Yanmar 4LHA-HTP – Inboard Marine Diesel Engine 160 HP

Featuring a cylinder block cast specifically for sustained commercial workloads, the Yanmar 4LHA-HTP outputs 160 horsepower at 3300 RPM. This 3.455-liter mechanical direct-injection diesel prioritizes raw reliability over complex electronic mapping. A robust direct-injection system completely eliminates delicate electronic fuel sensors entirely. Forced enclosed lubrication utilizes an 11-liter oil sump. This actively protects moving components across varying dynamic operational loads. The dedicated turbocharger maximizes combustion oxygen density. It maintains highly responsive throttle performance across mid-range operating speeds without requiring complex intercooled external setups.

Thermal stabilization occurs within an 11.5-liter closed freshwater heat exchanger system constantly. Raw seawater stays completely outside the internal engine cylinder waterways. This permanently prevents internal salt scaling and heavy metal corrosion inside the iron block. The native SAE 4 flywheel housing mounts seamlessly to HSW450A hydraulic marine gears. Auxiliary electrical systems rely on the standard 12V 60-amp alternator output for steady charging. Total dry weight registers at exactly 365 kg. Repower mechanics must factor this static physical mass into the vessel’s rear hull displacement center.

Engine Operation and Output

Operating completely independent of digital ECUs, this 3.455-liter Yanmar engine ensures exceptional physical reliability in remote operating locations. An 11-liter oil sump ensures forced pressure lubrication during demanding continuous commercial runs. The rugged mechanical injection setup satisfies stringent IMO Tier II emissions limits easily. This happens by utilizing an 18.4:1 compression ratio across the 1-3-4-2 firing order. Throttle synchronization runs directly through traditional mechanical push-pull cable linkages. This ensures immediate physical response during tight marina docking maneuvers and rapid heavy-duty shifting requirements under maximum load.

Why Choose the Yanmar 4LHA-HTP Inboard Diesel Engine

Commercial fishing captains select the 4LHA-HTP inboard diesel engine for its substantial 3.455-liter displacement and dependable 160 horsepower output. Mechanical direct injection provides remarkably rugged running conditions compared to modern digitally governed units. Featuring a reliable 60-amp alternator, it effectively sustains basic DC circuits and essential navigation screens. The SAE 4 flywheel housing adapts immediately to HSW450A hydraulic transmissions or heavy HSW450H gears. Total dry weight remains strictly at 365 kg. This minimizes drastic center of gravity shifts inside your commercial vessel’s dark engine room.

Warranty and Support

This 3.455-liter propulsion block includes a standard Limited Factory Warranty covering major internal assembly defects supplied by Yanmar. provides essential product-information support before purchase and technical assistance with order-related questions. A thorough pre-shipment visual inspection confirms the crated engine item and all documented included components. Mechanics and vessel owners should examine warranty coverage scope concerning specific commercial versus recreational duty cycles. Please review the detailed warranty coverage and eligibility details directly on before placing your final heavy freight purchase order for delivery.

Before Ordering the Yanmar 4LHA-HTP Inboard Diesel Engine

Evaluate your engine room hatch opening carefully to confirm adequate fitting clearance for this 365 kg block. You must verify your intended transmission reduction gear ratio and existing shaft coupling dimensions. Check that your onboard DC wiring system safely supports a 12V 60-amp alternator charging circuit output. Next, confirm whether your helm station supports required mechanical push-pull cables versus modern electronic control inputs. Ensure your existing diesel fuel filtration system matches the precise ISO 8217 DMA flow demands for mechanical direct injection networks completely.