Nissan NA20S

Nissan NA20SThe Nissan NA20S is a carbureted 2.0 liter (1,998 cc, 121.9 cu·in) straight-four, four-stroke cycle gasoline from Nissan NA-family. The Z20 engine was manufacturing from 1989 through 1999. It replaced the Nissan Z series engines.

The Nissan NA20S engine features an aluminum block and aluminum alloy cylinder head with two valves per cylinder with a single overhead camshaft. An 86.0 mm (3.39 in) cylinder bore and 86.0 mm (3.39 in) piston stroke give the NA20S engine a total of 1,998 cc of displacement. Compression ratio rating is 8.7:1.

The Nissan NA20S engine produced 100 PS (74 kW; 99 HP) at 5,000 rpm of maximum horsepower and 167 N·m (17 kg·m, 123.1 ft·lb) at 3,000 rpm of peak torque.

The breakdown of the engine code is as follows:

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

General information

Engine Specifications
Engine codeNA20S
LayoutFour stroke, Inline-4 (Straight-4)
Fuel typeGasoline
Displacement2.0 L, 1,998 cc (121.9 cu in)
Fuel systemCarburetor
Power adderNone
Max. horsepower100 PS (74 kW; 99 HP) at 5,000 rpm
Max. torque167 N·m (17 kg·m, 123.1 ft·lb) at 3,000 rpm
Firing order1-3-4-2
Dimensions (L x H x W):

Cylinder block

The NA20S engine has an aluminum cylinder block, bore is 86.0 mm (3.39 in) and stroke is 86.0 mm (3.39 in). Compression ratio rating is 8.7:1. 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 alloyAluminum
Compression ratio:8.7:1
Cylinder bore:86.0 mm (3.39 in)
Piston stroke:86.0 mm (3.39 in)
Number of piston rings (compression / oil):2 / 1
Number of main bearings:5
Cylinder inner diameter (standard):86.000-86.010 mm (3.3858-3.3862 in)
Piston skirt diameter (standard):85.965-85.975 mm (3.3844-3.3848 in)
Piston pin outer diameter:20.993-20.998 mm (0.8265-0.8267 in)
Connecting rod big end diameter (standard):53.000-53.013 mm (2.0866-2.0871 in)
Connecting rod center distance:147.95-148.05 mm (5.8248-5.8287 in)
Piston ring side clearance:Top0.040-0.075 mm (0.0016-0.003 in)
Second0.030-0.063 mm (0.0012-0.0025 in)
Piston ring end gap:Top0.240-0.430 mm (0.0094-0.0169 in)
Second0.420-0.660 mm (0.0165-0.026 in)
Oil0.200-0.690 mm (0.0079-0.0272 in)
Crankshaft journal diameter:54.942-54.955 mm (2.1631-2.1636 in)
Crankpin diameter:49.961-49.974 mm (1.967-1.9675 in)
Crankshaft center distance:43.0 mm (1.695 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
Cylinder head alloyAluminum
Valve Arrangement:SOHC, chain drive
Valves:8 (2 valves per cylinder)
Head height:98.8-99.0 mm (3.8898-3.8976 in)
Intake/Exhaust duration: Without hydraulic lifters: 232°/240°
With hydraulic lifters: 240°/248°
Valve head diameter:INTAKE38.0-38.2 mm (1.4961-1.5039 in)
EXHAUST34.0-34.2 mm (1.3386-1.3465 in)
Valve length:INTAKE121.72-122.32 mm (4.7921-4.8157 in)
EXHAUST123.30-123.80 mm (4.8543-4.874 in)
Valve stem diameter:INTAKE7.965-7.980 mm (0.3136-0.3142 in)
EXHAUST7.945-7.960 mm (0.3128-0.3134 in)
Cam height:INTAKE/EXHAUST With hydraulic lifters: 44.310-44.500 mm (1.7445-1.752 in)
Without hydraulic lifters:44.572-44.762 mm (1.7548-1.7623 in)
Outer camshaft journal diameter:32.935-32.955 mm (1.2967-1.2974 in)

Maintenance data

Valve clearance (HOT)
Intake valve0.30 mm (0.012 in)
Exhaust valve0.30 mm (0.012 in)
Valve clearance (COLD)
Intake valve0.21 mm (0.0083 in)
Exhaust valve0.23 mm (0.0091 in)
Compression pressure
Standard12.0 kg/cm2 (11.77 bar, 171 psi) / 350 rpm
Minimun10.0 kg/cm2 (9.91 bar, 144 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 SAE 10W-30,5W-30
Oil type APISE, SF or SG
Engine oil capacity (Refill capacity) With filter change 3.8 l
Without filter change 3.5 l
Oil change interval, km (miles)5,000-10,000 (3,000-6,000)
Ignition system
Spark plugNGK: BPR5ES
Spark plug gap0.8-0.9 mm (0.03 -0.035 in)
Spark plug tightening torque25 N·m (2.5 kg·m, 18.4 ft·lb)

Vehicle applications

ModelYears Produced
Datsun Truck D211989-1999
Nissan Atlas (F22, F23)1990–1999
Nissan Atlas H401990–1999
Nissan Homy1990–1999
Nissan Caravan E241990–1999
Author: Sergei Wers
About: Co-founder and CEO of a multi-brand auto repair shop (engine repair, chassis repair, body repair and painting) for over 15 years. I have been developing internet sites with technical specifications for more than seven years.

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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.


  1. My pick up engine power has gone down. It can not drive on ahilly place. It is NA engine. Sahara petrol engine. Assist

  2. My NA20 is consuming a lot of fuel (13l/100km). What could be the problem? It has a carburetor

  3. I think you need to change the following, spark plugs , air filter and clean your distributor cap you may use a water paper to clean all the whitish accumulated in the carbon nodes in the cap . Your car performance will definitely change for the better ever , try this , thànk you

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