VANOS
Encyclopedia
VANOS is an automobile
variable valve timing
technology developed by BMW
in close collaboration with Continental Teves. VANOS varies the timing of the valves
by moving the position of the camshaft
s in relation to the drive gear. This movement varies from 6 degrees of advanced to 6 degrees of retarded camshaft timing.
VANOS operates on the intake camshaft in accordance with engine speed and accelerator pedal position. At the lower end of the engine-speed scale, the intake valves are opened later, which improves idling quality and smoothness. At moderate engine speeds, the intake valves open much earlier, which boosts torque and permits exhaust gas re-circulation inside the combustion chambers, reducing fuel consumption and exhaust emissions. Finally, at high engine speeds, intake valve opening is once again delayed, so that full power can be developed. VANOS significantly enhances emission management, increases output and torque, and offers better idling quality and fuel economy.
VANOS was first introduced in 1992 on the BMW M50
engine used in the 5 Series.
series of inline 6-cylinder engines, which changed the mechanism from fixed position operation to continuously variable, and added the same functionality to the exhaust
camshaft, on a number of its cars. Double-VANOS (double-variable camshaft control) significantly improves torque and emissions since valve timing on both the intake and exhaust camshafts is adjusted to the power required from the engine as a function of gas pedal position and engine speed. On all BMW engines that use single VANOS, except S50B30, the timing of the intake cam is only changed at two distinct rpm points, while on the double-VANOS system, the timing of the intake and exhaust cams is continuously variable through a range of ~40 crankshaft degrees for the intake, and 25 degrees for the exhaust. The advantage of double-VANOS is that the system controls the flow of hot exhaust gases into the intake manifold
individually for all operating conditions. This is referred to as "internal" exhaust gas re-circulation, allowing very fine dosage of the amount of exhaust gas recycled.
Note: The engines starting with an "N" also have valvetronic
variable intake valve opening.
Automobile
An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...
variable valve timing
Variable valve timing
In internal combustion engines, variable valve timing , also known as Variable valve actuation , is a generalized term used to describe any mechanism or method that can alter the shape or timing of a valve lift event within an internal combustion engine...
technology developed by BMW
BMW
Bayerische Motoren Werke AG is a German automobile, motorcycle and engine manufacturing company founded in 1916. It also owns and produces the Mini marque, and is the parent company of Rolls-Royce Motor Cars. BMW produces motorcycles under BMW Motorrad and Husqvarna brands...
in close collaboration with Continental Teves. VANOS varies the timing of the valves
Poppet valve
A poppet valve is a valve consisting of a hole, usually round or oval, and a tapered plug, usually a disk shape on the end of a shaft also called a valve stem. The shaft guides the plug portion by sliding through a valve guide...
by moving the position of the camshaft
Camshaft
A camshaft is a shaft to which a cam is fastened or of which a cam forms an integral part.-History:An early cam was built into Hellenistic water-driven automata from the 3rd century BC. The camshaft was later described in Iraq by Al-Jazari in 1206. He employed it as part of his automata,...
s in relation to the drive gear. This movement varies from 6 degrees of advanced to 6 degrees of retarded camshaft timing.
Single VANOS
VANOS is a combined hydraulic and mechanical camshaft control device managed by the car's DME engine management system. The VANOS system is based on a discrete adjustment mechanism that can modify the position of the intake camshaft versus the crankshaft. Double-VANOS adds continuous adjustability to the intake and exhaust camshafts.VANOS operates on the intake camshaft in accordance with engine speed and accelerator pedal position. At the lower end of the engine-speed scale, the intake valves are opened later, which improves idling quality and smoothness. At moderate engine speeds, the intake valves open much earlier, which boosts torque and permits exhaust gas re-circulation inside the combustion chambers, reducing fuel consumption and exhaust emissions. Finally, at high engine speeds, intake valve opening is once again delayed, so that full power can be developed. VANOS significantly enhances emission management, increases output and torque, and offers better idling quality and fuel economy.
VANOS was first introduced in 1992 on the BMW M50
BMW M50
The BMW M50 is an I6 piston engine. It was introduced in 1990 to replace the BMW M20 in the new 3-series and was replaced by the BMW M52 in 1995. Displacement ranges from 2.0 L to 3.2 L. It is a DOHC 24-valve engine...
engine used in the 5 Series.
