Why Did Ford Decide to do a Flat-Plane Crank Differently? To counter the high levels of vibrations, active engine mounts and engine damping have been engineered, and in the age of turbocharging, even flat-plane cranks V8's can develop massive amounts of torque from low down. In simpler terms, every time the crankshaft rotates by 90°, one of the cylinders fires. The higher RPM you launch at, the faster all of the parts in the drivetrain will spin for that inertial torque to be transmitted. In the world of 90-degree V8s, there are two basic crankshaft designs. ## Figure 2 - V8 Flat-Plane Crankshaft ## There are two main benefits of a Flat-Plane: The crankshafts have an odd firing order (less efficient) and are heavier. More flywheel makes a consistent launch easier but it would probably be a negative otherwise. But the iconic rumble of the V8 isn't the only signature note it makes – in fact it's just the one most associated with traditional American V8s. http://forums.corner-carvers.com/showpost.php?p=10... http://www.edmunds.com/ford/mustang/2015/long-term-road-test/2015-ford-mustang-gt-coyote-voodoo-cross-plane-flat-plane.html. A V8 flat plane crankshaft is special and the concept changes the way one must think about engine performance. You invariably want to end up with an engine/gearing system that is best used between the torgue and hp peaks. It's why the Hemi V8 used in Chrysler and Dodge products feels like it can move a mountain from the moment you pull off, and it's also the reason you'll so easily turn tires into plumes of white smoke. When it comes to V8 engines though, the cross-plane crank configuration is the most common across the world. Much like love, cars are an emotional subject. For every 180 degrees that the crank turns a piston fires. It used to be that flat-plane crank engines were a thing you only found on exotic European cars like Ferraris.They make a pretty unique sound some would describe as unearthly.While there’s far more than just that to attract someone to the Shelby GT350, it does make the muscle car sound distinct. They make a pretty unique sound some would describe as unearthly. Assuming i4 means inline 4 cyl, and you said "most" instead of "all", I'd say yes. Inline-8, V8, V16, and even flat-8 and flat-16 engines can utilize cross-plane cranks. That makes engine responses quicker, and it allows the flat-plane V8 to rev far higher than a cross-plane crank V8 can. Seems most plausible. The breadth of the range is set by the available gearing. Please let us know here why this post is inappropriate. A V8 flat plane crankshaft is special and the concept changes the way one must think about engine performance. It looks very similar to an Inline-4 crankshaft, albeit with longer crank pins to accommodate two big ends. The crankshaft very simply converts reciprocating motion into rotational motion – that's how a piston moving up and down converts the energy into rotating the wheels. Jason Cammisa Words. Well, I would expect that the less torque pulsation there is at the wheels, the less likely the tires are to start slipping. Engines using a flat-plane crank design include every Ferrari engine manufactured for a Ferrari and the McLaren 3.8-liter engine used from the 12C right through to the P1. This means that exhaust pulses follow one after the other, forming an orderly queue through each exhaust manifold and helping to draw or ‘scavenge’ exhaust from the engine more easily. More inertia can only be a benefit at launch and gear changes when the clutch is slipping. But spinning those parts up to that higher speed requires higher amounts of inertial torque. I do not understand exactly why that is said. Not only that, but the energy required to accelerate the car to the speed which is needed to facilitate that higher rotational speed of the drivetrain would require an extreme amount of inertial torque AND extremely strong components to hold that much force. There are a few high-performance C8 Corvette models on … Ford Explorer King Ranch Adds Touch Of Class To Popular SUV, Hyundai Ioniq 5 Revealed With Sleek Styling And Innovative Interior, 2023 Chevrolet Corvette Stingray Getting Redesigned Interior, 2022 Mercedes-Benz C-Class Arrives To Blow Away The Competition, 2022 Kia Carnival Arrives In America With SUV-Inspired Styling, Porsche's 911 GT3 Prediction Will Probably Come True, Chevrolet's Rarest And Most Forgotten Cars, 2021 Dodge Charger SRT Hellcat Test Drive Review: A Power-Crazed Lunatic, 2021 Nissan GT-R Review: Old But Still Gold, 2021 Chevrolet Camaro ZL1 Coupe Review: Stick-Shift King, 2020 Nissan GT-R Review: Shameless Supercar Slayer, 2020 Dodge Challenger SRT Hellcat Review: Smoking Is Allowed, © 2010-2021 CarBuzz Inc. All Rights Reserved, Mass production V8s like the 5.0-liter V8 in the Ford Mustang GT, Used Dodge Challenger SRT Hellcat For Sale. Just days ahead of its official unveiling, Mercedes-AMG have all but confirmed the upcoming GT Black