ENGINE BALANCE: Inline 6 vs. Odd fire V6 vs. 90 degree V6 vs. 60 degree V6

[@d4a]

Support d4a: driving-4-answers-shop.fourthwall.com/ Bussisimo: amzn.to/37wLhX4 GTV6: amzn.to/2ZvB9JF Such a bore: bit.ly/36jYWQI Build the flat: amzn.to/2OpcIfa Wear the VR: amzn.to/3qOHDhM

[@electric7487]

(Posting this here so that hopefully people will see it) I'd like to add a few extra points in addition to what you pointed out in the video: Most people don't know this, but another reason that most V6's are 60° is because this V angle offers perfect primary balance while maintaining even firing intervals. 120° and 90° even fire V6 have bigger horizontal imbalances than vertical for each pair of cylinders resulting in a rocking moment. If the peak primary force of each piston is 1, the peak horizontal and vertical imbalances are 1.5 and 0.5 respectively for a 120° V6. The crank weights are sized to balance out the average of the imbalances so that the remaining imbalance is circular. In this case the remaining imbalance has magnitude 1, so a single balance shaft generating a force of 0.5 (with weights 180° out of phase) would have to be used. But as D4A mentions in the video, a 120° V angle is very wide, and you might as well use a boxer 6 at this point. For a 90° odd-fire V6, primary balance is perfect as a 90° V-twin has perfect primary balance, and crankshaft weights can be used to balance out primary vibrations. The problem is that when you have non-split crankpins on a V engine, at least one of the firing intervals must be equal to the V-angle, and what happens in the case of an odd-fire V6 is that the engine's firing intervals alternate between 90° and 150°, as he explains in the video. (This is also why the 90° V10's used in the E60 M5, Viper, R8, and Huracan are odd-firing, as their use of a 90° V angle and non-split crankpins results in firing intervals alternating between 90° and 54°.) For 90° even-fire V6, each crank pin has a -30° split to give 120° firing intervals. Vertical imbalance is 2 * cos(90° / 2) * cos((90° - (-30°)) / 2) = sqrt(2) / 2 = 0.7071 (again relative to a peak piston primary force of 1) and horizontal imbalance is 2 * sin(90° / 2) * sin((90° - (-30°)) / 2) = sqrt(6) / 2 = 1.2247. The average of the imbalances is cos(15°) = (sqrt(6) + sqrt(2)) / 4 = 0.965925, so the crank weights are sized to generate that force. The balance shaft weights are then sized to generate a force of (sqrt(6) - sqrt(2)) / 4 = 0.258819 and are again 180° out of phase with each other. For a 60° V6 with -60° flying arms, both the horizontal and vertical imbalances are 2 * sin(60° / 2) * sin((60° - (-60°)) / 2) = 2 * cos(90° / 2) * cos((90° - (-30°)) / 2) = sqrt(3) / 2 = 0.866. This means that primary forces on a 60° V6 can be almost completely cancelled with crank weights without needing balance shafts. All 3 configurations will also have a slight secondary rocking moment, but this does not appear to be an issue in V6's as the magnitude of the vibrations is normally pretty small.

[@KrustyKlown]

In summary.. the FLAT 6 is the perfect engine.

[@pwcraig65]

I have a 4.0 straight-six and a 225 Buick V6 odd fire. Thank you so much for the information.

[@actionjksn]

I would like to see you cover at this mess kzbin.info/www/bejne/ZpCul2BtoMxpe80

[@simonBAGL]

Can you make a video about the Alfa Romeo 690T in the current guilia since it has a 90 degree v angle. Also the Ferarri 296 has a 120 degree v6, would be interesting to see what you opinion is

[@denisminigarage2030]

I wish there was a separate subject called "automotive engineering" in school and you were my teacher

[@brentonellis213]

There was at the school I went to

[@denisminigarage2030]

@@brentonellis213 👀 I want to go to your school

[@Looptydude]

Could easily be covered in both math and physics courses, however the average student couldn't care less. Remember you are here because this is a subject that interests you, you are in a minority. There is a reason why there are more youtubers subscribed to make up tutorials than engine dynamic tutorials.

