FreeValve Isn't a Big Deal. Here's why

[@trumanhw]

CAN WE PLEASE all take a minute to acknowledge how GENIUSLY he explained what a cam does ... both graphically, and, by explaining that it's a physical (metallic) punchcard basically. It's basically software embedded in the hardware. And I'll bet it wasn't quick for him to make those graphics that we experienced for all of 10 seconds ... and probably took him a few hours!

[@eriktempelman2097]

I will take more than a minute 😊

[@peytonj1599]

Well said very well done been a mechanic 40 + yrs and this was absolutely perfectly presented !!!

[@prabhusankar8346]

Oh yeah !!

[@gottliebdee263]

The guy is the best I’ve seen on KZbin, (well actually he ties for top spot with the guy from, ‘Engineering Explained’). Don’t agree with everything he says but he’s so far ahead of the motoring journos that think they know everything, Clarkson, Hammond and a few others I can’t mention right now.

[@vejet]

Never realized a cam shaft was really so damn basic 😮

[@TheGorf]

In the mid-90's in college (EE degree) we built a valve control system that was operated via electrical actuation. We wrote all the code with 68HC stuff. The code was pretty trivial. Finding mechanical solutions that worked reliably and would do so under the conditions of an engine was super difficult. We never got it to idle more then a couple minutes at a time. Fun project though.

[@memadmax69]

The good ol days. Now we can do all that stuff with an apple watch.... while watching a 4k vid... and messaging our folks. ^.^

[@PinkFZeppelin]

Damn that’s pretty cool. Young self taught software engineer here (28yo 5yoe). I’ve done some binary and bitwise coding for building controls with modbus and bacnet protocols. I’d love to cross the bridge into electrical engineering and microcontrollers like you have. I would probably default to raspberry pi as proof of concept, which is the baby version of working with those old microcontrollers IMO.

[@BlackCatRedScarf]

68HC... I still got ECU with these things. It's a really great choice for these systems that must work with a reliable timing.

[@Ozhull]

​@@memadmax69 uh, no we can't. Kinda the point of the video.

[@magran17]

So very cool! The Mech & EE at UVic (Victoria, BC, Canada) did a single cylinder engine in 1990-91 with solenoids. I unfortunately had to stop EE and go to CS, so I did not see results and lost track of those involved. Where did you go to school?

[@defnotatroll]

This brother is a genius. Explains stuff so well

[@endurofan9854]

agreed 👌

[@pjschafer5786]

even if I had been thinking the way he does (which.., pat myself on the back - I have).. I don't have the eloquence, factual research, simple yet great video to be able to explain like him.. truly gifted

[@StarCo11]

Saw the comment, and was skeptic… then, after few minutes… i agree ☝️

[@richsackett3423]

You’re easily fooled. Be careful.

[@crisnmaryfam7344]

yeah, sometimes, other times he just repeats false information he read online and is Sooo far off the mark its not even funny.

[@gbaldonado]

One possible good use for Freevalve is instead of trying to make a little engine more powerful, make a big engine more efficient and versatile. For instance, you can have a 800hp V8 monster that can also cruise around town or on the highway and get really good gas mileage when all 800hp isn't needed. That's something that wasn't covered in this video.

[@carlossmith7043]

👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏 EXACTLY !!! He just compared the numbers, when we know the main difference is shown on graphics, at real world use.

[@olivierb9716]

so, an expensive cars , useless on the road.

[@mitchdaks6363]

It was covered... sort of - just not dwelled upon as you want. The exact counterpoint was made vis-a-vis the Corolla GR - 300hp from a 3cyl 1.6L, factory warranty, Toyota refinement, and.... 21/28 mpg. This engine is quite literally a rolling and affordable example of why Freevalve improvement is much more marginal then the marketing claims. You will not be finding any 800hp V8's getting a similar 21/28 merely due to Freevalve - the physics of increased friction surfaces alone will insure that. moreover... exactly how many people who can afford a 800hp V8 vehicle care one whit about good gas mileage while merely "cruising around town"?

[@arthurhq5741]

Big V8s are not inefficient because of valve timing. They're inefficient because they are big and have 8 cylinders.

[@WilliamKennedywmk3]

@@mitchdaks6363 He forgot to mention that the Corolla GR also comes turbocharged.

[@elektro3000]

Back when BMW introduced Valvetronic on top of Double VANOS, I thought the combination was super impressive. Those engines could optimize intake and exhaust flow at almost any RPM and run with the throttle plate full open all the time, what more could you ask for? But Multiair is incredible and FIAT sort of changed the game without anybody here in the US even noticing. It basically does everything on the intake side that Freevalve can do.

[@chehystpewpur4754]

vanos was a joke and so is bmw. i owned an old e39 that was specifically bought because it was pre vanos. they ran better had less problems and made more top end power. imagine that.

[@graham7513]

@@chehystpewpur4754 Even if it's true that the pre-VANOS M62 made more power than the VANOS equipped M62's, the VANOS was not the ONLY difference between the non-VANOS and VANOS equipped M62 engines. What is a fact is that the Valvetronic equipped N62 made more significantly more power AND torque than any M62. 50 more HP and 30N-m more torque, and it made that peak torque earlier, and made torque for many more RPM's.

[@chiraedisk702]

@@chehystpewpur4754 I grew up with one, inherited one, and maintained one. The issue isn't that they're bad and non vanos runs better. It's that the seals go bad, but not enough for people to notice over the time it goes bad. So the car gets worse but at a snails pace. You can rebuild/replace the system real cheap, but it's a pain in the ass as it involves basically taking apart the case. Removing the front of the car work. If you're a car person, this is cheap. If not? oof. BMW is cheap to self-maintain, but not otherwise. So with the second hand market being what it is for BMW, you get a lot of newer drivers and generally lower/middle class peeps that can't do the work AND can't afford to pay someone to do the maint. You end up with a lot of cars with VANOS going bad and no longer functioning. Crazy part is, there's no engine light for it. My car went from being capable of 30mpg to 20 on a good day on the highway. Thing ran great with the automatic 4 speed transmission but boy was it more fuel dump than optimization to get its power still.

[@PVi01]

You do a really good job! As an ex-petrol-head, let me thank you for your continuous explanation and uncovering of secrets that once in a time bothered me!

[@d4a]

Thank you, much appreciated.

[@nuttyDesignAndFab]

another neat trick with freevalve is that you don't need a wastegate anymore, half the exhaust valves (1 per cyl) are connected to the turbo, half past it; by varying the amount each opens you can control boost

[@d4a]

True, and it also eliminates the need for a pre-cat. Of course there are benefits, no doubt about that. I'm just saying the cost and complexity is massive to achieve them.

[@flappingflight8537]

@@d4aactually it’s much simpler than some sophisticated mechanical systems ,also it has great potential for reducing the cost since you have to produce 16 identical parts ( for one 4 cylinder engine ) , as is known the quantity bring the price down and the actuators can be standardized and used on every brand and model car .

[@endurofan9854]

@Flapping Flight thats easy to think it is, but the materials used for even just 1 is possibly costly than a set of head parts like 16 valves plus the cam plus the springs, its like comparing price of an electricfan with an airconditioning

[@lqr824]

@@flappingflight8537 I understand what you're saying but there must be big reasons not to use it, because no-one's using it. You say it's "much simpler than some sophisticated mechanical systems" but none of these greedy competitive car manufacturers are switching to it. It may be that this "much simpler" approach actually costs more and is less reliable. It actually doesn't matter how complex something is as long as it works great for a long time! My Canon R5 has probably 100x the parts of my old Leica M6 camera. But it's far cheaper and far more reliable. So who cares about the parts count? And sure, there are efficiencies of scale, but the production run of current engines already has reduced the cost of the engineering and factory cost to only a few percent of the final cost. There may be a huge gain to turn a production run of 100 items into 1000, or 1000 into 100k, but little to gain by turning a production run of 1M items into 5M.

[@flappingflight8537]

@@endurofan9854 most probably it isn’t absolutely ready yet . On the rest you are wrong . Producing precision mechanical parts is much more complicated , time consuming and costly than producing pneumo- electric actuators .

[@hpa101]

Great content as always. We constantly get course requests for 'FreeValve tuning' despite the fact no one owns or has access to tune such an application! The Chinese development was exciting at the time and even though this isn't quite as magical as people believe off the cuff, I was still interested to see something come from that. If nothing else at least we got that awesome MX5/Miata build to watch 😂 - Taz,

[@maracaman1]

I hope Wesley is still doing something with the Miata, that was great project.

[@TheWinjin]

Let me guess, people also come often for these Bose electric suspension things?)

[@conanruisi]

“No one owns or has access to such applications” Literally all you have to do is contact freevalve and get them to send you an engine, but alright lol

[@slybesker]

I think they request it bcs such course would perfectly explain camshafts and valves timings and what it does to your engine.

[@Narinjas]

My take in FreeValve is that the most useful feature is figuring out how to improve an engine, so it should be a manufacturer tool to figure out the most efficient while still powerful and with good emissions variable cam profiles and timings for production vehicles.

[@danshort3147]

I’m 50 years old and a hot Rodder ,when I’m watching these videos, I learn all kinds of new stuff .THANK YOU ever so much.

[@TMmodify]

It's the first vid I'm watching on your channel and I wanted to wait until the end of the vid but I can't. You're just too good. Simultaneously very clear and very thorough, impeccable scripting and delivery... I loved every bit of it

[@brainkill7034]

First of his videos I have seen as well and I also enjoyed it. Thanks for sharing.

[@bigshotcelebrity_]

Design yourself into a corner with a hundred million or so on the line and anyone will come up with a groundbreaking and revolutionary new idea. Even if it never makes it into a road car its gotten a lot of people talking about Koenigsegg for the past 10 years I'd consider that a success.

