Nissan Z20S

Nissan Z20S engineThe Nissan Z20 or Z20S is a carbureted 2.0 liter (1952 cc) straight-four, four-stroke cycle gasoline from Nissan Z-family. The Z20 engine was manufactured from 1979 through 1984. It replaced the Nissan L20B while using many of the same components.

The Nissan Z20S engine features a cast-iron block and aluminum alloy cylinder head with two ignition plugs per cylinder, but for some commercial vehicles, a single-spark plug head was used. It has a single overhead camshaft and 8 valves (2 per cylinder).

It has an 85 mm (3.34 in) cylinder bore and 86 mm (3.38 in) piston stroke with a compression ratio of 8.5:1 or 9.3:1. It produced from 86 HP (87 PS, 86 kW) up to 108 HP (110 PS, 88 kW) of horsepower at 5,200 rpm and 161 Nm (120 ft-lb) of torque.

The breakdown of the engine code is as follows:

  • Z – Engine Family
  • 20 – 2.0 Liter Displacement
  • S – carburetor

General information

Engine Specifications
Engine code Z20S
Layout Four stroke, Inline-4 (Straight-4)
Fuel type Gasoline
Production 1979-1984
Displacement 2.0 L, 1,952 cc (121.92 cu in)
Fuel system Carburetor
Power adder None
Max. horsepower 108 HP (110 PS, 88 kW) at 5,200 rpm
Max. torque 161 Nm (120 ft-lb) at 3,200 rpm
Firing order 1-3-4-2
Dimensions (L x H x W):
Weight

Cylinder block

The Z20S engine has a cast-iron cylinder block, bore is 85 mm (3.34 in) and stroke is 86 mm (3.38 in). The cylinder block, a monoblock specially cast structure, employs the five bearing support system. The pistons are each fitted with two compression rings and a single oil ring.

Cylinder block
Cylinder block alloy Cast iron
Compression ratio: 8.5:1 or 9.3:1
Cylinder bore: 85 mm (3.34 in)
Piston stroke: 86 mm (3.38 in)
Number of piston rings (compression / oil): 2 / 1
Number of main bearings: 5
Cylinder inner diameter (standard): 85.000-85.050 mm (3.3465-3.3484 in)
Piston skirt diameter (standard): 84.985-85.035 mm (3.3459-3.3478 in)
Piston pin outer diameter: 20.993-20.998 mm (0.8265-0.8267 in)
Piston ring side clearance: Top 0.040-0.073 mm (0.0016-0.0029 in)
Second 0.030-0.063 mm (0.0012-0.0025 in)
Oil
Piston ring end gap: Top 0.25-0.40 mm (0.0098-0.0157 in)
Second 0.15-0.30 mm (0.0059-0.0118 in)
Oil 0.30-0.90 mm (0.012-0.035 in)
Crankshaft journal diameter: 54.942-54.955 mm (2.1631-2.1336 in)
Crankpin diameter: 49.961-49.974 mm (1.9670-1.9675 in)
Crankshaft center distance: 42.97-43.03 mm (1.6917-1.6941 in)

Cylinder head

The cylinder head is made of a light, strong aluminum alloy with good cooling efficiency. Intake valves are 42 mm in diameter and the exhaust valves are 38 mm.

Cylinder head
Valve Arrangement: SOHC, chain drive
Valves: 8 (2 valves per cylinder)
Intake/Exhaust duration: 248°/248°
Valve head diameter: INTAKE 42.0-42.2 mm (1.654-1.661 in)
EXHAUST 38.0-38.2 mm (1.496-1.4504 in)
Valve length: INTAKE 122.8-123.1 mm (4.835-4.846 in) – Datsun 510
124.1-124.4 mm (4.885-4.898 in) – Nissan 720
EXHAUST 123.6-123.9 mm (4.866-4.878 in) – Datsun 510
125.1-125.4 mm (4.925-4.937 in) – Nissan 720
Valve stem diameter: INTAKE 7.965-7.980 mm (0.3136-0.3142 in)
EXHAUST 7.945-7.960 mm (0.3128-0.3134 in)
Cam height: INTAKE/EXHAUST 38.477-38.527 mm (1.5148-1.5168 in) – Datsun 510
38.481-38.531 mm (1.5150-1.5170 in) – Nissan 720
Outer camshaft journal diameter: 32.935-32.955 mm (1.2967-1.2974 in)

