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F1 Pneumatic valves

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This topic contains 17 replies, has 6 voices, and was last updated by Bob Williams 1 day, 4 hours ago.

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  • #38667

    Wheels-Of-Fire
    Participant
    @grahamdearsley

    I just found out that the pneumatic valves that they use in F1 engines are not quite as clever as I thought they were.

    I thought that F1 engines replaced the cam’s with pneumatic actuators but in fact they still use plain old cam’s.

    The pneumatic part replaces the valve springs. By changing the pneumatic pressure you can vary the spring rate at different RPM’s and the gas springing also introduces a certain amount of damping that helps prevent valve “float” at high RPM.

    Like I said, not as clever as I thought and next to useless on a road car ☹

Viewing 17 replies - 1 through 17 (of 17 total)
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  • #38676

    Wheels-Of-Fire
    Participant
    @grahamdearsley
    Forumite Points: 4,073

    No comments at all ?

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    #38681

    Mark Turner
    Participant
    @turner74
    Forumite Points: 581

    If your into that type of stuff Graham Koenigsegg are the ones developing this tech for cars I’ve seen a few programmes in the past about this and there are some videos on the tube about it

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    #38682

    Wheels-Of-Fire
    Participant
    @grahamdearsley
    Forumite Points: 4,073

    I am Mark. Watched a few of those videos. My interest was sparked by David Visard’s book “Tuning BL’s A Series Engine”. Lots of detail about CAM timing, lift and duration in there. I picked a Kent Cam’s 276 for my last engine. Slightly lumpy idle but still gives power above 6000 RPM.

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    #38683

    Wheels-Of-Fire
    Participant
    @grahamdearsley
    Forumite Points: 4,073

    Had it on a rolling road and it gave 86 BHP at my self imposed limit of 6500 RPM. Not bad for a 1293cc pushrod engine.

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    #38685

    Les.
    Participant
    @oldles
    Forumite Points: 1,087

    Everything in this world is moving towards economy (BMW and Mercs excepted), so the idea of pneumatic valve closing strikes me as stupid outside of F1. Valve springs are almost energy waste free, pneumatics must be very energy inefficient. Work done compressing a gas it HIGH, all wasted on exhaust expansion. If you want the valves to follow the cam profile, follow the Ducati profile and go desmodromic. In the ’40s, they adopted “pull rods” for controlled closure on their 48cc moped engine.

    Late fifties, a fully developed race motor that won races. Early ’70s, production 250’s and 350’s , later followed by roddie 750s, then 860s, and from 1978, ALL production desmo operated.

    No energy waste, and cam profiles followed.

    Les.

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    #38694

    Bob Williams
    Participant
    @bullstuff2
    Forumite Points: 5,729

    Right on Les! Ducati desmos rule, mate!

    Graham, the amount of money and research poured into F1 is enormous. The engineering brains and experience behind the top teams, is surely enough to know what they are doing. As a former motor engineer, I can understand the truth of Les’s comment:

    Valve springs are almost energy waste free, pneumatics must be very energy inefficient. Work done compressing a gas it HIGH, all wasted on exhaust expansion.

    The metals and lubricants used to manufacture F1 working parts will be the latest, best specifications. The technology behind these companies is always cutting edge and they employ the best people, because they can afford to pay top money. Check this out:

    https://tinyurl.com/sbt85do

    They start with kids, they invest in future employees. They get the best.

    If it’s the Psychic Network why do they need a phone number?

    What’s right is what’s left if you do everything else wrong.

    If women ran the world we wouldn’t have wars, just intense negotiations every 28 days.
    --- Robin Williams

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    #38697

    Wheels-Of-Fire
    Participant
    @grahamdearsley
    Forumite Points: 4,073

    I am going to take a guess here. The energy used to compress a really stiff valve spring must be quite substantial. You only need a very stiff spring at very high RPM so the valve stays under control. They must be saving something somewhere with a gas spring or they wouldn’t bother?

    I fitted dual valve springs on my Mini engines because David Vizard’s book and Kent Cams said I should but I never did know why 🤔

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    #38699

    keith with the teef
    Participant
    @thinktank
    Forumite Points: 2,217

    Of course pneumatic will be better than hydrolic.

    Pnue is French. I don’t like frog words creeping into the English language. Always, always it should be English words creeping into the frog language, making them more civilized. 🙂

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    #38701

    Bob Williams
    Participant
    @bullstuff2
    Forumite Points: 5,729

    Graham, this gives the best explanation of the real, technical reason for dual valve springs:

    ” Dual springs are a good option for performance engines with a heavy valvetrain. The two springs rub against each other and act as a damper. The second spring also acts as a safety measure. Broken springs can be found before they drop a valve into the engine. ”

    Then there is this American publication, Summit Racing:   https://tinyurl.com/uyhgzhj

    Triple springs, even. Scrolling down into the 5 ‘Other answers’ at the bottom of page, gives more interesting information.

