NIssan P40

NIssan P40The Nissan P40 is a 4.0 liter (3956 cc) straight-six, four-stroke cycle gasoline engine manufactured by Nissan Diesel Motor Co., Ltd. from 1959.

The Nissan P40 engine has a cast-iron block, overhead valves, featuring bathtub-shaped combustion chambers, a fully balanced seven-bearing crankshaft, and a two-barrel carburetor.

The P40 engine in the Nissan Patrol 160 (MQ\MK) was different from the P40 that was used in the Nissan Patrol G60. The bore and stroke are the same so therefore the pistons and rods are the same. The cylinder heads are also the same, but the intake manifold is different.

Cylinder bore and piston stroke are 85.7 mm (3.374 in) and 114.3 mm (4.500 in), respectively. The compression ratio is 7.6:1. It produced form 114 HP (116 PS, 85 kW) at 3,400 rpm up to 143 HP (145 PS, 107 kW) at 3,400 and from 270 N·m (200 lb·ft) to 318 N·m (235 lb·ft) at 2000 rpm of torque.

The breakdown of the engine code is as follows:

  • P – Engine Family
  • 40 – 4.0 Liter Displacement

General information

Engine Specifications
Engine code P / P40
Layout Four stroke, Inline-6 (Straight-6)
Fuel type Gasoline
Production
Displacement 4.0 L, 3,956 cc (241.40 cu in)
Fuel system Carburetor
Power adder None
Max. horsepower 143 HP (145 PS, 107 kW) at 3,400 rpm
Torque output 318 N·m (235 lb·ft) at 2000 rpm
Firing order 1-5-3-6-2-4
Dimensions (L x H x W): 904 x 671 x 937 mm
Weight 650 lbs (295 kg)

Cylinder block

The P40 engine has a cast-iron cylinder block, bore is 85.7 mm (3.374 in) and stroke is 114.3 mm (4.500 in). The pistons are each fitted with two compression rings and a single oil ring. The crankshaft of the P40 engine is fully balanced and supported by seven main bearings.

Cylinder block
Cylinder block alloy Cast iron
Compression ratio: 7.6:1
Cylinder bore: 85.7 mm (3.374 in)
Piston stroke: 114.3 mm (4.500 in)
Number of piston rings (compression / oil): 2 / 1
Number of main bearings: 7
Cylinder inner diameter (standard): 85.690-85.740 mm (3.3736-3.3756 in)
Piston skirt diameter (standard): 85.650-85.699 mm (3.3720-3.3740 in)
Piston pin outer diameter: 20.648-20.653 mm (0.8129-0.8131 in)
Piston ring side clearance: Top 0.031-0.078 mm (0.0012-0.0031 in)
Second 0.031-0.078 mm (0.0012-0.0031 in)
Oil Combined
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 0.20-0.90 mm (0.008-0.035 in)
Connecting rod center distance: 200 mm (7.87 in)
Connectin rod small end inner diameter: 20.618-20.630 mm (0.8117-0.8122 in)
Crankshaft journal diameter: 69.275-69.300 mm (2.7274-2.7283 in)
Crankpin diameter: 57.131-57.150 mm (2.2492-2.2500 in)
Crankshaft center distance: 57.150 mm (2.25 in)

Cylinder head

Intake valves are 43 mm in diameter, intake duration is 244 °, and the exhaust valves are 36.2 mm, exhaust duration is 244 °.

Cylinder head
Valve Arrangement: OHV, chain drive
Valves: 12 (2 valves per cylinder)
Intake/Exhaust duration: 244° / 244°
Valve head diameter: INTAKE 43.0 mm (1.693 in)
EXHAUST 36.2 mm (1.425 in)
Valve length: INTAKE 130.05-130.35 mm (5.1201-5.1319 in)
EXHAUST 131.35-131.65 mm (5.1712-5.1831 in)
Valve stem diameter: INTAKE 8.637-8.650 mm (0.3400-0.3406 in)
EXHAUST 8.627-8.640 mm (0.3396-0.3402 in)
Cam height: INTAKE 41.246 mm (1.6239 in)
EXHAUST 41.246 mm (1.6239 in)
Outer camshaft journal diameter: №1 49.124-49.149 mm (1.9340-1.9350 in)
№2 48.920-48.925 mm (1.9260-1.9270 in)
№3 48.161-48.641 mm (1.9140-1.9150 in)
№4 48.311-48.336 mm (1.9020-1.9030 in)
Rocker shaft outer daimetr 19.975-20.000 mm (0.7864-0.7874 in)
Rocker arm bushing bore daimetr 20.020-20.033 mm (0.7882-0.7887 in)

