Engine Hyundai G4JS

Description of the G4JS engine

Used G4JS engine
The two-shaft gas distribution circuit with 16 valves operated on a belt drive. The latter could not ensure the safety of the valves; if they broke, they would bend, since the pistons do not have counterbores. Such parts break valve stems quite quickly.

The latest version 4G64 was chosen for good reason. It initially increased power, providing maximum KM. An important feature of this motor is also the presence of automatic adjustment of valve thermal clearances. The presence of hydraulic compensators eliminates the need to adjust complex mechanisms every time.

The in-line internal combustion engine design ensured compact dimensions. The engine easily fit under the hood of a car and did not take up much space. In addition, such a unit is easy to maintain and repair. For example, overhauling other engines is very difficult to do with your own hands, but on the G4JS it is easy to do.

Let's look at other installation features:

• The cylinder head is made of duralumin material;
• silumin intake manifold;
• cooling is done initially with high quality, the engine always receives a sufficient amount of coolant;
• the oil system operates according to a forced scheme;
• the ignition system uses 2 coils, each supporting two cylinders;
• Both camshafts are driven by one toothed belt.

Characteristics

Service

G4JS cylinder head

The G4JS engine requires timely maintenance and replacement of consumables and technical fluids.

1. It is recommended to update the oil every 7-8 thousand km to ensure the functionality of the complex plunger pair of hydraulic compensators.
2. Change the coolant after 25-30 thousand kilometers, no later, since the coolant on this engine quickly loses its useful properties.
3. Clean the crankcase ventilation holes every 20 thousand km.
4. Renew filters (fuel, air) every 20-30 thousand km.
5. Change the water pump and drive belts every 50 thousand kilometers.

Malfunctions

Despite the fact that the G4JS intake manifold is cast, it is short and begins to burn out after 70-80 thousand kilometers. There are other common problems with this motor.

1. The revs fluctuate at XX. As a rule, this indicates a failure of the sensor that regulates the speed. It is also possible that the damper is clogged, the temperature sensor is broken, or the injectors are clogged. Solution: replace the IAC, clean the throttle, replace the heat sensor or clean the injector.
2. Strong vibrations. They appear for several reasons. Most likely the engine mounts have worn out. The most common wear area on the G4JS is the left pad.
3. Broken timing belt. As mentioned above, this poses potential risks. The cause of the breakage on this engine is associated with pieces of broken balancers getting under the timing belt. To prevent this from happening again, you need to fill only high-quality oil, regularly check the balancers, or simply remove them. In addition, they introduce unnecessary knocking and clicking noises into the engine after a mileage of 50 thousand km.

Inserts for G4JS

Timing belt

There are two timing belts under the timing cover. The long belt drives the timing belt, and the short belt drives the rear balancer shaft. The timing belt has a hydraulic tensioner, the balancer belt has a mechanical tensioner.

These belts should be changed every 60,000 km. Practice shows that even a high-quality non-original product does not last longer. And when the timing belt breaks, the pistons and valves collide. A break in a short belt leads to the same consequences, because... in many cases it gets pulled under the timing belt.

When installing the timing belt, you must observe the marks on the crankshaft, both camshafts, as well as the marks on the oil pump pulley and on the rear balancer shaft pulley.

Modernization

G4JS is initially equipped with a tuned VK. This is already a big plus, considering also the two-shaft design, which is ideal for modernization. First of all, let's look at how standard, atmospheric tuning of this unit is carried out.

1. The VK channels are polished and their lengths are equalized.
2. The factory throttle is changed to an Evo and a cold intake is installed.
3. Viseko pistons and Egli connecting rods are installed, which increases the compression to 11-11.5.
4. All balancing shafts are removed, and more efficient ready-made or homemade alloy steel studs are installed.
5. A Galant fuel rail with high-performance 450cc injectors is installed.
6. A high-performance Walbro fuel pump is installed, pumping 255 liters of gasoline per hour.
7. The exhaust size increases to 2.5 inches, the exhaust manifold changes to the “Spider” type.

Engine tuning

Such changes will lead to an increase in engine power to 220 hp. With. True, you will still need to reinstall the ECU program.

If such indicators are not satisfactory, you will have to equip the engine with a classic turbine or compressor.

1. It would be better to use a cylinder head from Lancer Evolution rather than select separate supercharging kits. Everything is already provided on this head, including expensive components and mechanisms. There is a turbine and intercooler, an intake manifold and a fan.
2. The oil supply to the turbine will need to be improved.
3. It is also necessary to replace the original camshafts with similar ones with 272 phases.
4. There is no need to increase the compression ratio; 8.5 units is enough. You need to select pistons for these parameters.
5. A reinforced ShPG should be installed. Forged Egli has proven itself best, since conventional cast options are unlikely to cope with increased loads.
6. You'll have to install a more efficient fuel pump - the same Valbro will do.
7. You will also need injectors from Lancer Evo.

