Nissan SD33T

Nissan SD33TThe Nissan SD33T is a 3.2 l (3245 cc) straight six, water-cooled turbo-charged diesel engine from SD family, manufactured by the Nissan Diesel Motor Company since 1980.

The Nissan SD33T with AiResearch T03 turbo-charger produced from 103 PS (75 kW, 101 HP) up to 110 PS (81 kW, 108 HP) at 4000 rpm of horsepower and from 237 Nm (175 ft-lb) to 255 Nm (188 ft-lb) at 2000 rpm of torque.

The turbo-charged SD33T was based on naturally aspirated SD33, but a number of modifications have been made to assure durability under the increased power output generated by turbocharging:

  • An oil jet to cool the piston has been intalled on each cylinder and three oil passages been established to connect left and right oil galleries;
  • The oil pump has been redesigned to increase oil flow from 42 liters (11 US gal) per minute to 48 liters (12.4 US gal), to accomodate the piston oil jet spray and lubrications of the turbocharger;
  • The oil pump drive spindle has been strengthened;
  • Camshaft journals have been enlanrged;
  • Crankshaft arms have been redesigned;
  • Cylinder head ports have been enlanrged;
  • A full keystone design has been adopted for the top ring of the pistons and a ring carrier has been added to the ring groove;
  • The oil cooler capacity has been increased from the three cores to five cores;
  • A larger air cleaner element has been used;

The breakdown of the engine code is as follows:

  • SD – Engine Family
  • 33 – 3.3 Liter Displacement
  • T – Turbocharged

General information

Engine Specifications
Engine code SD33T
Layout Straight-6, vertical
Fuel type Diesel
Production 1980-
Displacement 3.2L, 3245 cc (198.02 cu in)
Injection pump Diesel Kiki-Bosch (in-line)
Power adder Turbocharger AiResearch T03
Horsepower net 110 PS (81 kW, 108 HP) at 4,000 rpm
Torque output 255 Nm (188 ft-lb) at 2,000 rpm
Firing order 1-4-2-6-3-5
Dimensions (L x H x W):
Weight 305 kg (452 lb)

Cylinder block

The cylinder block has a monoblock high-strength cast-iron structure with replaceable dry liners and four-bearing-support system. The engine has a drop-forged steel crankshaft with balance weights, all main and connecting rod bearing surfaces are induction-hardened. Bearings are a precision type, steel-backed trimetal shell.

The SD33T motor has an aluminum alloy piston for high strength, lightweight and good heat conductivity; two compression and single oil control ring are chrome-plated for long service life. The cylinder bore is 83 mm, piston stroke is 100 mm and the compression ratio rating is 21.6:1.

Cylinder block
Cylinder block alloy Cast iron
Compression ratio: 21.6:1
Cylinder bore: 83 mm (3.27 in)
Piston stroke: 100 mm (3.94 in)
Number of piston rings (compression / oil): 2 / 1
Number of main bearings: 4
Block Height: 268.00 mm (10.55 in)
Cylinder liner inner diameter: 82.995-83.025 mm (3.2675-3.2687 in)
Piston skirt diameter 82.935-82.965 mm (3.2652-3.2663 in)
Piston ring side clearance: №1 0.06-0.010 mm (0.0024-0.0039 in)
№2 0.05-0.09 mm (0.0020-0.0035 in)
№3 0.02-0.06 mm (0.0008-0.0024 in)
Piston ring end gap: №1 0.30-0.45 mm (0.0118-0.0177 in)
№2 0.20-0.35 mm (0.0079-0.0138 in)
№3 0.15-0.30 mm (0.0059-0.0118 in)
Piston pin outer diameter 25.993-26.000 mm (1.0233-1.0236 in)
Piston pin bore diameter 26.025-26.038 mm (1.0246-1.0251 in)
Connecting rod center distance: 170.0 mm (6.69 in)
Crankshaft journal diameter: 70.907-70.920 mm (2.7916-2.7921 in)
Crankpin diameter: 52.913-52.926 mm (2.0832-2.0837 in)

Cylinder head

The SD33T has a one-piece high-strength cast iron cylinder head, special cast-iron valve inserts are shrink-fitted. It has high-quality cast iron camshaft, lobes are specially processed to improve hardness and durability.

