TOYOTA TUNDRA – NEW FEATURES
13
NEW FEATURES
J1UR-FE ENGINE
1. Description
The 1UR-FE engine is a 4.6-liter, 32-valve DOHC V8. This engine uses the Dual Variable Valve
Timing-intelligent (Dual VVT-i) system, Direct Ignition System (DIS), Acoustic Control Induction System
(ACIS), Electronic Throttle Control System-intelligent (ETCS-i), air injection system and Exhaust Gas
Recirculation (EGR) control. These control functions achieve improved engine performance, fuel economy,
and clean emissions.
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TOYOTA TUNDRA – NEW FEATURES
"
Engine Specifications A
No. of Cyls. & Arrangement
8-cylinder, V Type
Valve Mechanism
32-valve DOHC, Chain Drive (with Dual VVT-i)
Combustion Chamber
Pentroof Type
Manifolds
Cross-flow
Fuel System
SFI
Ignition System
DIS
Displacement
cm3 (cu. in.)
Bore × Stroke
mm (in.)
Compression Ratio
94.0 × 83.0 (3.70 × 3.27)
10.2 : 1
Max. Output (SAE-NET)*1
Max. Torque
4608 (281.2)
231 kW @ 5600 rpm (310 HP @ 5600 rpm)
(SAE-NET)*1
Intake
Valve Timing
Exhaust
443 N⋅m @ 3400 rpm (327 ft⋅lbf @ 3400 rpm)
Open
–18_ to 22_ BTDC
Closed
70_ to 30_ ABDC
Open
62_ to 30_ BBDC
Closed
– 8_ to 24_ ATDC
Firing Order
1–8–7–3–6–5–4–2
Octane Rating
87 or higher
Research Octane Number (RON)
91 or higher
Tailpipe Emission Regulation
LEVII-ULEV, SFTP
Evaporative Emission Regulation
Engine Service
Mass*2
(Reference)
LEVII, ORVR
kg (lb)
216.1 (476.5)
*1: Maximum output and torque ratings are determined by revised SAE J1349 standard.
*2: The figure shown is the weight of the part without coolant and oil.
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TOYOTA TUNDRA – NEW FEATURES
"
Valve Timing A
: Intake valve opening angle
: Exhaust valve opening angle
Exhaust VVT-i
Operation Range
Intake VVT-i
Operation Range
22_
TDC
8_
18_
24_
70_
62_
Intake VVT-i
Operation Range
Exhaust VVT-i
Operation Range
30_
30_
BDC
"
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Performance Curve A
320
240
300
220
280
Torque
N⋅m (ft⋅lbf)
460
440
420
400
380
360
340
320
340
320
300
280
260
240
260
240
180
220
160
200
180
120
140
100
100
80
60
40
2000
3000
4000
5000
Engine Speed (rpm)
140
160
120
1000
200
Output
(HP) kW
80
60
40
20
20
0
0
6000
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TOYOTA TUNDRA – NEW FEATURES
2. Features of 1UR-FE Engine
The 1UR-FE engine has achieved the following performance through the use of the items listed below:
(1) High performance and reliability
(2) Low noise and vibration
(3) Lightweight and compact design
(4) Good serviceability
(5) Clean emission and fuel economy
Item
Engine Proper
Valve
Mechanism
Lubrication
System
(1)
(2)
(3)
A taper squish shape is used for the combustion chamber.
f
An aluminum alloy cylinder block containing an engine
coolant distribution pathway is used.
f
f
Spiny-type liners are used in the cylinder bores.
f
f
Cylinder block water jacket spacers are used.
f
The piston skirt is coated with resin.
f
f
A No. 1 oil pan made of aluminum alloy is used.
f
f
Timing chains and chain tensioners are used.
f
Hydraulic lash adjusters are used.
f
Roller rocker arms are used.
f
f
f
f
f
f
f
f
f
A linkless-type throttle body is used.
f
f
An intake manifold made of plastic is used.
f
f
A step motor type EGR valve is used.
f
A water-cooled type EGR cooler is used.
f
Stainless steel exhaust manifolds are used.
f
f
f
Ceramic type Three-Way Catalytic converters (TWCs)
are used.
Fuel System
Ignition System
f
f
A carbon filter is used in the air cleaner cap.
Intake and
Exhaust System
(5)
f
An oil filter with a replaceable element is used.