Performance COBB injectors from Lancer Evo

In this way it will be possible to increase the power of the unit to 300 horses. However, this will affect the life of the motor, which will drop sharply. Scheduled maintenance will need to be carried out as often as possible.

Engine G4JS

Applicability of G4JS engine

Description of the G4JS engine

The G4JS engine is a 2.4 liter power unit with a maximum power of 139-145 horsepower. It is noteworthy that when developing the engine, the engineers took the latest modification of the Mitsubishi 4G64 as a basis. The engine is equipped with 16 valves. The arrangement of the cylinders is in-line, making the internal combustion engine quite compact. This made it possible to install the engine even on small cars.

Advantages of an internal combustion engine The G4JS engine is considered a quite powerful unit with good torque performance. Let us note the main features and advantages of this motor: 1) The presence of hydraulic compensators that automatically adjust the thermal clearances of the valves. 2) The ignition system operates on a pair of coils. Each of them produces a spark for two cylinders. Thanks to this design, high-quality and proper operation of the engine is ensured. 3) The cylinder head is made of duralumin material. This solution made it possible to obtain a relatively light weight while maintaining the rigidity and power of the unit. 4) A very high-quality cooling system, thanks to which a sufficient amount of refrigerant always flows into the engine. Such a balanced decision made it possible to ensure that overheating of the engine is almost impossible. 5) The intake manifold is cast from silumin - a material with good reliability indicators. 6) To ensure the operability of the camshafts, one toothed belt is used. 7) Forced oil supply system.

Prospects for tuning To increase the power of the internal combustion engine, the following options are possible: tuning the control unit; 1. tuning the intake manifold; 2. installation of direct release; 3. exhaust system 4-2-1; 4. use of tuning shafts from Evolution; 5. standard damper 4G63T.

Disadvantages and problems of the G4JS engine

The G4JS engine does not have many weaknesses, but nevertheless it does exist. Let's list the most common problems with this engine: 1. Feeling of vibrations, which may be caused by worn out bearings. It must be said that in the G4JS internal combustion engine it is the left cushion that wears out most often and faster. 2, Floating speed at XX. There may be several reasons for this: the valve or injector is clogged, the temperature sensor has failed, or the sensor that regulates the speed has broken down. 3. Quite rapid wear of the timing belt. Therefore, it is necessary to promptly change and fill only high-quality oil.

Final verdict

By incorporating balancer shafts that effectively dampen vibrations and the effects of torque, the G4JS engine should be very reliable. However, this advantage is offset by constant breaks of attachment belts - parts of them fall under the timing belt, breaking it too. The consequences have already been written about - the valves bend, the piston group and cylinder head fail. For this reason, many owners get rid of excess balancers by dismantling them.

Another advantage is the presence of hydraulic compensators. Automatic adjustment allows you to save on the operating budget, because professional clearance adjustment is not cheap. In the absence of a plunger pair, adjustments would have to be made every 30 thousand kilometers, as required by the technical manual. However, not everything is so rosy here. As soon as low-grade oil is poured into the internal combustion engine or the lubricant is not replaced in a timely manner, the gaps in the plunger pair of hydraulic compensators increase or the ball valve wears out. This is a very sensitive, delicate mechanism that requires high-quality maintenance, otherwise the PP will jam and the expensive hydraulic compensator will deteriorate.

Apart from the situations described above, G4JS in general has high maintainability and good boost potential. For example, you can easily increase the size of the pistons by boring the cylinders. This will not affect the durable, cast-iron BC in any way.

Technical specifications G4JS 2.4 l/150 – 156 l. With.

Initially, the engine used a DOHC 16V gas distribution scheme. The drive is a belt, which does not ensure the safety of the valves - there are no counterbores at the ends of the pistons; they bend the valve stems when they meet them. The in-line engine design ensures compact dimensions and convenient maintenance/repair.

Intake manifold G4JS

The manufacturer Kia-Hyundai took as a basis the latest modernization of the 4G64 engine in order to initially increase power and provide maximum torque. An important feature of the power unit is the presence of hydraulic compensators that automatically adjust the thermal clearances of the valves without user intervention. The management of the Kia/Hyundai concern used this engine in their cars and vehicles of several Chinese manufacturers.

The operational technical characteristics of G4JS correspond to the following table values:

Major repairs on your own are not difficult. This does not require complex devices or special tools.