You missed the most important point. The resonance frequency. It is easy to build a non-linear spring, and the time that springs break is long gone. You can see it in modern motorcycles 16.000 rpm is not a problem at all and these engines run easily for 40.000km without failure. The problem with larger displacements is that the valves get bigger and therefore naturally heavier, so you must increase the spings force, but by stiffening the spring you increase their resonance frequency to higher rpm so the springs starts to resonate when it really counts at high rpm. You can still overcome this effect to a degree by using two springs with different spring forces. There are roadcars that use this method. The 1st series of Golf GTI is such an example. The fun thing with the gas spring is that it has basically no mass and it can't resonate, or at least not in a rev range where it matters.
oh that's interresting too. Do you know that when Toyota was active in F1 they even tested Desmotronic for their F1 engines. At the end they decided against Desmo but they played around with it. You can see a prototype in their facility in Cologne, Germany.
Yes, today's springs and metallurgy are much more advanced than back in the 80s, so the statement about breaking springs was in context of the F1 cars back then. They had some issues with springs breaking due to fatigue as well as heat but you are definitely correct that resonance can cause a spring failure also. I sort of glossed over this with the mention of valve bounce and resonance effects, but perhaps could have put more time into discussing resonance as a whole and it being a cause of total failure. I try to keep my videos easy to understand for a general audience and I wasn't sure I could get into this without the video becoming too long/too advanced for the average person. I didn't know that about Toyota playing around with Desmodromic valves, very interesting stuff! Thanks very much for the comment and for watching!
Great solution. I know how 2 and 4 stroke combustion engines work but i didn't know about spring resonance and floating. Using a tank of nitrogen is great idea. For a race car. The regulator reminded me of the one i used on my airbrush compressor that my old man made out of a fridge compressor,a tank,valves,connectors,and most important,the regulator. It was the one with a glass lower part with a spring that sealed it when the compressor made enough pressure with of course enough strength to push the round plate down and seal it. We live we learn. Great video.
@@themotorsportstory Just found you ,really enjoyed your video and it is a pleasant suprise to see someone who admits they may have maybe not explained it correctly ,as you definetly know what you are talking about,Though you where mainly talking about the early 80s..It is amazing how small the F1 cars of the time where so small...Every positive has its negatives for the revs the average family saloon reaches,springs are fine ,,With F1 everything in the engine has to last, say 6 races before they can fit a new engine ,i am not up to speed on how long an engine has to last as they are only allowed so many a year
@@themotorsportstory haha, First I'll try with regular springs. Until I Win the lottery, then I'll have a solution custom made. (And probably a few sets so others can enjoy it too
Sorry, but you hit one of my sensitive points. A spring fatigue failure is not like bending a paperclip until it breaks. A paperclip breaks because you are plastically deforming the metal (stressing it past its yield point) and this causes work hardening, embrittling it. Fatigue failures are cyclic failures of a material that has been stressed below its yield point (you haven't plastically deformed it), but causes accumulated damage. These are two separate failure mechanisms.
Not quite. The paperclip example IS in fact fatigue, but "low cycle" i.e with significant plastic deformation (and work hardening, yes). What you refer to is the (much more common) "high cycle fatigue", with essentially zero plasticity. Source: materials engineer, 30 years of experience, including automotive reliability engineering 😊
that's why, once, during the Monza GP, BMW managed to reach 21000 rpm....during 3 laps (during the early 2000's) It works, it works perfectly but...better be gentle with it or your rear tyres will lock at 350kph (that's what happened to one of the Williams BMW pilots during this race, when his engine decided to quit the race...after 3 laps)
First introduced by Renault in the Lotus. To be more precised, a Matra and Renault invention. Because this invention is stock and displayed in the Matra museum in France. Back then Matra was still this amazing engineering compagny, which had a great competitions history. Often forgotten nowadays. Matra had the advantages, to work in so many types of industries, which allowed them very excellent engineering in different domains.
I wish pneumatic valve springs were more common. They are so effective. They are used in MotoGP (Except Ducati) as well as F1. The MotoGP bikes have a small, probably carbon, tank and small compressor that pressurizes the valves. I'd love to see one of the new Dart Block 2JZ engines paired with a pneumatic valve head ran by timing gears. That could easily rev to over 15k. Joel Grannas money shifted his orange Supra and hit 12k, and everything was fine. It was a billet 2JZ though.
So for a road car the advantage is that I can ramp up the pressure with RPM? If you don’t race with displacement regulations, going above 12k gives you no power.
He is talking about race engines though. Or at least fun, fast street car engines. Dart is a manufacturer of aftermarket, high performance engine parts. And people enjoy trying new things and tinkering with machines. Increased rpm will give any displacement engine that can handle it and is designed for it, more horsepower. So even without a displacement rule, you can make more hp.
