Yanmar 4JH4 HTE Specifications
| Engine Model: Yanmar 4JH4 HTE |
| Engine Type: 4-stroke inline 4-cylinder turbocharged water-cooled diesel |
| Total Displacement: 121.7 cu.in (1.99 L) |
| Rated Engine Power: 110 Hp (80.9 kW) at 3200 rpm |
| Fuel System Type: Direct injection |
____________________________________________________________________________________
The Yanmar 4JH4-HTE is a four-cylinder,
turbocharged and intercooled marine diesel engine representing the
high-output variant of the JH4 series. This engine was designed for
sailboats and power vessels requiring substantial power from a compact
footprint. The Yanmar 4JH4-HTE utilizes direct injection technology in
combination with a turbocharger and intercooler to achieve higher power
output compared to the naturally aspirated and standard turbocharged
versions within the JH4 family.
The engine features fresh water cooling with a heat exchanger, isolating
the engine block from corrosive seawater while efficiently dissipating
heat. Produced during the mid-2000s to early 2010s, the 4JH4-HTE is
certified to EPA Tier 2 emission standards and is available with
recreational or commercial application ratings depending on the specific
vessel type. The engine’s mechanical controls and robust cast iron
construction provide the reliability required for extended marine duty
cycles.
The Yanmar 4JH4-HTE is a four-stroke, vertical, water-cooled diesel
engine operating on the compression-ignition principle. The engine
architecture is an inline four-cylinder configuration with a total
displacement of 1.995 L (121.7 cu.in), derived from a bore of 84 mm
(3.31 in) and a stroke of 90 mm (3.54 in). The combustion system
utilizes direct injection with a Bosch distributor-type VE injection
pump.
The aspiration system employs a turbocharger with an intercooler (charge
air cooler) to increase air density entering the cylinders, enabling
higher power output without increasing engine displacement. The maximum
output at the crankshaft is 80.9 kW (110 hp) at 3,200 rpm. The
continuous rating output is 74.3 kW (101 hp) at 3,100 rpm. The maximum
torque is 280 Nm (207 lb-ft) achieved at 1,900 to 2,100 rpm. The
cruising rpm range is 2,400 to 2,800 rpm. The direction of rotation is
counter-clockwise when viewed from the flywheel.
The cylinder block is manufactured from cast iron, providing the
rigidity and wear resistance required for sustained marine diesel
operation. The block is a vertical, four-cylinder design with the
cylinders arranged in-line. The cylinder bores are finished with a
plateau honing process that optimizes oil retention and piston ring
sealing. The crankcase houses a forged or cast steel crankshaft with
counterweights for balanced operation.
The main bearing caps are secured with bolts torqued to specifications
appropriate for the engine’s power output. A gear housing is mounted at
the front of the cylinder block, containing the camshaft drive gears,
injection pump drive gear, and the fresh water pump drive. The
lubricating oil sump (oil pan) is mounted at the lower section of the
block.
The cylinder head is manufactured from cast iron, matching the cylinder
block material to ensure uniform thermal expansion. The valvetrain is an
overhead valve (OHV) configuration with the camshaft located in the
cylinder block, driven by the front gear train. Each cylinder utilizes
two valves - one intake and one exhaust, for a total of eight valves.
The valves are actuated via pushrods and rocker arms.
Valve clearances require periodic mechanical adjustment. The cold valve
clearance is set at 0.2 mm (0.008 in) for both intake and exhaust
valves. The cylinder head incorporates the intake manifold mounting
flange, exhaust manifold mounting flange, and the fuel injector ports
positioned for the direct injection combustion system. A rocker arm
cover (bonnet) seals the top of the cylinder head. The suction manifold
(intake manifold) is mounted on the cylinder head.
The 4JH4-HTE is equipped with a direct injection fuel system utilizing a
Bosch distributor-type VE injection pump. The injection pump is
camshaft-driven and features a mechanical governor that controls fuel
delivery based on engine speed and load. The injection pump is supplied
with fuel from a feed pump mounted on the injection pump body. The
injection pressure is set at 200 to 210 kg/cm2 (19.6 to 20.6 MPa / 2,845
to 2,985 psi).
The injection lines are high-pressure steel tubes routed individually
from the injection pump to the injectors mounted in the cylinder head.
The injectors are of the nozzle-and-holder type, incorporating a
spring-loaded pintle nozzle that opens at the predetermined pressure. A
fuel filter and water separator assembly provides primary and secondary
fuel filtration to protect the injection pump and injectors from
contamination. An electric stop solenoid controls fuel shutoff.
The lubrication system is a forced-feed design utilizing a trochoid-type
oil pump mounted within the front gear housing assembly. The oil pump
draws lubricant from the sump through a strainer and delivers it to the
main oil gallery. A pressure regulating valve maintains stable system
pressure. An oil cooler is integrated into the lubrication system to
maintain oil viscosity under high-load operation.
The engine employs a full-flow spin-on oil filter mounted on the engine
block. The total oil capacity including the filter is 7.0 L (7.4 US qt).
The engine requires SAE 15W-40 diesel engine oil meeting API CD or
higher specification. The lubricating oil dipstick is provided for level
checking. An oil filler port is located on the rocker arm cover.
The 4JH4-HTE utilizes an indirect freshwater cooling system with a heat
exchanger. The system maintains fresh coolant within the engine block
and cylinder head while raw seawater passes through the heat exchanger
to reject heat overboard. A fresh water pump is gear-driven from the
engine front cover. A separate sea water pump is also gear-driven and
mounted on the front of the engine.