Double VANOS
The first double VANOS system appeared on the S50B32 engine in 1996. Later, BMW added "double" VANOS to its M52TUBMW M52
The BMW M52 is a Straight 6 piston engine. Displacement ranges from 2000 cc to 3200 cc. It is a DOHC 24-valve engine, originally introduced with VANOS Variable Valve Timing. It replaced the BMW M50 engine in 1994 and was replaced in 2001 with the BMW M54 engine...
series of inline 6-cylinder engines, which changed the mechanism from fixed position operation to continuously variable, and added the same functionality to the exhaust
Exhaust system
An exhaust system is usually tubing used to guide reaction exhaust gases away from a controlled combustion inside an engine or stove. The entire system conveys burnt gases from the engine and includes one or more exhaust pipes...
camshaft, on a number of its cars. Double-VANOS (double-variable camshaft control) significantly improves torque and emissions since valve timing on both the intake and exhaust camshafts is adjusted to the power required from the engine as a function of gas pedal position and engine speed. On all BMW engines that use single VANOS, except S50B30, the timing of the intake cam is only changed at two distinct rpm points, while on the double-VANOS system, the timing of the intake and exhaust cams is continuously variable through a range of ~40 crankshaft degrees for the intake, and 25 degrees for the exhaust. The advantage of double-VANOS is that the system controls the flow of hot exhaust gases into the intake manifold
Inlet manifold
In automotive engineering, an inlet manifold or intake manifold is the part of an engine that supplies the fuel/air mixture to the cylinders...
individually for all operating conditions. This is referred to as "internal" exhaust gas re-circulation, allowing very fine dosage of the amount of exhaust gas recycled.
VANOS Performance
Single and Double VANOS systems due to age and mileage often experience performance issues as well as complete failure of the BMW OEM Buna-N VANOS piston seals (which are often successfully repaired by the use of aftermarket Viton seals to replace the OEM Buna-N seals). Another common effect is a rattling sound coming from the upper valve train assembly. The original seal material was found to be inferior for the application and tends to break down within 75k - 100k miles. VANOS Seal & Rattle kits are available to address these shortcomings from aftermarket suppliers (but not from BMW -- BMW's solution when VANOS units fail is to remove the entire VANOS unit and replace it with a new one). VANOS repair may require special tools (cooling fan clutch wrenches, etc.) that can be rented or purchased from a variety of vendors.List of VANOS engines
| Name | VANOS Type | Infinite Adjustments | Solenoids |
| M50TU BMW M50 The BMW M50 is an I6 piston engine. It was introduced in 1990 to replace the BMW M20 in the new 3-series and was replaced by the BMW M52 in 1995. Displacement ranges from 2.0 L to 3.2 L. It is a DOHC 24-valve engine... |
Single | No | 1 solenoid I/O |
| M52 BMW M52 The BMW M52 is a Straight 6 piston engine. Displacement ranges from 2000 cc to 3200 cc. It is a DOHC 24-valve engine, originally introduced with VANOS Variable Valve Timing. It replaced the BMW M50 engine in 1994 and was replaced in 2001 with the BMW M54 engine... |
Single | No | 1 solenoid I/O |
| M52TU BMW M52 The BMW M52 is a Straight 6 piston engine. Displacement ranges from 2000 cc to 3200 cc. It is a DOHC 24-valve engine, originally introduced with VANOS Variable Valve Timing. It replaced the BMW M50 engine in 1994 and was replaced in 2001 with the BMW M54 engine... |
Double | Yes | 2 solenoid pwm |
| M54 BMW M54 The BMW M54 is a straight-6 engine, debuting in the year 2000. It is an evolution of the BMW M52. The engine has Double VANOS variable valve timing to adjust timing of both intake and exhaust valves.-M54B22:... |
Double | Yes | 2 solenoid pwm |
| N52 BMW N52 The BMW N52 is a straight-6 engine made by BMW, which debuted in 2004 on the BMW E63 630Ci. The N52 is BMW's 12th generation production straight-6 engine.Its crankcase is made entirely of magnesium and aluminum, a first in the world of engine construction... |
Double | Yes | 2 solenoid pwm |
| S50 | Single | Yes | 1992-1994 not in u.s - 2 solenoid pwm |
| S50 | Double | Yes | 1995-1998 not in u.s - 4 solenoid pwm |
| S52 | Single | No | 1996-1998 u.s - 1 solenoid I/O |
| S54 | Double | Yes | - 4 solenoid pwm |