@@9rjharper flame front needs time to travel. Friction losses rise. Race cars don’t have torque converters, and shifts in a corner may send you flying. So pilots like the flexibility to rev beyond max power.
there is still the problem of piston speed. the average speed of a piston cant go above about 60mph, even in formula 1 engines. that is why they have such short strokes, down around 2" or 50mm to rev to 15k
@@ArneChristianRosenfeldtlots of race cars have torque converters, and torque converters work fine with high rpm if they are built with that in mind, just look at what mclarren is doing with thier "single speed" supercar, which basically just uses a specially built torque converter as the transmission to go from 0mph to 250mph with 0 shifts. these engines are also tuned to male power until very high in the rev range, and because of the short stroke they lose less to friction than youd expect. flame front travel speed is also a bit of a myth in a highly tuned engine, the flame kernel is used to make a spike in pressure and cause the rest of the cylinder to burn at nearly the same time through what is esentially controlled detonation, similar to a diesel but using the spark plug to control the pressure spike rather than pure cylinder pressure and temperature
Thanks for the explanation of the gas spring. I don't think the fatigue in the paper clip is fully accurate but it does convey the idea of failure causation. I have a suggestion for a future topic if you haven't covered it. Ducati Motorcycles many years ago designed & put into production a Desmodranomic(I think I butchered the term) valve system. This is a fully mechanical system were by an additional 'follower' added to the valve captures the cam lobe. So the cam opens/closes the valve(s) w/ assistance of a small spring at lower rpm & a tensioning system of minuet travel to accommodate the mfg. tolerances to seal the valve into the valve pocket. I think that would be an interesting video, if you haven't made one all ready on the topic. I think that system could be used in any IC engine.
There is also a natural limit for steel springs. Stronger ones are heavier and so add mass to the valve they need to move. More mass -> more force needed -> bigger spring. Until you reach the limit. Also coil springs resonate. That’s the reason why you often see a large spring with a small one inside. They have different resonance frequencies and together both resonance peaks flatten out. Gas just behaves more ideal than bend iron. 😂
Coil bind is another issue that limits how strong a coil spring can be made. The sum of all the spaces between the coils has to be less than the maximum valve lift.
There's one small thing you forgot, pneumatic springs don't have the mass of metal springs so as the cam lobe passes it's peak the poppet will actually apply force back to the cam sooner than with a metal spring return more of the initial opening load back to the engine. It also allow a more aggressive closing profile on the cam because the valve follows the ramp better.
Pneumatics come in to eliminate steel fatigue and surge in normal compression springs. N2 is purely for dryness. Eliminates vapor pressure of any water vapor in air. Tires are same except eliminating O2 saves tire inners from deterioration after many months/years.
You skipped over whole aspect of pneumatic valve springs. Due to the geometry of how cam lobes open the valve, the power required to operate the cam as it moves thru opening the valve is almost perfectly inverse to the power required operate the valve.
He forgot to mention that like all metals, Valve springs have a 'Resonant Frequency' at which they begin to feedback the energy and fail. It also takes a specific time for the valve springs to do their job which limits the RPM they can achieve. The solution is being explored by Konesigegg with their 'Free Valve' engine which completely eliminates the camshaft and al other components of the Valve Train.
They fill them with Nitrogen because its non corrosive to the seal compound and Nitrogen Molecules are larger than Oxygen Molecules so they can't get past the seal tolerances easily.
I'm also assuming you have to be very careful on startup to make sure that you put the gas on. I mean if a engine sits, do the valves slowly loose pressure and then the valves sink down into the cylinder until somebody airs them back up?
To be honest, I couldn't find much info on this. I did find a few sources describing how it is difficult to keep oil out of them, so it's possible that engine oil might lubricate them, but I'm not 100% sure. Also possible they have their own lubricant
Please please dona video on Eric Mann's "Mannic Beattie" race car!! It used a "gas turbine" that bled off compression to boost the 1.7 Sierra Cosworth engine to 700hp at over 40psi. People keep calling it a APU, it's literally a jet engine made from a turbocharger to boost the engine. The turbo runs off diesel
I understand, but in motorsport you want to eliminate as much moving parts (and weight) as possible, so it doesnt make sense especcialy when youre trying to chase high rpm’s.
In fact they don’t go beyond 11000 because of turbo/fuel flow. The pneumatic valves become really a must when the V10 Renault went over the 15000 in 92 and subsequent yrs.
FIRE VID. I’m trying to figure out why teams haven’t put more effort into electromagnetic valve actuation?? seems like it would save the need for a camshaft or at least replace it with a computer of sorts that could for sure save space, and hopefully in turn weight as well. do you think it’s just costly, they don’t view the pros to outweigh the cons, or has truly no one been able to figure it out? (that last one i doubt)
Also I just thought of this, but do you know exactly how much pressure is regulated inside the system before the PRV discharges nitro? How much is it designed for?
@gothicpagan.666 I'm interested to know more as well. I've never seen a two stroke with poppet valves but I'm not as familiar with the world of two strokes in general.
Doing some searching I found this: ruclips.net/video/WFity0Tc1js/видео.htmlsi=Narkbr3DkLltdbWx Looks like they're used on an exhaust valve on this marine engine. Fascinating!
You over-simplified the gas compression equation by reducing it to Boyle's law which implies constant temperature. In a rapidly compressed or expanded gas, such as the case in point, there is not time for heat to flow across the walls so the gas eqn (p.v exp n =1) is appropriate where n is the polytropic index probably nearer 1.4 (adiabatic) than 1 (isothermal).
