about at the start of any repower project, the majority of them going well beyond the initial, repower vs. rebuild issue. For instance, the next step for McCoy, once he’d decided to repower with the Yanmar brand (based primarily on the company’s reputation for long-term reliability and service), was figuring out precisely which engine model to go with, a decision that was fairly easy for him to make, the way things turned out.
“I’ve never been one to try and defy hull speed on a trawler,” he says. “I’m perfectly comfortable with speeds between 7 and 9 knots over long distances. So coming up with the appropriate engine model wasn’t a tough job. In fact, converting from 210-horsepower Cats to 220-horsepower Yanmar 6BY3-220s was a flat-out no brainer.”
Settling on how much horsepower to shoot for is not always as straightforward as it was for McCoy, though. While most displacement boats, as well as many others vessels with semi-displacement-type hull forms, are indeed best served with a new powerplant that closely matches the original in terms of rated horsepower, planing watercraft, which are typically speedier and more weight-sensitive, may benefit greatly from a much more significant changeup. In fact, according to the repower gurus at Yanmar, today’s lighter engines often make it possible to install