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I wasn't aware there would be so much interest in the tech. I'll make an effortpost when I can get around to it. Basically the summary is that the only losses in a cam system are friction and noise. All three types (pneumatic, hydraulic, and electromagnetic) of camless system have conversion losses on top of friction and noise. There is a hydraulic valve holding mechanism that isn't very well explained in FreeValve which may recuperate losses/increase efficiency, but I have no way to be sure. Speaking of alternatively driven components:  This was an attempt at an all wheel drive hydraulically driven front Formula car in 1969. It never raced because it was too heavy to be competitive. um excuse me fucked around with this message at 22:52 on Dec 26, 2016 |
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Dec 26, 2016 22:44
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I assume there is a safety mechanism to make sure the valves don't simply drop into the cylinders if/when the system fails.
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Dec 26, 2016 22:48
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Probably actual springs?
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Dec 26, 2016 23:27
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um excuse me posted:Basically the summary is that the only losses in a cam system are friction and noise. Valve springs get hella hot. Still interested, please continue.
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Dec 27, 2016 00:53
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While entirely elective with a camless system, most of the designs I have seen have return springs, making that loss cancel out.
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Dec 27, 2016 01:41
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Metal Geir Skogul posted:Marty from MCM, I think, is jaded with the whole thing. He's more of a "yes...no...yes..." type guy for the last year or three. Haven't watched the crossover yet, and that's kind of what's turned me off of MCM of late. Marty just seems so "meh" about the whole thing. I still say the Supergramps series is my favorite series of all of theirs.
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Dec 27, 2016 01:42
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), but it's pretty obviously a shtick by now.
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cakesmith handyman posted:Valve springs get hella hot. Wouldn't that be classified under friction? Really, whether it is a net benefit or not comes down to the net increase in valvetrain load versus the efficiency gains by the vastly more variable valve timing and lift.
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Dec 27, 2016 01:51
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Rigged Death Trap posted:gently caress direct injection CPE makes an aftermarket intake manifold for the MS3 which allows you to add port injection but the added cost,complication, etc to do that instead of it being an OEM design is not something I would consider doing on my DD. MetaJew fucked around with this message at 02:36 on Dec 27, 2016 |
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Dec 27, 2016 02:24
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WAR CRIME SYNDICAT posted:Haven't watched the crossover yet, and that's kind of what's turned me off of MCM of late. Marty just seems so "meh" about the whole thing. I still say the Supergramps series is my favorite series of all of theirs. He seemed to be enjoying what they do on the cross over ep despite the insane jetlag and 36 hours with no sleep.
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Dec 27, 2016 02:37
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Marty seems his happiest when he's hunched over a bench vise with a drill, angle grinder, or welder in hand. It's when he turns to the camera that all joy is sucked from his soul.
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Dec 27, 2016 02:41
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They have been doing Mighty Car Mods for SIX YEARS and have had to pretty much go and hide filming their workshop stuff because people started to come to their homes and steal poo poo. I'd be looking a tad over it too. Apparently Mardy is going to be defeating all nissans and seeing just how far you can push an EZ36 motor in the new year... Could that EZ block you see on the engine stand in the 2 Sexy workshop scenes be a forged version to drop in when the factory one pops? I hope hes aiming at the double unicorn!
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Dec 27, 2016 02:56
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Ferremit posted:They have been doing Mighty Car Mods for SIX YEARS and have had to pretty much go and hide filming their workshop stuff because people started to come to their homes and steal poo poo. 
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Dec 27, 2016 02:59
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IOwnCalculus posted:Really, whether it is a net benefit or not comes down to the net increase in valvetrain load versus the efficiency gains by the vastly more variable valve timing and lift. I know the cams on a DD are pure efficiency and the cams on a race car are pure power and lol VTEC for a+b. Actual effects of infinitely variable valve lift and duration? Very interested. Coredump posted:Yeah I wanna learn too.
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Dec 27, 2016 04:53
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honda whisperer posted:I know the cams on a DD are pure efficiency and the cams on a race car are pure power and lol VTEC for a+b. Actual effects of infinitely variable valve lift and duration? Very interested. He doesn't come out and say it, but he implies that they're dynamically adjusting not just lift, timing, and duration, but also ramp rates and such, which could lead to all kinds of cleverness. An Atkinson cycle engine with this kind of valvetrain would be kinda mindblowingly cool. I'd be extremely interested in seeing how they power the pneumatics, since as mentioned; that could be a significant power draw. Besides that, with infinitely variable individual valve control, I TOTALLY buy the power and efficiency gains they're claiming. There really is that much to be gained if you're not chained (lol) to a single or a few cam profiles.
