The Sound of American V8: A Deep Dive into Firing Orders and Flat-Plane Cranks

If you're a car enthusiast, you know that the sound of an American V8 is music to your ears. But have you ever wondered what makes that distinctive chunky rumble? It all starts with the firing order of the engine.

In most V8 engines, including the 6.2L V8 in the C8 Corvette, the cylinders fire in a specific pattern. For example, in this particular engine, it's one, two, three, four, five, six, seven, eight. But what if we look at just one bank of cylinders? They have an uneven firing order that creates that distinct sound.

Now, some engines use a crossplane crankshaft, which fires the cylinders in a specific sequence. This is what gives the engine its unique sound. The firing of the cylinders is uneven, with a slight delay between each cylinder. This creates a pulsing effect as the exhaust gas leaves the cylinder and flows down the headers.

On the other hand, there's also the flat-plane crankshaft, which has been around for longer than you might think. It's actually simpler in design compared to the crossplane crankshaft. Flat-plane engines fire every 180 degrees of rotation, no matter the firing order. This means that they alternate between the two cylinder banks, producing more efficient exhaust scavenging.

One of the benefits of flat-plane engines is that they produce a unique sound. The rush of gas leaving the cylinder creates a high-speed pulse that produces a pressure difference and pulls a vacuum, which in turn pulls more exhaust gas out and fresh air in. This makes for a more efficient engine with more power as RPMs increase.

The downside of flat-plane crankshafts is that they have less counterweights on the crankshaft, which means more vibration issues as the engine size gets larger. But for racing drivers who want more efficiency and power, this can be a trade-off worth making.

There hasn't been an official release from GM about the Z06's engine, but insiders claim it has a flat-plane crankshaft. In fact, footage of the C8 Corvette Z06 driving around the canyons shows that it sounds nothing like the base C8 model. This has sparked speculation among car enthusiasts, with some even calling it an Italian stallion.

Overall, the sound of an American V8 is a complex topic that involves firing orders and crankshaft designs. Whether you prefer the chunky rumble of a crossplane engine or the smoothness of a flat-plane engine, there's no denying the music to your ears that these engines produce.

So, what do you think? Do you prefer the sound of a classic American V8 or something new like the flat-plane crankshaft? Let us know in the comments!

This episode is sponsored by Omaze. We've worked with them before to give away dream cars like the BMW M8 Competition Coupe and Porsche 911 GT3 RS. Now, we're giving you the chance to win a 2020 Corvette Stingray Z51, all you have to do is go to OMAZE.COM/DONUT and enter right now. Right now for a chance to win this car with taxes and shipping included plus $20,000 cash to spend however you want. And the best part is every donation supports an organization that means so much to me and the rest of the Donut Media family, the Ronald Reagan UCLA medical center. It was their critical work that helped save the life of our very own James Pumphrey. So please click the link or go to OMAZE.COM/DONUT and donate right now. Thank you so much for your support. We love you. Bye for now.