The engine has OHV design with two valves per cylinder: one intake and exhaust made of special heat-resistant steel. The exhaust valve with a stellite-treated surface. Intake valves are 38.0 mm (1.496 in) in diameter, and the exhaust valves are 32.0 mm (1.260 in).

Cylinder head
Cylinder head alloy Cast iron
Valve Arrangement: OHV
Valves: 12 (2 valves per cylinder)
Intake valves diameter: 38.0 mm (1.496 in)
Exhaust valves diameter: 32.0 mm (1.260 in)
Intake valve timing: 275 °
Exhaust valve timing: 275 °
Valves length: 117.0 mm (4.61 in)
Intake valve stem diameter: 7.970-7.985 mm (0.3138-0.3144 in)
Exhaust valves stem diameter: 7.945-7.960 mm (0.3128-0.3134 in)
Camshaft journal diameter: Front:45.434-45.447 mm (1.7887-1.7892 in)
Center:43.897-43.910 mm (1.7282-1.7287 in)
Front:41.218-41.231 mm (1.6228-1.6233 in)
Cam height: 37.28-37.32 mm (1.4677-1.4693 in)

Problems and malfunctions

The SD33 family of Nissan engines are very reliable, strong, and ask for little in the way of maintenance. The engine uses industry-standard BOSCH injection system components (license-built by Diesel Kiki) and is known worldwide as a reliable, long-lived powerplant.

Maintenance data

Valve clearance (HOT)
Intake valve 0.35 mm (0.014 in)
Exhaust valve 0.35 mm (0.014 in)
Oil system
Recommended engine oil Semi Synthetic 10W-30 or 10W-40 (“CD” or higher: “CH”, “CI”)
Engine oil capacity 9 l (9.5 U.S. qt, 7.9 imp. qt)
Oil filters Nissan: 15208-61525
Baldwin: PT-153
FleetGuard: LF 720
Purolator: L44754
FRAM: CH3505
Fuel system
Idling 550-600 rpm (withuot power steering)
650-750 rpm (wiht power steering)
Max engine speed under no load 4200-4400 rpm
Glow plugs NGKY-103
Primary fuel filters – Spin-on, mounts on core support LONG STYLE
Baldwin – BF-979
FleetGuard – FF5020
WIX – 33341

Baldwin – BF-984
FleetGuard – FF196
WIX – 33339
Secondary fuel filters – Cartridge filter, mounts in canister above injector pump Nissan – 16444-99125
Baldwin – PF-861
FleetGuard – FF221

