54 Boating New Zealand
working closely with Surtees and Grant Allen, Sales Application
Manager at Mercury.
Fitting a sterndrive necessitated a total re-design of the
750’s transom, plus a whole lot of extra structure under the
foor, including 10mm plate girders and dedicated engine
bearers. Te hull is 6mm thick and the sides and decks are 4mm.
Tis boat was custom-built, but the lessons learned will carry
over to subsequent sterndrive installations, of which Surtees
and Mercury hope there will be many. Te engine box will also
accept V6 petrol engines.TIDY INSTALLATION
Nick not only sought Mark’s advice when choosing his dream
boat, he relied on his technical skills to ft the engine and engineer
the vessel’s various systems. Mark also has experience installing
Mercruiser TDi sterndrives for manufacturers like Stabicraft.
When we joined the boat in Whitianga, Grant had just
fnished fnal engine checks and noted that the temperature
inside the engine box on a very hot January day was only two
degrees higher than ambient, indicating the engine was getting
plenty of fresh air.
Getting the air fow right was just one of the challenges forthe Surtees team; they’ve done well to design the ventilation so
that sufcient air gets into and out of the engine box, without
allowing water ingress.
Te two-tier engine box is a modest size too, so it’s easy to work
around with good transom access either side. Te front section
makes a comfortable seat or handy work surface with built-in rod
storage; neoprene Deck Grip, also glued to the coamings, softens
its aluminium surfaces and provides grip in the wet.
Te sterndrive’s installation is tidy with excellent access to
engine service points at the front and the ECU tucked safely
away out of the elements in a dry locker against the cabin
bulkhead on the starboard side.
Batteries – engine and house – are stored in a transom locker
which is also a ventilation channel for the engine box. Te
transom on the port side features a live bait tank and a drop-in
door for access to the full-width swim platform and T-bar-style
boarding ladder. A high-volume 3,700gph bilge pump in a sump
drains any water from the cockpit.
Grant and Mark are completely happy with the way the
Mercruiser TDi performs: Nick had already clocked up 50 hours,
going out 16 times in a month, so any teething issues were well-
sorted by the time we stepped aboard.