How does the vanos work?

smorris_12 said:
Think of a traditional camshaft where there's a big gear nailed to the end of the shaft. Everything is rigidly fixed together. The gear is driven by the cam chain and the cam lobes open valves at the same position every time the crank goes round. Cam variators like VANOS work by removing that rigid connection in the camshaft and instead let the gearwheel move up to (something like) 15 degree from that fixed position. This changes the timing (sometimes called phasing) between crank and cam shafts and this is A Good Thing.
Click to expand...
But.......................... on the M54 engine, how does it do this??? Does anyone know?
I fully understand the theory of ewhat it does and why. I would really like to know the engineering involved in this particular engine for achieving this adjustment of the cam timing.
 
I think it is all controlled hydraulically and the movement to increase or decrease the rotational angle of the cam gear is by an actuator (hydraulic cylinder). I'm sure there are a few video's explaining how to change/service the actuator if you look. The actuator, operated by altering the hydraulic pressure, is scripted and controlled by the ECU/DME. Increasing pressure will move the valve timing one way and a spring will turn it the other way once the pressure reduces.
 
axelleveau said:
My bad, indeed, instead of a "pie piston" you get a linear piston with a screw mechanism!
View attachment 284014
Click to expand...
Brilliant! Thank you!
So basically oil pressure applied to a piston that has something similar to rifling inside, so as it moves in it twists the cam? That would imply no return spring required, as removing oil pressure would allow the cam to drive the piston back.
This also explains why the seals need replacement as if worn the oil pressure would bleed past them and not push the piston inwards.

I’m guessing though, that from the less than technical content of all his previous posts, you have finally answered the question that Pondrew didn’t actually need to know. 🤣
 
sars said:
If you'd not just insulted B21, he may of mansplained it to you ;)

Yes it is like VVT, the double vanos is for both the intake and the exhaust camshafts to vary the timing of both independently.
Click to expand...
He "may HAVE " not " may OF". Please use correct English
 
Zedist said:
I’m guessing though, that from the less than technical content of all his previous posts, you have finally answered the question that Pondrew didn’t actually need to know.
Click to expand...
No I'm not interested in the finer mechanical details....just how it is supposed to affect the driving of the car.

I try and walk before I can run.

Also looking at the above diagram I think I may be in trouble, as I have removed the BMW oil temp sensor and replaced it with a different one to operate a gauge!! ;)
 
sars said:
I do try darling, will you work on developing a personality :poke:
Click to expand...
You forgot your question mark Sars….☝️

If the arse spanking imoji was still available you’d have got it…..not because I give 2 fucks about the question mark but….well….just because…:eek:🫣
 
john-e89 said:
😚😚You forgot your question mark Sars….☝️

If the arse spanking imoji was still available you’d have got it…..not because I give 2 fucks about the question mark but….well….just because…:eek:🫣
Click to expand...
Because every girl needs a good spanking?
 
You must log in or register to reply here.
Back
Top Bottom