PROJECT BOAT Part 6 - Pace Maker
Ralfy, our 34-year-old Mariner Pacer 760, is now a far cry from the rather tired specimen we towed up to Queensland all those months ago and left to the tender mercies of the good folk at Maritimo.
Over the past few editions we’ve covered the saga of stripping down the monster to find what was salvageable, cleaning up and restoring the interior and then, last issue, the massive job of reviving the hull to a mirror finish.
This time around we’re tackling the repower, which is a lot easier said than done. The ambitious plan was to move from a mid-mounted engine with shaftdrive to a rear-mounted small-block V8 with sterndrive — altogether a far more modern package.
To that end, the serious work began while the hull was in the Maritimo build shop. New strengthened engine bearers were put in place, while the transom underwent extensive reinforcement to cope with the stern unit. That’s where most of the pressures are exerted.
There was some discussion over how the new configuration would affect the weight distribution, however, the engine installation crew reckoned that with the fuel tanks and powerplant effectively swapping places, there was little to worry over. Subsequent sea trials have proven this correct.
MerCruiser was chosen to provide the horses and drive, as the engine giant naturally has a turnkey solution for this type of project. It comes in the shape of a 383 MAG Stroker power unit, which is an impressive 6.3lt donk remanufactured in the
and based on a GM small-block V8 aka the ubiquitous Chev 350 motor that’s been in production since 1955. The 383 MAG Stroker produces 350 horses or about 50 more than was typical for the elderly big-block 454s that it generally replaces. The standard Chev 350 is 5.7lt but stroked out to 6.3lt, as in the MerCruiser, you get big-block power from a small block engine for more bottom-end torque, thus quicker get up and go. In fact the Chev 350 engine has for many years been the chosen power source for the majority of skiboats.
The engine is also saltwater or raw-water cooled with a heat exchanger delivering hot showers aboard. But fear not about the longevity of the raw-water cooling, as the 383 Mag Stroker has a cast iron block and the push for closed cooling today is due to the advent of alloy blocks. Ralfy is from the iron age instead.
Why a remanufactured engine? David Meehan, a MerCruiser Director, tells us there is a strong trend towards this type of package. “The beauty of this kind of engine is that it’s really hit a niche price point in the marketplace,” he explained, “Obviously, when times are a bit tough, it offers a low-cost alternative for repowering.”
He also says that repowering in general is now very strong. “There are a lot of good old hulls out there and you can revive some really beautiful old boats,” Meehan says, “We used to sell around 90 per cent new installations to 10 repower, but now it’s more like 70/30.”
Our 383 Stroker, complete with flame-graphics on the cover, is remanufactured with new components including camshaft, forged-steel crankshaft, intake manifold and injector assembly, pistons, engine bearings, valves, oil pump, valve springs, roller rockers, wire harness, flame arrestor, dry-joint exhaust manifolds and elbows, and serpentine belt drive system. Oh, and there’s a 12-month warranty.
The real surprise was seeing the package fitted and how quick that installation was. Once the V8 engine was dropped through the hatch it was a matter of gently shuffling it into place and bolting it down. Maritimo’s installers say that, while you wouldn’t attempt this without an expert (not to mention a crane!), it is a relatively straightforward job. The fiddly part is ensuring all the controls are in place and working.
Rounding out the package is the MerCruiser Bravo Three sterndrive unit with counter-rotating prop for rip-it-and-grip-it turning and superb low-speed handling and steerage. In theory you might be tempted to try sticking with the original mid-mount and shaftdrive configuration, but the consensus was a modern sterndrive would enable the skipper to get the best out of that shiny V8.
Not only is the power transfer far more efficient in sterndrive form but the Pacer benefits from much improved manoeuvrability, efficiency, top-end speed, and practicality in respect of cartage, storage, and getting in slow to the shore. Leg up, the boat draws less than a metre.
Like the engine, the sterndrive slipped on quickly and easily — most importantly it hooked up to the powerplant with the absolute minimum of fuss. In the end, having them as a matched set makes a lot of sense and provides a stress-free upgrade.
Incredibly, the time from unwrapping the new toys and having them mounted in Ralfy was just a few hours — although the Maritimo blokes warned that preparation is everything and that’s where they burned up the real hours with things like strengthening the transom. What they were too modest to add was that it makes all the difference in the world to have a crew of experts on the job.
There was no disguising the undercurrent of excitement in the Maritimo factory as the word got around that Ralfy now had some serious grunt sitting in the hull. “How fast do you reckon it’ll go?” was the favourite topic for debate. Let’s just say it might turn out to be a bit more lively than its ‘Dad’, Bill Barry-Cotter, originally intended.
Mercury MerCruiser 383 Stroker
TYPE: Remanufactured fuel-injected petrol V8
RATED HP: 350
DRIVE: Bravo III sterndrive
NEW COMPONENTS: Camshaft, forged steel crankshaft, intake manifold and injector assembly, pistons, engine bearings, valves, oil pump, valve springs, roller rockers, wire harness, flame arrestor, dry-joint exhaust manifolds and elbows, and serpentine belt-drive system.
WARRANTY: Standard 12-month remanufacturing warranty