Engines with an OverHead Camshaft doesn't have rocker arm to push down the valves of the engine, it's only used on engine with the camshaft in the center of the V.
If a small tank allows to drive pretty far, there is absolutely no problem to use a small electric pump to periodically pump up a small reservoir for the valves. Of course with normal air.
Rotary valves open slowly, are only wide open for an instant, and close slowly. Poppet valves hammer open, stay fully open for a designed duration, then slam shut allowing more gas flow.@@thiswillprobhrt
With the advances that have been made with 3D printing I wonder if anyone has tried, or if it would be legal to have parts of an F1 car's bodywork constructed from capillary air ducts. The labyrinth of capillary tubes could be designed to change the direction and flow of the air, both to improve cooling and improve stability. In theory, the ducting could even include micro switches that closed or opened the ducting so when corning the side which would benefit from more downforce could have air redirected from the other side passed through the bodywork.
Don't forget that too little force when the valve is seated can result in valve bounce as the valve returns to its seat at ever-increasing rates, as the engine rpm is elevated!
To me Desmodromic distribution like a Ducati’s design is eliminating all valve springs altogether by using one cam pushing down the valves to open and another complimenting cam pushing up and closing the valve down and maintaining it close. This is the ultimate road worthy high rpm solution…but both maintaining the valve closed without any spring load and limiting the impact shock valve to the fixed valve Stellite seat is then the main high precision and hot and cold issue to resolve…😂
someday someone will come up with a clean two stroke engine architecture and then F1 power will double and F1 cars will sound absolutely insane. if you think petrol engines are going to be replaced by electric anytime soon then I've got a bridge to sell you too.
Two strokes will never come back. If you burn oil it’s dirty and dirty is not a good thing.. if you think they will, you might like to buy the Sydney Opera House.🇦🇺
@@MICHAEL-ys3pu current 2 strokes burn oil, that doesn't mean they always have to. hence why i said "clean" in "clean 2 stroke". i'll pass on the opera house, probably doesn't garner much ticket revenue if you're representative of the potential patronage.
On the infintesimally small chance that the guy that didn't get this during my interview at the UK atomic energy institute sees this - see I told you :) I hope your conviction that pneumatic valves don't have a camshaft keeps you up at night :)
Interesting video there. But you don t say how much max rpm this new technology allowed Renault engines running in 1986. It would be an interesting fact to compare with other engine suppliers at the time it was introduced.
I just want to say I appreciate your video titles. You give a vague hook followed by exactly what you're going to explain. Clickbaiters should learn from this.
Thanks, I really appreciate this as it's exactly what I'm trying to do! The way RUclips works, you have to hook people in with something or your video won't get any views, but it's never my intention to deceive anybody or bait them with something that isn't actually in the video.
🤯🤯🤯 omg that is extraordinary to think such an incredible idea came (renault of all teams) by dumping springs for pneumatic has completely changed f1 forever i must congratulate you tms in making this video and have a great day bye now😊.
You say Renault of all teams, but you have to remember that Renault invented the turbocharger, supercharger, driveshaft and mass damper, introduced the turbo in F1, have won many titles as an engine supplier and 2 as a constructor, and won the first ever grand prix
If my memory swerves me right, some of the American V8 monsters from the '60s were using hydraulic valve mechanisms, not because they were high-revving, but because they were quieter. You have to be careful saying who invented what, and when.
The Mercedes F1 engine in the mid 1950s used desomodromic valve actuation... no valve springs at all (pneumatic or steel)... therefore no spring pressure for the cams to overcome. Desmodromics are (IMHO) the ultimate poppet valve actuation system. Ducati is currently the only engine manufacturer embracing desmo valve actuation.
Valve float....chey bad about it at higher rpm spring just can't bounce back fast enough.... cause loss of valve control which leads to rpm loss or worse
Great vid! I'm amazed pneumatic valves haven't got the attention they deserved over the years. They're comparable to ground effects as far as their importance to the sport in my stoned opinion 🤔
Thank you! Yeah, there isn't much info out there on them by comparison which might be one reason. I suppose F1 teams don't want to give out too much design info
Good video, but don't apologize for the "complex math". It isn't, and if people don't get it, too bad. I honestly didn't realize that this was the level of simplicity that Renault had come up with. I thought that the opening of each valve was controlled with a pneumatic solenoid rather than just replacing the spring. I thought with a pneumatic solenoid the benefits would be major: 1. INFINITE valve timing all adjustable with computer, and 2. Simplified engine design with no camshaft requirement.
Thank you, glad you enjoyed it! I'm not positive but I believe that F1 cars can't have variable valve timing per the rules which might be why there is no computer control.
Im not sure if your theory about gas is completely correct, that you can just assume that one side of the equation has very small variations and can be set as a constant, because as pressure increases so does temperature and vice versa when decompressing. Setting temperature as a constant throughout the cycle of compression and decompression would completely disregard this fact. Its basically disregarding mechanical work that happends when you compress a chamber of gas but im not sure how this impacts the equation and how the valve is pressing against the camshaft over its travel
Thanks for the comment! You're absolutely correct that the temperature will change. The assumption wasn't made to ignore that fact but more to simplify the equation to a point where it could be compared to a regular spring which only has the variables of spring force and distance of compression or extension; which can be compared to pressure and volume of the pneumatic spring. Regardless of the temperature changing, the progressive curve will still be there, it just might look more flat or more sloped depending on what the numbers work out to. I probably could have done a better job of justifying the assumptions in the video, but the main idea was to illustrate that progressive curve in as simple of a way as possible for people who might not have much of an understanding of math or physics.
