Exclusive Content
Original Shows, Motorsports and Live Events
Due to the EU’s Global Data Protection Regulation, our website is currently unavailable to visitors from most European countries. We apologize for this inconvenience and encourage you to visit www.motortrend.com for the latest on new cars, car reviews and news, concept cars and auto show coverage, awards and much more.MOTORTREND.COM
  • |
  • |
  • Hyundai Seasall S270; Advanced Ultralight Marine V-6

Hyundai Seasall S270; Advanced Ultralight Marine V-6

Advanced Ultralight Marine V-6 is the Perfect Inboard Upgrade for Pleasure Cruisers

John Lehenbauer
Feb 6, 2018
Photographers: Courtesy of Manufacturer
The Hyundai SeasAll Company, an independent corporate venture of Hyundai-Kia Motors, was founded in 2009. In that short time, the company has made a name for itself as an innovative marine diesel engine builder.
However, SeasAll did not just jump into engine building immediately. Hyundai had engineers researching and developing the seagoing oil-burners years before the company’s official launch. It wanted to make sure the diesels would meet the demanding standards of a marine vessel.
Today, Hyundai SeasAll continues working to advance the technology used in its diesels. The resources provided by Hyundai-Kia’s array of automotive diesel engines gives SeasAll a large base of powerplants to choose from for development of the marine line. One such engine that has roots in automotive is the Hyundai SeasAll S270, which features a compacted-graphite-iron block and graphite-infused piston technology that come directly from on-road diesels. However, that is where the similarities end.
Photo 2/9   |   After being drawn into the camshaft-driven pump, seawater goes through the intercooler into the heat exchanger (mounted on the lower front of the engine), then onto the oil cooler just above the exchanger. Upon exiting the cooler, seawater is routed to the exhaust elbow before being expelled.
The marine-specific S270 is a compact, lightweight, powerful, efficient 3.0L V-6 engine. SeasAll achieves these advances by incorporating different technologies and ideas. Making the engine efficient is key to meeting the current EPA Tier III emissions and having it poised to meet the even more stringent EPA Tier IV regulations. The compact size (36.7 inches long, 31.6 inches wide, 31.7 inches high) and impressive power (267 hp and 417 lb-ft of torque) make the S270 ideal for new applications or retrofitting older inboard gas and diesel engines in pleasure craft and maritime patrol boats.
The block’s compacted-graphite iron makes it lighter, quieter, and stronger than gray cast-iron pieces. The graphite iron has an 85 percent higher tensile strength and is 45 percent stiffer, giving it double the fatigue strength of iron and aluminum. This stronger design also gives the block a much longer service life.
Much of the engine’s light weight (736 pounds) and performance come from DOHC 24-valve aluminum cylinder heads. These marine-specific castings are designed for optimal airflow and combustion. The two camshafts per head are spun by a low-noise duplex timing chain. The chain is kept tight with hydraulic tensioners. Valve lash is minimized with hydraulic lash adjusters.
Photo 3/9   |   The electronic variable-geometry turbocharger (E-VGT) is positioned on the upper-rear section of the engine. The exhaust manifolds’ temperature is regulated by engine coolant, while the exhaust elbow is cooled by seawater.
A common-rail direct-injection system with 1,800-bar piezoelectric injectors delivers fuel to the cylinders. These injectors use a piezo crystal actuator that is five times faster than a standard solenoid. The reaction speed facilitates multiple injection events per combustion cycle for a more efficient burn. Another benefit of the piezo injectors is their ability to manipulate injection duration by adjusting the amount of voltage they receive. Fuel delivery is properly balanced by the electronic variable-geometry turbocharger’s boost, and a seawater-cooled intercooler regulates the boost air’s temperature.
The S270 has two separate cooling systems. The first is an open system that pumps seawater through the intercooler, oil cooler, heat exchanger, and exhaust elbow. The seawater pump is driven by the camshaft. The other system is sealed and filled with coolant that flows through the block’s integrated water jacket and heat exchanger and the exhaust manifolds. The impellers in both cooling systems are mounted to the front of the engine for easy accessibility.
Another design feature of Hyundai SeasAll’s marine diesel is the ease in which it can be serviced. Oil is drained via an extraction pump with a drain hose, mounted conveniently at the front of the engine. The oil and air filters are mounted toward the top of the engine.
The S270’s electronic engine management system has an Engine Operating Indicator interface that displays information like throttle position, fuel consumption, engine speed, temperatures, and diagnostic error codes to the skipper. It also provides audible alarms and control lamps for warnings. A unique feature of the EOI is the SeasLink interface. SeasLink is an application that allows all the engine’s data, diagnostic functions, alarms, and pop-ups to be accessed and monitored from a smartphone or tablet.
Photo 4/9   |   Hyundai SeasAll S270 Diagram Dimensions


Engine: Hyundai SeasAll S270
Displacement: 3.0L (180 ci)
Engine Layout: V-6
Valvetrain: 24-valve DOHC
Bore x Stroke: 3.30 x 3.50 inches (84 x 89 mm)
Compression Ratio: 17.5:1
Head material: Aluminum
Block material: Compacted-graphite iron
Piston material: Graphite-infused steel
Power: 267 hp (199 kw)
Torque: 417 lb-ft (565 Nm)
Emissions: EPA Tier III, EU RCD Stage II, IMO NOx Tier II
Induction: Electronic variable-geometry turbocharger
Exhaust: Cast iron
Intercooler: Water-to-air
Cooling System: Liquid-cooled
Fuel System: Common-rail direct injection with piezoelectric injectors
Lubrication System: Wet sump
Lubrication Capacity: 7.6 quarts (7.2L)
Dry Weight: 736 pounds (334 kilograms)
Length: 36.7 inches (933.4 mm)
Width: 31.6 inches (803.8 mm)
Height: 31.7 inches (805.3 mm)


Hyundai SeasAll