[@monstrositygamers]

Mechanical engineering is the closest you'll find in most schools, there are specific automotive engineering programs but then you're limited on jobs

[@redneckhippiefreak]

Sadly, The depth of the Auto Tech programs in Accessible High Schools has fallen by the wayside along with Numerous explorative arts, Social studies and extra curricular activities like Horticulture, Animal Husbandry, Industrial Mechanics, Drafting and Design as well as Carpentry, Masonry and Weapons education. Instead of learning how the world works and why, and being able to seek out the experience in a welcoming environment with their peers, they have been left to their own devices, thus staring into another device in their hands while being fed easily retained information that is in many ways absent of relativity. . I fear for our Kids Children.

[@ruanstrydom6471]

Bru this is really a legit video, we the unwashed masses really appreciate it. ❤️

[@d4a]

I'm not very washed myself

[@lordjaashin]

who the f is unwashed masses here? talk about lame self deprication humor attempt

[@sainig1996]

Now you are washed with this videos knowledge.

[@ruanstrydom6471]

@@lordjaashin its a term he uses in his videos get educated before you make stupid comments.

[@ProtoAzula]

@@d4a question: couldnt you make a v6 without splay using a 60 degree angle? I was thinking you could use a firing order more similar to a v8? Just wondering since i dont have time or resources to figure this out myself.

[@Lidekys]

It's an interesting way to explain stuff, by bringing up problems and explaining how to fix them, love these videos! If possible, throw in a rotary engine, when you'll talk about balancing again :D

[@mehdihani2932]

I dont think rotary would have primary imbalance

[@andyharman3022]

Every Wankel engine is perfectly balanced.

[@-oiiio-3993]

@@andyharman3022 So they said: kzbin.info/www/bejne/e53OpoqnnbFsjJo

[@michaelcuff5780]

That is a cool engine! If you like rpms! Thats the engine for you!

[@vd4534]

O tom pochybuji. Není to klasická rotace, ale šmatlavý motor, který potřebuje vavážení. Proto se asi dělá min. dvourotorový.🤔

[@evanhoffman3574]

This channel and engineering explained are really so valuable to people who actually care about this type of stuff. Explained perfectly and never boring while doing it

[@mattb9343]

"Nobody really gets engine balance the first time." You explained it well enough I got it the first time. 120° popping up again. Just so happens to be the natural angle of hexagons. Wich generally provide better balance and structure.

[@edim108]

To quote CGP Gray "Hexagon is Bestagon!"

[@philkensebben157]

Further showing that indeed, hexagons are the bestagons.

[@KORTOKtheSTRONG]

🅱️exagon

[@TheDrvenisovac]

I had to stop in the middle of the video to write a comment because this is THE BEST video explanation of the said matter! Congratz!

[@sicstar]

I highly appreciate your effort in all those videos and that you smack so many informations that are pretty much well digestable inside em. Thats the stuff YT and the world needs (or at least i need it lol) keep em coming. I'm staying here... this stuff is pure gold

[@MikeNebgen]

I've been trying to figure all this out for 30 years and never quite got there. THANK YOU!

[@neetones]

You are such an incredibly good teacher.

[@flaviopk50s]

"he never talks about the strange Alfa v6..." Oh shit, here it is!! 😂 Beautiful!

[@killerdinamo08]

He has a special video dedicated to Busso's wonder ❤.

[@flaviopk50s]

@@killerdinamo08 where??? :D

[@killerdinamo08]

@@flaviopk50s Drat, I've mistaken him with an Italian guy who made a video about it, I beg your pardon ✌.

[@nvl2691]

@@killerdinamo08 Confused him with Roadster Life eh ?

[@killerdinamo08]

@@nvl2691 Right you are 😉.

[@nickzapletal9421]

We really need teachers like you. Presents the data effectively and clearly. Kudos !

[@gedavids84]

Looking forward to the flat-6 and VR6 videos. :)

[@davosworks]

Yup, I have 300ps 3.6L VR6 with 10,6° angle, so Im waiting with you :D

[@SomethingFunny454]

I almost commented that

[@NYRNJD1987]

If only nissan didn't suck hey

[@Jesus_Christ_loves_you_alot]

This is my new favorite car youtube channel. Your voice is so calming I literally started falling asleep.