[@darkally1235]

Excellent video. I think you are quite correct. Freevalve (or similar non-camshaft technologies) makes the most sense on hypercars or similar cars where the top priority is maximum performance, cost be damned. What Freevalve does is allow the engine to reach that maximum performance over the entire rev / speed / torque range while also providing acceptable drivability at city driving speeds and also meeting emissions and fuel economy mandates.

[@m.k.1340]

Actually, once fully implemented and developed, it can theoretically make mainstream engines better, and require less overhead capacity. It can probably make an incremental improvement the same way that VVT, direct fuel injection, turbocharging, and variable compression have, or at least have the capability of. And with freevalve taking a step beyond mechanically-driven VVT, it can combine with the rest of those methods to make smaller, lower-displacement engines both more power efficient, and more fuel efficient across the RPM range, and keep cars performing as expected, not under-powered in their normal use cycles. It also clearly has capability in a true hybrid system, for Koenigsegg to be using it in Gemera as both a generator, and as a high-vehicle-speed kinetic energy source for direct drive, bypassing a kinetic-electric-kinetic double energy conversion at high heat, current, thermal, and velocity load, where EV drivetrains start to lose advantage.

[@darkally1235]

@@m.k.1340 Did you watch the entire video?

[@msmeyersmd8]

I hate turbos because of lifetime durability. They are only good to cook your steaks on the hood for 1-2 hours after shutdown. The heat degrades all of the plastics and lubricants much faster than a NA engine. I think FreeValve can improve low rpm power and torque without a turbo? Much better than these variable valve technology engines can without a turbo. Repairs have got to be simpler and cheaper? Once the costs per unit by increased scale of production occurred. This would make the engine percentage performance increase much better. 5% is still significant. I don't know the cost differential so my assessment depends on that considerably. Can anyone give me a ballpark cost differential?

[@mikaelwolgast2705]

agreed. A few % can be a huge deal on a hypercar but not a normal car.

[@bocahdongo7769]

@@msmeyersmd8 I don't know the exact figure. But each pneumatic valve failure only made your blood boil even more. Because those tiny thing require complete top disassembly. And there's 24 of them at least, ready to throw blink on your dashboard.

[@Dominik189]

Freevalve would have been absolutely groundbreaking and truly revolutionary... If it could have been made functional in 1990...

[@V0ID_beats]

i'm curious what made that impossible to happen besides not inventing it sooner?

[@RCmaniac667]

​@@V0ID_beats reliability and cold weather conditions maybe

[@Dominik189]

@@V0ID_beats ... 1990's era ECU tech if I'd had to guess.

[@richsackett3423]

@@Dominik189 Because you clearly are.

[@nobodynoone2500]

It almost was, but only in bespoke F1 engines.

[@eriktempelman2097]

Incremental innovation is hugely underrated. Great to see it getting quality playtime.

[@scottwatrous]

I would love to see Freevalve used on a modernized radial engine. It would simplify the construction quite a bit not needing cam rings and such. If naturally aspirated it would eliminate any need for an intake system entirely, so between all of that it would make a multi-row radial very simple to build.

[@irvinewayne4086]

Plain and simple: electric drive is not as efficient as a straight-forward mechanical drive😀

[@rafaelrp07]

My dream is to be used in a boxer 6 engine, cause it does not need timing chain or any other source of mechanical syncronization. It would overcome most downsides of a boxer engine, because it's also shorter than any variable valve time system and reduce width of the engine.

[@bocahdongo7769]

The problem is just.... modern radial engine are quite rare already and most manufacture opted to boxer engine. I mean, the point of radial engine is to make more power while sacrificing frontal area (which is not a big deal if you had big plane already), but about the big power, let's talk about elephant in the room shall we? Gas turbine engine

[@mobilememes1313]

I got a couple ideas if your interested in hearing em

[@thekraken1173]

If cars become simpler how will they sell replacement parts? Ingenious ideas won’t be used as they are less profittable.

[@johnmcdonnell81]

Another brilliant vid. I really liked the idea of Freevalve and that it came from a small and innovative company and genuinely sad to hear efficiency gains etc are not too great compared to modern engines. Also, I'm annoyed that Freevalve was compared to non VVT engines by Koenigsegg, I just can't get my head around that.

[@davidhollenshead4892]

Who does Koenigsegg sell cars to? the ultra wealthy. These are usually the people who make their money buy exploiting other people and not by innovative intelligent people. Why? Because smart people obtain the information they don't have before spending a lot of money. And when it comes to "super cars" they are usually super unreliable and super expensive to own. I'll challenge anyone to find a better sports car than the following: Miata, Camaro, Mustang GT*, 911 before Porsche screwed them up, some BMW products like the 2002tii before they became break my wallet, etc. etc. Every sports car that costs more than these also spends more time at the repair shop than it does on the road and thus sucks to own... [*I own a 2007 Mustang GT and it is a fine car to live with except for the shifter and seats, but then getting a Hurst gated shifter & Recaro seats fixed that. You can't fix the inherent problems that come with a Ferrari, Acura, Lexus, Corvette, Lamborghini, Maserati, Alfa Romeo, etc. because you can't fix a car made with soft metallurgy, thin sheet metal, fiberglass or duraplast for any price. Also said companies charge way too much for parts and have month long delays to get them with the exception of the Corvette...]

[@andrewhigdon8346]

Acura is essentially Honda and Lexus is essentially Toyota, both at the top of the list in the world for reliability. Lexus especially is well known for reliability eclipsing even Mercedes. The Italian car listed are high strung performance cars designed to handle extreme conditions and actually don’t do well when they sit or when they are not run hard. Very high revving engines have to be able to handle greater variations in expansion and contraction as the tolerances need to be tight when cold and not be too great when hot so thermal insulation is a must. At extreme RPMs the combustion chamber and exhaust manifolds have less time to recover from extreme combustion events, which is why your car’s engine gets hot and the exhaust systems makes crackling noises after a spirited drive. Heat destroys engine parts but is a side effect of exotic high performance cars. So they are designed to be driven hard, not sit, and not run hard while cold. Running the, hard cold does more damage than driving hard in general. The various components benefit from somewhat equal heating rates, and the mating surfaces stay sealed better when subjected to that kind d of heat cycle. One part getting hot rapidly while the mated part is still cool causes indiscernible warping or irregularities to those surfaces, so it’s a fine line between thermal coupling for predictable expansion and contraction, and thermal barrier for reducing unwanted excessive heat where it would be harmful. Wherever gaskets are needed at mating surfaces, a good thermal break can be had, and the gasket material is designed to help dissipate the heat also, but benefits greatly in certain places such as exhaust manifolds in transferring heat from the head to the manifold. The hotter the exhaust gases remain, the better the chamber can be scavenged and therefore make space for a more pure and homogenous air and fuel charge to enter. Aluminum dissipates heat better than iron as well as helps reduce weight. But it does expand and contract more, so all of these factors must be taken into consideration when manufacturing a high performance automobile. If you drive a Ferrari timidly, or let it sit for long periods, you will have problems.

[@eddnshoulders]

Freevalve wasn't created by Koenigsegg, but rather bought by them. It started off as part of the Scuderi split-cycle engine project in the early 2000s, trying to solve the problem that has always stalled the efforts to create a split-cycle engine - trying to inject the air with the fuel in the shortest possible time as close as possible to TDC. The valve speed and variable lift (control of the air mass) elements were potentially going to make the split-cycle engine finally work. Unfortunately, the demise of Scuderi is well-documented.

[@tracylemme1375]

I first heard of “electronic camshaft” about fifty years ago. The benefits were well known. A neat idea is to have the engine to be self starting. The major problem in those days was the actuator itself. There are already electronic controled in use for medium and slow speed Diesel engines. But they turn at a max RPM of 1000. I do wish manufacturers good luck in the development.

[@eDoc2020]

How could that lead to a self-starting engine?

[@medicenchepibe]

@@eDoc2020 You can open the intake valve, inject fuel, close it and ignite it. With a closed intake valve (normal camshaft engine with springs) that isn't possible.

[@eDoc2020]

@@medicenchepibe I suppose that could work if the cylinder happens to be near the top of the power stroke. This seems unlikely at first but with multiple cylinders chances are at least one of them is close enough.

[@tracylemme1375]

When the engine stops one of the pistons is near tdc on the compression stroke. A bit of fuel is injected into that cylinder and ignited. This makes the crank turn in reverse. Another cylinder with closed valves comes to compression and before tdc injection and ingnition occurs which gives enough energy to start the engine in the forward rotation. Quite a simple concept,but requires valve actuation not available with a traditional camshaft.