    Keith, I would be interested to know if you ever had pneumonia, and what you named it! Fact is, 58% of English is derived from French and Latin. 29% of that is French. 26% is from Germanic roots, 10% is Greek, The rest comes from other languages. All European languages, with the exception of Hungarian, are descended from one root, called Indo-European. What we Brits should be proud of, is that English is now the world’s language of business, spoken all over the world. That is what annoys the French! Listen to some TV programmes when other language speakers are interviewed in English. They all speak it with varying success. On the other hand, what we should be ashamed of, is that so few of us can travel abroad and speak another language, because the universality of English has  made us lazy.

    French and words from other languages, were “creeping into” our speech, before there was a nation called England. The English, on becoming a nation, took all these roots and made of it a simple, gender-free language that anyone could learn.

    Here endeth the lesson. Wake up at the back!

    If it’s the Psychic Network why do they need a phone number?

    What’s right is what’s left if you do everything else wrong.

    If women ran the world we wouldn’t have wars, just intense negotiations every 28 days.
    --- Robin Williams

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    #38707

    Mark Turner
    Participant
    @turner74
    Forumite Points: 581

    Graham my cousins 2 brothers about 32 years ago used to drive around in minis. One was a 1340cc the other a 1312cc my auntie their mum had a yellow clubman with one of the above engines I can’t remember which though the 3 of them had noisy exhausts as well

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    #38709

    Wheels-Of-Fire
    Participant
    @grahamdearsley
    Forumite Points: 4,073

    You don’t actually need a really noisy exhaust these days. The RC40 system sold by Mini Spares Centre is a straight through absorption  type with almost zero back pressure and it just has a “sporty” note 😁

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    #38710

    Ed P
    Participant
    @edps
    Forumite Points: 8,707

    Hate to be a nay-sayer, but is F1 even relevant in today’s political environment?

    At one time it could be argued that it was the bleeding edge of car design — but in today’s world of climate scaremongering, I really wonder. In any case the higher torque of electric cars means that all they need do is fix battery weight/technology to quietly beat the pants off any internal combustion engined car.

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    #38711

    Wheels-Of-Fire
    Participant
    @grahamdearsley
    Forumite Points: 4,073

    Ah but it can’t be fixed Ed. You just can’t have the power in a battery that you have in a tank of fuel.

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    #38712

    Ed P
    Participant
    @edps
    Forumite Points: 8,707

    Perhaps not, but you can have huge numbers of batteries but not many fuel tanks.

    Move over to super-capacitor storage and the potential energy stored becomes dangerously large in a very small volume.  On their own, the super-capacitor self discharge rate is a problem, but use them combined with regenerative braking on an electric car and this then becomes a very different animal.

    I just wish they would take the huge number of restrictions off Formula E then we could see the development value that racing cars bring to the industry.

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    #38713

    Bob Williams
    Participant
    @bullstuff2
    Forumite Points: 5,729

    That will change, Graham, because the necessity to change it has been gathering momentum for a while now. Research is being carried out that will inevitably bring a solution. That’s the way humanity has always progressed, since some oddball became an arsonist another oddball looked at sledges, compared the runners with the shape of a circle and invented the wheel. Progress. (Or, to put it another way, sh1t happens)

    If it’s the Psychic Network why do they need a phone number?

    What’s right is what’s left if you do everything else wrong.

    If women ran the world we wouldn’t have wars, just intense negotiations every 28 days.
    --- Robin Williams

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    #38774

    Ed P
    Participant
    @edps
    Forumite Points: 8,707

    Jaguar have just announced that through their “i-Pace e” racing experience they have added 12 miles to the battery mileage for their road-legal electric road vehicle range. It demonstrates that the powers that be should open up the ridiculously heavily constrained  Formula-E specifications to get widespread benefits for an ever-growing marque.

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    #38784

    Bob Williams
    Participant
    @bullstuff2
    Forumite Points: 5,729

    Yup. Progress through competition. There must be an Elfin Safety rule against it somewhere.😆

    If it’s the Psychic Network why do they need a phone number?

    What’s right is what’s left if you do everything else wrong.

    If women ran the world we wouldn’t have wars, just intense negotiations every 28 days.
    --- Robin Williams

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