WEBVTTKind: captionsLanguage: en(car engine roars)- Through out the CA Corvette's release.All the hype has circledaround one major buzzwordand that buzzword is MID-ENGINEand that's sorta old newsbut more recently there's also been talksand leaked footage regarding the upcomingC8 Z06 using anothervery European technologyand that is a flat-plane CRANK ENGINEand that is super cool thatthat is going into anAmerican mid-engine car.So today I wanna take a look at the C8and first explain whymid-engine is, well it's better,it just is but there's more science to itand we're gonna get into itand then we're gonnadive into the differencebetween a normal cross plane crankshaftand a flat-plane crank and whythe Corvettes move from oneto the other is actuallya pretty big deal.It took them over 60years to pull the triggeron this technology.Let's find out why.(upbeat music)Now before we get to the nittygritty of the C8 Corvettewouldn't it be nice if youhad your own C8 Corvette.This is your chance to win one,that's right to support a great cause,our friends over at Omazeare offering you the chanceto win a 2020 CORVETTE STINGRAY Z51with taxes and shipping includedand $20,000 for whateverthe heck you want,all you have to do is headover to OMAZE.COM/DONUTand enter for your chance to win.I put the link in the description belowhonestly guys you couldbe driving a 2020 Corvettethat's insane, just doit click the link below.Go win you a Corvette.Talks of a mid-engineCorvette have been aroundsince the 1960s but finallyGM has delivered with the C8.And if we look at the majorityof cars on the road today,the engine is in the front,only high end sports carsfrom the likes of Ferrari,Lamborghini and Pontiacuse the mid-engine design.Waddup my Fiero fans, heck yeah.So if they use it, theremust be a good reason, right?Let's break it now.(upbeat music)Weight distribution, andthis is where mid-enginecomes into play in a very big way.Whenever you startchanging the distributionof weight in a car,you start to change its center of gravityand it's polar moment of inertia.Now, center of gravityis a pretty basic conceptand I'm sure the majorityof you guys watchingknow what it is, butfor those who might not,it's just an imaginary point in an objectwhere the distribution of weightis equal in all directions.Now, the concept ofpolar moment of inertiais just an extension ofNewton's law of inertiaand it's how difficultit is to get an objectto rotate around an axisand here's a practical examplehelp better understand.If I take a baseball andI throw it in the airand I try to get it to rotate,it's pretty easy to do that, right?You can toss it up inthe air and it'll spin.You can see that it's spinning, right?It has a low polar moment of inertia.Now, if I were to take a baseball batand it had the same amount of mass,same point of center of gravityand I throw it in the airand try to get it torotate, it is much harder.And that's because it has ahigh polar moment of inertia.The mass is in the ends of the batand the farther way from theaxis of rotation the masses,the harder it is to make it rotate.So with a mid-engine car,it has a low polar moment of inertia.The mass is more centrally locatedand therefore it's easier to turn the car.And in sports cars, that is a good thing.So by moving the 500 pound engine,seven and a half feet backwards,as well as moving the300 pound transmissionthree foot backwards,it changes the Vetspolar moment of inertia.Now a bonus in moving theengine and the transmission backis that you could place the driverin a more centrally located area closerto the center of mass.Now you know that a lowpolar moment of inertiameans the car actually turns in quicker.Well from a driver experience,it actually feels likeit's turning in quicker,which is pretty cool.(car engine roars)So what does all thoseweight distribution equate toin the C8, well you get a 40-60 balance,that means 40% of the car'stotal weight is in the frontand 60% is in the back.When you move the vet'sheaviest component,the engine further back behind the driver,you put more weight on the rear wheelsand that added weighteffectively increasesthe amount of power youcan put to the groundand therefore you canget up to speed quicker.Not only that,as you accelerate the weightof the car shifts backwards,giving you more tractionand further helping thecar move forward quicker.Now if we compare the C7 vet to the C8,the C8 gets from zero to 60 in 2.9 secondsthe C7 with the same Z51 package,it gets there almost a fullsecond slower in 3.8 seconds.Now there is some gearingchanges which cause that numberto be differentbut about 50% of thatincrease in zero to 60 timeis achieved by gettingmore grip to the wheels.They even designed thecar to run a wider tireat 305 wide rear tirecompared to the C7 285,that's 20 more millimeters.So by managing where theweight of the vehicle is,we can improve upon the car's performance.We can load up the reartire and get better tractionand all sorts of driving situations.We can go into corners faster,we can pull more G'swithout breaking traction.We can become a mid-engineAmerican made super car.But what about if you wanna slow down,is there any mid-enginebenefit to stopping?You bet your hot sticky bonds there