[@flappingflight8537]

Guys , if you are interested please check Mazda’s “ I stop “ start/ stop system , it use the same principle. The alternator load and the intake vacuum level ( throttle position)are used in order to stop the engine in convenient for self starting position . The piston in expansion stroke cylinder must be stopped after TDC , it works even if the piston is stopped up to 90 degrees after TDC .The direct injection inject some amount of fuel and multispark high energy ignition evaporate and ignite the mixture . The start is extremely fast , like the engine jump straight from 0 to 800RPM . Also this sometimes work on carbureted cars , because there after turning off the ignition , the crankshaft continues to turn on few revolutions which still suck fuel from the carburator but since the ignition is off , this fuel remain trapped in the cylinder which is in expansion stroke . If the car has multi spark ignition, then when you turn the ignition on again, the heat from the continuous sparks evaporate condensed fuel and ignite it . The start is amazingly fast as like momentary. Also 4 cylinder 4 stroke engines tend to stop most of the times in 2 positions ( the 4 pistons try to equalize in the middle of the stroke , the 6 cylinders has 3 such positions , the 8 cylinders 4 and the 12 cylinders 6 . On two stroke engines this positions numbers doubles . So the probability for the engine to stop in favorite for self starting position isn’t so low . I personally has such experience since my cars always been equipped with modified high energy ignition systems. Once one of the cars with 4cyl/4 stroke , carburetor engine self started after all night staying outside on - 20degree Celsius. Another one 3 cylinder/ 2 stroke engine have started by itself when turn the ignition on , many times . Unfortunately this was many moons ago when the mobile phones doesn’t existed yet , so I don’t have video on the events . Here is a video where two stroke / 2 cylinder motorcycle engine perform self starting multiple times consequently .And those motorcycles aren’t equipped with electric starters ! Enjoy! kzbin.info/www/bejne/bZi0Xqivfct2Z9U

[@phillm156]

The biggest possible advantage to Freevalve might be the reliability attributed to amount of moving parts. Modern complicated valve controls are sensitive to oil quality. Even with perfect maintenance, they are still high wear and most likely to cause problems in high mileage cars.

[@endurofan9854]

common failure realy come from lubrication, the more complex the internals the more sensitive they are, thats why old cars last longer because they only have a few and simple internal parts and

[@currymasterrace7153]

Considering the number of bmw engines with valvetronic and vanos with more than 350 000 km it seems that it’s not even that bad… (I only really know bmw)

[@-Jethro-]

Ironically, my first thought was that this seems just as complex as a variable valve timing cam system, and it’s relatively unproven. So I would worry that it would be less reliable.

[@BeNNstAh]

Another big advantage only becomes apparent if you plot the opening and closing of a valve in a graph. Since Freevalve is actuated with solenoids, it can open and close the valves almost instantly, compared to a regular cam and valve, where the valve follows the cam profile, and therefor opens and closes much slower than Freevalve would. This would mean a Freevalve engine is capable of a level of responsiveness that is previously only found in high end, purpose build race engines. Obviously technology such as BMW's Valvetronic and Fiats MultiAir do close this gap significantly, they also add complexion to the engine (certainly in Valvetronics case) which means more moving parts that can break (for instance, the Valvetronics shaft, the Valvetronic actuator) and more mass (and rotational mass). Even though Freevalve requires an air compressor, you won't have to drive two camshafts from the crank, which means less parasitic power loss in Freevalve. True, the advantages od Freevalve have become a little diminished, but Freevalve in itself raises the ceiling of theoretical performance.

[@phillm156]

@@currymasterrace7153 you must know some serious hardcore BMW enthusiasts. I know very few with mileage over 100k miles who have not done major Vanos work.

[@lorenzovettor2566]

Great explanations, great animations, great argoumentation. In 17 minutes you made clear the entire topic of freevalve. Absolutely brilliant.

[@personaldronerepair6141]

The Bob Ross of engines. I Love it. Thank you for the time in. Great video!

[@mogwix]

It's actually super impressive how manufacturers continue to improve efficiency in their modern engines. Things like mild or plugin hybrid, turbocharging, variable valve timing, variable valve lift, and variable compression have all made engines more efficient, more powerful, and more complex. Hopefully these technologies are reliable and relatively easy to maintain as the vehicles are used in the real world. It's great that the industry as a whole continues to innovate.

[@cannaroe1213]

the irony is that variable valve timing/lift/duration was all perfected in the 90s but patent disputes are the main reason we're only seeing those innovations 30 years later. The reduction in fuel costs alone afforded by optimal gas-control is like 30%, which if you told Exxon or Shell they'll be making 30% less money next year, they're probably not have the same optimistic attitude towards the technology. Hell if you really want to get nerdy, sleeve-valve engines (used to get WW2 bombers high into the air and run on dwindling fuel supplies) are still better in every respect to every technology listed in the video, except in the 40s they wore out slightly quicker than traditional valves. Why wasn't sleeve-valves "innovated" on? Because actually engine innovation is highly regulated, and slow.

[@davisjohnson5688]

GDI as well.

[@alphaforce6998]

@@cannaroe1213 You can blame it on "the government" or you can educate yourself on the Organic Laws of the United States and learn that unless you are infringing upon the rights of another man or woman by causing them injury or loss, you can do pretty much as you please. Decades of unquestioned ignorance, where people believe codified statutes are laws (but don't even know what the word "code" means), have resulted in these limp, spineless whiners who lay around hoping someone else does something.

[@chrisvig123]

Unfortunately any type of Rand D into ice engines at this point is kind of useless…electric engines are dead simple…far mor reliable….far more powerful and on another level of efficiency

[@cannaroe1213]

@@chrisvig123 There's no such thing as an electric engine. i think you mean electric motor - which of course has to be powered by something. Personally I think it'll be another 10 or 20 years until batteries reach the level of diesel. Some diesel generators are more efficient than the gas turbines used at the power plant.

[@phillgizmo8934]

It was positive to hear about Fiat's Multiair, because I was thinking that FreeValve patented old solenoid valve idea and was monopolizing it, which is not helping the tech developement sometimes. Reliability is still the main concern, failing of electronics cannot kill a camshaft engine normally, but a freevalve engine can be destroyed.

[@GTFour]

Yeah you’d want the solenoids to be super easy to individually replace

[@m.k.1340]

If reliability is primary, a camshaft, camshaft phaser, and the entire valve train is oil lubricated, and oil pressure drives the cam timing mechanisms in some cases... and the timing set still drives the camshafts regardless. With mechanical damage shedding metal shavings into that system, it gets destroyed. With oil starvation, that system gets destroyed, as the engine continues to drive the valve train. If the electronics or the air pressure system fails with Valvetronic... the valves close and fail to open. They don't continue to wear, they don't impact the piston in an interference engine design. The engine loses power in one cylinder, or shuts down, until the problem can be fixed... but the oil is less likely to be full of debris, there is no timing mechanism at all, and the pistons and valves themselves have likely not come into contact. The engine probably doesn't need a rebuild, it just needs the freevalve solenoids individually tested and replaced as necessary, or the pneumatic supply repaired.

[@3xeplodng_3agle_studios]

​@@m.k.1340 And all that's avoided in a cam engine by simply maintaining it properly. Moot point. To cover defective product, a freevalve system can be defective, and fail as a result as well.

[@Kirillissimus]

​@@m.k.1340With BMW Valvetronic the most common issue is as always electrical. The actual electric motor driving the thing dies and the thing gets stuck in some random setting. If you are lucky enough to have them in a somewhat open position then the throttle gets utilized as a backup and you can just slowly drive the thing to the repair shop. And even in the rare occasion when the thing dies on a still engine and the valves are all closed you can take the cover off an manually spin the motor and set the thing to a some intermediate position. I can only hope that FreeValve system has some valve retention springs so when the coils die the pistons would not hit the low hanging valves causing expensive engine damage.

[@sethschneider9764]

You're videos have taught me so much in the last year. Keep doing what you are doing man. The only argument I can come up with in favor of FreeValve is for tuning. It would be so simple and easy to completely change the nature of the engine with just a tune swap. You could jack up the valve overlap for the car show on the weekend in a second, and just as easily change it back for your drive to work on Monday. Obviously this is a very small reason and wouldn't be enough to justify the creation of the design, but it is cool to think about.

[@bluesky-ud9wg]

Yep your correct that basically the only benefit is tuning individual cylinders. Some things cannot be improved upon such as drive shafts, brake rotors, etc. On paper FV sounds great but in reality not worth the effort along with durability & longevity. It won't ever happen

[@ksavage681]

Also no changing timing belt every 60,000 miles.

[@bluesky-ud9wg]

@@ksavage681 Who has a T belt anymore?

[@Blaquer17]

I know you can get a "Ghost cam" tune for your 5.0 Coyote engine that does exactly that- it advances the cam to the max RPM setting at idle and gives your car the 60's muscle car engine lope. As soon as you hit the throttle, it goes back to the default settings for maximum power and torque.

[@bluesky-ud9wg]

@CannedCoochie So what's your point, that this is a viable valvetrain system because it's not yet, maybe someday but not now...

[@williamrgrant]

Fantastic video. It really gets to the heart of engineering - where you must wrestle with "what could be" but also "what makes sense". FreeValve is like a unicorn - so awe inspiring and the possibilities are magical! But you can still accomplish what you need to with a horse.

[@richardpetker4337]

Very well said!!

[@dalektrekkie]

I hope freevalve does come out eventually, but I more hope that they change their marketing to target the audience that would actually benefit from it; the people who restomod classic cars. As you pointed out, their numbers are only accurate if you compare them to those older engines, but the promise of being able to convert an older engine to hold similar power to a modern equivelant would be compelling to the people who like to push those older cars without swapping the engine or doing anything crazy to it.

[@dragonbutt]

Given the relative complexity of doing a "Freevalve head swap" without mega corporation money to back it up, its about as crazy as the SOHC conversions hotrodders were doing way back when, despite being in essence "Just a head swap".

[@darrencurry4429]

@@dragonbutt I could see this being packaged as a head swap solution. Possibly requiring only a hi-res encoder being mounted on the crank as well as an air compressor being added to the accessories.

[@laurisikio]

Now I really want a video about all the different valve lift and valve timing things you quickly mentioned in this video! I didn't know they are that common, I wish you could explain more carefully how they work and what are the most used types

[@leoneloliveira5829]

i want too i upvoted

[@endurofan9854]

i believe there are already a bunch of videos about that, other than d4a

[@laurisikio]

@@endurofan9854 other than d4a = nowhere near as good

[@dielaughing73]

Engineering Explained has a good video on Nissan's VVEL system. I found it worked really well on my 370Z. Very linear power delivery.