A water-cooled type oil cooler is used.*
(4)
f
12-hole type fuel injectors are used to improve the
atomization of fuel.
f
The Direct Ignition System (DIS) makes ignition timing
adjustment unnecessary.
f
f
f
Long-reach type iridium-tipped spark plugs are used.
f
f
f
f
(Continued)
*: Models with towing package
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TOYOTA TUNDRA – NEW FEATURES
Item
(1)
(2)
(3)
(4)
(5)
Charging
System
A segment conductor type generator is used.
Starting System
A planetary reduction type starter is used.
f
Serpentine Belt
Drive System
A serpentine belt drive system is used.
f
Blowby Gas
Ventilation
System
A separator case is provided between the cylinder block
and the intake manifold.
f
An magnetic Resistance Element (MRE) type crankshaft
position, a camshaft position, and VVT sensors are used.
f
The Electronic Throttle Control System-intelligent
(ETCS-i) is used.
f
f
The Dual Variable Valve Timing-intelligent (Dual
VVT-i) system is used.
f
f
The Acoustic Control Induction System (ACIS) is used.
f
f
Engine Control
System
f
f
f
f
The Exhaust Gas Recirculation (EGR) control is used.
f
An air injection system is used.
f
A starter control (cranking hold function) is used.
An evaporative emission control system is used.
f
f
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TOYOTA TUNDRA – NEW FEATURES
3. Engine Proper
Cylinder Head Cover
D Lightweight yet high-strength aluminum cylinder head covers are used.
D An oil delivery pipe is installed inside the cylinder head covers. This ensures lubrication to the sliding
parts of the valve rocker arms, improving reliability.
D Large baffle plates are built into the cylinder head covers. As a result, the speed of blowby gas flow is
reduced, and the oil mist is removed from the blowby gas. Due to this, the amount of oil lost is reduced.
Cylinder Head Cover RH
Cylinder Head Cover LH
Oil Delivery Pipe
Baffle Plate
Baffle Plate
Oil Delivery Pipe
Cylinder Head
Cover Gasket LH
Cylinder Head
Cover Gasket RH
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Cylinder Head Gasket
D 3-layer steel-laminate type cylinder head gaskets are used. A shim is used around the cylinder bore of
each gasket to help enhance sealing performance and durability. This results in improved fuel economy,
reduced consumption rate of engine oil and reduced emission of exhaust gases.
D The surface is coated with highly heat-resistant fluoro rubber to support high power output.
A
Front
Right Bank
A
Shim
A – A Cross Section
Left Bank
04E1EG07C
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TOYOTA TUNDRA – NEW FEATURES
Cylinder Head
D The cylinder head structure has been simplified by separating the cam journal portion (camshaft housing)
from the cylinder head.
D The cylinder head, which is made of aluminum, contains a pentroof type combustion chamber. The spark
plug is located in the center of the combustion chamber in order to improve the engine’s anti-knocking
performance.
D The port configuration is an efficient cross-flow type in which the intake ports face the inside of the V
bank and the exhaust ports face the outside.
D A siamese type intake port is used. The port diameter gradually decreases toward the combustion
chamber to optimize the airflow speed and intake pulsation.
D An air injection port is provided for the air injection system.
Intake
Valve
Camshaft Housing
A
Intake Side
Intake
Side
Spark
Plug
Hole
Exhaust
Valve
Exhaust
Side
Exhaust Side
A
Bottom Side View
A – A Cross Section
080EG31TE
04E1EG09C
Air Injection Port
Front
Exhaust Side View
04E1EG10C
— REFERENCE —
Siamese Type
Independent Type
036EG28TE
036EG29TE
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TOYOTA TUNDRA – NEW FEATURES
Cylinder Block
1) General
D The cylinder block is made of aluminum alloy.
D The cylinder block has a bank angle of 90_, a bank offset of 21 mm (0.827 in.) and a bore pitch of 105.5
mm (4.15 in.), resulting in a compact block in its length and width considering its displacement.
D Spiny-type liners are used.
D An engine coolant distribution pathway is provided between the left and right banks. The engine
coolant sent by the water pump passes through the engine coolant distribution pathway and flows to
the cylinder head and water jackets of both banks. The engine coolant distribution pathway also cools
the engine oil in the main oil hole located directly below the pathway.
D A water passage is provided between the cylinder bores. By allowing the engine coolant to flow
between the cylinder bores, this construction keeps the temperature of the cylinder walls uniform.
D Plastic cylinder block water jacket spacers are inserted in the water jacket. They control the flow of
the engine coolant in order to attain a uniform temperature around the combustion chambers.
D Installation bosses of the 4 knock sensors are located on the inner side of the left and right banks to
enhance the accuracy of the knock sensors.