@@themotorsportstory Actually when I took a closer look at the numbers it seems like the pressure will increase more exponentially when you have temperature as variable so the original calculation actually underestimates the effect. Anyways, great video and thanks for the answer!
Yes, in theory, but in reality you're also dealing with increased friction which will lead to an energy loss, plus severely increased wear on the rubbing surfaces of cam and follower.
Besides what the other person explained, the valve train also has inertia, so when the cam is on the closing side of the lobe, the valve spring isn’t push back with as much force as it was when opening. If you know what valve float is, imagine that (except not necessarily to the extent of being completely off the lobe).
The f1 engine is designed to rev that high. Same as motorcycles designed to rev higher than car engines. The reason is that torque is not needed for f1 engines, i.e. racing up a hill or up a very high mountain pass plus being very lightweight racing cars property all F1 cars nowadays are under 1 ton (2000 lbs). Most FIA F1 tracks have very little elevation changes. Spa has the most elevation changes 102.2 m. However, there is no clue if the slopes are a gradual rise or a sudden/fast rise. Maybe someone has information and can share slope ratio information for Spa.
You missed the most important point. The resonance frequency. It is easy to build a non-linear spring, and the time that springs break is long gone. You can see it in modern motorcycles 16.000 rpm is not a problem at all and these engines run easily for 40.000km without failure. The problem with larger displacements is that the valves get bigger and therefore naturally heavier, so you must increase the spings force, but by stiffening the spring you increase their resonance frequency to higher rpm so the springs starts to resonate when it really counts at high rpm. You can still overcome this effect to a degree by using two springs with different spring forces. There are roadcars that use this method. The 1st series of Golf GTI is such an example. The fun thing with the gas spring is that it has basically no mass and it can't resonate, or at least not in a rev range where it matters.
oh that's interresting too. Do you know that when Toyota was active in F1 they even tested Desmotronic for their F1 engines. At the end they decided against Desmo but they played around with it. You can see a prototype in their facility in Cologne, Germany.
Yes, today's springs and metallurgy are much more advanced than back in the 80s, so the statement about breaking springs was in context of the F1 cars back then. They had some issues with springs breaking due to fatigue as well as heat but you are definitely correct that resonance can cause a spring failure also. I sort of glossed over this with the mention of valve bounce and resonance effects, but perhaps could have put more time into discussing resonance as a whole and it being a cause of total failure. I try to keep my videos easy to understand for a general audience and I wasn't sure I could get into this without the video becoming too long/too advanced for the average person. I didn't know that about Toyota playing around with Desmodromic valves, very interesting stuff! Thanks very much for the comment and for watching!
Great solution. I know how 2 and 4 stroke combustion engines work but i didn't know about spring resonance and floating. Using a tank of nitrogen is great idea. For a race car. The regulator reminded me of the one i used on my airbrush compressor that my old man made out of a fridge compressor,a tank,valves,connectors,and most important,the regulator. It was the one with a glass lower part with a spring that sealed it when the compressor made enough pressure with of course enough strength to push the round plate down and seal it. We live we learn. Great video.
@@themotorsportstory Just found you ,really enjoyed your video and it is a pleasant suprise to see someone who admits they may have maybe not explained it correctly ,as you definetly know what you are talking about,Though you where mainly talking about the early 80s..It is amazing how small the F1 cars of the time where so small...Every positive has its negatives for the revs the average family saloon reaches,springs are fine ,,With F1 everything in the engine has to last, say 6 races before they can fit a new engine ,i am not up to speed on how long an engine has to last as they are only allowed so many a year
Back then I used the tappets from the 2-litre Alfa Romeo engine in my GTI, which were lighter. They had exactly the same diameter.
As a Miata driver, feel called out.
Also as you are are reading this I'm trying to figure out how to put pneumatic valve springs into said Miata
Find a cosworth V10 to put in there!
It's ok, I'm a fellow Miata enjoyer 😉 So if you ever get it working in your car let me know haha
@@themotorsportstory haha, First I'll try with regular springs. Until I Win the lottery, then I'll have a solution custom made. (And probably a few sets so others can enjoy it too
@@Birb_of_Judge Just like my Mini S, the AC off button is the sport mode.
@@sirhcsuiris my Miata doesn't even have ac 😂
As a an automotive technician that was an excellent explanation.
Much appreciated, thank you!
They just need spoilers front one
Sorry, but you hit one of my sensitive points. A spring fatigue failure is not like bending a paperclip until it breaks. A paperclip breaks because you are plastically deforming the metal (stressing it past its yield point) and this causes work hardening, embrittling it. Fatigue failures are cyclic failures of a material that has been stressed below its yield point (you haven't plastically deformed it), but causes accumulated damage. These are two separate failure mechanisms.