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Dec 27, 2016 05:00
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Not to mention with more intake and exhaust plumbing, you also have cylinder deactivation as well as the ability to turn deactivated cylinders into superchargers.
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Dec 27, 2016 05:08
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I have no significant other as of right now so can someone please get into the individual cylinder throttling he was talking about?
Preoptopus fucked around with this message at 05:22 on Dec 27, 2016 |
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Dec 27, 2016 05:19
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Preoptopus posted:I have no significant other as of right now so can someone please get into the individual cylinder throttling he was talking about? My best guess is that you dont need a throttle body anymore with this design. The main function of a throttle is to raise and lower the volumetric efficiency of the engine. Volumetric efficiency is how much air an engine takes in as a percentage of its displacement. In an ideal world, an 2.0L engine would intake 2 liters of air every full cycle. This isn't true in real world scenarios. Pumping losses caused by restrictions in the intake and exhaust mean that volumetric efficiency for a N/A engine will always be less than the displacement of the engine per cycle. I specifically mention N/A because that is not the case for turbocharged engines. If a 2.0L engine takes in 1.5L of air, it has a volumetric efficiency of 75%. At that VE, the engine can only use 75% of its fuel capacity. As a throttle closes, the pressure in the intake goes down as a result of the air thinning out, lowering VE. With a camless system, you can make the throttle the intake valves themselves by changing lift and duration. Because each cylinder has it's own intake valves, each cylinder gets its own throttle.
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Dec 27, 2016 05:34
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BMW already does away with the need for the throttle body on some Valvetronic engines - so yes, that's definitely something manufacturers are looking at.
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Dec 27, 2016 05:54
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I can also see a scenario where an engine adjusts it's individual "throttle valve action" per cylinder if there were cylinder-specific sensors that could measure each cylinder's efficiency, which would probably be in place for cylinder deactivation and cylinder-supercharging moments. Where a car could adjust its fuel and valving along with engine wear.
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Dec 27, 2016 05:56
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MrYenko posted:He doesn't come out and say it, but he implies that they're dynamically adjusting not just lift, timing, and duration, but also ramp rates and such, which could lead to all kinds of cleverness. Wouldn't you be able to just program the valve timing to achieve the Atkinson cycle? Very cool, but not that hard.
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Dec 27, 2016 06:02
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With complete free control over timing and ignition and water injection, you could run it as a crower six stroke when it's beneficial, too.
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Dec 27, 2016 06:29
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kimbo305 posted:Wouldn't you be able to just program the valve timing to achieve the Atkinson cycle? Very cool, but not that hard. There are vehicles that emulate the Atkinson cycle with a static cam profile, so you can do it for sure with a camless system.
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Dec 27, 2016 06:32
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kimbo305 posted:Wouldn't you be able to just program the valve timing to achieve the Atkinson cycle? Very cool, but not that hard. Toyota is already doing this in the Tacomas. Lotsa cool poo poo happening now. vvv The Tacoma does that BlackMK4 fucked around with this message at 08:49 on Dec 27, 2016 |
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Dec 27, 2016 07:08
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EightBit posted:There are vehicles that emulate the Atkinson cycle with a static cam profile, so you can do it for sure with a camless system. Can those go back to regular Otto? That's the appeal of the flexibility of the camless valve, right?
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Dec 27, 2016 07:53
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I believe the widely used FCA multiair system already offers throttle less operation with cylinder and engine stroke specific adjustment of valve lift, timing and ramp angles. Only on the inlet valves and up to ~6000 rpm though. Probably due to valvetrain weight and cost limitations.
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Dec 27, 2016 08:40
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kimbo305 posted:Can those go back to regular Otto? That's the appeal of the flexibility of the camless valve, right? Yes, but for a N/A engine, you could shut down an intake valve per cylinder, stick it into Atkinson mode for the remaining four valves, and have enough power just for maintaining speed. I don't think the current Otto->pseudo-Aktinson can shut down a valve, but I could be wrong. That's one of the other advantages of the camless engine is you can have "displacement on demand", but you can pick how many cylinders you want instead of arbitrarily shutting down half. Oh, just cruising on a flat road? Shut down all but two cylinders and put them in Atkinson with an intake shut down. Though again, there was that other goon mentioning the downsides of the camless system as a whole.