[@Stewalkin]

Truly the best explanation for a common man to understand.. You are a gem of value to the engineering students. What made it simple for us to understand was the pictures and animations which made us relate to your explanation. thank you

[@dimitripereira2552]

Man, I’m 1.29 minutes in the video, and I just understood secondary inbalances even tho I had already watch other videos since many time and never understood it. Thanks man, I’m pretty sure the rest of the video will be as interesting !

[@justinkostelecky6201]

I have a 225ci odd fire Buick in my old Willys Jeep, such a neat engine. One thing to mention, the flywheel is like +70 lbs. I’m not sure if this helps the off balance issues, but it does give it tractor-like torque. Great video, and great explanation!

[@brianb-p6586]

The flywheel mass is to add rotational inertia to smooth out the effect of the uneven firing intervals; it is not related to balance. It also does not increase torque, but it makes torque delivery at low speed more acceptable.

[@stevenash4408]

You are so incredibly talented plain and simple!!

[@williamstenger8452]

I love this video! Your explanation helps me better understand the imbalance in the Buick 231. I was working on these things in my younger years, knew they were rough running, even knew they were the offspring of their v8 cousins (evident in the distributor cap), I just never saw an explanation as detailed as yours, thanks!

[@lenhart8487]

As a kid my buddy had a 231v6 In a jeep commando pickup, and I did really know about V° or anything, I just remember it had a distinct sound idling

[@feanorflame9384]

Man, this video is just God´s blessing. I have an exam in 10 days on this exact topic. Now I have a deeper understanding. THANKS!!!

[@HarnessDavid]

The KZbin gods just recently started putting some of your videos in my recommended section and it has been a great experience. Thank you for the many great informative videos

[@rodbrown8306]

You're the best presenter/teacher on KZbin....seriously you are brilliant. I will watch all this series for sure.

[@JazzbLu]

I still find it amazing how much I learn about the basics of engines from you! The simple stuff like this make a huge difference in engineering an engine. We all appreciate your knowledge and thank you for sharing!

[@rogerandersson279]

As usual, my daily goal of learning something new is fulfilled by watching your videos. Thanks :)

[@emmajacobs5575]

This is the first explanation of odd firing vs even firing that I’ve actually understood! Thanks :-)

[@danj9339]

I could never get my head around why the v angle made any difference. You've just answered that brilliantly. Thanks.

[@chupachups6098]

One or the best divulgative channel on piston engines, great job.

[@ogobetse]

i've not found anyone (professional or otherwise) that does a better job explaining this concept with more passion that you have. You're amazing and i can't wait to see what other content you come up with. Great job.... just amazing!

[@nvl2691]

A perfect video, right on time for the reveal of the McLaren Artura and it's hot-V 120 degree V6!

[@siddharthsingh7508]

bruh that tata nano bit cracked me up, thank you for the great content

[@fridaycaliforniaa236]

Damn, these videos are my go-to when I need to understand anything related to cars. I've spent many years modding engines, but I never really knew about why the engines were built like they were. Excellent videos that you make =)

[@guidoheeling1179]

i think this is one of the best series you did so far!

[@JerryPrado]

Wow. Explaining engineering in ways that we can all understand is just not talent..it's an art!!! Now I understand why my sister's 1976 V6 Buick Regal shook like mad and my 78 downsized Regal was smooth! Thanks.

[@DM-wp9vq]

Another spectacularly detailed explanation of a complex subject that we (the learning laymans) can wrap our heads around. Love it! And thank you as always for taking the time to educate us!

[@Chuckius]

Beauty, nice focus on important aspects. I don't know what a dialect that is, but it's well pronounced and understandable. I think some teachers of technically focused high schools can highly benefit from using your videos even directly in classes. Technical part nicely graphicaly explained with nice english training involved. I'm glad to be subscribed. Keep it up.

[@Tommysmess]

This video alone was why I subscribed, my little chevy s10 has the 2.8 v6 and it's 60° . I never really understood why until this video! Thank you for sharing your wonderful knowledge and wisdom with everyone on here :)

[@Joshua5654]

Nobody: Buick: let’s defy physics

[@raoulrr]

Well, the latest Maserati V6 (the 'Nettuno' engine for their upcoming Maserati MC20) is a 90deg V6 without balance shafts, so maybe it can be done, contrary to what this video might want you to believe.