D Air passage holes are provided on the bulkheads of the cylinder block. As a result, the air at the bottom
of the cylinder flows smoother, and pumping loss (back pressure at the bottom of the piston generated
by the piston’s reciprocating movement) is reduced to improve the engine’s output.
Water Passage
21 mm
(0.827 in.)
105.5 mm
(4.15 in.)
#1
Engine Coolant
Distribution Pathway
Knock Sensor
Boss
#2 #4
#6
#3
#5
#8
#7
Top Side View
Air Passage Hole
90_
Main Oil
Hole
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TOYOTA TUNDRA – NEW FEATURES
2) Spiny-type Liner
D The liners are the spiny-type which have been manufactured so that their casting exteriors form large
irregular surfaces in order to enhance the adhesion between the liners and the aluminum cylinder
block. The enhanced adhesion helps heat dissipation, resulting in a lower overall temperature and heat
deformation of the cylinder bores.
D The shape of the cross-hatching of the liner surface has been optimized to improve oil retention
performance, resulting in reduced friction.
Irregularly Shaped
Outer Casting
Surface of Liner
Cylinder Block
Cylinder Block
A
Enlarged View of
Cross-hatching
A
Liner
A – A Cross Section
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3) Cylinder Block Water Jacket Spacer
The temperature in the intake side of the cylinder bore tends to be lower. For this reason, a wide cylinder
block water jacket spacer covers the cylinder bores in order to suppress the flow of the engine coolant
and prevent excessive cooling. On the other hand, the temperature of the exhaust side of the cylinder bore
tends to be higher. A cylinder block water jacket spacer covers the lower area of the cylinder bores in
order to direct the engine coolant to the upper area of the cylinder bores where the temperature is higher.
This makes the temperature around the cylinder bores more uniform. As a result, the viscosity of the
engine oil (which lubricates the area between the wall surface of the cylinder bore and the piston)
decreases, thus reducing friction between the cylinder bore and the piston.
Cylinder Block
Water Jacket Spacer
Water Jacket
Intake Side
Exhaust
Side
Front
Cylinder Block
Water Jacket Spacer
: Engine coolant flow
: Engine coolant
Cross-sectional
Image of Cylinder Bore
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TOYOTA TUNDRA – NEW FEATURES
Piston
D The pistons are made of aluminum alloy.
D A compact combustion chamber is provided on top of the piston to achieve stable combustion. Together
with the pentroof type combustion chamber of the cylinder head, this achieves a high compression ratio,
resulting in both high performance and excellent fuel economy.
D A taper squish combustion chamber is used to improve anti-knocking performance and intake efficiency.
In addition, engine performance and fuel economy are improved.
D In order to reduce weight, cast holes are provided on the bottom of the piston head near the pin bosses
as shown in the illustration below.
D The piston skirt is coated with resin to reduce friction losses.
D A Physical Vapor Deposition (PVD) coating has been applied to the surface of the No. 1 compression
ring and oil ring, in order to improve its wear resistance.
D By increasing the machining precision of the cylinder bore diameter in the block, only one size of piston
is required.
Resin Coating
PVD Coating
Taper Squish Shape
No. 1 Compression Ring
Weight Reduction Area
No. 2 Compression Ring
Oil Ring
PVD Coating
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Service Tip
The same pistons are used for both right and left banks. When installing a piston, the front mark
should face the front of the engine.
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TOYOTA TUNDRA – NEW FEATURES
Connecting Rod and Connecting Rod Bearing
D Connecting rods that have been forged for high strength are used for weight reduction.
D Knock pins are used at the mating surfaces of the bearing caps of the connecting rod to minimize the
shifting of the bearing caps during assembly.
D Plastic region tightening bolts are used on the connecting rods.
D Resin-coated aluminum bearings are used for the connecting rod bearings. The connecting rod bearings
are reduced in width to reduce friction.
Oil Jet
Resin Coating
Knock Pin
Plastic Region
Tightening Bolt
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Crankshaft
D A crankshaft made of forged steel, which excels in rigidity and wear resistance, is used.
D The crankshaft has 5 main bearing journals and 6 balance weights.
Balance Weight
Balance Weight
Engine
Front
No. 1 Journal
No. 3 Journal
No. 2 Journal
No. 4 Journal
No. 5 Journal
036EG02TE
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TOYOTA TUNDRA – NEW FEATURES
Crankshaft Bearing and Crankshaft Bearing Cap
D The crankshaft bearings are made of aluminum alloy.
