VQ37VHR 3.7 Engine Specs, Problems, Reliability

The 3.7-liter V6 engine Nissan VQ37VHR has been assembled at the company’s plant in Iwaki since 2007 and installed on many well-known models of the Japanese concern on the Front Midship platform. At the moment, such a engine is installed only on the Fuga sedan and 370Z coupe.

In 2007, an improved version of the famous VQ35HR sports engine was introduced, which was distinguished by the presence of a continuous variable valve timing system VVEL. In all other respects, it was a similar aluminum V6 engine with a pair of DOHC cylinder heads and a timing chain.

Due to the increase in the piston stroke from 81.4 to 86 mm, its working volume increased from 3.5 to 3.7 liters, which, coupled with an increased compression ratio from 10.6 to 11, made it possible to remove up to 355 hp from the engine.

Enormous work was done by engineers to strengthen the design of this engine, they also replaced the intake and exhaust, expanded the cylinder head channels, installed other valves and springs. But hydraulic lifters did not appear here, so valve clearances have to be adjusted.

Read Also: 6G75 Mivec / GDi 3.8 Engine Specs, Problems, Reliability

Nissan VQ37VHR Engine Specs

ProductionIwaki Plant
Engine brandVQ37
Release years2007-present
Block materialaluminum
Supply systeminjector
Type ofV-shaped
Number of cylinders6
Valves per cylinderfour
Piston stroke, mm86
Cylinder diameter, mm95.5
Compression ratio11.0
Engine volume, cc3696
Engine power, hp / rpm330/7000
333/7000

355/7000

Torque, Nm/rpm361/5200
363/5200

365/5200

Fuel95
Environmental regulationsEuro 4/5
Engine weight, kg
Fuel consumption, l / 100 km (for Q70)
 – city
 – highway
 – mixed.

15.3

8.4
10.9
Oil consumption, g/1000 km up to 500
Engine oil0W-30
0W-40

5W-30

5W-40

10W-30

10W-40

15W-40
How much oil is in the engine, l5.7
Oil change is carried out, km 15000

(preferably 7500)
Operating temperature of the engine, hail.
Engine resource, thousand km
 – according to the plant
 – in practice



400+
Tuning
 – potential
 – without loss of resource


450+

 —
The engine was installedNissan 370Z
Nissan Skyline
Infiniti QX50 (EX37)
Infiniti QX70 (FX37)
Infiniti Q50
Infiniti Q60
Infiniti G37/Q40
Infiniti Q70 (M37)/Nissan Fuga/Mitsubishi Proudia

Engine number VQ37VHR is located at the junction of the block with the box.

Nissan VQ37VHR Engine Performance summary

Here, we will investigate the characteristics of this engine by referring to the data of the VQ37VHR type naturally aspirated engine installed in Nissan’s Z34 type Fairlady Z Version-NISMO 2010/11 model.

nissan FAIRLADY Z VQ37VHR 3.7 Engine
Nissan’s Z34 type Fairlady Z Version-NISMO
Vehicle modelCBA-Z34
Car name & gradeFairlady Z
Version-NISMO
Engine modelVQ37VHR
typeV-type 6 cylinder
Displacement3696cc
Inner diameter × stroke95.5mm×86.0mm
Bore stroke ratio0.90
Single cylinder volume616.0cc
Compression ratio11.0
Intake methodNaturally aspirated
use fuelHigh octane gasoline
Maximum output355PS/7400rpm
Maximum torque38.1kgm/5200rpm

First of all, as a basic structure, the VQ37 engine is a short stroke engine with a bore (inner diameter) of 95.5 mm, a stroke (stroke) of 86.0 mm, and a bore stroke ratio of 0.90 (the piston diameter is larger than the stroke amount).

When the displacement and the number of cylinders are the same, the torque characteristics in the low rpm range are inferior to those of the long stroke type, and the engine is difficult to handle, but in the high rpm range, the filling efficiency is improved and the sliding resistance is also increased ( The output is expected to improve because it is minor (compared to the long stroke type).