is.Braking, in pretty much all cars,the front brakes do themajority of the brakingbecause as you break the weightof the car shifts forwardin the front, like just like the opposite.When we talk about acceleration,when you accelerate,you move backward, whenyou brake, you move forwardand in a front engine car,this is exacerbated by the factthat there's already a lot ofweight already in the front.So how does a mid-enginelayout affect braking?Well, when you have a moreevenly distributed car in regardsto its weight, each of the four brakescan then apply braking forceat each of the four wheelsand that creates morestability during braking.Also because weight transfers forward,when you break an a mid-engine layout,you have less mass upfrontand more weight on the rear wheels.And in fact during deceleration,also known as breakingthe C7 carried 66% of thecars mass on the frontversus 57% on the C8.And because of that,the front brakes don'thave to work as hard nowand they actually drop thesize of the front rotorsand made the rears larger,which is unheard of.They went from a 13.6inch front rotor in the C7to 13.3 inch rotor in the C8and the rears went from13.3 to 13.8 inches.They made the front smallerand the rear is bigger.And look at the rotorsizes in front engine cars,the front are always going to be biggerbecause they have to work hard.But with the mid-engine car like the C8,the rears can finally carrytheir weight around here.(chuckles)So you can see there'sobviously some benefitsto having a mid-engine carand it might sound like,oh it's pretty easy.We'll just move the enginefrom the front to the back.Well actually it's not that easy.It's actually a lot of work.I actually got to speak toone of the chief engineerson the C8 and there are alot of engineering challengesthey had to overcome.When moving the enginefrom the front to the back.So they didn't have a mid-enginechassis in their GM fleetand they weren't going togo dig up old Fiero joinsdust those bad boys offand kinda use what theylearned back in the Fiero days.No, they had to start from scratch.So they built theirfirst prototype by handand they didn't have a body for it.So they disguised itin a holding nute body,which is pretty cool.It costs them about $10 million to make,they use that car as atest bed for about a year.So they took everything they learnedfrom the first prototypeand they built another 15 by hand.They crash tested five of them.They got a bunch ofinformation from those 15they then a year later builtanother hundred again by hand.Two years after that,straight off the bowlinggreen Kentucky plant.We got our first productionmid-engine Corvette,the C8 heck yeah brother.So the C8 team had a bunch of challengesthey had to face along the way.I mean they had everything thrown at them.And one of the main thingsis they had to still makeand build a practical car.I mean the majority of peoplewho are buying Corvettes,they need luggage space.They need a spot for their golf bagsand at the end of the daythey made a mid-engine car.That's from a practicalitystandpoint, pretty useful.So we talked about engine placementand how they did it better,but we haven't talked about the engineand how they're making itbetter, CRANKSHAFT! (giggles)(car engine roars)Now the engine that comes in the C8is a 6.2L PUSHROD V8 LT2.We talked about thedifference between pushrodsand overhead valve engines a few weeks agoback when we releasedepisode of the Viper,but one thing we didn't focus onis the kind of crankshafts engine useand when the C8.R Chevy'srace car version of the C8came out to Daytona this yearto race people's ears perked upto the exhaust notes coming out the back.Have you ever wondered whyEuropean high revving V8'shave an engine sound that differsso greatly from the low rumble of V8'sand American made cars?I mean they both have eight cylinders.They both are in a V formation.They both are four stroke engines.But an American, it sounds like this.(car engine roars)In a European engine, it sounds like this.(car engine roars)So what gives.Well you might jump tosay, well Jerry baby,they have different exhaust systemsso of course they're gonna sound differentand I'm gonna say, yeah,I'm sure they got different exhausts.But what if we take the exhaustout of the equation huh?The reason they sound so different isbecause of the kind ofcrankshaft they use.The job of the crankshaft isto take the linear motion of the piston,that's their up and down moving like thisand turn that into a rotational motion.So the crankshaft sits in thebottom of the V in the blockstays right here, right?And it's connected to thepistons via the connecting rods.And along the length of the crankshaft,are crank journals also called crankpinsand those are the exact spotsto where those connectingrods attached to.And the orientation ofthose crank journalsdetermines the type of crankshaftas well as the firingorder on that engine.And this is where we can startto differentiate the flat-plane crankshaftand the crossplane crankshaft.Now flat-plane crankshafthas cranked journals180 degrees out of phasefrom each other,meaning that every 180degrees of rotation,a cylinder fires.Now if you were to crosssection that crank by drawinga line through it,you only need a single