Tightening torque specs

Tightening torque specs (engine outer parts)
Water outlet bolt 10-13 Nm; 1.0-1.3 kg·m; 7-9 ft·lb
Water pump bolt (M8) 10-13 Nm; 1.0-1.3 kg·m; 7-9 ft·lb
Water pump bolt (M10) 20-25 Nm; 2.0-2.5 kg·m; 14-18 ft·lb
Manifold bolt and nut 15-18 Nm; 1.5-1.8 kg·m; 11-13 ft·lb
Injection pump nut (in-line) 20-25 Nm; 2.0-2.5 kg·m; 14-18 ft·lb
Injection nozzle to cylinder head 59-69 Nm; 6.0-7.0 kg·m; 43-51 ft·lb
Oil cooler bolt 10-13 Nm; 1.0-1.3 kg·m; 7-9 ft·lb
Oil cooler pipe nut 10-13 Nm; 1.0-1.3 kg·m; 7-9 ft·lb
Timing gear cover bolt 10-13 Nm; 1.0-1.3 kg·m; 7-9 ft·lb
Injection pump timer nut 59-69 Nm; 6.0-7.0 kg·m; 43-51 ft·lb
Injection tube flare nut 29-34 Nm; 3.0-3.5 kg·m; 22-25 ft·lb
Spill tube with cap nut 39-49 Nm; 4.0-5.0 kg·m; 29-34 ft·lb
Oil filter bracket bolt 26-36 Nm; 2.7-3.7 kg·m; 20-27 ft·lb
Alterator bracket bolt 26-36 Nm; 2.7-3.7 kg·m; 20-27 ft·lb
Alterator to adjusting bar bolt 11-14 Nm; 1.1-1.4 kg·m; 20-27 ft·lb
Diesel pump controller bolt 10-13 Nm; 1.0-1.3 kg·m; 7-9 ft·lb
Thermostat housing 10-131 Nm; 1.0-1.3 kg·m; 7-9 ft·lb
Turbocharger to exhaust manifold 29-39 Nm; 3.0-4.0 kg·m; 22-29 ft·lb
Turbocharger to connector 29-39 Nm; 3.0-4.0 kg·m; 22-29 ft·lb
Engine internal parts
Main bearing cap bolt 167-172 Nm; 17.0-17.5 kg·m; 123-127 ft·lb
Crank pulley nut 294-324 Nm; 30-33 kg·m; 217-239 ft·lb
Flywheel bolt 44-49 Nm; 4.5-5.0 kg·m; 33-36 ft·lb
Flywheel bolt w/washer 127-147 Nm; 13-15 kg·m; 94-108 ft·lb
Front cover bolt (M6) 4-6 Nm; 0.4-0.6 kg·m; 2.9-4.3 ft·lb
Front cover bolt (M8) 10-13 Nm; 1.0-1.3 kg·m; 7-9 ft·lb
Front end plate bolt 10-13 Nm; 1.0-1.3 kg·m; 7-9 ft·lb
Camshaft gear bolt 44-49 Nm; 4.5-5.0 kg·m; 33-36 ft·lb
Oil pump bolt 13-19 Nm; 1.3-1.9 kg·m; 9-14 ft·lb
Oil pan bolt 7-10 Nm; 0.7-1.0 kg·m; 5.1-7.2 ft·lb
Cylinder head bolt Sub: 44-54 Nm; 4.5-5.5 kg·m; 33-40 ft·lb
Main: 118-127 Nm; 12-13 kg·m; 87-94 ft·lb
Rocker arm shaft bolt 20-25 Nm; 2.0-2.5 kg·m; 14-18 ft·lb
Rocker arm lock nut 20-25 Nm; 2.0-2.5 kg·m; 14-18 ft·lb
Camshaft thrust plate bolt 4-6 Nm; 0.4-0.6 kg·m; 2.9-4.3 ft·lb
Connecting rod big end nut 51-56 Nm; 5.2-5.7 kg·m; 38-41 ft·lb
Rocker cover bolt 10-13 Nm; 1.0-1.3 kg·m; 7-9 ft·lb
Oil jet (for piston) 29-39 Nm; 3.0-4.0 kg·m; 22-29 ft·lb

Vehicle applications

Model Years Produced
Nissan Patrol MK 160 1983-1987
International Scout II 1980
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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  1. Suppose it is not a good idea to add a turbo to a 1980’s standard SD33; considering all the changes made by Nissan to add a turbo package in the 90’s.
    Is there another way to boost power in my CJ-10

  2. No, the cj10a motors are all upgraded the same as a turbo motor. Different injection pump,no turbo,timing different. I’ve been running a turbo setup on my tug motor for 40k mls. No problems, adjusted/turned up fuel pump and running an intercooler. Pyrometer is a must for long life.

  3. Turbo specs on the Hitachi HT18S-BM used?
    Look to me the same turbo used on Mazda Rx7 1984 12AT.

  4. My Nissan patrol SD33T has excessive oil blowback and has done 444000 km, with no loss of power easy starting, no loss of oil pressure, and runs like a dream any suggestions would be helpful and greatly appreciated

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