[@KubuśpuchatekTVN]

Anything about v-tec probably

[@fremenondesand3896]

thanks for reminding me how cool the FIAT multiair system is.

[@JohnFrumFromAmerica]

Great analysis of diminishing returns in engineering. This is applicable to a lot of different technologies

[@garymanis6305]

The problem I remember with electronic actuation was speed. The electronic actuators struggled to keep up at 1500 rpm. Getting to 3000 rpm would make it usable on the street, but there would be little to no benefit. The main idea being to provide optimal power and efficiency over a broad rpm range.

[@Real_MisterSir]

I think the main part being overlooked here, is how Freevalve scales linearly -meaning that you just have one unit (valve system) that you can expand depending on the amount of cylinders, their position, and layout. You don't have any gearing, shafts, and pulleys you need to worry about, only the electrical cables and hoses that are adaptable by default with no extra cost. So if you have an i3 engine, or a W16 engine, the actual piston can stay the same you just add more depending on the need. This is something that you previously could never do when you had to customize the shafts and valve interaction and housing blocks to accommodate the wear of all the moving components depending on the type of engine, rpm, etc. One of the key reasons Freevalve hasn't been adopted, first of all is due to manufacturers wanting to do as much inhouse production as possible, and when sharing platforms with not just multiple car models, but also across multiple brands, the overall cost difference diminishes so the idea of buying from an external supplier is less relevant, especially when they already have r&d invested into their own in-house alternatives that may get close to the performance and efficiency. Lastly, a main point is also that the major established automakers are diverting more and more funds into green alternatives like electric, so spending extra cost on a system like Freevalve that only optimizes the products that are getting phased out year by year, makes little sense. Realistically, the benefits simply aren't enough to outweigh the already standardized methods and strategies. For big companies to shift their internal structure like this, they would need a much better reason than "5-10% real world difference" for the applications they may have in mind. Also COVID didn't do the Freevalve implementation any favors either, so realistically it's only a few years of adoption period which is by no means enough to make any radical shifts. Where companies do invest, is in systems that they know they will have to change sooner or later, which means hybrid and electric is at the forefront, so any new expenditures will go to that direction before looking into things like Freevalve. Big ships take a long time to turn, especially when the turn isn't strictly mandatory they'll rather stick with their existing course for as long as possible, as that is consistent and predictable.

[@zahjav]

Freevalve sounds way more interesting from a manufacturers perspective, and I think the technology could be waaaaay more useful in other applications than "performance". Valves could eventually just become modules you swap out, resync digitally, and go. It would remove failure points of a complex mechanical cylinder shut off system, and would reduce the cost of manufacturing a complex cam shaft. Furthermore, the Suze reduction might not help with conventional inline or V shape engines, but what about Boxers? Or wat about reliability for heavy duty applications? Extend service life for various mechanical components by adjusting valve settings for minimum wear in adverse conditions. I think these are very real potential benefits, just not for performance. Maybe thus will be the future for hybrids?

[@hozisalehi]

I was also hyped back in the day when they announced it, I would imagine the kind of cars and power curves would've been possible. And the thought of something like freevalve in the aftermarket scene made me really excited. I'd even tell my old man about it and he would also be excited about this new tech. But then yeah, reality happened, technology advanced. And you're absolutely right, we could be sad that it didn't happen fast enough to the point it may not be that awesome game changer anymore, but we should be happy about how far we've come.

[@petermoller8337]

Turbo air induction ICE is dead electric gives max torque from zero rpm

[@rpatrick2]

@@petermoller8337 that's where hybrid diesel for Semi Trucks will really shine for emissions and operator costs, as well as combined hybrid to get performance and range for the mild sports car market. I wish the CRZ was able to run on electric alone so I could pull away in 1st without touching the clutch.

[@Ramsi-Berlin]

I don't think ICE's are dead and electric cars are the future ❕😅 I believe in 5-10 years, they will realise that the whole E-Cars thing, isn't the right way ❕😂

[@flappingflight8537]

@NbomberI would say Plug-in hybrids with around 50miles pure electric range . Will be ideal if they use CNG/LNG fuel .

[@gilsonrogeriolimaoliveira2807]

​@@flappingflight8537these gases are hard to contain. Better use the methanol from renewable energy, just like the Gemera uses.

[@carmencrincoli]

Your scripts and narration are so immaculately put together that I have essentially stopped following other automotive creators on KZbin. Their content isn't bad, but as someone who has an engineer's heart pumping inside him, I value the kind of clear and factual explanations you excel at. Thank you so much for your passion and commitment to your channel.

[@oldolfmann8927]

You should never stop listening to others. Yes, this guy is great, but in this video he is wrong on so many statements. So many I don't have the time or the want to list them all, but just as an example, at 13:44 he mentions just sticking freevalve on a regular engine and you wont get great results.... No Duh! The engine needs to be designed specifically for a free valve tech. If you don't understand that, then I do understand why you don't watch others anymore.

[@carmencrincoli]

@@oldolfmann8927 I think perhaps you missed his intent. That statement was clearly making a point that the extra efficiencies that FreeValve promises with their marketing statements are simply not available if they were to be retrofitted to an existing modern engine with another form of variable valve control. That is literally the thesis behind the entire video. FreeValve does what it promises, but it's not revolutionary when so many other forms of valve timing have been created and implemented across the industry already without it.

[@johngiraldi1150]

Back in the early 80's I had to analyze the error-detection capabilities of small 8 and 16-bit microprocessors that would be used to operate the solenoids for an electronically controlled valve system in an engine being developed by a large automotive company. This analysis was not for the automotive company but for a potential bid by my employer to supply a "better" microprocessor. There is a mean-time-between-failure (MTBF) for digital circuits especially in the harsh environment of an engine compartment. There is always a possibility that a solenoid-controlled valve will open when not intended and while the piston is in full compression thereby causing damage to both. This can be mitigated by sufficient error-detection in the digital system to prevent this condition. However, there are a predictable number of engines that will sustain damage while under warranty because of undetected circuit failures. At that time the estimate of the costs of warranty repair exceeded the cost benefits of the digital valve control system given the lower error-detection capabilities of existing microprocessors. IMHO, the traditional/improved mechanical methods mentioned still appear to be a more economical solution for automotive companies.

[@Soho9111]

As an electrical engineer I so much enjoy your videos 👍🏼 keep it up

[@chocolatethunder3218]

One major aspect to consider that I thinks has been overlooked is the massive reduction in friction surfaces that Freevalve could theoretically have. almost All of the major failures from modern engines come from lack of lubrication in one way or another, so if there is a technology that stands to make modern engines more reliable, my money would be on Freevalve.

[@karlisbanis2442]

Another aspect that has been overlooked is the valve control, i.e. acceleration and deceleration curves, especially as it nears the valve seat. If I recall correctly, this has been a major problem with freevalve and it will take a serious chunk out of longevity of the system. If I had to imagine this system entering a second hand market like eastern Europe where the majority of cars are driven past half a million km mark, somehow I just don't see this system surviving, the maintenance must be a nightmare. If we are about to advertise the green ideology then making things last is paramount, otherwise we offset the benefits in more frequent manufacturing.

[@MikkoRantalainen]

@@karlisbanis2442 The lifetime of the valvetime solenoids is also totally unknown. I would assume the the lifetime problems is the cause for the delays.

[@silentsushix3]

haha... you Koenigsegg fanboys....

[@MikkoRantalainen]

@@GeorgeWashingtonLaserMusket Yes, when you consider how many parts a single freevalve solenoid has inside, it's far from simple solution. Basically one solenoid is replacing one segment of valve lift cam and the valve spring. That's total of 2 parts. If (/when!) freevalve solenoid has more than 2 parts, the probability of failure goes up, not down. As a result, the solenoid requires higher manufacturing quality to result in similar lifespan. That doesn't exactly sound like the cheap solution, which is probably why it hasn't taken off. In theory, freevalve is a great product still.

[@Dowlphin]

It might just shift the reliability issue to a different area. Freevalve has the potential to brick your engine with one tiny glitch, no?

[@aboyd1988]

Very nice video. I wonder if the delay in adoption/implementation of FreeValve has to do with reliability concerns. I work in an industry where the German-made manufacturing machines use numerous, expensive neumatic controllers. These controllers fail often and need to be replaced. Usually they fail to actuate, but sometimes they stick open. Imagine an old-school timing belt lasting longer than a much more costly FreeValve actuator...💥😮

[@thebaddestogre-3698]

Oh man, can you imagine a valve sticking open at 8k rpm?😮

[@spacebound1969]

Or we had a 2 year pandemic that destroyed shipping and production lines all over the world.

[@mraaaaaaa]

Can't imagine those being more reliable than any VVT system today. I drive a BMW and would take a chance on FreeValve over Vanos...

[@kilura1]

It's been 15-20 years since marine 2-stroke main engines have changed to hydraulically controlled exhaust valves actuating system. And as of now this system doesn't give too much problems (I'm marine engineer and this is my responsibility to keep machinery in good condition) . And the system is used not only to control exhaust valve, but it also controls injection timings and some auxiliary machinery work. Pneumatic system that only controls valves, should be much more reliable then hydraulics. So I don't think it's about reliability issues.

[@jonf2009]

It's mostly to do with the giant push to remove gasoline as a vehicle fuel. Most auto manufacturers won't move on a new engine tech that they likely won't ever be able to use long term because nutters want us all to have giant paperweights that we can't charge.

[@UncleKennysPlace]

This reminds me of the way that CVTs were supposed to introduce huge performance and economy gains, before a simpler solution reared its head: more speeds in the gearbox.