Tightening torque specs

Tightening torque specs
Front cover bolt M8: 10-16 Nm; 1.0-1.6 kg·m; 7-12 ft·lb
M6: 3.9-9.8 Nm; 0.4-1.0 kg·m; 2.9-7.2 ft·lb
Chain guide bolt 5.9-9.8 Nm; 0.6-1.0 kg·m; 4.3-7.2 ft·lb
Chain tensioner bolt 5.9-9.8 Nm; 0.6-1.0 kg·m; 4.3-7.2 ft·lb
Water pump bolt M8: 10-16 Nm; 1.0-1.6 kg·m; 7-12 ft·lb
M6: 3.9-9.8 Nm; 0.4-1.0 kg·m; 2.9-7.2 ft·lb
Crank pulley bolt 118-157 Nm; 12-16 kg·m; 87-116 ft·lb
Water inlet bolt 10-16 Nm; 1.0-1.6 kg·m; 7-12 ft·lb
Water outlet bolt 10-16 Nm; 1.0-1.6 kg·m; 7-12 ft·lb
Intake manifold bolt and nut 16-21 Nm; 1.6-2.1 kg·m; 12-15 ft·lb
Alternator bracket bolt 39-59 Nm; 4.0-6.0 kg·m; 29-43 ft·lb
Alternator to adjusting bar bolt 20-29 Nm; 2.0-3.0 kg·m; 14-22 ft·lb
Engine mounting bracket bolt 29-39 Nm; 3.0-4.0 kg·m; 22-29 ft·lb
Exhaus manifold bolt and nut 16-21 Nm; 1.6-2.1 kg·m; 12-15 ft·lb
EGR tube nut 34-44 Nm; 3.5-4.5 kg·m; 25-33 ft·lb
EAI tube nut 34-44 Nm; 3.5-4.5 kg·m; 25-33 ft·lb
Cylinder head bolt 69-78 Nm; 7.0-8.0 kg·m; 51-58 ft·lb
Cylinder head to front cover bolt 3.9-7.5 Nm; 0.4-0.7 kg·m; 2.9-5.8 ft·lb
Rocker shaft bracket bolt 15-25 Nm; 1.5-2.5 kg·m; 11-18 ft·lb
Camshaft sprocket bolt 118-157 Nm; 12-16 kg·m; 87-116 ft·lb
Rocker arm nut 16-22 Nm; 1.6-2.2 kg·m; 12-16 ft·lb
Main bearing cap bolt 44-54 Nm; 4.5-5.5 kg·m; 33-40 ft·lb
Connecting rod big end nut 44-54 Nm; 4.5-5.5 kg·m; 33-40 ft·lb
Gusset to cylinder block 43-58 Nm; 4.4-5.9 kg·m; 32-43 ft·lb
Flywheel bolt (M/T) 137-157 Nm; 14-16 kg·m; 101-116 ft·lb
Drive plate bolt (A/T) 137-157 Nm; 14-16 kg·m; 101-116 ft·lb
Clutch cover bolt (M/T) 16-21 Nm; 1.6-2.1 kg·m; 12-15 ft·lb
Torque coverter bolt (A/T) 39-49 Nm; 4.0-5.0 kg·m; 29-36 ft·lb
Starter motor bolt 29-39 Nm; 3.0-4.0 kg·m; 22-29 ft·lb
Transmission to cylinder block bolt 43-58 Nm; 4.4-5.9 kg·m; 32-43 ft·lb
Transmission to gusset bolt 43-58 Nm; 4.4-5.9 kg·m; 32-43 ft·lb

Maintenance data

Valve clearance (HOT)
Intake valve 0.30 mm (0.012 in)
Exhaust valve 0.30 mm (0.012 in)
Compression pressure
Standard 12.0 kg/cm2 (11.77 bar, 171 psi) / 350 rpm
Minimun 9.0 kg/cm2 (8.83 bar, 128 psi) / 250 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
5W-40
10W-30
10W-40
Oil type API SE
Engine oil capacity (Refill capacity) With filter change 4.4 l
Without filter change 3.9 l
Oil change interval, km (miles) 5,000-10,000 (3,000-6,000)
Ignition system
Ignition timing (B.T.D.C./rpm) 6-12°/600 rpm (depends on the country and vehicle model)
Spark plug Cold: BP7ES, BPR7ES
Standard: BP6ES, BPR6ES
Hot: BP5ES, BPR5ES
Spark plug gap 0.8-0.9 mm (0.03 -0.035 in)
Spark plug tightening torque 15-20 Nm; 1.5-2.0 kg·m; 11-14 ft·lb

Vehicle applications

Model Years Produced
Datsun 510 1979-1981
Datsun 720 1981
Nissan Cabstar
Nissan / Datsun Caravan, Urvan, Hony (E23) 1980-1986
Nissan Laurel C230 1979-1980
Nissan Laurel C31 1980-1984
Datsun D21
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We try to use verified sources and official documentation, however, differences between sources or errors in entering information may occur. We do not provide advice on technical issues related to the engines operation or repair. We do not recommend using provided information for engines repairing engines or spare parts ordering, use only official service manuals and spare-parts catalogs.

12 Comments

  1. Wooow. A great site. I commend you. I need a part number for carburetor. z20 1986 Atlas 150. Many thanks in advance.
    Ash.

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