Maintenance data

Valve clearance (HOT)
Intake valve 0.38 mm (0.015 in)
Exhaust valve 0.38 mm (0.015 in)
Compression pressure
Standard 11.5 kg/cm2 (11.28 bar, 164 psi) / 250 rpm
Minimun 10.5 kg/cm2 (10.30 bar, 149 psi) / 250 rpm
Compression differential limit between cylinders 1 kg/cm2 (0.98 bar, 14 psi) / 350 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 5.7 l
Without filter change 5.1 l
Oil change interval, km (miles) 5,000-10,000 (3,000-6,000)
Ignition system
Ignition timing (B.T.D.C./rpm) 10°/550 rpm – Except Europe and Hong Kong
5°/650 rpm – For Europe and Hong Kong
10°/500 rpm – For Australia
Spark plug Cold: BP7ES, L44PW, BPR7ES
Standard: BP6ES, L45PW, BPR6ES
Hot: BP5ES, BP4ES, L46PW, L47PW, BPR5ES, BPR4ES
Spark plug gap 0.8-0.9 mm (0.03 -0.035 in)
Distributor
Point gap 0.45-0.55 mm (0.018-0.022 in)
Dwell angle 35°-40°

Tightening torque specs

Tightening torque specs
Main bearing cap bolt 98-118 Nm; 10-12 kg·m; 72-87 ft·lb
Connecting rod big end nut 44-59 Nm; 4.5-6.0 kg·m; 33-43 ft·lb
Water pump bolt (M10) 20-25 Nm; 2.0-2.5 kg·m; 14-18 ft·lb
Flywheel bolt 78-98 Nm; 8.0-10.0 kg·m; 58-72 ft·lb
Front cover bolt M8: 11-21 Nm; 1.1-2.1 kg·m; 8-15 ft·lb
M10: 30-40 Nm; 3.1-4.1 kg·m; 22-30 ft·lb
Front plate bolt 30-40 Nm; 3.1-4.1 kg·m; 22-30 ft·lb
Fliwheel housing bolt 51-72 Nm; 5.3-7.4 kg·m; 39-54 ft·lb
Cylinder head bolt 68-88 Nm; 7.0-9.0 kg·m; 51-65 ft·lb
Rocker shaft bracket bolt 34-48 Nm; 3.5-4.9 kg·m; 25-35 ft·lb
Valve rocker adjusting screw 30-38 Nm; 3.0-3.8 kg·m; 22-28 ft·lb
Camshaft sprocket bolt 30-40 Nm; 3.1-4.1 kg·m; 22-30 ft·lb
Camshaft locating plate bolt 6-8 Nm; 0.6-0.8 kg·m; 4.3-5.8 ft·lb
Oil pump bolt 25-34 Nm; 2.5-3.5 kg·m; 18-25 ft·lb
Water pump nut and bolt 25-34 Nm; 2.5-3.5 kg·m; 18-25 ft·lb
Crank pulley nut 149-163 Nm; 15.2-16.3 kg·m; 110-120 ft·lb
Rocker cover bolt 18-27 Nm; 1.8-2.8 kg·m; 13-20 ft·lb
Spark plug 18-24 Nm; 1.8-2.4 kg·m; 13-17 ft·lb
Manifold bolt and nut 25-34 Nm; 2.5-3.5 kg·m; 18-25 ft·lb
Water outlet bolt 10-12 Nm; 1.0-1.2 kg·m; 7-9 ft·lb
Thermostat housing 10-12 Nm; 1.0-1.2 kg·m; 7-9 ft·lb
Distributor support bolt 10-12 Nm; 1.0-1.2 kg·m; 7-9 ft·lb
Alternator bracket 22-29 Nm; 2.2-3.0 kg·m; 16-22 ft·lb
Engine mouting bracket 37-50 Nm; 3.7-5.0 kg·m; 27-37 ft·lb
Carburetor nut 14-18 Nm; 1.4-1.8 kg·m; 10-13 ft·lb
Fuel pump nut 11-21 Nm; 1.1-2.1 kg·m; 8-15 ft·lb

Vehicle applications

Model Years Produced
Nissan Patrol 4W66 1959-1960
Nissan Carrier 4W73 1959-
Nissan 680 Truck 1959-1968
Nissan 690 Bus 1960-1968
Nissan Patrol 60 1960-1980
Nissan FR40 1963-1968
Nissan 681 Truck 1968-1969
Nissan 691 Bus 1968-1969
Nissan G780 1969-
Nissan Patrol 160 1980-1989
Nissan Patrol 260 1986-2003
Nissan Cabstar E690
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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6 Comments

  1. That is a picture of the Nissan “P” engine inside of a Nissan Patrol. The P40 has a different intake/exhaust setup

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