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Dec 27, 2016 16:43
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The whole thing of course seems pretty likely to sip more power than a regular DOHC setup or whatever, but the claimed benefits, if they aren't absolute horseshit, should more than offset it. This is by my completely uneducated and unqualified estimate. But 30% more power, 30% less fuel consumption and 50% lower emissions is an enormous improvement. Plus I'm thinking maybe they could use the extra boost that would've been vented to drive this thing somehow. E: actually they claimed the system uses 10% less energy to run this valvetrain: http://www.autoevolution.com/news/freevalve-engine-what-is-it-and-how-will-it-change-the-car-industry-113057.html
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Dec 27, 2016 17:39
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The crucial piece of information that is missing is where that 10% energy reduction includes the air pump or not. If it does, they've solved it somehow. If it doesn't, air pumps generally are below 90% efficient, leading to a net loss. However some emission systems actually consume more fuel in return for a cleaner exhaust, which still makes FreeValve a feasible project, just not the cure all they're advertising.
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Dec 27, 2016 18:02
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Yeah. And realistically, until this thing is in a running production vehicle, all this stuff is "who the gently caress knows". They could come up with all sorts of numbers that may be absolutely true, but only be applicable to their current development stage and testing environment. Just like we've been reading about everyone making a 50% improvement in battery density or solar panel efficiency, but by the time the tech hits production, it's a modest improvement over what's already on the market at best.
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Dec 27, 2016 18:09
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mobby_6kl posted:Yeah. And realistically, until this thing is in a running production vehicle, all this stuff is "who the gently caress knows". They could come up with all sorts of numbers that may be absolutely true, but only be applicable to their current development stage and testing environment. Just like we've been reading about everyone making a 50% improvement in battery density or solar panel efficiency, but by the time the tech hits production, it's a modest improvement over what's already on the market at best. I believe it technically is, if you consider a Koenigsegg a production vehicle. They run this system on their hypercars, and are developing it for a Chinese mainstream production car. I guess they know it works on their million € stuff, but there's no reason it can't scale and be sold to anyone interested.
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Dec 27, 2016 19:30
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IOwnCalculus posted:Wouldn't that be classified under friction? Hysteresis is internal friction I suppose? So okay, yes. I think this discussion is fantastic by the way.
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Dec 27, 2016 19:36
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Finger Prince posted:They run this system on their hypercars No, not yet. It's going to be absolutely mindblowing when they finally do, though!
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Dec 27, 2016 20:24
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I think they're running the direct-drive system already in the Regera, but not Freevalve yet. I'd be curious to see it at least in that application, they could work on making it cheaper if it actually works well in that application.
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Dec 27, 2016 21:58
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Another question is compared to what the "30% more power, 30% less fuel consumption and 50% lower emissions" is. Fixed valve timing? VVT? Valvetronic? Multiair? I think that Multiair already does a good portion of the advertised features of Freevalve. (with some weight and packaging penalties) In Multiair the basic motion of the valve is generated by a cam but the hydraulic actuator between the cam and valve is fast enough to alter the timing and profile during the actuation (independently if needed for each cylinder and stroke, throttle less operation, cylinder deactivation). Because the base curve is provided by the cam, the actuator only has to cover the alterations unlike freevalve, where the actuator has to cover the whole range of motion. DoLittle fucked around with this message at 22:10 on Dec 27, 2016 |
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Dec 27, 2016 22:02
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DoLittle posted:Another question is compared to what the "30% more power, 30% less fuel consumption and 50% lower emissions" is. Fixed valve timing? VVT? Valvetronic? Multiair? I think that Multiair already does a good portion of the advertised features of Freevalve. (with some weight and packaging penalties) I think it's compared to the stock source engine that they're using in the video.
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Dec 27, 2016 23:03
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I'd like to know what one of those shithouse engines would make just with a high level individual tune and nice parts though. That always seemed odd to me.
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Dec 27, 2016 23:12
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Dec 28, 2016 09:31
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It's been done: 
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Dec 28, 2016 13:42
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It's entirely possible Marty is just experiencing getting old.
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Dec 28, 2016 17:54
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Repairing the rusted out rockers on my own car, had med youtubeing body repair videos. I hope Arthur is gonna pour a bottle of vodka down his facehole friday after work, because he sure as poo poo deserves it. https://www.youtube.com/watch?v=ctGWOau0iIA https://www.youtube.com/watch?v=Gb9znFAAZO8
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Dec 28, 2016 20:56
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