The Japanese Nissan SD33T diesel engine is certainly outdated. Its production began back in 1976, ending in the late 80s. With a cylinder volume of 3.2 liters, its weight reaches 350 kg with a power of only 82 “horses”, but the reliability is phenomenal. The maximum simple design provides a cast-iron block, one camshaft with drive through gears, pre-chamber fuel injection and a huge-sized fuel injector. In the presence of a turbine, the engine output increases to 105 hp.
The engine can be found on Nissan Patrol MQ SUVs and Nissan C80 commercial trucks. In the United States, the engine was used for Jeep CJ-10 pickup trucks and International Scout, but these cars will not be found on Russian roads.
Technical characteristics
| Characteristics | SD33T atmospheric | SD33T turbo |
|---|---|---|
| Engine displacement, cc | 3246 | 3246 |
| Maximum power, hp | 110 | 110 – 120 |
| Maximum torque, Nm (kgm) at rpm | 255 (26) / 2000 | 255 (26) / 2000 263 (27) / 2000 265 (27) / 2000 |
| Fuel used | Diesel fuel | Diesel fuel |
| Fuel consumption, l/100 km | 13.5 | 12.5 |
| Engine type | Arow, 6-cylinder | Arow, 6-cylinder |
| Maximum power, hp (kW) at rpm | 110 (81) / 4000 | 110 (81) / 4000 115 (85) / 4000 120 (88) / 4000 |
| Compression ratio | 21.6 | 21.6 |
| Cylinder diameter, mm | 83 | 83 |
| Piston stroke, mm | 100 | 100 |
| Supercharger | No | Turbine |
| Valve drive | OHV | SOHC |
| Number of valves per cylinder | 2 | 2 |
Reliability of the power unit
Fans of old Patrols speak very warmly about the Nissan engine, noting its phenomenal survivability and unpretentiousness. Despite its size, it is not difficult to repair the engine or perform its maintenance.
Of course, each of the motors is already over 30 years old, so periodic problems with them arise, up to jamming, as in the copy in question, released as early as 1985 (37 years ago). In recent years, it is not easy to get spare parts for such an engine, and owners of off-road vehicles simply “killed” their cars in the harshest possible operating conditions, not wanting to invest in normal maintenance. Breakdowns in such a situation simply cannot be avoided.
Pressure sensor
This element over time fails, and in some cases there is a banal break in the wire. The malfunction is signaled by the control lamp of the oil level on the dashboard. Unfortunately, it is very difficult to find such a sensor on sale.
TNVD
The in-line pump was originally created by Bosch, but the official manufacturer is Diesel Kiki. The fuel injector demonstrates excellent reliability, is able to work even with low-quality fuel, in fact, only the presence of water in the fuel can become a problem.
The pump is six-plunger, each of which works with its own motor cylinder. Control is mechanical (on some versions vacuum). The presence of an all-mode regulator allows you to provide fuel supply in accordance with the cycles of the piston group. Technical problems with the fuel injector mainly concern the natural wear of the plungers, which will need to be replaced and a new adjustment.
Fuel injectors
The fuel system provides for the presence of nozzles in the cylinder head, into which fuel is injected through injectors at low pressure (from 105 bar). Over time, the atomizers simply wear out physically. The quality of the fuel mixture deteriorates, incomplete combustion with a lot of soot occurs. It is necessary to check the injectors when black smoke appears. Another cause of incomplete combustion of fuel may be insufficient air supply to the chambers.
CGB
The cylinder-head with cast-iron housing and a single camshaft is very reliable. At the same time, the huge size of the head must be recognized as a disadvantage, at significant engine overheating it is the cylinder head that suffers first of all, cracking between the valves or along the location of nozzle seats. In a number of cases after dismantling the head simply disintegrates into several fragments.
The absence of hydrocompensators provides the need to manually adjust thermal clearances, it is not difficult to do this, having only a screwdriver with a wrench. Recommended by the manufacturer clearances are 0,35mm.
The cylinder-head gasket
Any gasket is not eternal, so over the years it can break, after which oil will get into the cooling or vice versa, but such cases are typical only for cars with significant mileage.
Cylinder block
If necessary, cylinder liners are pressed out to replace with new ones. You can buy them at a price of about 190 dollars, but you can buy quite decent analogs for 60-70 dollars. The shoulder on the upper edge of the liner allow you to reliably press it against the cylinder head. Gradually wear out and piston rings, and the most noticeable sign of this phenomenon is the appearance of significant oil burn.
Pistons
Pistons in the engine are made of light alloys. There were two versions of pistons on Nissan SD33T engines. The so-called “cargo” versions of the engine had pistons of greater mass, for each of which there were five rings, three of which are responsible for compression, and two are oil-lifting. The engineers managed to place so many rings due to the considerable length of the piston skirt. In all cases, the diameter of the pistons is 83mm.
On versions of the engine of recent years, used for Nissan Patrol SUVs, the number of piston rings is reduced to three.