planeto split the crank journalsat their center line.You need a single flat-plane.With crossplane cranks,the journals are 90 degreesout of phase from each otherand if we apply the same crosssection method from before,you need two planesto cut through the centerline of those journals.And if you look downthe barrel of the crank,those planes form a crosshence the name crossplane.Go tell your mom you just learnedsome fricking mechanical nerd stuff.She's gonna be like, Dylan,go eat your corn pops.Now with American made V8 engines,the most common of the twocrank shaft is the crossplane.Hemi uses a crossplanecrankshaft, Camaro's used them.Almost every Mustang uses them.I know the GT 350 does it,even the base model Corvetteuses it with their LT2 engine.Pretty much any American made V8comes with a crossplane crankshaft.One of the main reasonscrossplane engines are more commonis due to the fact that theyhave a smoother operation.And to explain this,let's take a V8 engineand let's number the cylinders like this,cylinders, one to eight,one, two, three, four,five, six, seven, eightand if we look at the firing orderin the 6.2L V8 in the C8Corvette, for example,it's cylinders fire inthe following order.It goes from one to eight toseven to two to six to fiveto four to three.We can see that we go fromone side of the engineto the other side.There's a balance betweenthe two banks of cylinders.This added in the fact thatthere are counterbalanceson the crankshaft to accountfor the weight of the pistonsand rods as well as theforces in between the strokes.We have a very smooth operating engine.If we look at the order of thefiring inside a single bank,they have uneven space firing.That's what createsthat distinct chunky rumblesound of a good old American V8because the firing ofthe cylinders is uneven.The exhaust gas isleaving, it's also unevenand it's an exhaust pulsesthat make that noise, that(car engine roars)Perfect, perfect sound inAmerican V8, nailed it.So that is the crossplane.What's all the hubbub aboutthe flat-plane cranks?And flat-plane cranks hadactually been around longer.From a design standpoint.They're actually simpler.Like I mentioned earlier,flat-plane cranks fire every180 degrees of rotation,no matter the firing order.Flat-plane engines will alwaysalternate back and forthbetween the two cylinder banks.It's the equivalent of havingtwo inline fours firing offand this in turn produces moreefficient exhaust scavenging.See during the exhaust stroke,you create a pulse of high-speedgas leaving the cylinderflowing down the headersand this fast moving pulsecreates a pressure differenceand it turn, pulls a vacuum,pulling more exhaust gas outand more fresh air in.And as RPMs increase the air flows fasterand the effects ofscavenging become stronger.And the more efficient you are with that,the more power you're make.It's also what gives the flat-plane crank.It's unique sound.That rush of gas leaving the cylinderhas a very on beat order.This is actually thebest way to visualize it.Watch and listen.(car engine roars)Pretty cool, prettyAmerican, blah blah, blah.(car engine roars)Also pretty cool which one do you like?Let me know in the comments.So that's why flat-planeV8 sound different.Why are they considered betterthan it's crossplane walbro?Well, one, you havelower rotating mass dueto less counterweightsneeded on the crankshaft.Now the downside is youget more vibration issuesbecause you no longerhave any counterbalanceson the crankshaft.And as the engine size getslarger, so does the roughnessand vibration of the engine.The bigger the engine is,the more that vibration propagates.But in end of day, who cares man,you got freaking race car engine,race car drivers don'tcare about some vibrations.They wanna go faster,they want more efficient,more powerful engines.And that is what a flat-plane crank does.Now there hasn't been anofficial release from GMabout the Z06,but there's some footage out there of itof one driving around the canyonsand it sounds nothing like the base C8.I got a little insider informationfrom one of the chiefengineers at the C8 program.He told me, be quiet.That remember when theyraced that C8.R in Daytona?Well homologation rule statethat for them to race that car,they had to build 300 production models.So if you read between the lines,we're getting Z06 with aflat-plane crank engine baby,woo dude, Ferrari, we're comingfor your Italian stallion.(car engine roars)This episode is sponsored by Omaze.We've worked with them beforeto give the dream cars away,like at BMW M8 CompetitionCoupe, a Porsche 911 GT3 RS.And now we're giving you the chanceto win your very own 2020CORVETTE STINGRAY Z51all you gotta do is go to OMAZE.COM/DONUTand enter right now.Right now for a chance to win this carwith taxes and shipping includedplus $20,000 cash to spendhowever you want.And the best part is everydonation supports an organizationthat means so much to meand the rest of the Donut Media family,the Ronald Reagan UCLA medical center,it was their critical workthat helped save the life ofour very own James Pumphrey.So we love them over there.So please click the linkor go to OMAZE.COM/DONUTand donate right now.Thank you so much for your support.We love you.Bye for now.