Vanos....

[munky30]

Can someone explain them please....

I now know its a variable timing thing and that it breaks.

How does it work? Is it similar to a vtec where it just adjusts the valve timing etc. Vtecs seem to be a very blunt method of doing it, its all or nothing as it were.

Systems like mazda's VRIS use different methods to achieve the same effect of improving/evening out power and torwue through the rev range. Varying the intake length...

How good is the vanos system? When does it 'kick in' etc....

[maxfield]

http://en.wikipedia.org/wiki/VANOS

http://www.bmwworld.com/technology/vanos.htm

[munky30]

lazy f*cker.

[munky30]

so... the double vanos uses an egr system? I've always been told they are just another emissions thing and apart from improving the emissions do nothing for power etc...

Is the single vanos similar to the vtec in effect? ie nothing until you hit *k rpm then it kicks in? Is it noticeable?

Double vanos I assume is less so as its constantly variable.

[maxfield]

I don't think the vanos has a 'kick in' effect just keeps the torque lower down the rev range.

I'm not lazy just didn't have a clue on how it works.

[kam-325i]

Vanos is nothing to do with EGR (Exhaust Gas Recirculation), thats the domain of the Vauxhal Ecotec engine.

Vanos is a system of constant variation of cam lift and duration. The Vtec only works at a certain Rpm.
Single Vanos works on the Inlet side only, double on exhaust aswell.

Id love to have a Vanos motor, very smooth power delivery.......

[munky30]

Vanos is nothing to do with EGR (Exhaust Gas Recirculation), thats the domain of the Vauxhal Ecotec engine.

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.

Every car I have ever had with an egr system has had it removed by someone at some point in its life as they sap power..

[kam-325i]

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.

From BMW

"The VANOS system is based on an adjustment mechanism that can modify the position of the intake camshaft versus the crankshaft. Double-VANOS adds an adjustment of the intake and outlet 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."

The Point i make is that Vanos alone is about cam timing variation. EGR is a seperate system on top of Vanos.

[hoshy]

the point should be... can we easily mod a double vanos to fit the m42 and single vanos for all you poor poor single cam owners

[kam-325i]

the point should be... can we easily mod a double vanos to fit the m42 and single vanos for all you poor poor single cam owners

Erm............Nah.

[hoshy]

but it's got to be possible.. if not a BM vanos maybe a ford unit, I think they use a similar setup.

[kam-325i]

It would be easier and cheaper just to fit the M50TU engine.......

[Speedtouch]

Ecotec was sh*t on my Vauxhall Cavalier 2.0CDX engine, it clogged the idle control valve leading to abrupt cutting out of the engine at very awkward moments. It had some weird electric fan & charcoal filter arrangement buried in a front wing that was supposed to recirculate the emissions gasses.

Then the head gasket went and I disposed of the shitter...and bought an E30

[tailoutcharlie]

bottom line then if you fit a vanos engine from e36 into an e30, its awesome, just be prepared to sell you missus if it dies!

[Andyboy]

Inlet vanos is about increasing low speed torque and believe me, it works - especially on the 2 litre. The exhaust Vanos is purely for emissions, nothing else. Generally it's pretty reliable although tyhey can get a bit rattly in old age, at which point you look at the secondary chain tensioner or fit another Vanos unit. The only bad one is the Evo M3, a piece of poor quality rubbish made by Rolls Royce.

[stuartgallafant]

the only reason the E36 M3 Evo got a poor rap, is because so many of them were thrashed around and when the vanos units got rebuilt, they wern't setup correctly

VANOS is difficult to install, setup and time, however, once you've done a few, it gets easier.

the great thing about VANOS, esp. double VANOS, is that you can have the advantage of a very calm camshaft and a very wild camshaft, whilst only actually having one/two camshaft(s)

the DME basically sends a PWM signal to the VANOS actuators, which raise or lower the oil pressure, in-turn, adjusting the position of the camshaft

bloody brilliant!!

[Andyboy]

the only reason the E36 M3 Evo got a poor rap, is because so many of them were thrashed around

What, and the 3 litre M3's and Honda Vtec's didn't? The vanos units on the 3.2 are just not up to the job and the units on the E39 M5 aren't a lot better!
I guess the Evo units are okay if the car is properly warmed up but you can make excuses about any substandard bit of crap - talk to Triumph Stag owners and apparently the 3.0 V8 is 'really reliable'.........

[Toby_Unna]

Vanos is a system of constant variation of cam lift and duration. The Vtec only works at a certain Rpm.

vanos is just variable cam timing unless i'm missing something.

VTEC alters the actual cam profile, i.e. profile/lift/timing can all change.

[kam-325i]

Vtec use's a differnet set of cam lobes which kick in at a certain Rpm. It dose not alter anything (cam wise), it just switch's to the other set of lobes.

I think Vanos raise's and lowers the actual cam, but i will just check.

No it does'nt........My head hurts now from looking...........

[hoshy]

vtec changes lobes.
some systems change height
bmw and ford alter timing
ferrari use a 3d profile that sounds very cool

[Demlotcrew]

Vanos alters cam 'overlap' ie timing against the Crank. (Not lift)

Vtec from what i can work out after looking at quite a few has three lobes over two valves, during low RPM running the second valve only opens half way and when on vtec not only does the lift change but also the duration, this is why it has three lobes on two valves.

Not sure how else to explain it.

Andrew

[stuartgallafant]

andrew, you're correct about the vtec

[munky30]

So from what I can gather the single vanos is the one to go for?

Less to break than the double one and the same gains power wise, just without the emissions bit.

[Andyboy]

So from what I can gather the single vanos is the one to go for?

Less to break than the double one and the same gains power wise, just without the emissions bit.

Not really. The double vanos on the E46 and later E39 is just as reliable as single but you're into late EWS engines anyway and £Â£Ã‚£Ã‚£Ã‚£. Double vanos on the M52 didn't give any more power, it just cleaned up the emissions.

[munky30]

I only meant for the m50/52 tbh.

As you say e46 engines are a tad out of my price range.

[Brianmoooore]

BMW vanos system is effectively a hydraulically adjustable vernier cam pulley on the inlet or both cams (single and double).
The M54B25 engine's power output is actually back down to M20B25 levels.

[munky30]

Whats an M54?

[Brianmoooore]

Whats an M54?

21st century M50.

[Andyboy]

It's a late M52 (2001-2004) with an extra drain back in the block and bigger capacity - 2.2, 2.5 and 3 litre. It's highly strangled for emissions and insurance reasons - the 2 litre M54 320i race engine does about 225 bhp on the original crank, head etc and that on the original 1990cc capacity. It's reckoned that with 200 bhp it would be quite driveable on the road.