Also, since the average piston speed can be suppressed even at the same rpm, the load on the engine tends to be reduced accordingly.

Among the models registered on this site, the oldest model equipped with the VQ37VHR type naturally-inspired engine is the 12th generation Skyline [CKV36 type | 2010/01] released from November 2006 , and the newest model is 2009. It is the second generation Fuga [KY51 type | 2020/01] released from 11/11 , and 17 models of NA cars and 0 models of turbo / SC cars are registered in all 17 models.

Evaluation from the viewpoint of transient characteristics and liter equivalent horsepower

Image of engine performance curve
VQ37 engine performance curve diagram
Changes in horsepower276.6PS → 355PS
Transition of torque38.1kgm → 34.4kgm
Liter horsepower96.05PS/L
Liter torque10.3kgm/L

The Fairlady Z’s V6 3696cc, compression ratio 11.0, high-octane gasoline-powered naturally aspirated engine, which is the reference vehicle for this time, produces a maximum output of 355 horsepower at 7400 rpm and a maximum torque of 38.1 kgm at 7400 rpm. ..

If you know the horsepower and the number of revolutions, you can know the torque, and if you know the torque and the number of revolutions, you can know the horsepower. The torque at 7400 rpm is 34.4kgm.

The horsepower per liter of displacement is 96.05PS / L and the torque is 10.3kgm / L, and the horsepower per cylinder (single cylinder volume 616.0cc) is 59.2PS and the torque is 6.4kgm.

When the VQ37 naturally aspirated engine is applied to a 10-step evaluation based on deviation values ​​aggregated from all NA vehicles registered on this site, the evaluation is ” rare ” with a converted horsepower of [ 10 ] and a converted torque of [ 8 ]. It is categorized as ” high power engine seen in”.

By the way, among the models equipped with the VQ37VHR turbo / SC engine, the one with the highest output was the Z34 Fairlady Z 355PS / 38.1kgm, and the smallest was the KV36 Skyline 330PS / 36.8kgm.

Displacement increase, compression ratio increase, bore stroke ratio change

Normal displacement and compression ratio
BoreStrokeDisplacementCompression ratioB/S ratio
95.586.03696cc11.00.90
Displacement expansion by bore up
96.086.03735cc11.10.90
96.53774cc11.20.89
97.03813cc11.30.89
97.53852cc11.40.88
98.03892cc11.50.88
98.53932cc11.60.87
Displacement expansion by increasing stroke
95.587.03739cc11.10.91
88.03782cc11.20.92
89.03825cc11.30.93
90.03868cc11.50.94
91.03911cc11.60.95

There are three factors that determine the engine displacement: the number of cylinders, the bore diameter, and the stroke amount. By increasing or decreasing these, engines with various displacements are created.

Here, regardless of whether it is actually possible, the displacement when the piston diameter is expanded from the genuine 95.5 mm to 98.5 mm in 0.5 mm increments and when the stroke is extended from the genuine 86.0 mm to 91.0 mm in 1 mm increments. And, the change of the compression ratio when it is assumed that the volume of the combustion chamber does not change is listed.

* It is easy to say stroke up, but if you want to make a long stroke, you need a crankshaft and a compatible connecting rod, and if you can not divert it, you have to make it in one-off, so it is expensive anyway. It is a menu that requires considerable preparedness to put out.

Regarding the compression ratio, in most cases, the uneven capacity of the top surface of the piston changes as the diameter of the piston increases, so the compression ratio values ​​in the list do not match, but the displacement. Please enjoy the atmosphere that the compression ratio will naturally increase as you increase the size.

The B / S ratio is an abbreviation for the bore stroke ratio, and as the bore diameter is widened, the value becomes even smaller from 0.90, and the advantages and disadvantages of the short stroke type become more pronounced. In the case of VQ37 type engine, the ratio changes from 0.90 to 0.87 when the bore is increased by +3.0mm from the genuine piston.