[@andrewlace]

The old buick V6 and ecotec is one of the most reliable engines ever made.

[@FirebirdCamaro1220]

@@raoulrr the original Chevy 90°V6 didn't have balance shafts either (the 200 and the 229). Once it went up to the 262/4.3, balance shafts were finally added

[@jordananderson2728]

@@raoulrr interesting then how he literally says you don't need a balancing shaft.

[@-oiiio-3993]

One of the very best engines for a hot rod Willys Jeep is the old 225 Odd Fire. They fit well, are torquey, powerful, quick, run cool, and don't know how to stall. When Buick's new manager sought to dump the Fireball 6 they sold it to Kaiser, who gave them heavier flywheels, dubbed them 'Dauntless', and mounted them in Jeeps and Jeepsters. When AMC bought Jeep from Kaiser they sold the V6 back to GM where it was eventually fitted with the split cranks, then increased to 231 cubic inches and built by the zillions.

[@yuci4070]

man i admit that you're super underrated

[@pedersterll5007]

Great, great video series. Being a petrolhead for more than 50 years, I finally got to understand the concept of secondary balance/imbalance. Thanks again, and keep these videos comming (-:

[@Pappaoh]

I can't believe the depth you bring. Thanks for the great content!

[@ahnafzahid9450]

Your videos keep oozing with Infos....keep it up bro!!!!

[@jkim6200]

Phenomenal! The best video in your series on engine configuration (6cyl engines) fundamentals.

[@CarminesRCTipsandTricks]

I stand corrected to what I said in the last 6 Cylinder Balance video!! 😵😳 You covered the odd fire V6 brilliantly!

[@johnathanwathen4165]

This guy makes great videos. I am sharing them with my motorhead friends. These make you think and realize stuff never thought of before.

[@finlaymetcalfe6360]

Always seem to know how to make education videos entertaining and interesting. Really enjoy the content, love from NZ :)

[@Jasongy827]

Inline 6 and inline four I love those engines, just balance, feels more roary. Great explanation.

[@nordic5490]

In line 4s have rough harmonic resonances also.

[@pepitomov]

Very nice video, glad to see you are continuing the engine balance videos. Will be interesting to see the big boys like v8 vs v12 and even the i8. Keep the good work and stay safe 🙂

[@dutchgamerguy2446]

Math test belike: name the offset between pistons of a 2-stroke inline 7 I think its about 51.4 degrees

[@UNKNOWN-zb3qm]

Love how you did the recap instead of just saying to watch your other video 💕💕

[@00gt5speed]

I love these videos! I always wondered the differences between odd and even-fire V6s. Thank you!

[@TheRealTomLauda]

Amazing work ! Your videos never disappoints !

[@charleslowe522]

What an awesome upload. Great explanation of the odd fire v6 and why it was necessary to split the crankpin on the crankshaft. Great job. This is the video yet - just because I didn't understand what it meant by odd fire v6 and I didn't understand why the splitting of the crankpins was necessary.

[@timvanderstarre9021]

I really love your engine balance video's they made me fall in love with the inline six design. I have a request though, can you please make a video comparing the inline six with the v12 engine configuration, explaining why the added cillinders help the smoothness of the engine. I really hope you cover that one day. Keep up the good work man. Cheers!

[@d4a]

The v12 will definitely be covered eventually

[@yiannisargyrides8125]

EXCELLENT VIDEO AS ALWAYS PLEASE DO A VIDEO ABOUT THE TYPES VALVE LIFTERS HYDRAULIC ETC... THANK YOU

[@Tex777_]

These videos really are great, thank you for having such a concise explanation of all this that's actually easy to understand.

[@charlesjames1442]

I left my Probe GT with the Mazda KLDE 60 degree V6 running one day when I was half-asleep and stumbled into work that winter morning. It was so smooth running that 8 hours later when I got back in the car, I tried to start it and ground the starter after it had been turning all day.

[@bigsalo8598]

Just descovered your channel. I am studying different automotive engineering books, and I must say you really explain these subjects in an extreamly interesting way, and all in an easy to understasnd way. Love it!