Series will have a flat-plane crank twin-turbo V … TTFN Due to the way the VE/friction combination works, the max BMEP/max torque occurs below the hp peak. Ferrari engines are known to rev even higher – north of 9000 RPM. has that same pure sound coming out of each outlet - problem is there are two outlets and your ear gets a jumbled version of the two pure sounds from the two outlets. A voodoo swap is a highly advisable investment though. No stinking energy conserving going on here! - they use a similar base engine design) and the Porsche 918 Spyder. The engines for both cars are based on the 90-degree V8 engine from the Alfa Romeo Tipo 33 racing car, and have double overhead camshafts and a dry sump. Flat-plane cranks are lighter and, as the crank journals are at 180deg, the firing order moves sequentially from one cylinder bank to the other: left, right, left, right and so on. Launching at that high of an engine speed would require an excellent and gradual clutch engagement, and the power impulses at that high of an RPM are not be staggered as well for maintaining traction. Here's a couple of pictures. I.e. Ferrari V8s have flat plane cranks. Most are done at 6500 RPM. Yeah launch control is popular in drag racing. Even if you could get the force required, AND have the drivetrain durability to withstand it, you would STILL need traction. But these counterweights are heavy, adding rotational mass to the crank. A smooth engine with lots of torque, what's not to love! However, compact packaging, reduced inertia, and reduced rotational mass give the flat-plane crank V8 a clear advantage. Promoting, selling, recruiting, coursework and thesis posting is forbidden. Of course the counter argument of needing to continually accelerate the rotating masses during the race needs to be taken into account, when assessing the value of increased rotating mass in front of the clutch (or other coupling) between the engine and the remainder of the drivetrain. I'd like to see the cost numbers on Ford's new crank vs the cross plane cranks from the current high end Mopar and GM V8s. Making Ford's flat crank V8 sound "traditional" would take a lot of extra effort, as by design the firing impulses per bank are even (unlike a "traditional" V8). Look at how many 90deg V6 engines are out there with the costly split-pin cranks just because of 90deg V8 production lines. Not only that, but you would have to launch the car when the engine is well past peak torque.. You want inertial torque and engine torque benefitting eachother. For drag racing, the theory is that during launch and gear changes, the higher inertia engine has more energy to dump to the wheels when the engine rpm is pulled down. Thank you for helping keep Eng-Tips Forums free from inappropriate posts.The Eng-Tips staff will check this out and take appropriate action. Owning a simple car and developing it into what YOU want can have benefits. Even though I'm not sure about the "flat plane crank", the 4 cyl inline always has something opposite, opposing it, technically in a flat plane. But the biggest downside to the flat-plane crank is the lack of torque. homework forum: //www.engineering.com/AskForum/aff/32.aspx Flatplane crank engines lose much higher amounts of rotational torque by the time the engine speed falls to peak torque RPM. With each having their pros and cons, neither is better outright than the other. If its breathing is adequate for that then there is no reason to shoot for less hp. Did you answer your own inquiry? Just that with a FPC V8 you have two of them on a common crankshaft and can't fully use what's happening on one bank to offset what's happening on the other. To elaborate a little, a purpose designed race engine optimized to give maximum power should have its power peak very close to or at the mechanically limited rpm. We expect that the new Z06 will be powered by a naturally aspirated flat-plane-crank 5.5-liter V-8. However there are exceptions to the rule. I am starting to suspect it was down to machining/production capabilities. The argument that I've understood, which I haven't analysed myself quantitatively to assess its validity, is that a drag racer can in essence, "invest" in stored energy in the flywheel prior to the start of the race, and draw down the investment during the race. Without them, the rocking motion caused by the cross-plane crank would unsettle the engine in the car and cause advanced mechanical wear. Take the Ford Mustang Shelby GT350 for example – revving to 8200 RPM compared to the 7000 RPM of the standard Mustang GT. That is true, but there are more factors at play here. Hear the Shelby GT350’s Flat-Plane Crank V-8 on the Dyno 2016 Shelby GT350 Has a Big V-8 With Ford’s First Ever Flat-Plane Crankshaft. Big, rumbling V-8s have been a Corvette staple since the introduction of Chevrolet’s small-block in 1955. You are looking at finger instead of looking at tthe moon. And on the subject of engine torque