Increased displacement with engines with similar piston diameters

There are two VQ37 type engines with pistons that are similar in size to the piston diameter of 95.5mm, so as a side note, let’s calculate the displacement when the piston is diverted and the bore is raised.

Eg typePiston diameterDisplacement
Subaru
EJ22 type
96.9mm
[+1.4mm]
3805cc
[+109cc]
Subaru
EG33 type
96.9mm
[+1.4mm]
3805cc
[+109cc]

Engines with similar piston diameters include Subaru: EJ22 type 2212cc 96.9mm mounted on the BG7 type Legacy Touring Wagon, and EG33 type 3318cc 96.9mm mounted on the Subaru: CXD type Alcyone SVX.

(Although the number of people who find pleasure in such a quest has decreased) No matter how close the diameter is, there are factors such as the diameter of the piston pin, the height of the piston, and the convenience of valve recess, so if possible, the same manufacturer, If possible, if you choose the same fuel and the same intake method, and if possible, the one with a similar displacement, the possibility of genuine diversion may increase.

Average piston speed

strokeMaximum torque
5200rpm
Maximum output
7400rpm
86.0mm14.9m / s21.2m/s
Rotation speed / minuteper secondspeed
2000rpm5.7m / s21km/h
4000rpm11.5m/s41km/h
6000rpm17.2m/s62km / h
8000rpm22.9m / s82km/h
10000rpm28.7m / s103km/h

Next, let’s look at the average piston speed. The average piston speed at 7400 rpm, where an engine with a stroke of 86.0 mm produces maximum output, is 21.2 m / s , which is a piston speed that travels a distance of 21.2 meters per second (76.3 km / h at speed). It means that is moving up and down.

The average speed is 14.9 m / s at 5200 rpm, which generates the maximum torque, and 22.6 m / s when the rev limit is assumed to be 7900 rpm, which is 500 rpm higher than the 7400 rpm where the maximum output is generated.

For reference, I calculated the change in piston speed when a VQ37 engine with a stroke of 86.0 mm is rotated up to 10000 rpm. Looking at this, it seems that the speed increases by approximately 5.75 m / s as the number of revolutions increases by 2000 revolutions.

Considering only 20.0 m / s, which is a guideline for a general engine premised on mass production, I think that about 6980 rpm will be a good rpm, but this engine has the maximum output. It has already exceeded 20.0 m / s at the time of occurrence, and considering the rev limit, it will rotate a little more (300 to 500 rpm?), So it is an engine that is doing its best even though it will be difficult inside.

Mitsubishi VQ37VHR Engine Performance Summary

Here, we will investigate the characteristics of this engine by referring to the data of the VQ37VHR type naturally aspirated engine installed in Mitsubishi’s BKNY51 type Proudia 370 2012/07 model.

mitsubishi PROUDIA VQ37VHR 3.7 Engine
Mitsubishi’s BKNY51 type Proudia 370
Vehicle modelDBA-BKNY 51 type
Car name & gradeProudia
370
Engine modelVQ37VHR
typeV-type 6 cylinder
Displacement3696cc
Inner diameter x stroke95.5mm x 86.0mm
Bore stroke ratio0.90
Single cylinder volume616.0cc
Compression ratio11.0
Intake methodNaturally aspirated
Fuel usedHigh octane gasoline
Maximum output333PS / 7000rpm
Maximum torque37.0kgm / 5200rpm

First of all, as a basic structure, the VQ37 engine is a short stroke engine with a bore (inner diameter) of 95.5 mm, a stroke (stroke) of 86.0 mm, and a bore stroke ratio of 0.90 (the piston diameter is larger than the stroke amount).

When the displacement and the number of cylinders are the same, the torque characteristics in the low rpm range are inferior to those of the long stroke type, and the engine is difficult to handle, but in the high rpm range, the filling efficiency is improved and the sliding resistance is also increased ( The output is expected to improve because it is minor (compared to the long stroke type).

Also, since the average piston speed can be suppressed even at the same rpm, the load on the engine tends to be reduced accordingly.