[@dariomendoza1518]

Awesome explanation for begginers like me!!Thanks for sharing!!

[@blasphemian4837]

u know this was the kind of stuff that kept me up at night so thanks for making a video about it

[@BG.108]

I started off with your 3sg-te video and was blown away by the level of detail you go into describing it. Also in your 3sg-te video you mentioned wanting suggestions for new videos- have you heard of the GM LFX engine? It's a newer direct injection 60 degree, v6 engine that comes in the Impala, Equinox, Camaro, LaCrosse, and maybe others. It's north of 300hp stock, naturally aspirated, has a closed-deck aluminum block design, and can be bought from a wrecker for less than $1500USD. V8 Roadsters makes a kit that allows it to be swapped into a Miata chassis, as well as a few other manufacturers offering swap kits for it. It seems like a great option for those seeking good power with low cost, although wiring might be tricky. Just an idea! Keep up the great work!

[@jakespeed63]

Excellent explanation. As a veteran mechanic I had to always contend with those horrible Buick V-6 engines. My sister's 1976 Buick Skyhawk broke the crankshaft in 2, like so many others. How ironic, that the Buick 3800 would become one of the best engines of all time.

[@AhmedHassan-er5jt]

You are a genius!! You make explaining this look easy, which it is not

[@alimcanuff6056]

Bro you are the best channel to watch you teach me a lot about how to fix my car thanks you keep on doing the good work my brother blessing

[@frosty98412]

This is the exact information that I was missing to understand crankshaft and flywheel balancing of the Alfa V6. It is much clearer now why the crank itself cannot be lightened and why only the complete rotating assembly can be balanced and lightened (with bobweights). Thank you!!! Also, maybe you could make a guide for each type of engine about lightening the crank, flywheel and balancing to add power, free revving and smoothness?

[@gabewhisen3446]

You just made it so I can teach this to kids and I thank you

[@ttabani211]

Oh my God!! I wish you were my teacher in real life. Thanks dude, as a mechanical engineering student, this expands my knowledge. 🙏❤❤

[@mutt8553]

Absolutely incredible video. I could watch these for days

[@sushpants]

Awesome video D4A! I'm super impressed with your ability to explain and educate.

[@d4a]

Thanks my man!

[@xynostasos9022]

My favorite series! Can't wait for the next episode!

[@taydencornish]

discovered your channel yesterda, massive fan, thankyou for all you do, i appreciate it, love from australia

[@rugbyladice574]

Fantastic video, and absolutely fantastic teacher. So glad I found this channel.

[@cipher2508]

Ma boy D4A KILLIN the game

[@mvdesigncustomworks5460]

Good to see you're feeling better!

[@kylecurry6841]

Hats off to you sir! This video puts all questions of the why's for V6 bank angles to the drawing board. I had this question the other day on why a 60deg V6 was ideal when 120 deg was the ideal bank angles...of course I found a form post that confirmed that 60 deg V6's have splitpin cranks, but this video was what I was looking for!

[@martin-vv9lf]

I think you're mistaken, as i understand it, 90 degree v6 have splitpin cranks with no balance shaft, and 60 degree v6 do not, because they have balance shafts. it's all so confusing lol.

[@kylecurry6841]

@@martin-vv9lf honestly I think the balance shafts are ideal for any V6 given the rocking-couple effect caused by the V6 acting like 2 3cyl engines unlike an I6 where these motions are cancelled out by symmetry. Both the 90 and 60 would have split-pin journals to accommodate an even firing order, while the 90deg needs less aggressive splay angle on it's journal centerlines vs the 60. In either case, much of these principles are pretty common place due to the V6 being the package-friendly favorite among manufacturers, but I agree, you don't often question these indifferences between the everyday V6 vs a simple 90 deg V8 which naturally doesn't need any changes to it's crank to work, and work as either a crossplane (America) or flatplane (Euro).

[@triggerwarning2439]

I love the sound of the odd fires, great video 👍

[@GIGABACHI]

Great work putting it all together AND EXPLAINING IT ! That's the hard part, explaining it in a way everyone gets it. 😎👍

[@clintoncvl]

Loving your videos. Cant wait for V6 vs VR6 and V6 vs V8 and different types of V8!