[@thebaddestogre-3698]

Cvt's would be awesome if they had the torque capacity to handle super short launch gearing. Like having the "first" gear redline at like 15mph before it starts navigating through the ratios.

[@177SCmaro]

A torque converter combined with 10 gear ratios is like 90% of what a cvt can do.

[@camerone397]

@@thebaddestogre-3698 I think Toyota actually makes a transmission like that, IIRC

[@davidwickboldt712]

The problem is, those 10 speed trans are showing reliability problems. They are going to cost a fortune to be rebuilt, which is why they pull a bad one and put a new one in.

[@UncleKennysPlace]

@@kalmmonke5037 Stream of semi-consciousness. Chat GPT fails again.

[@chinabluewho]

9:30 1.6L engine putting out over 200 HP still impresses me as a kid of the 70's and growing up driving used 90 HP engines from 1.6L to 1.9L vehicles

[@JohnDoe-gn3rg]

1.6L engines are pushing 800+ in f1

[@hughturral2569]

So elegantly and clearly exxplained - like all your videos. A real pleasure to watch and I always learn plenty! Thanks.

[@Gabriel-vj1cf]

Fiats multi air is really cool and underrated.

[@Kirillissimus]

FIATs in general have very cool technologies. The most crazy ones are implemented in their AlfaRomeo cars with 2 spark plugs per cylinder and other monstrocities but more cost effective FIAT branded ones get their share of them too. I would evrn say that if you live in a dry climate so the weak italian electric connections can not cause any major problems then in terms of the amount of fun per dollar they are one of the best cars to own if not the best.

[@GBOtech-ukraine]

The similar story occured with liquid propane direct injection... where using gasoline fuel system looked very promising, but more than a decade later a vapor injection system took over by upgrading its components (injectors, ECU, reducer) and now the most sophisticated engines (direct turbo of dual injected turbo) run perfectly on LPG using a vapor system.

[@mrgcav]

Propane does not work with gasoline engines. Propane injection id for Diesels.

[@GBOtech-ukraine]

@@mrgcav would be great if you continue your comment with “because: …”

[@PedroBorgesNH]

There is also natural gas powered cars. In Brazil is very common to find "NGC (GNV in Portuguese)" kit for converting your gasoline engine to natural gas. There are a few drawbacks, like having to install a tank on the trunk of the car, and loss of performance, but the gas is cheaper than gasoline and fuel economy is much better. Its very common for fuel stations here to have natural gas available

[@rfrbz1269]

I think the big benefit of free valve would be repair simplicity. no complex linkages and oiling pathways like in some of the other VVT systems. VVT systems are so heavily reliant on using the correct oil viscosity and regular oil changes that regular consumers simply don't have the give a damn to keep up on, so a pneumatic/electric system really makes a lot of sense. Make it non-interference and you have the makings of a reliable economy vehicle. Never have to worry about timing chains. Fewer places to get oil leaks. If a valve solenoid fails, the computer can still keep the engine running until it can be fixed (2 intake valves per cylinder). The possibilities for high reliability make this technology super interesting to me.

[@nicholasagnew2792]

Ya know, it pisses me off that people are so quick to adopt new technology simply because it is new and dismiss proven century-old technology as if its garbage that they've merely been tolerating for their entire life. every good piece of automotive tech was invented in the 1960s at the latest. You've been on a roll lately man, really good stuff.

[@meltdown6165]

I saw an analysis that I found quite persuasive. You need about 20-25 machining operations for each freevalve solenoid. 12 solenoids in a 3 cylinder engine. Meanwhile, big manufacturers grind millions of camshafts for a dollar a piece.

[@williamjones11]

So the biggest advantage that I could think of regarding free valve is the ability to switch from Otto cycle to Atkinson cycle for fuel efficiency when you’re already at speed. But it looks like the various VVT mechanisms already in production could do this. Great video!

[@dirkmohrmann8960]

Yes Otto/Atkinson switching is pretty common already, Toyota does it in a few of their most popular engines

[@ksavage681]

Have fun changing timing belts on the old engines. lol

[@theowainwright7406]

Timing belts on a free valve engine?

[@Turboman_64]

What about Fiat Multiair engines? Those have been around for like 15 years or something and they have such technology for the intake valves, thus having 4 valves per cylinder with only one camshaft on the exhaust side and still having all those abilities on the intake side. I mean that concept on its own is not just not new, but it even is available in verry affordable cars for a long time now. Edit: never mind, i thought of that literally 10 seconds before you came to those engines in the video xD

[@michaelarchangel1163]

Did you not watch the entire video ? That was covered.

[@Turboman_64]

@@michaelarchangel1163 I did, i commented towards the end, just before it was covered. Hence my edit.

[@onlyeyeno]

@@Turboman_64 Yea that is why at least I personally never "post" a comment before having watched the whole video. I.m.h.o. it's akin to letting a person speak their whole sentence before objecting, or interjecting. It's a simple way of mitigating potential misunderstandings, while also avoiding making Yourself look a bit "out of the loop".. Best regards.

[@seanhammon6639]

Reel In Neck 😘

[@wesleydeer889]

Free valve is one of those things that sounds amazing in theory on paper, but it actually adds significant complexity and reliability issues due to pneumatic valves. The ideal valve is actually a rotary valve, driven hydraulically. We have the material and manufacturing capability to do this now using technical ceramics.

[@darthkarl99]

Actually the ideal valve is freevalve like, if it wasn't advanced racing engines, (even F1 where they have to be fairly reliable for a racing engine), would not use basically the same system. The problem is freevalve is going to take a good while to come down in price to a level thats mass affordable. Thats why it's been stuck in F1 engines since the 90's without going anywhere. It's just super expensive to do.

[@wesleydeer889]

@@darthkarl99 I’m talking theoretical. The ideal valve would not reciprocate, as that requires high power consumption to actuate, especially exhaust valves that have to push against hundreds of psi (exhaust gases) just to open. Free valve consumes KW’s of power. Rotary valves would also offer better, and shorter, flow paths. Problem is sealing, as is always, with rotary type devices. Google rotary valve, you’d have to see an illustration to really get it.

[@darthkarl99]

@@wesleydeer889 I get the feeling your thinking of what i've heard of as sleeve valves. They're a notorious pain to do, but also very powerful.

[@Toro_Da_Corsa]

But there is lots of variable valve systems on the marry today that are a total disaster. Like Ford F-150 engines. The phasers are a disaster. Or Audio V8's. Free valve might actually be simpler than some of the systems being used today

[@Toro_Da_Corsa]

​@@darthkarl99They made them work in WW2 planes

[@derekwoods8199]

I am a Mechanical Engineer in the automotive development field in the US, and must say this is one of the best channels I’ve found discussing and animating new (and old) powertrain technologies. Very well done!

[@IIGrayfoxII]

"Traditional Engines" may refer to Non Turbo Charged. Here a some other engines that could be "Compared" I used Honda as it rather easy for most people to understand their naming scheme. Honda B family which were performance based B16A: 150hp B16A(2nd gen): 170hp B16B: 180hp Honda D Family which were economy focused D16A: 130hp D16A1: 115hp D16A6: 110hp Honda R family, economy focused R16A:120hp Carburettor Equipped Honda 1.6l Engine EP: 94hp

[@Ralph19541954]

Wonderful explanation. You are terrific at explaining mechanical processes, as well as linking them to the practical use in vehicles. Kudos!

[@howlinhog]

I've been saying for years that the next big thing in IC motors is independent valve control. I still believe that. The technology just isn't quite here yet.

[@JohnFrumFromAmerica]

That is not what he is saying here. The take away is that the cost is likely not worth improvements.

[@Abrikosmanden]

Yet, this video clearly explains that it IS here.

[@Bahlzeron]

​@@JohnFrumFromAmerica not quite... the last part of the video shows examples of and describes other production independant valve systems, such as FIAT's (if I recall it was fiat) oil activated, computer controlled intake valves. OP stated independant valve control, not Freevalve specifically.

[@howlinhog]

@@Abrikosmanden Thanks Mr Obvious.

[@richsackett3423]

@@JohnFrumFromAmerica That's what he's saying, alright. He's wrong.

[@corystansbury]

I think it's important to remember that quite a few large OEM had running camless engines in the 90s. Similarly, GM had HCCI engines running in the 2000s. Neither are consumer products for (presumably) good reasons (yes, I'm aware of Skyactiv-X, which still isn't available in the U.S. and doesn't seem to fully deliver them promise of full HCCI).

[@erikscott5709]

GM has had electrically-operated valves going back to the late 70s or early 80s. They called them "helinoids" (helically wound solenoids). They were way too expensive for production but they used them to prototype cam grinds quickly.

[@KasperiVonSchrowe]

I think that Freevalve will eventually come but it will come because of manufacturing cost, not that much because of engine properties you mentioned in the video. To me, Freevalve is very simple and easy to assemble compared to typical variable cam system found in current cars. If you can cut 10% of engine production costs, it will happen.

[@maslascher]

We don't have problem with engine size. Complexity of cars and it's engines is whole different story and freevalve isn't gonna change that.

[@endurofan9854]

for me i think free valves are for those who are lazy to build up their skill and just rely on easy drivability issue 😅 it seems for sessy type people no offence

[@jaromirandel543]

Question: How does air speed affect the air-fuel mixing in engines with direct fuel injection?

[@marcchoo6254]

Although fuel is directly injected into the combustion chamber, the air is not. Therefore, the different velocities of the air at different RPM will still affect air-fuel mixing.

[@abdul-kabiralegbe5660]

I'm curious too.