On this site, the model equipped with the VQ37VHR type naturally aspirated engine is the second generation Proudia [BKNY51 type | 2012/07] released from 2012/07 , and there are two NA models, turbo / SC. All 2 models of 0 models are registered.

Evaluation from the viewpoint of transient characteristics and liter equivalent horsepower

Image of engine performance curve
VQ37 engine performance curve diagram
Changes in horsepower268.6PS → 333PS
Transition of torque37.0kgm → 34.1kgm
Liter horsepower90.10PS / L
Liter torque10.0kgm / L

The reference vehicle of this time, Proudia’s V6 3696cc, compression ratio 11.0, high octane gasoline specification naturally aspirated engine produces a maximum output of 333 horsepower at 7000 rpm and a maximum torque of 37.0 kgm at 7000 rpm.

If you know the horsepower and the number of revolutions, you can know the torque, and if you know the torque and the number of revolutions, you can know the horsepower. The torque at 7000 rpm is 34.1kgm.

The horsepower per liter of displacement is 90.10PS / L and the torque is 10.0kgm / L, and the horsepower per cylinder (single cylinder volume 616.0cc) is 55.5PS and the torque is 6.2kgm.

When the VQ37 naturally aspirated engine is applied to a 10-step evaluation based on the deviation value aggregated from all NA vehicles registered on this site, the evaluation is ” quite good” with a converted horsepower of [ 8 ] and a converted torque of [ 7 ]. It is categorized as ” high power engine “.

Displacement increase, compression ratio increase, bore stroke ratio change

Normal displacement and compression ratio
BoreStrokeDisplacementCompression ratioB / S ratio
95.586.03696cc11.00.90
Displacement expansion by bore up
96.086.03735cc11.10.90
96.53774cc11.20.89
97.03813cc11.30.89
97.53852cc11.40.88
98.03892cc11.50.88
98.53932cc11.60.87
Displacement expansion by increasing stroke
95.587.03739cc11.10.91
88.03782cc11.20.92
89.03825cc11.30.93
90.03868cc11.50.94
91.03911cc11.60.95

There are three factors that determine the engine displacement: the number of cylinders, the bore diameter, and the stroke amount. By increasing or decreasing these, engines with various displacements are created.

Here, regardless of whether it is actually possible, the displacement when the piston diameter is expanded from the genuine 95.5 mm to 98.5 mm in 0.5 mm increments and when the stroke is extended from the genuine 86.0 mm to 91.0 mm in 1 mm increments. And, the change of the compression ratio when it is assumed that the volume of the combustion chamber does not change is listed.

* It is easy to say stroke up, but if you want to make a long stroke, you need a crankshaft and a compatible connecting rod, and if you can not divert it, you have to make it in one-off, so it is expensive anyway. It is a menu that requires considerable preparedness to put out.

Regarding the compression ratio, in most cases, the uneven capacity of the top surface of the piston changes as the diameter of the piston increases, so the compression ratio values ​​in the list do not match, but the displacement. Please enjoy the atmosphere that the compression ratio will naturally increase as you increase the size.

The B / S ratio is an abbreviation for the bore stroke ratio, and as the bore diameter is widened, the value becomes even smaller from 0.90, and the advantages and disadvantages of the short stroke type become more pronounced. In the case of VQ37 type engine, the ratio changes from 0.90 to 0.87 when the bore is increased by +3.0mm from the genuine piston.

Increased displacement with engines with similar piston diameters

There are two VQ37 type engines with pistons that are similar in size to the piston diameter of 95.5mm, so as a side note, let’s calculate the displacement when the piston is diverted and the bore is raised.

Eg modelPiston diameterDisplacement
Subaru
EJ22 type
96.9mm
[+ 1.4mm]
3805cc
[+ 109cc]
Subaru
EG33 type
96.9mm
[+ 1.4mm]
3805cc
[+ 109cc]

Engines with similar piston diameters include Subaru: EJ22 type 2212cc 96.9mm mounted on the BG7 type Legacy Touring Wagon, and EG33 type 3318cc 96.9mm mounted on the Subaru: CXD type Alcyone SVX.

