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Registered:
June 2003
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Pnuematic valves on F1's
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Fri, 05 March 2004 03:51
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I've read about the new innovation, and how they let the engine now rev to 19,000rpm, as apposed to the previous 13,000.
So they do this by lifting the valves instead of using springs?
If anyone knows how they work I would be interested in knowing.
Also if using the pnuematics to lift the valves works then couldn't you program the open/close of valves to certain times at certain revs giving much better results then the current variable valve timing? or is this how it's done, or could the pnuematics replace cams and work indepently?
If anyone knows anything about this I'ld be quite interested in learning about it, as I'm going through a mechanical engineering degree at monash 
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Location:
c'town, NSW
Registered:
May 2002
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Re: Pnuematic valves on F1's
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Fri, 05 March 2004 04:16
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BMW are using this technology and possibly have released it in some production engines as it has been a long time since ive read about it on autospeed.
the valves can be controlled by the ECU for duration and lift and because of this they do not need a throttle buttlerfly as the valves are what control how much air going into the engine from accelerator pedal input (as well as other sensors).
has huge advantages for fuel economy, power and drivability as it is a true dynamic variable valve engine.
hope this helps.
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Location:
Cabramatta, NSW
Registered:
May 2002
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Re: Pnuematic valves on F1's
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Fri, 05 March 2004 04:29
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AFAIR, the current M3 engine uses the pnuematic valves.
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Registered:
June 2003
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Re: Pnuematic valves on F1's
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Fri, 05 March 2004 05:01
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| rob_RA40 wrote on Fri, 05 March 2004 15:16 |
has huge advantages for fuel economy, power and drivability as it is a true dynamic variable valve engine.
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That's what I was thinking about.
So how does it actually work though, instead of being forced by springs, it's just a controlled lift by the pnuematics?
I might try and base my final year project on redesigning the 3sge I've got sitting in my garage. Wonder if I could work this in somehow, maybe just design anyway probably be a bit out of my price range
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Location:
Cabramatta, NSW
Registered:
May 2002
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Re: Pnuematic valves on F1's
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Fri, 05 March 2004 05:18
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I think (and don't quote me on this 'coz it's been a while since I read anything on the subject).
The idea is to get rid of those pesky camshafts...
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Location:
Randwick Sydney
Registered:
November 2003
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Re: Pnuematic valves on F1's
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Fri, 05 March 2004 07:32
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anyone have pics ?
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Location:
Cabramatta, NSW
Registered:
May 2002
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Location:
The Eastwood MASSIVE !
Registered:
May 2003
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Re: Pnuematic valves on F1's
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Fri, 05 March 2004 09:25
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| Nark wrote on Fri, 05 March 2004 15:29 |
AFAIR, the current M3 engine uses the pnuematic valves.
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I'm quite sure they don't have pnuematic valves , but have VANOS units ( variable cam units ). But lots of current BMW engines use the variable valve gear that uses servo motors to adjust valve lift depending on pedal position and power / torque requirements. But still have a throttle body for emergency operation.
kekeke being a BMW technician is fun ^_^
Currently I have a X5 V8 4.4L with valve gear ripped off awaiting replacement.
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Location:
Cabramatta, NSW
Registered:
May 2002
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Re: Pnuematic valves on F1's
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Fri, 05 March 2004 09:32
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Yeah, I think I was wrong. I might have been thinking of their hydrogen car instead.
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: Pnuematic valves on F1's
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Fri, 05 March 2004 10:15
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Like this -
They use conventional cams to open the valves, but air pressure to shut them.
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Location:
Sydney
Registered:
May 2003
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Re: Pnuematic valves on F1's
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Mon, 08 March 2004 14:43
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ok ill be the one to bite and ask the ridiculous...
how much ?
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Pnuematic valves on F1's
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Tue, 09 March 2004 04:11
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the cost is more in power to drive tht thing instead of $$ 
the reason they use them (aiui) is becuase
a) springs have material limits and a lot of inertia
b) the force applied by a spring decreases as it extends.
the pneumatic spring has less inertai, and has a pretty constant force, so you can yse much larger, more aggressive ramp rates, and still keep the valve in contact with the back of the lobe.
pneumatic doe snot open them, there is some work into using solenoid operated valves, but again the power cost to drive them is very high...., heck even fuel injectors use abotu 1amp, and they only move a tiny pintle a few mm...
Cya, Stewart
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Location:
NSW
Registered:
September 2003
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Re: Pnuematic valves on F1's
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Tue, 09 March 2004 09:52
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Don't quote me as an authority, but I seem to remember an article that quoted the use of Nitrogen for this purpose, stored in a cylinder at high pressure. (>5000 psi) This way, the change in lift pressurises the gas by only an extremely small percentage with respect to the system pressure.
By the way, Scania have been using electric actuation for their valves for ten years or more.
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Location:
sydney
Registered:
March 2003
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Re: Pnuematic valves on F1's
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Tue, 09 March 2004 10:36
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just like an aftermarket ecu controls injector timing at certain crank degree
they use a computer to open and close valves at any time they want
so at a certain crank degree one valve would open
this means u can adjust lift(maybe) and duration just
by readjusting values on the programmable computer
when an f1 car dies in the ass from valvetrain problems
it usually means they have run out of gas which runs the system
one canister is used to run a whole race
so if u have a slight leak u might not make it a whole race
its old technology but would be hard to set up on an everyday engine
if u use pressure to open the valve then u would have to use pressure to close it
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Location:
Australia
Registered:
December 2002
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Re: Pnuematic valves on F1's
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Tue, 09 March 2004 10:57
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This is slightly off topic.
I did some research on the topic of ECV electronic controlled valves. Where they use solenoids at 48V to control the valves.
It has some interesting requirements one is that you can't just simply snap the valve open or closed you must bring it to a stop slowly or the valve will get damaged.
Eg you can't just slam the valve into the head to close it.
I would like to try setting it up on a single cylinder stationary engine one day and have some fun writing code for it.
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