[@PetAmer599]

Was about to ask you about vr6 and flat 6 but you answered it in the end hehe

[@d4a]

Thank you for watching until the end. Everyone's asking without watching.

[@msudawg1997]

Excellent video. I knew I6 engines were better than V6 engines as far as balance goes but didn't fully understand the reasoning. Your graphics and explanation made this complex subject easier to understand.

[@tensevo]

I6 are better if you just think about the engine itself, but V6 can be packaged in a shorter wheelbase with centre intake and exhaust either side. edit: in other words the V6 has lower c of g.

[@msudawg1997]

@@tensevo if I just think about vehicles that I know of that used I6 engines and V6 engines, the V6 is definitely more common, by a long way. And I would assume that's for precisely the reasons that you listed. I'd guess that the more compact form factor and lower CG is the very reason the V6 was even created. At least I can't think of any other benefit over an I6.

[@BomarBuilds]

He's the Antov of cars! Amazing info!

[@doubletee4391]

It's funny. I just posted a comment on your recent Yamaha R1 crank video asking for something like this. Now i see you were way ahead of me. Cheers

[@PATRIK67KALLBACK]

Thank you for this great educating video! As you mentioned in the video, I look forward to see the comparison with the VR6 engine.

[@lollol-xp4mc]

I second this

[@ronjon7942]

Nice work. I watched your entire balancing series to help clear up the confusion I ran into researching balancing solutions for aircraft radial engines. I'm looking forward to doing the same w inline and v aircraft engines, and thanks to you I anticipate understanding the various crankshaft configurations I'm likely to observe.

[@johnellison3030]

Mate. That was an excellent educational video. Thanks for posting this.

[@raymondkrystofiak1617]

Thanks for this excellent video, supporting animations and dialogue. You have put a lot of time and effort into this very professional presentation, well done. Am looking forward to the next instalment.

[@TheWiiMatt]

Great video! Cant wait for the rest of series

[@andilemlindi7680]

Awesome! Great information thank you. I can’t wait to hear about the VR6😎

[@ineffable1129]

A VR or W (VV) is just a narrow V or a pair of narrow V, with shared crank hence VV or if you're a cheeky German W. A true W engine has three banks but I digress. So a VR4 is really a V4 with a very narrow V using a single head. The W8 is a pair of those VR4 in a V configuration again V V the W is play on the letters. It's design is all about compactness and makes compromises everywhere else. You have asymmetrical intake and exhaust runner for every other cylinder, have to use a split pin crank too. In practice they are under square, small bore long stroke good for torque not so much for power, they don't like to rev. Before you think but what about the W16 in the Bugatti, it's quad turbo 8L. You can make that kind of power with LSx even match the displacement with half the weight and only two turbo's. By half we're talking about 250kg or about 500lbs less. More over the LSx will likely be more reliable and last longer.

[@d.haroldangel241]

Fantastic video, great explanations. 100 thumbs up !

[@LeZturbo]

Great explanations, and your animations are great !!!!

[@QuintinKruse]

Thanks, been waiting for this one and also looking forward to the other two videos on the topic

[@manuelncl1769]

Excellent technical explanations. I will follow with great interesr this series of videos

[@marianlech3378]

Shyt, this is so damn comprehensive, oh my, time well spent! Thanx!

[@alidaraie]

That made it completely clear for me. Thanks for the great video

[@dmitrykhramov1832]

Great video! 👍 Awesome explanation ! 💪 It’s a pleasure to watch and listen! 👌 👌👍✌️

[@326piotrekify]

This is extremely interesting! I wish some day you'll make a video about a V8 - e.g. crossplane / flat plane

[@-oiiio-3993]

Very concise and well explained. Good stuff!

[@P_Ezi]

Excellent explanation - greatly appreciated.

[@bockariemansaray9196]

Dude great video! Very informative. The inline 6 engines lasted way longer than the v6. And less parts! Keep it up bro!

[@ethanruckert3871]

I was going to ask you to make a VR6 video but I waited to the end and sure enough you're already on it awesome content keep it up

[@richiiiiie1999]

Beautifully explained

[@donguhl2499]

Awesome Video! I love how you take the black magic stuff and turn it into easy to understand science! Well done! Thanks!