Air Controlled Valves in modern F1 engines.

[MGJohn]

That explosion of the gas container in Heidfeld's Renault got me thinking about Gas Controlled Valves in modern F1 engines. Been puzzled by this aspect of engine design for quite a while.

So, have it got it right when visualising it in this following way in my mind's eye?

Instead of a steel spring to return the open valve to a closed position when the Cam Peak on the shaft passes, a chamber of gas at high pressure is compressed by the Cam on the rotating Camshaft in the conventional way and thus as it opens the valve, further compresses the already highly pressurised gas in the chamber to an even higher pressure which immediately returns the valve to the closed position once the peak of the Cam has passed over the valve stem.

Compressed gas would not expire from metal fatigue @ F1 engines' 18-20,000 rpm as is the case with conventional metal valve return springs.

If I remember correctly, the Works racing three cylinder 50cc Honda Grand Prix machines ( yes 50cc not 500 ) of the mid 1960s peaked at 25,000 rpm all those years ago averaging about 80mph on the Isle-of-Man TT Mountain Circuit. I assume, maybe wrongly, their valves were returned to the closed position with conventional return springs.

Fascinating stuff and another facet of F1 racing which has always gripped my attention.

So, have I got the basic operation of the Air Valve Control on modern F1 engine right in my mind's eye having never actually seen these engine inteanals?

Any thoughts here will be appreciated.
..

[EDLT]

I thought they were banned a while ago, just good old fashioned springs.

[Life Saab Itch]

The honda 'bikes which you speak of were 2 strokes.

Air valves are still allowed. The theory that you describe is correct. The details aren't, but you have the gist right.

[jonnyb]

I always thought that with air controlled valves you didn't need a cam shaft.

[davepoth]

jonnyb said:

I always thought that with air controlled valves you didn't need a cam shaft.

These aren't really air actuated in the same sense. Technically it would be possible to make a system that used a pneumatic system to actuate the valves rather than a cam but it would be very complicated and wouldn't be of too much benefit in a race engine. Camless engines are very useful for getting extra power across the rev range, but if you only need power at one part of the rev range a cam is fine.

[MGJohn]

Thanks for the feedback folks. Interesting stuff.

Life Saab Itch said:

The honda 'bikes which you speak of were 2 strokes.

Air valves are still allowed. The theory that you describe is correct. The details aren't, but you have the gist right.

Again IIRC as it was a long time ago, no they were not. They were four strokes. I saw them in action. Three cylindered four-stroke 50cc engines IIRC. Suzuki and Yamaha we're the first Jap Two-stroke specialists soon after Ernst Degner, the works MZ Rider and development engineer for the then East German MZ Motor Cycle company, defected to the west. Coincidence .. yeah ... right. Then soon after disc valve two strokes became commonplace in the Japanese GP bikes like Yamaha and Suzuki. The noise of the Suzuki Square fours made was ... remarkable. IIRC, Honda were the last of the Jap bike firms to move to two-strokes when they realised if you cannot beat 'em with four strokes, join 'em. They soon got on the pace then after falling way behind.

EDIT to Add @ 10:34 :~


Have got more info elsewhere. There is a conventional CAMshaft to open the valves, the compressed air in a chamber is the 'spring' which returns the valve to the closed position after the Cam has passed over the valve stem. Clever stuff and enables those much higher reliable revs in the F1 engines to perform far more reliably, powerfully than a metal spring could ever achieve. I suspect the impressive reliability of the modern F1 engines is down to this simple device. Air Valve Return Springs...

Edited by MGJohn on Saturday 6th August 10:34

[Life Saab Itch]

Aaah, fair play. I guess I was thinking of the TT 'bikes that I've seen.