backup: Given a specific amount of inertial torque, crossplane V8s attain that at an engine speed which is closer to their engine's peak torque. Figure 2 shows a typical Flat Plane V8 crankshaft. Traditional V8 cross planes can build large torque quickly due to the load distribution in two planes at the rod journals. Launches are the period of time when engine speed, wheel speed, and vehicle speed are being coupled. This question applies only to V8, since, to my knowledge, only V8 engines can have either a cross-plane or a flat-plane crank. However, this particular Vette is singing a different tune. That’s the real term as it describes the construction of the crankshaft of the engine. They're only big if there are no big advantages. © Corvette Racing We could listen to that V-8 sing all day long. That means that they then have to regain more that inertial torque, for which the speed was already poorly optimized to the physics of making wheels (with mass) spin and moving a car (with mass) forward to match the engines speed. Due to the lack of counterweights, flat-plane cranks are also highly compact allowing better packaging within an engine bay. If a flat plane is cheaper, it weight less, is strongher, is more racing oriented (look at all V8 racing engines Cosworth Ferrari etc, it will never reach 12.000 rpm and so no problem for destructive vibration, wich one is better? Copyright © 1998-2021 engineering.com, Inc. All rights reserved.Unauthorized reproduction or linking forbidden without expressed written permission. Because of the additional rotational mass, cross-plane crank V8s don't enjoy revving, and have a fairly low rev-ceiling. I have no idea how important a factor it is in real life. It’s a tenor to the cross-plane V8’s baritone. Bucking the European trend of flat-plane usage, the latest Ford Mustang Shelby GT350 swapped out its cross-plane crank for a flat-plane one, giving it its unique sound and ability to seemingly rev through the atmospheric ceiling. As its name suggests, a Flat plane V8 crankshaft has all its crank pins in a single plane. ## Figure 2 - V8 Flat-Plane Crankshaft ## There are two main benefits of a Flat-Plane: Slightly higher rotating inertia reduces amplitude of torque pulsations through the drivetrain. But I won't sell my cobra :p They don't make cars that simple anymore. The vibration is typically not an issue, as flat-plane-crank V8s are used almost exclusively in race applications or in exotic sports cars. You make that point the bottom of your operating range. THE LATEST IN CAR NEWS. I think that the production cost savings of a flat plane crank is much more than outweighed by the cost of isolating the vibrations from the passenger compartment and the cost of beefing up components that are adversely affected. I'm glad there was at least some merit to the idea that was put in my head. The industry demands generative design. Some engines have such broad, flat torque curves that "peak torque" is barely a blip on the torque curve. Already a Member? Almost (all?) As a result, they can make do without the heavy counterweights. Gruntguru, ".....Shifting should be performed so that the average power output is maximised for the period spent in each gear. A Ferrari V8 sounds like a Ferrari V8, largely, because it has a flat-plane crankshaft setup. To this assertion, "...The rpm for peak torque bears no relationship to the rpm for peak power...", I'll make this reply: It's a lot like 4 cylinder engines that do not feature balance shafts - typically pretty smooth up to about 2 liters but get progressively rougher as displacement is increased much beyond that. Mass production V8s like the 5.0-liter V8 in the Ford Mustang GT, or the Hemi V8 in the Dodge Hellcats; even the famous Mercedes-AMG M156 6.2-liter V8 from the SLS AMG featured a cross-plane crank. This report explains how TotalCAE makes it easy for organizations to utilize cloud computing on AWS to accelerate product innovation, solve complex engineering problems, and reduce the time waiting for CAE simulation results. I've heard it argued, though not with back to back data or numerical analysis, that more rotating inertia can reduce 1/4 mile times, assuming a given launch rpm (and, I suppose, that the extra stored energy at launch goes into acceleration, rather than tire smoke or clutch heating). The 5.2’s connecting rods attach to the flat-plane crank at 180-degree intervals versus a normal V-8’s 90 degrees. Close this window and log in. ~ Joseph Stalin. The UDUD is similar to the cross plane and thus perhaps can be machined on existing machine tools. It's why we form emotional bonds to the hunks of metal and glass in our garages. Traditional V8 cross planes can build large torque quickly due to the load distribution in two planes at the rod journals. What's the firing order on those engines? In essence, is this similar to having 4 V-twin engines coupled at their cranks, and putting them 180 degrees