Not quite. The paperclip example IS in fact fatigue, but "low cycle" i.e with significant plastic deformation (and work hardening, yes). What you refer to is the (much more common) "high cycle fatigue", with essentially zero plasticity.
Source: materials engineer, 30 years of experience, including automotive reliability engineering 😊
that's why, once, during the Monza GP, BMW managed to reach 21000 rpm....during 3 laps (during the early 2000's)
It works, it works perfectly but...better be gentle with it or your rear tyres will lock at 350kph (that's what happened to one of the Williams BMW pilots during this race, when his engine decided to quit the race...after 3 laps)
Ouch😂
First introduced by Renault in the Lotus. To be more precised, a Matra and Renault invention. Because this invention is stock and displayed in the Matra museum in France.
Back then Matra was still this amazing engineering compagny, which had a great competitions history. Often forgotten nowadays.
Matra had the advantages, to work in so many types of industries, which allowed them very excellent engineering in different domains.
I wish pneumatic valve springs were more common. They are so effective. They are used in MotoGP (Except Ducati) as well as F1. The MotoGP bikes have a small, probably carbon, tank and small compressor that pressurizes the valves. I'd love to see one of the new Dart Block 2JZ engines paired with a pneumatic valve head ran by timing gears. That could easily rev to over 15k. Joel Grannas money shifted his orange Supra and hit 12k, and everything was fine. It was a billet 2JZ though.
So for a road car the advantage is that I can ramp up the pressure with RPM? If you don’t race with displacement regulations, going above 12k gives you no power.
He is talking about race engines though. Or at least fun, fast street car engines. Dart is a manufacturer of aftermarket, high performance engine parts. And people enjoy trying new things and tinkering with machines. Increased rpm will give any displacement engine that can handle it and is designed for it, more horsepower. So even without a displacement rule, you can make more hp.
@@9rjharper flame front needs time to travel. Friction losses rise. Race cars don’t have torque converters, and shifts in a corner may send you flying. So pilots like the flexibility to rev beyond max power.
there is still the problem of piston speed. the average speed of a piston cant go above about 60mph, even in formula 1 engines. that is why they have such short strokes, down around 2" or 50mm to rev to 15k
@@ArneChristianRosenfeldtlots of race cars have torque converters, and torque converters work fine with high rpm if they are built with that in mind, just look at what mclarren is doing with thier "single speed" supercar, which basically just uses a specially built torque converter as the transmission to go from 0mph to 250mph with 0 shifts.
these engines are also tuned to male power until very high in the rev range, and because of the short stroke they lose less to friction than youd expect. flame front travel speed is also a bit of a myth in a highly tuned engine, the flame kernel is used to make a spike in pressure and cause the rest of the cylinder to burn at nearly the same time through what is esentially controlled detonation, similar to a diesel but using the spark plug to control the pressure spike rather than pure cylinder pressure and temperature
Cracking video with the perfect amount of details. 😀
Much appreciated, thank you!
The ducati desmodromic system is on another level
Thanks for the explanation of the gas spring. I don't think the fatigue in the paper clip is fully accurate but it does convey the idea of failure causation. I have a suggestion for a future topic if you haven't covered it. Ducati Motorcycles many years ago designed & put into production a Desmodranomic(I think I butchered the term) valve system. This is a fully mechanical system were by an additional 'follower' added to the valve captures the cam lobe. So the cam opens/closes the valve(s) w/ assistance of a small spring at lower rpm & a tensioning system of minuet travel to accommodate the mfg. tolerances to seal the valve into the valve pocket. I think that would be an interesting video, if you haven't made one all ready on the topic. I think that system could be used in any IC engine.
This is one of thise rare instances where reinventing the wheel actually happened and suceeded.
There is also a natural limit for steel springs. Stronger ones are heavier and so add mass to the valve they need to move. More mass -> more force needed -> bigger spring. Until you reach the limit.
Also coil springs resonate. That’s the reason why you often see a large spring with a small one inside. They have different resonance frequencies and together both resonance peaks flatten out.
Gas just behaves more ideal than bend iron. 😂
That's exactly it! Gas does just behave much better for this application😂
somebody get this man views 🙏🙏🙏
seriously this is awesome
Yes it is, share it with your group.
Haha thank you! I'm glad you enjoyed it!
Yeah this channel rules.
Very good explanation, even my antarctic cat understood the lecture
Thanks for an easy to understand look at pneumatic valve trains, nice graphics too.
Great video. Quality content, well edited.
Coil bind is another issue that limits how strong a coil spring can be made. The sum of all the spaces between the coils has to be less than the maximum valve lift.
What a great video! Excited to look through your catalog.
Thanks so much! Hope you find something else you enjoy too! I cover technical stuff like this but also have some videos more focused on history.
We need to develop rotary valves for IN and EX, those will require only a fraction of the torque needed to operate
Getting them to seal has always been the problem 🇦🇺
@@MICHAEL-ys3pu 🤔
Aspin engine
Just discovered your channel. Nice job on pneumatic valve springs. Looking forward to your presentations of other motorsport technologies.
Wow! That's some great valve train education. Learn something new every day. 😊
Very cool, great video!