(Although the number of people who find pleasure in such a quest has decreased) No matter how close the diameter is, there are factors such as the diameter of the piston pin, the height of the piston, and the convenience of valve recess, so if possible, the same manufacturer, If possible, if you choose the same fuel and the same intake method, and if possible, the one with a similar displacement, the possibility of genuine diversion may increase.

Average piston speed

strokeMaximum torque
5200rpm
Maximum output
7000rpm
86.0mm14.9m / s20.1m / s
Rotation speed / minuteper secondSpeed
2000rpm5.7m / s21km / h
4000rpm11.5m / s41km / h
6000rpm17.2m / s62km / h
8000rpm22.9m / s82km / h
10000rpm28.7m / s103km / h

Next, let’s look at the average piston speed. The average piston speed at 7000 rpm, where an engine with a stroke of 86.0 mm produces maximum output, is 20.1 m / s , which is a piston speed that travels a distance of 20.1 meters per second (72.4 km / h at speed). It means that is moving up and down.

The average speed is 14.9 m / s at 5200 rpm, which generates the maximum torque, and 21.5 m / s when the rev limit is assumed to be 7500 rpm, which is 500 rpm higher than the 7000 rpm where the maximum output is generated.

For reference, I calculated the change in piston speed when a VQ37 engine with a stroke of 86.0 mm is rotated up to 10000 rpm. Looking at this, it seems that the speed increases by approximately 5.75 m / s as the number of revolutions increases by 2000 revolutions.

Considering only 20.0 m / s, which is a guideline for a general engine premised on mass production, I think that about 6980 rpm will be a good rpm, but this engine has the maximum output. It has already exceeded 20.0 m / s at the time of occurrence, and considering the rev limit, it will rotate a little more (300 to 500 rpm?), So it is an engine that is doing its best even though it will be difficult inside.

Problems, weaknesses and malfunctions of Nissan VQ37VHR engines

  1. High oil consumption. Catalysts are the root of evil here, on this engine they are sensitive to the quality of gasoline and can quickly become unusable, simultaneously clogging the lower catalysts with ceramic dust, and after this sand enters the engine and grinds off the cylinder walls, compression drops, oil and fuel consumption increases, interruptions appear in the operation of the engine, the car constantly stalls, does not start right away, etc. The issue is being resolved by overhauling the VQ37VHR or replacing the engine, plus the purchase of four new catalysts. To prevent such troubles, you need to immediately go and change the upper catalysts to flame arresters, this will reduce the toxicity standards, but the above problem will bypass you. If it’s not the catalysts, then look for the problem in the oil scraper rings.
  2. Overheating VQ37VHR. The problem is not frequent, but there is a place to be and its consequences are warping of the valve cover, leading the head, etc. Check the radiator tanks for leaks, the cooling system for air pockets, clean the radiator.
  3. Unstable idle on VQ37VHR. The most common cause is the exhaust camshaft covers, check and replace them.

All other problems and malfunctions are not of a systemic nature and arise from operating conditions. The VQ37VHR engine itself is reliable as a hammer, has a huge resource and runs more than 500,000 km during normal operation. Definitely recommended for purchase.

Conclusion

The VQ37VHR cylinder block has grown slightly in height, along with its rigidity has been increased. A crankshaft with a piston stroke of 86 mm, long connecting rods, light pistons with a compression ratio of 11 were installed inside. This made it possible to increase the working volume from 3.5 liters to 3.7 liters.

Two modified cylinder heads were installed on top, equipped with a system for continuously changing the valve timing on the intake / exhaust camshafts and changing the height of the intake valves (VVEL). Valves have been changed, reinforced springs have been installed.

VQ37VHR engines are quite reliable and have a long service life. Maintenance of the engine must be carried out every 15,000 km, but experienced motorists recommend doing it after 10,000 km. Faults are present, but they are minor.

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