| M62TU BMW M62 The BMW M62 is a V8 piston engine, built in Munich, Germany. It has an aluminum block with 98 mm bore centers and two aluminum DOHC cylinder heads.-M62:... |
Single | Yes | - 2 solenoid pwm |
| N62 BMW N62 The N62 is a V8 from BMW, built in Munich, Germany. It has an Alusil aluminum engine block and aluminum DOHC cylinder heads.It uses SFI fuel injection, has 4 valves per cylinder with BMW's double-VANOS and Valvetronic technologies and features fracture-split forged powdered metal connecting... |
Double | Yes | - 4 solenoid pwm |
| S62 | Double | Yes | - 8 solenoid pwm + 1 pwm solenoid pressure regulator |
| S85 BMW S85 The BMW S85B50 is a DOHC 40-valve V10 automotive piston engine present in the E60 M5 sedan, E61 M5 touring and E63/64 M6 coupé. It was derived directly from BMW's Formula 1 racing division.... |
Double | Yes | - 4 solenoid pwm + 1 pwm pressure regulator |
| N73 BMW N73 The N73 was a V12 engine from BMW, built in Munich, Germany.The N73 was among the first BMW engines to receive the revolutionary Valvetronic technology, which surprisingly gives it more economical fuel consumption than older non-Valvetronic V8 BMW engines... |
Double | Yes | - 4 solenoid pwm |
Note: The engines starting with an "N" also have valvetronic
Valvetronic
The Valvetronic system is a variable valve timing system to offer continuous and precisely variable intake valve lift, from ~0 to 10 mm, and duration. It typically works in conjunction with the independent Double VANOS system that continuously varies the timing...
variable intake valve opening.
See also
- SubaruSubaru; is the automobile manufacturing division of Japanese transportation conglomerate Fuji Heavy Industries .Subaru is internationally known for their use of the boxer engine layout popularized in cars by the Volkswagen Beetle and Porsche 911, in most of their vehicles above 1500 cc as well as...
Active Valve Control SystemActive Valve Control SystemActive Valve Control System is an automobile variable valve timing technology used by Subaru. It varies the timing of the intake valves by using hydraulic oil pressure to rotate the camshaft in order to provide optimal air flow in and out of the engine... - Variable valve timingVariable valve timingIn internal combustion engines, variable valve timing , also known as Variable valve actuation , is a generalized term used to describe any mechanism or method that can alter the shape or timing of a valve lift event within an internal combustion engine...
- BMWBMWBayerische Motoren Werke AG is a German automobile, motorcycle and engine manufacturing company founded in 1916. It also owns and produces the Mini marque, and is the parent company of Rolls-Royce Motor Cars. BMW produces motorcycles under BMW Motorrad and Husqvarna brands...
's ValvetronicValvetronicThe Valvetronic system is a variable valve timing system to offer continuous and precisely variable intake valve lift, from ~0 to 10 mm, and duration. It typically works in conjunction with the independent Double VANOS system that continuously varies the timing...
Variable valve lift system - GM Northstar System VVTVariable valve timingIn internal combustion engines, variable valve timing , also known as Variable valve actuation , is a generalized term used to describe any mechanism or method that can alter the shape or timing of a valve lift event within an internal combustion engine...
- HondaHondais a Japanese public multinational corporation primarily known as a manufacturer of automobiles and motorcycles.Honda has been the world's largest motorcycle manufacturer since 1959, as well as the world's largest manufacturer of internal combustion engines measured by volume, producing more than...
VTECVTECVTEC is a valvetrain system developed by Honda to improve the volumetric efficiency of a four-stroke internal combustion engine. The VTEC system uses two camshaft profiles and electronically selects between the profiles. It was invented by Honda R&D engineer Ikuo Kajitani, and was the first system... - Toyota VVT-iVVT-iVVT-i, or Variable Valve Timing with intelligence, is an automobile variable valve timing technology developed by Toyota, similar in performance to the BMW's VANOS. The Toyota VVT-i system replaces the Toyota VVT offered starting in 24 December 1991 on the 5-valve per cylinder 4A-GE engine. The...
- 4-stroke power valve system4-stroke power valve systemA Four-stroke power valve is a device fitted to four-stroke engines that constantly adjusts the internal diameter of the exhaust system to better suit engine speed. At low engine speeds the wave pressure within the pipe network is low...