Thank you!
Great presentation. Keep it up
Thanks so much!
There's one small thing you forgot, pneumatic springs don't have the mass of metal springs so as the cam lobe passes it's peak the poppet will actually apply force back to the cam sooner than with a metal spring return more of the initial opening load back to the engine. It also allow a more aggressive closing profile on the cam because the valve follows the ramp better.
This was brilliantly done! Subd!
Pneumatics come in to eliminate steel fatigue and surge in normal compression springs.
N2 is purely for dryness. Eliminates vapor pressure of any water vapor in air.
Tires are same except eliminating O2 saves tire inners from deterioration after many months/years.
It was the mass of the valve spring that was eliminated, and they were massive to even try to keep timing geometry correct.
Awesome content and engineering theory!
Thanks, glad you enjoyed it!
Thanks for posting this video I’ve been trying to get a clear explanation on this for about a year now.
You skipped over whole aspect of pneumatic valve springs. Due to the geometry of how cam lobes open the valve, the power required to operate the cam as it moves thru opening the valve is almost perfectly inverse to the power required operate the valve.
Wonderful explanation, thank you kindly! 👊🏼
Thanks so much!
Very good content, thx for the video 👍
The force to compress the spring is a side issue. Important number is torque required to turn the cam when in use.
He forgot to mention that like all metals, Valve springs have a 'Resonant Frequency' at which they begin to feedback the energy and fail. It also takes a specific time for the valve springs to do their job which limits the RPM they can achieve. The solution is being explored by Konesigegg with their 'Free Valve' engine which completely eliminates the camshaft and al other components of the Valve Train.
And yet they failed to release product to the market ¯\_(ツ)_/¯
They fill them with Nitrogen because its non corrosive to the seal compound and Nitrogen Molecules are larger than Oxygen Molecules so they can't get past the seal tolerances easily.
Perfect sound effect at 3:15
😂
Great video
With a reasonably large accumulation volume, you can also have "constant rate" pneumatic springs.
Or at least "near constant rate".
Yes you could get close to "constant" with a large enough volume
I actually sat in the car in the thumbnail when I wad really young at the lotus museum/HQ I can't rlly remember
I'm also assuming you have to be very careful on startup to make sure that you put the gas on. I mean if a engine sits, do the valves slowly loose pressure and then the valves sink down into the cylinder until somebody airs them back up?
Amazing history, narration and explanation! These wonderful videos deserves our like, comment and gratitude.
100/100
I would love to know more about the seals. Are they lubricated somehow?
To be honest, I couldn't find much info on this. I did find a few sources describing how it is difficult to keep oil out of them, so it's possible that engine oil might lubricate them, but I'm not 100% sure. Also possible they have their own lubricant
about springs. there are also all kinds of harmonics and traveling waves
Please please dona video on Eric Mann's "Mannic Beattie" race car!! It used a "gas turbine" that bled off compression to boost the 1.7 Sierra Cosworth engine to 700hp at over 40psi. People keep calling it a APU, it's literally a jet engine made from a turbocharger to boost the engine. The turbo runs off diesel
Nice video, good animation. But why is there a rocker arm in the animation when the camshaft is directly above the valves?
It’s a follower. A lot of overhead cam engines use followers like shown in the animation.
Among other things, they allow a higher (or lower depending on the location) lift ratio than you can get with the cam directly over the valve.
I understand, but in motorsport you want to eliminate as much moving parts (and weight) as possible, so it doesnt make sense especcialy when youre trying to chase high rpm’s.
Glad you enjoyed it! The reply from
9rjharper is correct.
@@MrEdmr2 It can also eliminate side loading on the valve stem and guide caused by cam rotation.
In fact they don’t go beyond 11000 because of turbo/fuel flow. The pneumatic valves become really a must when the V10 Renault went over the 15000 in 92 and subsequent yrs.
FIRE VID. I’m trying to figure out why teams haven’t put more effort into electromagnetic valve actuation?? seems like it would save the need for a camshaft or at least replace it with a computer of sorts that could for sure save space, and hopefully in turn weight as well. do you think it’s just costly, they don’t view the pros to outweigh the cons, or has truly no one been able to figure it out? (that last one i doubt)
Also I just thought of this, but do you know exactly how much pressure is regulated inside the system before the PRV discharges nitro? How much is it designed for?
that's a lot simpler than i had imagined. i was thinking they opened pneumatically also.
marine 2 strokes which run at less then 100rpm also use pneumatic valve springs
Interesting, didn't know that! Thanks for sharing!
Poppet valves on a two stroke?
@gothicpagan.666 I'm interested to know more as well. I've never seen a two stroke with poppet valves but I'm not as familiar with the world of two strokes in general.
Doing some searching I found this:
ruclips.net/video/WFity0Tc1js/видео.htmlsi=Narkbr3DkLltdbWx
Looks like they're used on an exhaust valve on this marine engine. Fascinating!
@@themotorsportstory RTA-flex goes further and has binned the camshaft for opening the exhaust valves
You over-simplified the gas compression equation by reducing it to Boyle's law which implies constant temperature. In a rapidly compressed or expanded gas, such as the case in point, there is not time for heat to flow across the walls so the gas eqn (p.v exp n =1) is appropriate where n is the polytropic index probably nearer 1.4 (adiabatic) than 1 (isothermal).