D The crankshaft bearings are reduced in width to reduce friction. The bearing lining surface is coated with
resin to improve wear and seizure resistance.
D The upper crankshaft bearing has an oil groove around its inside circumference.
D The crankshaft bearing caps use 4 plastic region tightening bolts of different sizes in the inner and outer
sides to secure the journals. This makes the crankshaft bearing caps more compact and lightweight. In
addition, each cap has been tightened laterally to improve its reliability.
Plastic Region
Tightening Bolt
Upper Main Bearing
Oil Groove
Resin Coating
Crankshaft
Bearing Cap
Lower Main Bearing
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Crankshaft Pulley
The crankshaft pulley uses torsional damper
rubber and has been optimized to reduce noise
and vibration.
Torsional Damper
Rubber
04E1EG18C
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TOYOTA TUNDRA – NEW FEATURES
Oil Pan
D The No. 1 oil pan is made of aluminum alloy.
D The No. 1 oil pan is secured to the cylinder block and the transmission housing to increase rigidity.
D The shape of the oil pan baffle plate has been optimized to ensure the proper space between the crankshaft
and the engine oil surface. This enhances the separation of oil flow and ventilation gases, thus reducing
friction and improving lubrication performance.
Oil Pan Baffle Plate
No. 1 Oil Pan
No. 2 Oil Pan
080EG02TE
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TOYOTA TUNDRA – NEW FEATURES
4. Valve Mechanism
General
D Each cylinder of this engine has 2 intake valves and 2 exhaust valves. Intake and exhaust efficiency has
been increased due to the larger total port areas.
D This engine uses roller rocker arms with built-in needle bearings. This reduces the friction that occurs
between the cams and the valve rocker arms that push the valves down, thus improving fuel economy.
D A hydraulic lash adjuster, which maintains a constant zero valve clearance through the use of oil pressure
and spring force, is used.
D To ensure highly accurate valve timing, separate primary timing chains are driven by the crankshaft in
order to rotate the intake camshafts of the left and right banks. The exhaust camshafts are driven by the
intake camshaft of the respective bank via secondary timing chains.
D This engine has a Dual Variable Valve Timing-intelligent (Dual VVT-i) system which controls the intake
and exhaust camshafts to provide optimal valve timing in accordance with driving conditions. Using this
system, lower fuel consumption, higher engine performance, and lower exhaust emissions have been
achieved. For details of Dual VVT-i control, see page 78.
Exhaust Camshaft
Intake Camshaft
Secondary Timing
Chain
Valve Rocker Arm
Valve Spring
Retainer
Hydraulic Lash
Adjuster
Compression Spring
Valve Guide Bush
Valve Spring Seat
Valve
Primary Timing
Chain
Secondary Timing
Chain
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TOYOTA TUNDRA – NEW FEATURES
Camshaft
D The camshafts are made of cast iron alloy.
D Oil passages are provided in the intake and exhaust camshafts in order to supply engine oil to the VVT-i
system.
D VVT-i controllers are installed on the front of the intake and exhaust camshafts to vary the timing of the
intake and exhaust valves.
D Together with the use of the roller rocker arms, the cam profile has been optimized. This results in
increased valve lift when the valve begins to open and when it finishes closing, helping to achieve
enhanced output performance.
VVT-i
Controller
No. 2 Camshaft
(Exhaust)
Increased Valve Lift
No. 1 Camshaft
(Intake)
No. 3 Camshaft
(Intake)
Optimized Profile
of Camshaft Lobe
Timing
Rotor
VVT-i Controller
No. 4 Camshaft
(Exhaust)
Timing
Rotor
Oil Passage
VVT-i
Controller
Cross Section of End of Intake Camshaft
Oil Passage
Cross Section of End of Exhaust Camshaft
080EG34S
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TOYOTA TUNDRA – NEW FEATURES
Timing Chains and Chain Tensioners
D Both the primary and secondary timing chains use roller chains with a pitch of 9.525 mm (0.375 in.).
D A chain tensioner is provided for each primary timing chain and secondary timing chain in each bank.
D Both the primary and secondary chain tensioners use oil pressure and a spring to maintain proper chain
tension at all times. The tensioners suppress noise generated by the timing chains.
D The chain tensioner for the primary timing chain is a ratchet type with a non-return mechanism.
Furthermore, an oil pocket creates oil pressure when the engine is started, and simultaneously applies
oil pressure to the chain tensioner. This prevents the timing chain from flapping and reduces noise.
