[SomeRandomer123]

Sorry for being a douche and asking what is no doubt an easy question for you engine and tuning lot but what is VANOS?
It's something I haven't heard of before despite myself being rather familiar with a lot of engine components.
What is it? How does it work? Why do BMW use it?

Thanks in advance!

[SpeedOften]

Short version: VANOS is basically variable intake cam timing, double VANOS is variable cam timing for both the intake and exhaust cams

[SomeRandomer123]

Originally Posted by SpeedOften

Short version: VANOS is basically variable intake cam timing, double VANOS is variable cam timing for both the intake and exhaust cams

Ahh - thanks for that! I can sleep much easier now knowing I'm a wiser man.

[Joshboody]

I would be interested in learning more about VANOS. I believe this is double vanos system on the n54 so intake and exhaust advance / retard depending on engine rpm and load. Is this a variable system on the n54 with multiple profiles, or just 2 positions advance and retard... by probably 20 crankshaft degrees?

the intake will retard at idle, advance in the mid-range, and retard again in the top i believe... but not sure of the exhaust positioning.

[Rotorocious]

BMW vtec!

[Dr_Dirt]

Originally Posted by Rotorocious

BMW vtec!

Vtec had only two settings (high and low) whereas the BMW is continuously variable.

[Rotorocious]

anyone seen pictures of these cams? curious what they look like if its continuously variable.

[secretsquirrel]

Originally Posted by Dr_Dirt

Vtec had only two settings (high and low) whereas the BMW is continuously variable.

Yeah, the continuous variability was introduced with i-Vtech.

[Joshboody]

This is a tough thing to research. It's basically a inner and outer gear on the intake and exhaust which gives Xdeg of rotation. the little i did find was for the M62 which is N/A.

This is continuously variable in the design of the gears, BUT when actuated does the oil put the cam at various degrees, OR just advances or retards. How fast does it take to change min/max positions... I know the "VANOS changeover" as mentioned in log and dyno reviews takes about 1000rpms approximately starting at maybe 3500/4000rpms... you can see this in the stock timing table.

With intake some of the advantages of positions:
advanced: intake opens sooner and better cylinder fill; more compression
retarded: reduces overlap so less EGR effect and better idle.
not so sure about exhaust, but would assume the opposite... adv for intake then retard for exhaust.

anyway some more info would be nice.

I have a feeling it's just advanced or retarded... 2 positions... intake retarded at lower rpms and advanced at mid-range through the top during high load.

[SomeRandomer123]

Originally Posted by Joshboody

I would be interested in learning more about VANOS. I believe this is double vanos system on the n54 so intake and exhaust advance / retard depending on engine rpm and load. Is this a variable system on the n54 with multiple profiles, or just 2 positions advance and retard... by probably 20 crankshaft degrees?

the intake will retard at idle, advance in the mid-range, and retard again in the top i believe... but not sure of the exhaust positioning.

Hehehe "retard."
I'm sorry its just used so much as an insult its lost its actual meaning and just becomes funny!
VANOS seems to be quite a complicated and tricky topic! What does it stand for? Variable....

[SpeedOften]

Originally Posted by Rotorocious

BMW vtec!

Originally Posted by Dr_Dirt

Vtec had only two settings (high and low) whereas the BMW is continuously variable.

VTEC is more than just Vanos or Double Vanos... VTEC , is equivalent to double VANOS plus Valvetronic.