Good video. Took alot less psi than i imagined. I was thinking a thousand psi.
The base spring perch also needs reinforcement with higher rates. The pneumatic setup does not need it.
Engines with an OverHead Camshaft doesn't have rocker arm to push down the valves of the engine, it's only used on engine with the camshaft in the center of the V.
ThankYou !!!
I was expecting you to discuss desmodromic valve systems as well , like Ducati’s. With them, valve floating is avoided.
If a small tank allows to drive pretty far, there is absolutely no problem to use a small electric pump to periodically pump up a small reservoir for the valves. Of course with normal air.
Are solenoid top ends a thing? I recall speaking about them for ag applications in the 2000s
Why they didn’t use rotary valves?
Gretings✌🏻
Friction\heat and sealing difficulties...
Rotary valves open slowly, are only wide open for an instant, and close slowly. Poppet valves hammer open, stay fully open for a designed duration, then slam shut allowing more gas flow.@@thiswillprobhrt
Is there an other kinds of gases that have been tried???
With the advances that have been made with 3D printing I wonder if anyone has tried, or if it would be legal to have parts of an F1 car's bodywork constructed from capillary air ducts. The labyrinth of capillary tubes could be designed to change the direction and flow of the air, both to improve cooling and improve stability.
In theory, the ducting could even include micro switches that closed or opened the ducting so when corning the side which would benefit from more downforce could have air redirected from the other side passed through the bodywork.
What's about the desmodromic engine from Ducati? Wouldn't it work for F1 too? Or any racecar?
Don't forget that too little force when the valve is seated can result in valve bounce as the valve returns to its seat at ever-increasing rates, as the engine rpm is elevated!
To me Desmodromic distribution like a Ducati’s design is eliminating all valve springs altogether by using one cam pushing down the valves to open and another complimenting cam pushing up and closing the valve down and maintaining it close. This is the ultimate road worthy high rpm solution…but both maintaining the valve closed without any spring load and limiting the impact shock valve to the fixed valve Stellite seat is then the main high precision and hot and cold issue to resolve…😂
someday someone will come up with a clean two stroke engine architecture and then F1 power will double and F1 cars will sound absolutely insane.
if you think petrol engines are going to be replaced by electric anytime soon then I've got a bridge to sell you too.
Two strokes will never come back. If you burn oil it’s dirty and dirty is not a good thing.. if you think they will, you might like to buy the Sydney Opera House.🇦🇺
@@MICHAEL-ys3pu current 2 strokes burn oil, that doesn't mean they always have to. hence why i said "clean" in "clean 2 stroke". i'll pass on the opera house, probably doesn't garner much ticket revenue if you're representative of the potential patronage.
On the infintesimally small chance that the guy that didn't get this during my interview at the UK atomic energy institute sees this - see I told you :) I hope your conviction that pneumatic valves don't have a camshaft keeps you up at night :)
With a turbo the new 1.6l never have to rev to 15k more like 11k in race 12k in qualify.......thats it not like use to be
Rx8 mentioned 🎉🎉🎉🎉🎉🎉
🔻
Excelente explicação 👏👏👏
Thank you so much, bro! Best video ever about valves...
Glad you enjoyed it!
Where does the progressive rate come from if F=1/V?
Koenigsegg: freevalve.
Renault: pneumatic-spring valve.
you have the order backwards.
Interesting video there. But you don t say how much max rpm this new technology allowed Renault engines running in 1986. It would be an interesting fact to compare with other engine suppliers at the time it was introduced.
Why not pipe engine exhaust pressure thru check valve to fill valve chamber?
Makes me wonder how honda and other motorcycle manufacturer had engines in the 90s that reved to 18-20k
Less valvetrain inertia.
Thank you ❤
Now do a video on solenoid operated valves
the lower pressure at low lift, means the valve seats are not slammed and beaten to fail.
I just want to say I appreciate your video titles.
You give a vague hook followed by exactly what you're going to explain.
Clickbaiters should learn from this.
Thanks, I really appreciate this as it's exactly what I'm trying to do! The way RUclips works, you have to hook people in with something or your video won't get any views, but it's never my intention to deceive anybody or bait them with something that isn't actually in the video.
🤯🤯🤯 omg that is extraordinary to think such an incredible idea came (renault of all teams) by dumping springs for pneumatic has completely changed f1 forever i must congratulate you tms in making this video and have a great day bye now😊.
You say Renault of all teams, but you have to remember that Renault invented the turbocharger, supercharger, driveshaft and mass damper, introduced the turbo in F1, have won many titles as an engine supplier and 2 as a constructor, and won the first ever grand prix
@BurningmonkeyGTR oops i forgot how innovative renault was in history and one more thing to say is do you know of renault van with f1 engine.
@@milfordh.mercado2787 you mean the Espace F1?
Glad you enjoyed it! Thanks as always for watching!
@themotorsportstory 😃😃😃 A big thanks to you sir as usual wanting for part 2 of odd race cars in the future bye now.