The cooling system includes a fresh water cooler (heat exchanger) where
heat transfer occurs between the engine coolant and seawater. A
thermostat regulates coolant temperature by controlling flow through the
heat exchanger. The system includes an expansion tank for the fresh
water cooling system. A mixing elbow combines exhaust gases with cooling
water discharge to reduce exhaust temperatures in the engine
compartment. The total coolant capacity for the engine and heat
exchanger is 8.4 L (8.9 US qt). The recommended coolant mixture is a
50/50 glycol-water blend.
The electrical system is 12V with a 1.8 kW electric starter motor. The
standard alternator is a 12V unit rated at 125A, with optional 12V 130A
or 24V 75A secondary alternators available including a smart regulator.
A glow-type air heater is available for cold-start assistance. The
engine meets SOLAS (Safety of Life at Sea) certification requirements
when factory-fitted with the appropriate options.
Air Intake and Turbocharging: The engine is equipped with a turbocharger
that compresses intake air before it enters the cylinders. A charge air
cooler (intercooler) reduces the temperature of the compressed air,
increasing density and combustion efficiency. The air intake system
includes a suction silencer to reduce induction noise.
Engine Management: The 4JH4-HTE utilizes mechanical engine controls with
a stop solenoid for fuel shutoff. The engine is equipped with a B20
instrument panel as standard equipment, with an optional C30 panel
available. A trolling valve is available as an optional accessory for
the KMH4A transmission variant. The engine is not equipped with
electronic engine management beyond basic monitoring functions.
Exhaust System: The exhaust system incorporates a water-cooled exhaust
manifold that injects cooling water into the exhaust stream and an
exhaust mixing elbow that further cools exhaust gases before discharge.
An L-type exhaust mixing elbow is supplied as standard equipment, with a
high-riser mixing elbow available as an option.
Transmission: The 4JH4-HTE is commonly paired with the KM4A2 marine
gear, with the engine length dimension of 933 mm (36.7 in) including
this transmission. The ZF30M marine gear is also compatible. The SD60
sail drive leg is available for sailboat installations, including a 75
mm extension option.
Dimensions including the KM4A2 marine gear: length 933 mm (36.7 in),
width 661 mm (26.0 in), and height 659 mm (25.9 in). The dry weight
without marine gear is 217 kg (478 lbs). These compact dimensions and
weight allow installation in engine compartments of sailboats and power
vessels where space is at a premium.
The service life of the 4JH4-HTE under proper operating conditions is
engineered to exceed 8,000 operating hours in recreational marine
service with regular maintenance. Oil change intervals are recommended
at 250 operating hours for normal operation. The engine requires SAE
15W-40 diesel engine oil meeting API CD or higher specification. The
total oil capacity including the filter is 7.0 L (7.4 US qt).
Valve clearance inspection and adjustment is mandated every 500
operating hours. The cold valve clearance is set at 0.2 mm (0.008 in)
for both intake and exhaust valves. Replacement of the fuel filter is
required every 500 operating hours. The fuel/water separator should be
serviced at the same interval. Sea water pump impeller replacement is
recommended every 200 to 500 operating hours depending on usage.
The coolant must be replaced every 2 years or 2,000 operating hours,
using a 50/50 glycol-water mixture. The zinc anodes in the heat
exchanger and raw water circuit require inspection every 250 operating
hours. The timing gears require no periodic adjustment as they are
gear-driven from the crankshaft. The turbocharger should be inspected
every 1,000 operating hours for shaft play and seal condition.
Cylinder Head Bolts (M12), Stage 1: 40 Nm (30 lb-ft).
Cylinder Head Bolts (M12), Stage 2: 90 Nm (66 lb-ft).
Connecting Rod Bolts (M9): 50 Nm (37 lb-ft).
Main Bearing Cap Bolts (M12): 65 Nm (48 lb-ft).
Flywheel Bolts (to crankshaft flange, M12): 80 Nm (59 lb-ft).
Crankshaft Pulley Bolt (center, M16): 230 Nm (170 lb-ft).
Camshaft Thrust Plate Bolts (M8): 26 Nm (19 lb-ft).
Rocker Arm Shaft Bracket Bolts (M8): 26 Nm (19 lb-ft).
Injector Hold-Down Clamp Bolts (M8): 26 Nm (19 lb-ft).
Injection Pump Mounting Nuts (M8): 26 Nm (19 lb-ft).
High-Pressure Fuel Line Nuts (M12): 25 Nm (18 lb-ft).
Oil Pump Mounting Bolts (M8): 21 Nm (15 lb-ft).
Water Pump Mounting Bolts (fresh water, M8): 21 Nm (15 lb-ft).
Seawater Pump Mounting Bolts (M8): 15 Nm (11 lb-ft).
Thermostat Housing Bolts (M8): 15 Nm (11 lb-ft).
Starter Motor Mounting Bolts (M12): 70 Nm (52 lb-ft).
Alternator Pivot Bolt (M10): 40 Nm (30 lb-ft).
Turbocharger Mounting Nuts (M10): 40 Nm (30 lb-ft).
The Yanmar 4JH4-HTE is exclusively a marine propulsion engine designed
for recreational and light commercial vessels. The engine is suitable
for sailboats in the 36- to 45-foot length range and power vessels
requiring up to 110 horsepower.
____________________________________________________________________________________
| Industrial Engines Technical Specifications |
| Car Engines Technical Specifications |
| Small Engines Technical Specifications |
| Outboard Engines Technical Specifications |
