Heat exchanger housings in solid marine bronze
We don’t just offer a spare part. We offer a technical upgrade: same dimensions, same mounting, but cast in solid tin bronze, so the saltwater cannot eat it away.
The heat exchanger is the engine's radiator. If it leaks, the engine will overheat.
A car engine has a radiator at the front, where air cools the liquid. A boat cannot do this: the engine is enclosed below deck, and no air blows there.
Therefore, the boat uses the sea instead. A pump sucks cold seawater in through the hull, into a metal box where it cools the engine's own coolant, and sprays it out again. That box is the heat exchanger.
The two liquids never touch each other. They are kept separate by a bundle of thin copper pipes inside the housing. The heat passes through the metal, the liquids remain separate.
Sea water in
A pump draws cold seawater in through a hole in the bottom of the hull.
The heat is switching sides
In the heat exchanger, the seawater flows past the copper pipes and extracts heat from the engine's coolant.
The water back out
The heated seawater is sprayed into the ocean along with the exhaust.
The engine maintains its temperature
The coolant returns to the engine cooled down. If the housing breaks, the engine will overheat immediately.
Volvo Penta has been casting these housings in aluminum for 20 years. Saltwater eats the aluminum from the inside until a hole develops and the engine fails. This typically happens after 5–7 years.
Internal corrosion
Saltwater and aluminum in an engine compartment cause galvanic corrosion. The housing is eaten away from the inside, where you cannot see it.
Corrosion
Eventually, a hole forms. Then seawater and coolant mix, and the engine overheats.
Oxide-jacking
Aluminium swells when it corrodes. The pressure pinches the copper pipes, so a mechanic cannot pull them out for service.
The bill is coming again
A new original house costs 17,000-19,300 DKK. And you know that it will wear out again in 5-7 years.
Exactly the same dimensions, so it bolts straight on without modification. But cast in solid tin bronze, the metal originally developed for extreme military and industrial marine environments.
100% saltwater resistant
No pitting, no galvanic corrosion. The bronze will last the entire life of the boat.
Self-healing patina
Upon contact with water, the bronze immediately forms a dense, stable film that seals the metal.
No oxide jacking
No swelling corrosion products, so your expensive copper tube bundle is protected.
Natural anti-fouling
The alloy resists algae, salt crystals and biofilm, ensuring optimal cooling flow.
Plug and play
Same dimensions as the original. Bolts directly on, no modifications, no drilling.
Better for resale
A corroded heat exchanger housing is a classic red flag during a boat inspection. Bronze in the engine room signals uncompromising maintenance.
Original aluminium housing
Volvo Penta, OEMAnd again in 5-7 years, when the salt water has eaten it up. And again after that.
Schøtt-Tech bronze housing
HX SeriesOnce. The corrosion is 0.015 mm per year, so the housing will outlast the boat.
Copper rod, end caps, thermostat, high-temperature sensor, drain cock, and 3/8" blanking plug from your existing heat exchanger must be reused. They are not included. If one or more of these parts are defective, they must be replaced.
With the housing, you get a complete assembly kit: studs, collar nuts, manifold gasket, exhaust gasket, complete O-ring set, and silicone grease.
HX-13, HX-20 and HX-30 each fit a different D1 engine. If you are in doubt, please ask us before ordering.