If my memory swerves me right, some of the American V8 monsters from the '60s were using hydraulic valve mechanisms, not because they were high-revving, but because they were quieter. You have to be careful saying who invented what, and when.
The Mercedes F1 engine in the mid 1950s used desomodromic valve actuation... no valve springs at all (pneumatic or steel)... therefore no spring pressure for the cams to overcome.
Desmodromics are (IMHO) the ultimate poppet valve actuation system. Ducati is currently the only engine manufacturer embracing desmo valve actuation.
Why no mention of desmo?
History lesson ends and explanation starts at 5:40
History ends now with Renault leaving the engine game
Valve float....chey bad about it at higher rpm spring just can't bounce back fast enough.... cause loss of valve control which leads to rpm loss or worse
Lol . Worse , I think , was meant !
@@davidyendoll5903 lol thanks 😆👍👍
why they don't use someting like the desmodromic system from ducati?
Courtesy comment for an excellent video!
Great vid! I'm amazed pneumatic valves haven't got the attention they deserved over the years.
They're comparable to ground effects as far as their importance to the sport in my stoned opinion 🤔
Thank you! Yeah, there isn't much info out there on them by comparison which might be one reason. I suppose F1 teams don't want to give out too much design info
Why are they not use another crankshaft for valves?
Good video, but don't apologize for the "complex math". It isn't, and if people don't get it, too bad. I honestly didn't realize that this was the level of simplicity that Renault had come up with. I thought that the opening of each valve was controlled with a pneumatic solenoid rather than just replacing the spring. I thought with a pneumatic solenoid the benefits would be major: 1. INFINITE valve timing all adjustable with computer, and 2. Simplified engine design with no camshaft requirement.
Thank you, glad you enjoyed it! I'm not positive but I believe that F1 cars can't have variable valve timing per the rules which might be why there is no computer control.
Why not a Desmodromic setup ?
Yup variable Timing n kinetic energy and 1600 kw n sodium filled valves springless pneumatic gas for cooling 200 degrees cooler
Im not sure if your theory about gas is completely correct, that you can just assume that one side of the equation has very small variations and can be set as a constant, because as pressure increases so does temperature and vice versa when decompressing. Setting temperature as a constant throughout the cycle of compression and decompression would completely disregard this fact. Its basically disregarding mechanical work that happends when you compress a chamber of gas but im not sure how this impacts the equation and how the valve is pressing against the camshaft over its travel
Thanks for the comment! You're absolutely correct that the temperature will change. The assumption wasn't made to ignore that fact but more to simplify the equation to a point where it could be compared to a regular spring which only has the variables of spring force and distance of compression or extension; which can be compared to pressure and volume of the pneumatic spring. Regardless of the temperature changing, the progressive curve will still be there, it just might look more flat or more sloped depending on what the numbers work out to. I probably could have done a better job of justifying the assumptions in the video, but the main idea was to illustrate that progressive curve in as simple of a way as possible for people who might not have much of an understanding of math or physics.
@@themotorsportstory Actually when I took a closer look at the numbers it seems like the pressure will increase more exponentially when you have temperature as variable so the original calculation actually underestimates the effect. Anyways, great video and thanks for the answer!
@@easybuckets9740 Interesting! Thanks for looking into that and I'm glad you enjoyed the video!
I honestly had no idea this was a thing. Iv only heard of koenigseggs innovation to valves
The one that is vaporware?
@@robertsaca3512 camless freevalve technology
Wouldn't spring compression energy be given back when it expands?
Yes, in theory, but in reality you're also dealing with increased friction which will lead to an energy loss, plus severely increased wear on the rubbing surfaces of cam and follower.
Roger's reply nailed it! I probably could have made this more clear in the video, but was trying to keep everything at a relatively elementary level.
Besides what the other person explained, the valve train also has inertia, so when the cam is on the closing side of the lobe, the valve spring isn’t push back with as much force as it was when opening. If you know what valve float is, imagine that (except not necessarily to the extent of being completely off the lobe).
@@themotorsportstory They get no energy back if the spring can't close fast enough to keep up with the cam.
And I was expecting the air pressure to open & close the valves
Had these in marine engines for 40 years
So why not just use progressive valve springs. I understand it still has the other flaws but wouldnt a progressive spring be better than a linear?
When you get stranded on the side of the road because the nitrogen tank is depleted, that is when you truly ran out of gas.
Why not use Desmodromic valve train?
Why not Desmodronic valves like the Ducati?
Honda had traditional valves revving up to 22,000 rpm in the SIXTIES.
Easy with mini-engines.... Honda RC-116 50cc bicylinders.... small strokes and very light parts.... It's almost model-making at this level.
The f1 engine is designed to rev that high. Same as motorcycles designed to rev higher than car engines. The reason is that torque is not needed for f1 engines, i.e. racing up a hill or up a very high mountain pass plus being very lightweight racing cars property all F1 cars nowadays are under 1 ton (2000 lbs). Most FIA F1 tracks have very little elevation changes. Spa has the most elevation changes 102.2 m. However, there is no clue if the slopes are a gradual rise or a sudden/fast rise. Maybe someone has information and can share slope ratio information for Spa.