[@stasisthebest]

The higher the speed, the more tumbling rotations, mixture acheves in the cylinder before ignition

[@mixalisstathis274]

as only fuel is injected and not a/f mix that might be the answer to your question. the faster the air enters the combustion chamber, the more tumbling and therefor a better mix will occur.

[@herressen1271]

If I got it right then in a di gasoline engine the fuel gets introduced as the intake valve closes (round about that point). I know it's not the best analogy but imagine like an mixer running at 2 speeds (that would be the air speed). Throw something into it which one mixes faster. Ofc the faster one. You can imagine the air twirling around in the cylinder and the faster it enters the more it twirls. I hope I could get the point across

[@ThisRandomUsername]

This really does hit the nail on the head. Matt from the Dirty Garage Guy channel did quite a nice video a few years ago about how it might work, and all the pitfalls you might face. It really does seem to overcomplicate things. Fiat's Multi-air is already pretty complex, but at least it's in production and is so close to the perfect system that it hardly makes sense to complicate things more.

[@SilvaDreams]

I mean it's a fairly simple thing to do and quite sure it was tried some 40 years ago. Some engineer likely already tossed the idea out but getting an actuator to run that fast and in a hot and rather hostile environment for more than a short period is likely why it was never gone with

[@ivanjacob_]

Multi-air actually seems like a way better and easier solution

[@BigUriel]

Thing is if you look at it it's a similar system to what has already been used for decades for unit injector systems on Diesel engines, it's a camshaft used to drive a hydraulic piston which has an electronically controlled return valve. It doesn't actually require that many additional components and it uses engine oil and the existing valve system. If FIAT hadn't patented it I think everybody would be using Multiair by now, it just makes sense. Freevalve was never going to take off when it basically requires a whole new engine head and a new compressed air system to boot (and when you have an air leak, as compressed air systems always do sooner or later, you lose pressure in the entire system and your engine won't work).

[@carlossmith7043]

​@BigUriel you say "and it uses engine oil and valves sistem that already exists" like loss of oil pressure was never happened before...

[@alexanderSydneyOz]

These are excellent videos. Thanks. Precisely expressed with not a hint of click bait, showmanship or irrelevant fluff.

[@nikobitan7294]

Oh god I appreciate so much that you actually explain the why's and the logical consequences of the things you're talking about in step-by-step way! Almost no-one else actually does that.

[@joaoluistavares6046]

To me, this is great to show us the reality. I also was very glad and even told others about this Free-valve tech it was first announced. But as time passed by, I started to wonder what was happening, like why weren't we seeing this tech in other production cars (as Chris had announced). You just gave me (and I believe others too) the answer.

[@danewhitmire1542]

Also whats interesting is that Tucker made essentially a freevalve back before 1948. When he first developed an engine for what would become the Tucker 48, before he chose to use a modified helicopter engine, he was developing a 500+ cu in engine that would use a special distributor to send pressurized oil to open the valves at a timing set by the distributor. This wasnt done for performance though, as it was common back then to puncture your oil pan and run your engine without oil, this destroying it. So tucker opted for this distirbutor oil valve tech so that your engine would shut off if it ever didnt have oil. This engine, which was going to drive twin fluid drive torque converters as a sort of CVT back then, never made it past prototyping, as it required mains voltage to crank, weighed a gargantuan amount, and wouldve been too expensive.

[@brainkill7034]

Don’t believe I’ve heard of that, very cool.

[@johnathansmith3819]

Most people discard the thought of it, but people like him made America "special" in the World. IMO, though. 👀👀

[@badrakhariunchimeg1031]

Can be re programmed spécialement

[@PahaLukki]

Variable Valve Timing already gives low rpm and high rpm customized cams. So you get your eco-drive cams and your overtaking cams. There is not much to be gained from additional "programming". Honda got it right.

[@QuakeGamerROTMG]

@GangBalls69_Estonia Yes. That technology from more than 30 years ago that is in shitbox Hondas you can buy for $3000 Truly unobtainable scifi tech that we need this ridiculous monstrosity to solve.

[@sirtra]

​​@GangBalls69_Estonia Honda VTEC = VVT+VVL

[@sirtra]

@GangBalls69_Estonia VTEC is a type of variable valve-timing system developed and used by Honda. It stands for V ariable Valve T iming & Lift E lectronic C ontrol. Learn how to use a search engine bro, its right there at your fingertips!

[@sirtra]

@GangBalls69_Estonia en.m.wikipedia.org/wiki/VTEC ☠️

[@sirtra]

@GangBalls69_Estonia "nope, vtec doesn't include variable valve timing" Whats the VT in VTEC stand for? ☠️

[@RPO767]

What an excellent presentation. Very interesting, educational stuff here. You point out many unreailized and innovative capabilities a number of modern engines already have. Thank you!

[@bofty]

I’ve learnt more about how engines work in this video than I ever had, and I thought I had a good handle on it already. Fantastic video

[@srinitaaigaura]

Also one more example, it may be possible for Freevalve to achieve extremely high revs in future supercar engines. Like an NA V12. Cosworth had to ditch the belts and chains and go for gear driven cams for the Valkyrie and T50, and Freevalve can do that too. The mass manufacturers are moving to ultra hybrid or electric so they may not invest much in it anymore, but supercars definitely have a possibility for further improvements.

[@vitordelima]

And if the technology improved it could be cheaper and more durable since the competing mechanisms are very complex and it enables the use of engines that don't necessarily use linear crankshafts.

[@SpaceraverDK]

Perkins used gears in 1947..

[@7236399]

@@SpaceraverDK perkins 1947 engines did not reach 11500 rpm and 800 hp...

[@paulg3870]

Great video, but wasn’t also the freevalve concept to be able to achieve very high rpms? (Since you don’t need very hard valve springs) I heard that a very long time ago though so might be confused.

[@ARockyRock]

I heard that as well. It reduces the rotating mass and amount of mechanical parts which would theoretically allow engine to rev higher, faster and with less risk of failure

[@ThousandBlade]

I think for safety reasons and engineering simplicity, free valve would still need very hard valve springs. Incase the free valve system fails, you would want the valves closed during failure to protect engine, so the most reasonable choice would be to use springs to close the valves and use whatever free valve system to counter the spring force and open it. This also simplifies the system a bit since it only needs to provide force in one direction.

[@NBSV1]

The technology to have high rpm valve train has been around for a long time. They had small race motorcycles running 15,000+ rpm in the 60’s. The camshaft and valve train runs at half engine rpm. So, the bigger limit often becomes the pistons and rods at high rpm.

[@yashswimehta2286]

I'm literally making a report on valve timing on high performance and conventional engine currently and everything you shown was very useful and also helps me understand better via visual aid

[@geoffreyrood9589]

He simplified the description of scavenging a bit. When the exhaust valve opens (somewhere near BDC), the high pressure in the cylinder is released into the exhaust, which creates a high pressure wave that travels down the exhaust runner at the speed of sound. When the wave reaches a change in area (i.e. a merge collector on a tuned length system), a rarefaction (negative pressure) wave is reflected back up the exhaust runner. A properly tuned exhaust length will time this negative pressure wave so that it arrives during cam overlap (about 180 crank angle degrees later, near TDC). At TDC there is very little piston movement move gases, so the negative pressure helps not only pull residual exhaust gases out, but it can be a lower pressure than the intake manifold, and pull more fresh air into the cylinder than you would normally get. It only works in a narrow range during WOT though. On an I-4 or V-8 you can choose a 4-1 or 4-2-1 design. A 4-1 design delivers a strong rarefaction wave at a single higher engine speed, where the 4-2-1 delivers multiple weaker waves at several lower engine speeds. That's why 4-1 "are for power" and 4-2-1 "are for torque". Intake tuning is way more complicated though lol

[@nicolaasrobertse7565]

Man u make my day ,I love the sarcasm but u still keep it professional and 💯! U are a very educated individual and as i hope you never stop making videos for us I do have to be honest by saying u are wasting technology advancement in the automotive industry by not working for a big company like vag or Ford etc... as a design engineer!!!

[@billwelter4101]

Electromotive was building electronic valves back in late 80's, great technology. Thanks for the great video !

[@NautilusGuitars]

I love how you concluded this video, because that's exactly what was on my mind as you you said it. It's just amazing how far engines have come just over the past 10 years. I'm in the planning stages of building a Ford 300 for my 65 Mustang, and I've been considering taking a lot from modern engines to improve and modernize it. I'm not sure if anything in this video will be directly applicable to that, but it definitely has inspired me to think about more unique approaches utilizing modern tech.

[@clynesnowtail1257]

That sounds like a really cool project.

[@IllusionInfusion]

You make a lot of really good points, however I can still think of a handful of reasons why Freevalve could still be beneficial. A great example would be the little FB20 in my Subaru Impreza. Being a flat engine, it's incredibly wide for its displacement, but pretty short (to make the AWD work as the engine is ahead of the front wheels.) In addition to that, the engine has a seperate cam carrier which is probably at least an inch to an inch and a half tall and being a flat engine, you have two of these, one on each bank. In this case, I think that the reduction in width of the engine would be a huge win for something like a Subaru where the top of each bank is incredibly close to the frame of the vehicle. Reducing that width would make servicing the vehicle a whole lot easier or it would let Subaru stoke the engine a bit more and maybe squeeze a bit more compression and volume out of the engine without worrying about making the engine longer like with the 2.4L or the older 3.6L. So generally speaking, I agree with you when it comes for inline engines or V engines with enough room in the vehicle chassis, but I see there being some pretty big benefits for a flat engine where the dimensions of the engine influence the design of the entire vehicle to accommodate the AWD system. Either way, great explanation. On the balance, I agree with you though.

