The SR20DE engine is one of the most famous power units used in Nissan cars. It was first used back in 1989. This equipment was released as a replacement for the CA20 cast-iron engine, which was already obsolete by that time.
general description
At that time, the new SR20DE engine used an aluminum cylinder block and also used dry cast iron liners. The height of this block was 211.25 mm. As for the overall dimensions, this device is square type with dimensions 86 x 86 mm, the length of the connecting rods of the power unit is 136 mm, the height of the pistons is 32 mm. The cylinder head for this type of cylinder is twin-shaft with 4 valves per cylinder. The SR20DE engine has a multi-point injection system. Here it can be noted that in parallel with this type of motor the SR20Di was also produced, however its popularity turned out to be much less. He differed from his famous fellow in that the injection system was single-point with redesigned channels. This affected the power, as devices with single injection differed only 115 liters. from. and 6000 rpm. The SR20DE engine of the first modification was already rated at 140 liters. from. and 6400 rpm. Since it is the DE modification that has become the most common, it is worth considering in more detail.
The first model of the unit
The first engine of this class was distinguished by the fact that it had a red valve cover, which is why it was called the SR20DE Red top High port. As for the data of this model, it had inlet valves, an exhaust system with a 45 mm diameter pipe, camshafts with indicators such as 248/240, a lift of 10.0 / 9.2 mm. All these data have led to the fact that this modification of the power unit could reach 7500 rpm.
The next version was only released in 1994 and was an improved version of Redtop. In this case, the same cover turned black, and therefore in the name they changed Red to Black. As for the changes in the technical characteristics of the SR20, the second modification has become more environmentally friendly. She also had redesigned cylinder head intake valves, camshafts were 240/240 with 9.2 / 9.2 mm lifts, and the exhaust pipe diameter was reduced to 38 mm.
We can add that in 1995 the engine was released, which had a new camshaft with slightly lower parameters, due to which the number of revolutions in it fell to 7100 per minute.
Latest SR20DE Models
For example, the SR20 engine on the Nissan Serena or on other brands of the same company was slightly changed one more time. Recent changes occurred to him in 2000. Then the equipment called Roller rocker was released. Here we used roller rockers and camshafts with indicators 232/240 and rises of 10.0 / 9.2 mm. Here, springs and valves were slightly shortened (by 3 mm). Small changes were made to the pistons, a lightweight crankshaft was used, as well as a shortened version of the intake manifold. With these characteristics, the SR20DE Roller Rocker engine was produced for only 2 years, and in 2002 the company completely stopped the production of this equipment.
Other modifications
It is worth mentioning that in 1989 not only the atmospheric version of this type of engine was released, but also another modification of it, which was called SR20DET, its difference is that it used turbocharging.
The engines for the Nissan Liberty SR20 and SR20DET were similar in that the manufacturers supplied both versions with the same red cover, and the year of their start and end coincided. As for the differences, the SR20DET was additionally equipped with the same type of turbocharger as the Garret T25G. The working pressure of this element is 0.5 bar. Naturally, this change became significant and could not but affect the technical characteristics and design. Reinforced type connecting rods were used here, 370 cc / min nozzles were installed, as for camshafts, models 240/240 were mounted here with their corresponding lifts. Another design difference was the introduction of a throttle with dimensions of 60 mm. By technical characteristics, the SR20DET engine also in some cases greatly exceeded its fellow. In particular, the capacity increased to 205 liters. sec., but the number of revolutions was 6000 per minute. Torque was 274 Nm while maintaining 4,000 rpm.
Improved version of SR20DET
It is worth noting that from 1990 to 1994 an improved version of the Redtop was produced with a turbocharger. If on a conventional engine the compression ratio was reduced to 8.5, then here it was reduced by another 0.2 from this value. The turbine itself was also replaced by the T28, due to which the working pressure increased to 0.72 bar. There were also more powerful 248/248 camshafts with lifts of 10.0 mm. The nozzles were replaced from 370 to 440, and cylinder head bolts were also strengthened, and several other various minor improvements were made. All these changes led to the fact that the capacity increased to 230 liters. sec., the number of revolutions per minute increased by another 400, and the torque became equal to 280 Nm while maintaining 4,800 revolutions.
In the end, we can add that the improved version was used on only one type of machine - this is the Nissan GTi-R, which was specially prepared for participation in the WRC.
General Features of the entire SR20 Series
It is worth noting here that high quality makes itself felt, the reliability and durability of these motors are proven and are at a very high level. As for any significant shortcomings, they are actually absent. But there are small problems. These include floating idle. Usually this is due to the fact that the idle speed regulator is broken or poor-quality fuel is flooded. With an enviable periodicity, such an element as the DMRV can fail.
In general, for example, the timing chain resource is very high and amounts to more than 250 thousand km. SR20 engine specifications are acceptable even now. If you fill in high-quality oil, periodically carry out maintenance of the engine of the SR model, then it can drive over 400 thousand kilometers without any breakdowns.
Opportunity for improvement
Since the engine itself can last quite a while, it can still be adequately operated on older Nissan models. For this reason, it would be prudent to work on improving it.
As for the atmospheric type SR20DE, you need to start with the cylinder head. You need to decide whether to take Low or High Port. Here it is necessary to be guided by the following principle. If porting of the head is not carried out, it is better to take the Low Port. If such an operation is nevertheless carried out, then the High Port will be clearly preferable, since its potential is much greater.
To increase the power of this type of engine, you can start with the simplest. You will need to buy JWT S3 camshafts, as well as a cold intake system, direct exhaust pipe with a 4-1 collector. Since the option is considered to be a budget one, it will certainly give an increase, but it will be quite insignificant. To significantly increase the increase in power for such a power unit, it will be necessary to reduce the degree of compression. For this, the installation of light pistons, which can be taken from a model such as the SR20VE, is excellent. Installing these parts will help increase the compression ratio to 11.7.
Design features of the entire line, reviews
It is worth noting that replacing the right SR20 engine mount (or left) is a fairly simple task, since you can not completely remove the entire engine from the car. In general, several common features can be distinguished:
- all cylinders are made of cast iron and "dry" liners inside the block of aluminum;
- all inlet and exhaust manifold manifolds are made of steel;
- gas distribution scheme DOCH has two upper camshafts that control 16 valves;
- almost every version of this engine is boosted by the addition of a turbocharger.
Reviews about the SR20 engine, or rather about the entire line as a whole, are quite positive. Many noted that the quality of all parts and the entire power unit as a whole is very decent. If you monitor his condition and conduct timely inspection or any minor work, then he is able to serve for a long time. This is also confirmed by the fact that, for example, the last SR20DE was released in 2002, and to this day it is working properly in some models of cars. Therefore, the SR20 engine is the most popular among existing today.