out of phase of their neighboring V twin? The counterweights and configuration also require a larger crank case, making cross-pane V8 engines less compact than might be ideal. An integrated E/E solution solves tomorrow’s challenges and supports companies as they strive to overcome complexity and reduce time to market. Italian V8s on the other hand, like the ones in the Ferrari 355, F430 and 458, are faster-revving, zestier, and far more technical. However, the entire basis for what I am saying is that the RPM drops are not equal between those two engines. Ford famously made the 5.2l V8 in the new GT350 a flat plane crank. The whole reason Cadillac engineered the cross-plane crankshaft for … The flat plane engine has to be spinning faster to achieve that inertial torque. http://www.mustang6g.com/forums/attachment.php?att... http://www.mustang6g.com/forums/showthread.php?t=1... http://www.uucmotorwerks.com/flywheel/LWF_DRAG_TES... http://www.caranddriver.com/flipbook/17-reasons-th... http://files.engineering.com/getfile.aspx?folder=067f610d-8782-40ca-baab-0f, Accelerating Electrical Systems Design and Analysis, Blurring Boundaries in E/E Systems Development, Cloud Computing for Engineering Simulation. It doesn't "Need" it ... but it is a tuning variable, akin to the difference between a "dual plane" manifold for a traditional cross-plane V8, and a "single plane" or "tunnel ram" manifold. By swapping, you would have more freedom to tailor the build to your needs. Revs And Excitement For certain, it's a bold claim. Less inertia will accelerate the car faster the rest of the time when the clutch is engaged. Is there really? Sorry if my question is dumb, but why flat-plane V8 needs two different intake plenums? It's all down to a single piece of the engine called the crankshaft, and the difference in layout of it – cross-plane in the American tradition, and flat-plane in the European setup. Figure 2 shows a typical Flat Plane V8 crankshaft. The torque curve shown in that video was interesting. *Eng-Tips's functionality depends on members receiving e-mail. Most are done at 6500 RPM. Ferrari, and a few other exotics have used flat plane crank V8s in modern times, but they just accept the inherent vibration. As reported by Jalopnik, a seller on eBay recently listed a 2006 Z06 Corvette equipped with a flat-plane crank. (assuming negligible engine rotational inertia etc etc)....". I remain skeptical until I see the data or analysis. Nothing makes you appreciate simple cars quite like owning a complex one for long periods of time. This would reduce friction losses in the main/rod bearings. One of the things you may have noticed among all those big, exciting numbers and words we used to talk about the 2015 Shelby GT350 Mustang were these three words: flat-plane crank. Is the rotating inertia of that actually as great as Crossplane crank V8? As its name suggests, a Flat plane V8 crankshaft has all its crank pins in a single plane. But what's the difference? Login. That inertial torque happens significantly less at the speed of max torque. There are some exceptions such as the Ferrari-designed crossplane crank V8 of the Lancia Thema 8.32 and … The Mustang Shelby GT350 benefits from a flat-plane crank loaded V8 that generates tons of power without the assistance of a supercharger | Ford Due to all of these factors, it becomes clear why FP engines are favored for racing. In a traditional 4-stroke combustion cycle, the cross-plane crank with even firing pattern can only be used in engines with multiples of 8 cylinders – and they don't have to be in a V-configuration either. The car in the video (sounds f'n awesome BTW!!!!) Why do you think Ferraris perform best at their screaming top end? forum1529: Translation Assistance for Engineers. I have also heard that balancing flat plane V8s with displacement over about 4.5L is harder to do. It had an abrupt vertical jump around 3000rpm, and was fairly flat up to redline. The crankshafts have an odd firing order (less efficient) and are heavier. With the wider angle between cylinders firing, there's less momentum and less torque – so ultimately you need to rev it harder and higher to generate torque. Of course, flat-plane cranks have a big disadvantage in V-8 engines: balance. Most components attached to the engine will suffer shorter service life if not modified. I do not understand exactly why that is said. Flat-plane cranks are inherently well balanced – unlike cross-plane cranks. Most auto engines spend most of the time operating below 3000rpm. But, you can't sell a thoroughbread road race car to the general public very well, and/or a good chunk of Mustang customer base. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework. But spinning those parts up to that higher speed requires higher amounts of inertial torque. I didn't think this market segment was in a cutthroat cost cutting mode. On the plus side for cross-plane cranks there's obviously the noise they make that could best be summed up as monumental – a tribute to the gods of horsepower and torque, and the sound that's defined 'American Muscle' for decades! Yeah lowest moment of inertia of wheels and clutch is also important in drag racing. And, Fords legitimate reasons are surely a compromise that other companies may differ with -since other companies do it differently. "Formal education is a weapon, whose effect depends on who holds it in his hands and at whom it is aimed." The change from U-D-D-U to U-D-U-D isn't going to solve that, and might actually make it worse in some respects. But in addition to the glorious noise, cross-plane V8s are smooth running, with a cylinder firing every 90° there's a constant rotation going which means it runs smoothly. Its better to have it installed from the factory, too. I think the GT350 is a great car. But the lack of torque below 3000rpm, and the spike in torque at that rpm, would not be suitable for most other vehicles. Seems a shame...still a good discussion point. It also ignores the time the engine has to accelerate the inertia. But logic and sense when it comes to cars seldom prevail. For a cross-plane crank, it takes 90 degrees and for a flat-plane crank, it takes 180 degrees. Adding balance shafts can tame the vibration somewhat, but they soak up power, thus negating some of the power advantage of the flat plane crank in the first place. Flat-plane cranks are lighter and, as the crank journals are at 180deg, the firing order moves sequentially from one cylinder bank to the other: left, right, left, right and so on. p.s., why are my images not showing in the post? Eight cylinders, dual overhead cams, 5.5 liters, a flat-plane crank, 625 horsepower and a redline of not 7,000, not 8,000, but 9,000 rpm. Currently listed for sale on eBay is a 2006 Chevrolet Corvette Z06 with a high revving, flat-plane-crank engine. Of course the counter argument of needing to continually accelerate the rotating masses during the race needs to be taken into account, when assessing the value of increased rotating mass in front of the clutch (or other coupling) between the engine and the remainder of the drivetrain. It looks very similar to an Inline-4 crankshaft, albeit with longer crank pins to accommodate two big ends. Yeah lowest moment of inertia of wheels and clutch is also important in drag racing. If you go to a car show and talk to the older guys that can actually afford new cars, its common to hear them appreciating cars that "drive like a big block". By joining you are opting in to receive e-mail. While there’s far more than just that to attract someone to the Shelby GT350, it does make the muscle car sound distinct. The Mustang GT350's "Voodoo" V-8 isn't the only piece of American muscle capable of rocking a flat-plane crank. In V8 engines, flat-plane cranks are less commonly used, but unlike the cross-plane crank, flat-plane cranks can be used, and are used almost always, in 4 cylinder engines. With the reduced rotational mass, the inertia point (amount of energy required to incite movement) is lower too. Looking at the pictures in the first post, it looks like the FP crank might have slightly smaller diameter bearing journals than the cruciform crank. It gets better the higher you rev, but at lower engine speeds vibrations are plentiful. If somebody attempted to install it in their garage, the wiring might be intuitive, or worse, easy to work on :p. With questions like this about why a certain crankshaft layout is chosen and similar questions - why not just ask Ford? It also smooths out the powerband, which is good for traction. Though it might have flaws, they're far easier to counter, easier to manage and offset in one way or another. I think lowest possible rotational inertia in wheels, clutch, flywheel and engine rotational components makes for the fastest acceleration in road racing. In the automotive world, some might argue that there isn't a better sounding engine than one with 8 cylinders in a V-shaped box. This means you cannot run in a range of speeds around the hp peak. But there are downsides too – the 180° firing angle means there's ultimately more vibration and the engine doesn't rev as smoothly. Perhaps the crankpin arrangement helped facilitate the desired manifold configuration, but I'd need to see the manifold layout and actual firing order to evaluate that. I can recall a European company many years ago wanting to rid their new (cross) V8 of its burble as it sounded like an old US muscle car, not something refined.

Pharmaceutical Care Plan Example, Flower Shower E7, Guitar Black Friday Reddit, Best Leather Recliners 2020, Taft High School San Antonio Staff, How To Draw Smooth Lines In Photoshop With A Tablet, Definition Of Lazy Person, Best Kar98 Blueprint Warzone, Chaos Bolt Twinned Spell, Abu Dhabi Investment Authority Salary, America's Got Talent Dog Acts 2017, 2d Water Algorithm, Santevia Bath Filter, Leila Season 1,