[@endurofan9854]

good point, but i guess it will all fall down to costs and complexity

[@IllusionInfusion]

@@endurofan9854 That's another excellent point as two banks on Subaru engines tend to make them more expensive all around.

[@raoulrr]

Freevalve for ONE head would be expensive compared to current VVT, but for TWO heads it would be a lot MORE expensive. It would be an order of magnitude cheaper for Subaru to just modify slightly the chassis rails if they wanted more clearance for the heads, compared to implementing freevalve. And when you think about how many iterations of the EJ it took them to fix the oiling and headgasket issues for KNOWN tech aka regular heads with camshafts, I can't even imagine how many years and costly recalls it would take them to make a brand new tech like freevalve even close to reliable. Especially in the twilight of ICE and the transition to EVs where most carmakers are getting out their last gens of ICE engines and have stopped developing them much further.

[@IllusionInfusion]

@@raoulrr I was taking you seriously until you mentioned the head gasket issue with the N/A EJ engines. You do realize that those were phased out over a decade ago. That's like calling Jaguars crap because they're a Ford. Given what Subaru has managed with the FA24 along with their collaboration with Toyota in the BRZ, I wouldn't put it past them to do something more innovative. The worst thing to come from the F series engines is leaky cam carriers which I'd take over a failing head gasket any day, unless you own a 2011-2013 FB engine, in which case it probably eats oil. Just avoid those model years. Either way, you're right, but cost will always be a barrier to entry for Freevalve unless they can produce it at scale which would bring costs down like any other mass produced part. The problem is that modern VVT systems and cams are mass produced at scale. Freevalve is not. It could be, but that's a lot of up front investment and most investors aren't willing to take that sort of risk.

[@snapcountersteer]

Didn't subaru already fix that problem with their offset conrods in their F engines? They have much bigger strokes than the EJ series already.

[@crashlandingcity]

Camshaftless designs have been common in large marine diesels for a while. It's possibly a lot more straightforward at 80rpm with one valve per (96cm bore) cylinder.

[@patrickbrady447]

Many years ago, about 25 or so my Son inlaw who at the time was at university studing politics came up with the idea of replacing the camshaft with solenoids. At the time I was working in the motor repair industry and it was the first time I had come across the idea and it was from someone who had never worked in the motor industry. At the time before Vtech etc it was such a great idea, I wish I had the time and facileties to put it int practice back then. As you have pointed out in your video its day has passed now.

[@graham7513]

12:42 BMW's Valvetronic does not have any way to open one intake valve more than the other. All valves on the intake camshaft are varied in lift by the same eccentric camshaft. When the Valvetronic motor advances the eccentric camshaft, it changes the geometry of all the camshaft followers at the same time, which changes the lift. It can not change them independently.

[@arctic_void]

What about the mechanical losses of a valvetrain system? FreeVavle theoretically would put less strain on the whole bottom end, meaning reduced wear and an increase in performance due to no parasitic loss. It would be interesting to know how much parasitic loss is added through the alternator that generates the power for FreeValve.

[@d4a]

I wondered that too, but there's probably no simple answer.

[@taznz1]

Freevalve uses very little electrical power, It's an electric pneumatic system with electric hydraulic latching system, The systems primary parasitic device is a variable rate air compressor, basically a car A/C compressor. Electrically actuated pneumatic solenoids control the air pressure that opens and closes valve, and electrically actuated hydraulic solenoids control oil flow in and out of a chamber that prevents valve closing until commanded. The whole system probably has less parasitic loss than having your car A/C and car stereo on at the same time.

[@vitordelima]

@@taznz1 There are other kinds of linear actuators that maybe could replace everything with a single electromagnetic component but I don't know how possible this really is, such as the Permanent Magnet Assisted Linear Switched Reluctance Motor.

[@ProfessorOzone]

@@taznz1 Car AC compressors are a pretty big parasitic draw. Have you ever used yours?

[@taznz1]

@@vitordelima A pure electromagnetic system would need very large magnetic coils to overcome combustion chamber pressures to open exhaust valves and would use a lot of power to open valves and hold open. The use of a linear motor to give variable lift control could work but size and weight and speed would likely be an issue. pneumatics are fast, effective and reliable.

[@krakhedd]

One catastrophic failure - you discussed only peak numbers, while you did acknowledge the most benefit of FreeValve being at lower RPMs/off-peak. Still gets a thumbs-up and a comment cuz it's a really great job discussing what's actually there and how it doesn't push the peak very much!

[@Fyrespit]

Did we watch the same video? Seemed to me like the majority focus was on the shortcomings and peaky nature of camshaft engines with fixed timing/profile and how those issues have been mitigated over the last 10~15 years, closing the gap to Freevalve.

[@krakhedd]

@@Fyrespit did you hear any figures discussed other than 6% of peak rated HP? Cuz I didn't. Perhaps I missed it, or we did indeed watch different videos? Do you have that figure? I would love to know what the difference is in total area under the curve!

[@Fyrespit]

@@krakhedd Sure I can give you a few figures, since you weren't watching. 0:51 - 8 years since Freevalve announced The video talks about why fixed valve opening is bad - trade off between high/low rpm. 7:48 - Graph showing the area under the curve - this is an obviously exaggerated example because engines aren't made like that any more, this is the point of the video which you missed. 9:00 - Claims made in favour of Freevalve by its proprietors, contested at 13:42 9:25 - Comparison to a 10 year old Mini Cooper S JCW 10:18 - Comparison to Toyota Corolla GR 12:04 - The key point of the video, followed by competing technologies If you're looking for some hard data on the difference between modern engines and a theoretical Freevalve competitor, that's going to be hard to come by because Freevalve is borderline vapourware.

[@juliannuber3852]

There is no benefit of FreeValve at lower RPMs compared to modern "traditional engines". Look at the BMW S55 for example: A twin-turbocharged inline-6 with 3l displacement producing ~430 HP. The engine has VANOS -> variable valve timing The engine has VALVETRONIC -> variable lift and duration As a result of these two technologies this engine produces its maximum torque (550 Nm) starting at ~2000 RPM up to ~5500 RPM, in 2014! This engine produces its maximum torque 1000 RPM after idle and up to 2000 RPM before redline. These limits result from streaming effects of the ducts in the cylinder head and intake manifold which FreeValve can't compensate either. There just are some physical boundaries that can't be crossed regardless of the technology used.

[@krakhedd]

@@Fyrespit still not being answered - the 7:48 time stamp shows an "old" style (read: non-variable design) The GR again looks only at peak numbers Comparing boosted engines without regard for charge cooling, let alone reference for mass air flow, does not satisfy my curiosity So yeah....still not answered

[@manojm2984]

I could only agree with you on the small marginal power output increment, but the main benefit which is not discussed here is the energy lost in powering the camshaft. Main advantage of freevalve is initial power / crisp acceleration.

[@hedgeearthridge6807]

I guess the question is does the air compressor and pneumatic system use less energy overall than camshafts? Idk, if you want more power it seems like there's plenty of other ways to accomplish that than trying to make the valve timing system slightly more efficient, I'm not sure about it.

[@weareallbeingwatched4602]

Absolutely, you'll need loads of kilowatts to make all those valves dance. You have to get the power somewhere, but it will (maybe) save weight, rev higher, and enable more programmable timing. Depends what you're trying to do. There are ways of doing electronic valve timing by using electric motors rather than individial valve control.

[@Bikerbuoy]

Congratulations on writing and producing such a brilliant video on what is for most people, a very complicated subject. Your use of graphics is first class and matches your own wide knowledge of state of the art engine design. Not wishing to steal anyone's thunder, when I was a petrol engine designer (1970 - 1977), Intake Valve Throttling was the latest idea in my sphere alongside CVCC not to mention Ralph Sarich. The Arab-Israeli conflicts and threatened fuel rationing in the UK was the impetus behind my employer's interest in magnetic and hydraulically operated valves; in breakerless (ie Electronic) ignition using reed switches in the HT leads and in 'iris' throttles - amongst many other ideas designed and prototype tested. The management's objective then was to produce a car returning 50mpg (Imperial) at 50mph. 50 years on, I now realise just how advanced such projects were. The dates on the patents are the unequivocal proof were it needed.

[@charleslavender935]

I have never understood how varying the intake valve opening instead of having a throttle body can reduce pumping losses, because either way is still restricting airflow into the cylinders and creating a vacuum in the cylinders. Great quality content as always. Thank you

[@intercity125]

Because you're always going to have the valve, so you have the *additional* restriction of the throttle body if you need it to be there.

[@mrgcav]

FreeValve is a great achievement. I ought to know I invented the concept in 2005. The valve is much closer to the cylinder than a Throttle body. Air is highly compressible. Making changes at the valve provides much quicker response because the air pressure has virtually no time to vary. Think of three rooms 1,2 & 3 in series all connected by one door with the middle room having a doors an in and an out. Flow is one way. Room1 is your intake before the throttle body, Room two is your manifold, Room 3 is the engine cylinder. Door1 is your intake system, Door2 is your throttle body, door3 is your intake valve. Door 4 is your exhaust valve Room one is fill of people and the people must get into room three as quickly as possible, Initially the middle room, room2 is empty. The What is the fastest way to get all the people into room 3 ? Simple eliminate room 2, the manifold and connect room 1 directly to room 3. Freevalve eliminates many friction power robbing parasitic parts. Hope this helps.

[@matthewbeasley7765]

@@intercity125 The throttling function is still the throttling function. To get the same percentage of engine power, the total restriction is the same. If it didn't have the same total air restriction, then more air would come in and the engine would either run lean or produce more power than desired.

[@Towelie726]

Similar to ITBs. Instead of having vacuum to overcome in a plenum due to a traditional throttle body, you have atmospheric pressure at the each individual throttle bodys, or in the case of freevalve, the valve itself.

