The Toyota 1UZ-FE is a 4.0 L (3,968 cc, 242.1 cu·in) V8, four-stroke cycle water-cooled naturally aspirated internal combustion gasoline engine, manufactured by the Toyota Motor Corporation since 1989 to 2004.
The 1UZ-FE engine has 8 cylinders in a V-arrangement at a bank angle of 90° The 1UZ-FE features aluminum cylinder block with a five-bearings crankshaft and two aluminum heads with two camshafts (DOHC) and four valves per cylinder (32 in total). Until 1994 the Toyota 1UZ-FE engine is equipped with Multi-port fuel injection (MFI) system, and after 1994 it used Sequential multi-point fuel injection (SFI). The latest engine versions (after 1997) were equipped with a VVTi (Variable Valve Timing) system for the intake camshafts.
Cylinder bore and piston stroke are 87.5 mm (3.44 in) and 82.5 mm (3.25 in), respectively. Compression ratio rating is 10.0:1 (1989-1994), 10.4:1 (1994-1997) and 10.5:1 (after 1997).
The Toyota 1UZ-FE engine produced from 259 PS (191 kW; 256 HP) at 5,400 rpm to 300 PS (221 kW; 296 HP) at 6,000 rpm of maximum power and from 333 N·m (34 kg·m, 245.4 ft·lb) at 4,000 rpm to 420 N·m (42.8 kg·m, 309.5 ft·lb) at 4,600 rpm of peak torque depending on year and vehicle model.
The breakdown of the engine code is as follows:
- 1 – 1st generation engine
- UZ – Engine family
- F – Economy narrow-angle DOHC
- E – Multi Point Fuel Injection
General information
| Engine Specifications | |
| Engine code | 1UZ-FE |
| Layout | Four stroke, V8 |
| Fuel type | Gasoline (petrol) |
| Production | 1989-2004 |
| Displacement | 4.0 L, 3,968 cc (242.1 cu in) |
| Fuel system |
Before 1994: Multi-port fuel injection (MFI) After 1994: Sequential multi-point fuel injection (SFI) |
| Power adder | None |
| Power output |
From 259 PS (191 kW; 256 HP) at 5,400 rpm to 300 PS (221 kW; 296 HP) at 6,000 rpm |
| Torque output |
From 333 N·m (34 kg·m, 245.4 ft·lb) at 4,000 rpm to 420 N·m (42.8 kg·m, 309.5 ft·lb) at 4,600 rpm |
| Firing order | 1-8-4-3-6-5-7-2 |
| Dimensions (L x W x H): | – |
| Weight | – |
Cylinder block
The 1UZ–FE engine has 8-cylinders in a V-arrangement at arrangement at a bank angle of 90°. The cylinder block made of aluminum alloy. Cast-iron cylinders are installed inside the cylinder block. This engine’s ignition order is 1-8-4-3-6-5-7-2. The crankshaft is supported by five bearings inside the crankcase, these bearings are made of a copper and lead alloy. The crankshaft is integrated with 8 weights for balance.
Pistons are made of high-temperature resistant aluminum alloy, and depression is built into the pistons head to prevent interference with the valves. Piston pins are full-floating. Each piston is fitted with two compression and single oil ring. The top compression ring is made of steel and the second ring is made of the cast-iron, the oil ring is made of a combination of steel and stainless steel.
The cylinder bore is 87.5 mm (3.44 in) and the piston stroke is 82.5 mm (3.25 in). Compression ratio rating is 10.5:1, 10.4:1 or 10:1.
| Cylinder block | ||
| Cylinder block alloy | Aluminium | |
| Compression ratio: |
1989-1994: 10.0:1 1994-1997: 10.4:1 1997-2004: 10.5:1 |
|
| Cylinder bore: | 87.5 mm (3.44 in) | |
| Piston stroke: | 82.5 mm (3.25 in) | |
| Number of piston rings (compression / oil): | 2 / 1 | |
| Number of main bearings: | 5 | |
| Cylinder inner diameter (standard): | 87.500-87.510 mm (3.4449-3.4453 in) | |
| Piston skirt diameter (standard): | 87.470-87.480 mm (3.4437-3.4441 in) | |
| Piston compression height: | – | |
| Piston pin outer diameter: | 21.997-22.009 mm (0.866-0.8665 in) | |
| Connecting rod bushing inner diameter: | 22.005-22.014 mm (0.8663-0.8667 in) | |
| Piston ring side clearance: | Top | 0.020-0.060 mm (0.0008-0.0024 in) |
| Second | 0.015-0.055 mm (0.0006-0.0022 in) | |
| Piston ring end gap: | Top | 0.250-0.450 mm (0.0098-0.0177 in) |
| Second | 0.350-0.600 mm (0.0138-0.0236 in) | |
| Oil | 0.150-0.500 mm (0.0059-0.0197 in) | |
| Crankshaft main journal diameter: | 66.988-67.000 mm (2.6373-2.6378 in) | |
| Crankpin diameter: | 51.982-52.000 mm (2.0465-2.0472 in) | |
Main bearing cap bolts tightening procedure and torque specs:
For nut:
- Step 1: 27 Nm; 2.7 kg·m; 20 ft·lb
- Step 2: Turn bolts 90°
For bolt:
- 49 Nm; 5.0 kg·m; 36 ft·lb
After securing bearing cap bolts, make sure crankshaft turns smoothly by hand.