Primary Chain Tensioner LH
Gasket
Secondary Chain Tensioner RH
Main
Spring
Ball
Ball
Spring
Chain Tensioner
Oil Pocket
(Primary)
Chain Damper RH
Secondary Chain
Chain Slipper LH Tensioner LH
Secondary Timing
Chain RH
Plunger
Primary Chain Tensioner RH
Secondary Timing
Chain LH
Spring
Chain Slipper
RH
Chain Damper LH
Cam
Cam Spring
Primary Timing
Chain RH
Primary Timing
Chain LH
080EG23S
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TOYOTA TUNDRA – NEW FEATURES
Timing Chain Cover
D The timing chain cover has an integrated construction consisting of a cooling system (water pump and
water passage) and a lubrication system (oil pump and oil passage). Thus, the number of parts has been
reduced, resulting in a weight reduction.
D A chain oil jet is provided in the oil pump cover to lubricate the timing chains.
Water Pump
Swirl Chamber
Water Pump
Gasket
Timing Chain Cover
Oil Pump
Cover
Chain
Oil Jet
Water Pump
Timing Chain Cover
Front Side View
Oil Pump Chamber
Oil Pump Rotor
Back Side View
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Hydraulic Lash Adjuster
D The hydraulic lash adjuster, which is located at the fulcrum (pivot point) of the roller rocker arms,
consists primarily of a plunger, a plunger spring, a check ball, and a check ball spring.
D The engine oil supplied from the cylinder head and the built-in spring actuate the hydraulic lash adjuster.
The oil pressure and the spring force, that act on the plunger, push the roller rocker arm against the cam,
in order to adjust the clearance between the valve stem and rocker arm. This prevents the generation of
noise during the opening and closing of the valves. As a result, engine noise has been reduced.
Plunger
Oil Passage
Hydraulic Lash
Adjuster
Cam
Roller Rocker Arm
Oil
Passage
Check Ball
Check Ball
Spring
Plunger Spring
04E1EG24C
Service Tip
Valve clearance adjustment is not necessary because hydraulic lash adjusters are used on this model.
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TOYOTA TUNDRA – NEW FEATURES
5. Lubrication System
General
D The lubrication circuit is fully pressurized and oil passes through an oil filter.
D A cycloid rotor type oil pump is used.
D An oil filter with a replaceable element is used.
D A water-cooled type oil cooler is provided as optional equipment.
Oil Delivery Pipe
(Cylinder Head Cover)
Camshaft Timing
Oil Control Valve
Oil Pump
Oil Filter
Oil Strainer
Oil Cooler*
*: Models with towing package
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TOYOTA TUNDRA – NEW FEATURES
"
Oil Circuit A
Main Oil Hole
Cylinder Head LH
Chain Cylinder Block
Oil Jet
Oil
Filter
Crankshaft
Journals
Oil
Cooler*1
Crankshaft
Pins
Oil
Pump
Connecting
Rods
Primary
Chain
Tensioner
Camshaft
Timing
OCV*2
Intake
Camshaft
Journals
Oil
Jets
Camshaft
Timing
OCV*2
Exhaust
Camshaft
Journals
VVT-i
Controller
Secondary
Chain
Tensioner
Cylinder Head RH
Hydraulic
Lash
Adjusters
Primary
Chain
Tensioner
Intake
Camshaft
Journals
VVT-i
Controller
Secondary
Chain
Tensioner
Exhaust
Camshaft
Journals
Hydraulic
Lash
Adjusters
Relief
Valve
Oil Pan
*1: Models with towing package
*2: Oil Control Valve
04E1EG26C
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TOYOTA TUNDRA – NEW FEATURES
Oil Pump
D A compact cycloid rotor type oil pump, directly driven by the crankshaft, is used.
D This oil pump uses an internal relief method which circulates relief oil to the suction passage in the oil
pump. This aims to minimize oil level change in the oil pan, reduce friction, and reduce the air mixing
rate in the oil.
Timing Chain Cover
To
Cylinder Block
Oil Pump
Cover
Crankshaft
Oil Pump Rotor
(Cycloid Rotor)
Oil Filter
From
Relief Oil Oil Strainer
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Oil Jet
D 4 oil jets for cooling and lubricating the pistons are provided in the cylinder block, in the center of the
right and left banks.
D These oil jets contain a check valve to prevent oil from being fed when the oil pressure is low. This
prevents the overall oil pressure in the engine from dropping.
Oil Jet
Check
Valve
Oil
Oil Jet Cross Section
Cylinder Block
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