[@housemana]

@@mrgcav lmao you definitely did not

[@josephfigueroa3527]

The thing with freevalve is the potential to rev almost infinitely and make power throughout. Something that is immediately squashed when we remember that a cylinder head that can support high RPM flow sucks at low RPM.

[@exprimere]

I believe that for tuner/project racers, it can possibly become some kind of "performance revolution." I've had the idea floating in my head for a while of taking a very fuel hungry V8 and shoving individual intakes plus freevalves on an engine. It would allow you to run a miller cycle in highway driving but then press a button to switch into a racing regime when you need all of your power. The reason freevalve is perfect for this is because most small garages and one man modding shows don't have the manufacturing prowess to machine complicated bits of aluminum/steel, or to mold high temp plastics. Something like Freevalve, while requiring some heavy modification, are more of a "car mod" type thing and less of an "engineering degree" solution. Of course, I'm not trying to understate the difficulty of retrofitting freevalves to an engine that was not designed for them in any way, but it feels like a cool way to give an engine power on demand. Also, on cylinder deactivation, especially with individual intakes, you could use freevalve to prevent issues like oil burning when cylinders pull a vacuum. Yes modern engines have done it but that comes back around to complex mechanical bits and how to manufacture said bits. And I'm still curious, if you used oil pressure or even electrical impulses for the solenoids, could you avoid the extra losses from the air compressor and camshaft of a vvt engine?

[@darthkarl99]

Freevalve is basically racing engine, (notably F1), valve tech. Performance junkies would absolutely benefit enormously from it for the ame reasons racing has.

[@carlossmith7043]

BEST COMENT SO FAR, nice brain work, pall ! Tamo junto e misturado 🤜🤛👏👍

[@mr.hanfblatt9152]

4:49 enjoyed the little meatloaf sprinkled in there. great video as always.

[@adamfreeman3000]

Absolutely love your videos, keep up the excellent work and THANK YOU!

[@liveness2006]

I always though free valve would be a great tech for aftermarket support on older vehicles. Literally breathe new life in the engines extend the life of the cars. Can't imagine what my little vw bug would be like ❤

[@chehystpewpur4754]

doesnt work like that

[@liveness2006]

@chehystpewpur4754 what doesn't work?

[@chehystpewpur4754]

@@liveness2006 every engine is designed. you cant just delete parts. you either have an engine with camshaft or you dont. for example many engines are considered cam in block. theres a 3 foot long camshaft in there that literally runs your distributor oil pump ignition timing. you cant just take it out. your oiling system would also fail horrendously due to 8 gaping holes in it now. on an overhead cam engine yes you could effectively completely redesign the head and delete the cam. but anything else that may run off the timing belt or chain doesnt exist anymore. like a water or oil pump. your bug doesnt have water pump atleast so your in luck there but its gonna cost more than the bug costs to convert. youll see no real power difference. and chances are your bug would become an unreliable mess. electronics dont like heat or vibration. mount electronics to the hottest part of the engine inches from explosions. the other really big issue is your car doesnt have a computer. so now you need to add a rats nest of wires and supply it with power. youll need a crank sensor too. youll need an 02 sensor. throttle position sensor. oil pressure sensor. mass air flow sensor manifold pressure sensor. the list goes on. youd have to redesign the whole thing from the ground up. your car is just fine the way it is. reliable and simple. i was interested in the tech when they announced it then immediately didnt care once i seen their tech. it doesnt work. you wanna breathe life into you old bug. take my advice. save your money and take this for a pipe dream. buy a cheap small supercharger. amr500 would work. or look for eaton m62 or eaton m90 you can get those used for cheap too. or buy a standalone efi kit for your bug and you can fuel inject it. youll make more power get better mileage and it will run good. you could do both of those modifications for under 1000 dollars and absolutely love your little bug. probably even win a few small races.

[@philipp594]

Freevalve is not a big deal, because it still using a spring, so it's still as slow as spring driven systems and because it only really has two states. If you could open the valve to variable amounts and it was faster than springs everyone would be using it.

[@JunkCCCP]

Yeah everyone would be using them if they could theoretically exist and be built.

[@philipp594]

@@JunkCCCP Theoreticly they are very possible. You can hold an object in variable positions between magnetic fields. Someone just needs to do a ton of engineering work to make it happen.

[@v4skunk739]

Ehh free valve is hydraulically activated, if it has a spring it doesn't work like a conventional valve.

[@philipp594]

@@v4skunk739 No it's not it's electromagnetic against a spring. No one uses hydraulics in valves. Even old F1 used pneumatics.

[@TundeEszlari]

Magical video.

[@athan7199]

Hey, I was just wondering... If fuel can be injected precisely into the combustion chamber, then why can't air, too be injected into the combustion chambe or even the correct mixture of air and fuel be injected into the combustion chamber. If air can be injected, then the ECU can control the timing of the air or the air /fuel mixed mixture. Even the duration of the air being injected can be controlled. We can start the injection of the air or air/fuel mixture at precisely the time the piston is starting to move up the compression stroke. If this is viable, then the intake valve assembly is not needed and this could be a weight gain advantage.

[@trollies4847]

Sadly this would require a heavy and expensive air compressor to pressurize a heavy and expensive air tank and would also make the cylinder more cramped with another big injector in it

[@viper341]

It's not just about peak power and torque numbers it's about having more power across the entire RPM range

[@hotchihuahua1546]

Your videos are top notch and why I subscribe. 👍👍 It is amazing the piston engine is still a platform for all this technology to improve on its performance and the power numbers they can achieve. We are headed down a dark road with the green movement ! That worries me more about the future of the piston engine and the overall industry that is tied to it .

[@rpmqualityautoservice8337]

As always, great video! One point not mentioned is longevity. I have almost 300,000 miles on my push rod engine. I wonder how the long term reliability of the free valve would be?

[@PushyPawn]

'FreeValve' died before it was born. OTT engineering, complexity and tolerances = poor reliability, very costly and frequent maintenance. Economically it's a 'black hole' venture with miniscule advantages compared to modern engines.

[@sharunshaji6328]

I think Free valve is an equivalent to Fuel injectors to Carburetor for Cam actuation. But yeah the number you talked are perfectly sensible. I really like your videos dude!

[@billruss6704]

A friend of mine at a local college taught ICE theory He was trying to build a rotary valve. A disk with holes would spin around causing an unobstructed flow of air into the cylinder. Due to health issues he never finished it It would be nice to see someone continue his work and actually build one.

[@Skandalos]

Why is freevalve so expensive? Patents?

[@smiller225]

You cant judge the 1.6 turbo engines without knowing what boost level each is at. Also freevalve could be added to the gr engine and reduce a lot of rotating parts. I do agree in the opinion it might never be mainstream.

[@chrisgill1302]

I was working on a similar project in early 2000's for diesel engines. Really unique mechanical designs in some cases. One iteration involved a valve that did not move, but, instead, the port would move, recess, away from the valve. Reliability was probably the biggest hurdle. Ultimately, it was not feasible for cost vs. performance & reliability. I am sure they have come a long way in the past couple of decades, but with EV being all the rage, I don't see it coming to market in consumer vehicles or light duty trucks any time soon.

[@alexkitner5356]

Well when the world figures out that the energy generation required to move all the energy produced by ICEs over to electricity is impossible using current means, let alone emissions free, that collective facepalm will sound like the moon smashing into Mars. Or that millions of cars with thousands of lithium cells represent a massive safety issue that would be soundly regulated out of any other industry if it wasn't "all the rage" with people that reject reality to remain amongst the elites of the woke world. I think EVs could really be something with the correct design and concept but what we have now is absolutely not it... but it sure is job security for firefighters.

[@flacjacket]

I really see a good opportunity on outboard marine engines. Narrowing the mounting center allows more or larger displacement engines on the same transom and boats are very sensitive to engine weight in terms of how the boat sits in the water, also marine engines spend extended periods at constant (but not fixed) RPM which means being able to optimize valve timing with higher resolution than cam based VVT systems can will bring greater efficiency gains for a boat than it would for a car where the rpm is constantly sweeping. Also since most marine outboards are N/A I would expect the power gains to be more significant than they would be on a turbo application as in now ubiquitous on cars.

[@donaldhollingsworth3875]

I like the free valve concept but you would also to program the fuel injectors in concert with the free valves. Also I think, in my opinion, you would need high compression pistons like 11:1 or 12:1. You could also install a turbo charger or super charger with 11:1 compression since a lot of 1.5L turbo charged engines use very high compression. When back in the day that if wanted to install a turbo charger or super charger you would only be allowed to use 8:1 or 9:1 compression. When I was young, about 17 years old, I built a Chevy 350 bored .060 over size. Of course I had the heads & manifold ported & polished. I used 10:1 compression fly cut pistons with a GMC 671 roots super charger with a longer duration & higher lift camshaft & 2 Holley double pumper carburetors. Later on when I was building I came to realize I could have gotten away with 2 Rochester or Rochester style spread bore carburetors. And at the time it produced a respectfully 450 HP. All the people on the block used to complain to my parents when I fired that engine up because as a test engine that I was building for the first time I used open headers. Later on I had a speed shop pick up the engine to put it on the dyno. I forget what the torque was. I eventually put this engine in my 1979 Z28 Camaro with a rebuilt high performance Borg Warner Super T10 4 speed transmission & a hydraulic dual disc clutch. I sold it to a friend's father before I enlisted in the Marine Corps. But I wish I still had that car.

[@wvhdogg]

sorry if this is a noob question but, what happened to carburetors? why aren't they used anymore to restrict airflow for non-variable valves?