Connecting rod bearing bolts
- Step 1: 25 Nm; 2.5 kg·m; 18 ft·lb
- Step 2: Turn bolts 90°
Cylinder head
The cylinder heads are made of aluminum alloy, with a cross-flow type intake and exhaust layout and with pentroof type combustion chambers. The spark plugs are located in the center of the combustion chamber. The 1UZ-FE engine has dual overhead camshafts design (DOHC) with four valves per cylinder (32 valves in total). The intake camshafts are driven by the timing belt, and a gear on the intake camshaft engages with a gear on the exhaust camshaft to drive it. Since 1997, the engine began to use the VVTi (Variable Valve Timing-intelligent) system.
The first generation of the 1UZ-FE engine did not have variable valve timing and its intake duration was 224° and exhaust duration was 229°. In 1994, valve timing and valve lift for the intake valves were modified: valve overlap increased to 9°, intake duration to 232° and exhaust duration to 229°. From 1997, the 1UZ-FE engine was fitted with the VVT-i system. As a result, intake valve overlap ranged from -11 to 39°, intake valves duration was 230° and exhaust duration was 229°.
| Cylinder head | ||
| Block head alloy | Aluminium | |
| Valve Arrangement: | DOHC, belt drive | |
| Cylinder head height: | – | |
| Valves: | 32 (4 valves per cylinder) | |
| Intake valve timing: |
Non VVTi (before 1994): 224° Non VVTi (after 1994): 232° VVTi (after 1997): 230° |
|
| Exhaust valve timing: |
Non VVTi (before 1994): 229° Non VVTi (after 1994): 229° VVTi (after 1997): 229° |
|
| Valve head diameter: | INTAKE |
Before 1997: 33.5 mm (1.3189 in) After 1997: 34.5 mm (1.3583 in) |
| EXHAUST |
Before 1997: 28.0 mm (1.1024 in) After 1997: 29.0 mm (1.1417 in) |
|
| Valve stem diameter: | INTAKE |
Before 1997: 5.970-5.985 mm (0.2350-0.2356 in) After 1997: 5.470-5.485 mm (0.2154-0.2159 in) |
| EXHAUST |
Before 1997: 5.965-5.980 mm (0.2348-0.2354 in) After 1997: 5.465-5.480 mm (0.2152-0.2157 in) |
|
Head tightening procedure and torque specs:
- Step 1: 39 Nm; 4.0 kg·m; 29 ft·lb
- Step 2: Turn all bolts 90°
Maintenance data
| Valve clearance (Cold) | |
| Intake valve | 0.15-0.25 mm (0.006-0.010 in) |
| Exhaust valve | 0.25-0.35 mm (0.010-0.014 in) |
| Compression pressure | |
| Standard | 12.5 kg/m2 / 300 rpm |
| Minimun | 10.0 kg/m2 / 300 rpm |
| Compression differential limit between cylinders | 1.0 kg/m2 / 300 rpm |
| Oil system | |
| Oil consumption , L/1000 km (qt. per miles) | up to 0.5 (1 qt. per 1200 miles) |
| Recommended engine oil | 5W-30 |
| Oil type API | SH |
| Engine oil capacity (Refill capacity) |
Dru fill: 6.0 L (6.3 US qts, 5.3 Imp.qts) With filter change 4.8 L (5.1 US qts, 4.2 Imp.qts) Without filter change 4.5 L (4.8 US qts, 4.0 Imp.qts) |
| Oil change interval, km (miles) | 10,000 (6,000) |
| Oil Pressure |
Idle speed: 29 kPa (0.3 kgf/cm 2 , 4.3 psi) or more 3,000 rpm: 294 – 588 kPa (3.0 – 6.0 kgf/cm 2 , 43 – 85 psi) |
| Ignition system | |
| Spark plug | NGK: BKR6EP-11 DENSO: SK20R11 |
| Spark plug gap | 1.1 mm (0.0433 in) |
| Spark plug tightening torque | 18 Nm (1.8 kg⋅m, 13 ft⋅lb) |
Vehicle applications
| Model | Years Produced |
| Toyota Celsior | 1989–2000 |
| Toyota Crown | 1989–2002 |
| Toyota Crown Majesta | 1989–2002 |
| Toyota HiAce HiMedic Ambulance | 1989–2004 |
| Toyota Soarer | 1991–2000 |
| Toyota Aristo | 1992–2000 |
| Lexus LS 400 | 1989–2000 |
| Lexus SC 400 | 1991–2000 |
| Lexus GS 400 | 1992–2000 |
Author:
Do you have a torque curve for the 1UZ-FE engine ?
What is the standard height of the 1uz non vvti cylinder head. Many thanks.