[treehack]

Not a 50cc triple but just seen this of another of Hondas mechanical marvels.
The 125 5 clyinder (turn your sound down abit)
http://youtu.be/Xuvx15DLDmc

[anonymous-user]

They are called "air sprung" valves, and indeed allow valve accelerations and cam profiles that would be impossible with conventional metal sprung systems. (due to reduced inertia, infinite fatique life, and simpler harmonics).
The main problems are however:
1) getting repeatable settings (hence the air resevoir to try to maintain a constant pressure throughout the race and
2) sealing without leaking the moving parts (hence the air resevoir to "top up" the system throughout the race.

Over the last 10 years or so, air sprung valvetrains have become very robust (well, in a racing sense) and are now extremely reliable.

[Alfie Noakes]

treehack said:

Not a 50cc triple but just seen this of another of Hondas mechanical marvels.
The 125 5 clyinder (turn your sound down abit)
http://youtu.be/Xuvx15DLDmc

Twisting the throttle forwards to rev it!

[Alfie Noakes]

MGJohn said:

That explosion of the gas container in Heidfeld's Renault................

Assuming that is indeed what exploded.

[treehack]

Alfie Noakes said:

Twisting the throttle forwards to rev it!

Don't think so, would be impossible to ride

[DiscoColin]

Alfie Noakes said:

MGJohn said:

That explosion of the gas container in Heidfeld's Renault................

Assuming that is indeed what exploded.

My first instinct was that it might be the KERS batteries exploding - does anyone have an official verdict on it?

[egomeister]

DiscoColin said:

My first instinct was that it might be the KERS batteries exploding - does anyone have an official verdict on it?

Second half of this article explains it http://www.autosport.com/news/report.php/id/93623

[ralphrj]

From memory Renault introduced pneumatic valves in the 1980s on their V6 turbo F1 engine.

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

To see how they work

http://scarbsf1.com/valves.html

[MGJohn]

treehack said:

Not a 50cc triple but just seen this of another of Hondas mechanical marvels.
The 125 5 clyinder (turn your sound down abit)
http://youtu.be/Xuvx15DLDmc

The machine in that clip bears the name of works Honda rider Luigi Taveri. I was in the paddock at Mallory park in the post TT or "Race of the Year" meeting back then and he ran over my foot with his works 125. No health and safety mullarkey back then eh dad? ...

Some three decades later, Taveri "demonstrated" the fabulous works Six in its natural habitat ~ the Isle of Man TT Mountain Circuit. To my old ears, the finest automotive sound I ever witnessed with none other than Mike Hailwood riding it as it was designed to be ridden.

Here's that I-o-M clip ~ turn the sound up if you dare 28 seconds into the clip the Honda fires up...:~

http://www.youtube.com/watch?v=ymT91LupA6M&NR=...

Magic stuff...

I think I've got that F1 Air Valve stuff sussed now ..
.

[anonymous-user]

If it helps, i'm not sure they are the same, but there should be a video of Julian Ryder explaining how the motoGP engines work with compressed air, it's in depth, but easy to understand

[Scuffers]

as said, air springs are used as engine RPM's went over ~13,000...

[Steve UK]

Scuffers said:

as said, air springs are used as engine RPM's went over ~13,000...

Not quite, you can rev much higher with wire spring although you are right in the fact that air springs were introduced as revs steadily increased passed 13,000 over 18 years ago!!! I think there are gains with frictional losses and valve control with air spring.

I personally would like to see air springs banned with the new engine design V6 Turbo or even the current V8's. They give nothing to the spectacle but cost a fortune to manufacture/maintain.

Steve

[Scuffers]

Steve UK said:

Not quite, you can rev much higher with wire spring although you are right in the fact that air springs were introduced as revs steadily increased passed 13,000 over 18 years ago!!! I think there are gains with frictional losses and valve control with air spring.

I personally would like to see air springs banned with the new engine design V6 Turbo or even the current V8's. They give nothing to the spectacle but cost a fortune to manufacture/maintain.

Steve

they we would be back to 12,000 rpm rev limit's again.

Yes, I know it's possible to run higher with springs, but at what cost? their life is very limited (even by F1 standards), and air s[rings are pretty cheap these days