The first task was to strip it and assess the condition. The rings were seized in the ring lands in the pistons, and there was therefore no compression. A full rebuild was in order. The bores were excellent, hardly worn at all, which is typical of leisure marine engines - they hardly do any hours. Corrosion and neglect kill them, not wear. A full set of main and big-end bearings, rings, gaskets, as well as new injectors and glow plugs, were fitted.
Fair Maid, like most leisure craft, has a "wet" exhaust. This means that cooling water is injected into the engine exhaust and leaves the boat with the exhaust gases. The exhaust system is therefore "cool" (relatively, anyway) and is not a fire hazard. The Westerbeke/Universal engine has a coolant header tank which envelops the engine exhaust manifold, and at the exit of this assembly the sea water is directed into the exhaust itself via the tube atop this green exhaust elbow. This elbow is actually a Volvo Penta unit adapted for the task.
New engine mounts were fabricated, using the old engine as a template, so that the new engine mounts would "land" in exactly the same place in the boat, simplifying and speeding up the installation.
First start:
Some paint:
The next step was to procure a heat exchanger and mount that to the motor. The old Volvo Penta MD7A was raw water cooled, meaning that fresh water (sea or river) is taken into the cooling jacket, circulated, and then expelled through the wet exhaust. The new motor is coolant-cooled, meaning the raw water does not touch the engine, but instead is taken in via a sea-cock, pumped through a heat exchanger, then expelled via the wet exhaust. This is a much superior system, in that the engine is not subject to salty water and the resultant corrosion. Instead, the engine is cooled by normal anti-freeze and corrosion-inhibiting coolant, and the sea water cools the coolant via the heat exchanger.
Here is the heat exchanger being mounted. The approach was to mount everything together to create an engine/transmission/heat exchanger "package" to reduce installation difficulty and time. Ideally we will be able to drop the package into the boat and simply hook everything up.
