Balancing Shafts - Explained

[@AlexBlaxican]

Damn! This information has increased my interest to become a mechanic! I never realized all the physics behind an engine! Bro! You are such a blessing in my life right now! I have been learning so much from your videos! Thank you so much for the effort you have invested in making this videos! Much love from an car enthusiast in Texas 🙏🏽

[@RetiOrchid58]

Your videos get straight to the point and say things comprehensively without drawing it out in length..Good teaching/sharing, good for learning.

[@gilsonrogeriolimaoliveira2807]

Your explanation helped me place the shafts in the correct position Today in a Mercedes M274 engine, because they have no markings in the gears. Keep up the good work.

[@awesomeluis]

My engine (2.6L s.o.h.c. mitsubishi) had the balance shafts removed so the vibrations get pretty annoying at certain rpms so I'm thinking about putting the silent shafts back in. They were installed for a reason in the first place and if they help the engine last longer, it's worth having them. Thank you so much for the great video.

[@scottyhankemeier9380]

What rpms and how bad is it? Did you have your rotating assembly balance checked when you did that Delete? I have a Mazda 2.6l SOHC G6 engine I'm thinking about deleting balance shafts.

[@mitsuturbo]

Simply put, balance shafts were essentially created and installed to smooth the engine operation. This means the ENTIRE engine assembly in its fixed mounts, wherever that may be. Contrary to what some may believe, balance shafts actually have NO effect on the ROTATING ASSEMBLY. They don't counteract an out of balance rotating assembly, including crankshaft, rods, pistons, pins, flywheel, clutch, torque converter or harmonic damper (the last of which actually CAN help counteract minor rotating assy vibration/imbalance). Balance shafts help sell cars. They're not good for performance. They're a potential point of failure. They spin at twice the speed of the crankshaft. They're often removed from many engines to be used in racing applications because a grossly out of balance shaft spinning at 22k rpm isn't a great idea. In a car, they simply make the engine not vibrate externally, thereby causing a quieter, smoother operation. In some vehicles, they're called "silent shafts". Again... they basically help sell cars. It's all about that test drive!

[@oluskloc]

Does this shafts not rob power on high rpm?

[@carsonfranks3138]

any spinning mass on the engine will rob power during any rpm change. It is like adding more flywheel. It takes power to spin them up but not to keep them spinning.

[@oluskloc]

Yes I understand. But is it any significant amount of horsepower and torque (measurable) or just 0.1hp?

[@piotreknowickiyt]

even 10hp on 2.0L engine

[@oluskloc]

That's a lot. I have 1100 motorcycle engine, is it worth to delete it?

[@russbarrows6689]

You're very good at explaining both complex and simple engineering.

[@suryaagung7560]

I am about to modify my Toyota 3rz for boost (racing) and a common thing to do is to remove the balance shaft/s, I've been told to allow the engine to rev higher. Please explain how or why I would need to remove the shafts and how it benefits me in a race scenario

[@vinigretzky97]

How about a video about some more 'exotic' 4 cylinder layouts, like a dual-crank V4 or a square four?

[@larrywiehe706]

I know this is old but it is THE ONLY place on the net that explains these in a way that makes sense. I needed to time an Audi oil pump/balance shaft and there’s absolutely no information out there for once the marks are changed.

[@iamamirzamani113]

Hello I'm from Iran and I'm studying automotive mechanic at technical school . Thanks for you videos and practical explanations about automotive . Since there's a lack of educational provide in Iran , particularly in automotive industry I follow various types of programs and methods in order to gain my knowledge . As a constructive criticism it would be awesome if you explain things in more engineering details with SIMPLE LANGUAGE , in fact I do only understand less than half of your videos *** but if I have background about the related topic I recieve more from your explanation.

[@keithjohnson7311]

this is a good way to constantly polish the info you've learnt.. nice bro

[@mingyew6915]

thank you so much engineering explained for making lots of explanation vids....help me a lot as a automotive student..thanks bro.

[@A.F.H.]

Me trying to decide whether or not to do a balance shaft delete on my F22 to try and free up as much power the SOHC, non-VTEC engine can eek out. Thinks about engineering explained and whether or not he already did a video on it. The next day KZbin algorithm brings me here. Thanks EE!!!

[@stephenbogert2109]

you said the 2 balance shafts rotate in opposite directions but as you drew your diagram they will rotate in the same direction along with the crankshaft!

[@gordonglasgow8781]

In your previous video on Secondary Engine Balance, you indicated that the secondary forces are slightly less at the 180 degree point (BDC) than at 0 and 360 (TDC). That would seem to imply that even with balancing shafts, there will still be some residual imbalance, since the counterweights on the balance shafts are fixed weight. Is this correct? Great videos, BTW!

[@alvinbalonglong206]

Thanks for the video. Very important question: if the balance shaft is off from it's correct position does it affect the fuel pump timing? Please advise. Thanks.

[@daleleis5563]

I have Heard of some people deleting counter balance shaft with delete kits. Can this cause vibration in The engine and possible engine failure? The reason I’m asking this is because I’ve been anticipating doing this to a block on a Toyota 3rz because the bearings Spun in the block for the counter balance shaft and I was hoping to salvage the block to rebuild the engine . Any information on this would be appreciated

[@sinegra30]

@Engineering Explained There are v6 engines with balancing shafts too!

[@robertbritt3129]

Remember it's centripital not centrifugal so the force is at a 90° like if your swinging a plum Bob people say it pulls outward from the center but it does not it has an ever changing vector perpendicular to directly out from center. When you let go of the plum Bob or weight at the top when the string strait up and weight at the top hand in the middle of course let go and the weight will not fly into the cealing it will hit the wall perpendicular to the cealing

[@dasdasdsdasdasdasd363]

I think the balance shafts also help to stop the con-rod and crank journals from hammering themselves to death due to the longer stroke and greater forces and con-rod angle at BTC in larger 4 cylinder engines, say 2.0L and above, thereby increasing engine life. Which is probably why some smaller 4 cylinder engines don't use balance shafts; less than 2.0L for example.

[@SuperCookieGaming_]

has any engine integrated the balance shafts into the cam shafts? a lot of inline fours have dual cams so just grind the exhaust cam so you can spin it the opposite direction the intake and put the weights at the end of the cam shaft since there isn’t a distributer

[@ximi456]

Great effort done in these nice videos I just need to understand more .. why do we need the weight balancing shafts while the piston is in the mid stroke as it is just going down with normal speed and with no secondary forces ( as i understand that the secondary forces appears only two times from 0 to 90 and from 270 to 360 where the piston moves faster ) if that's right so why do we need to balance the piston while going from 90 all way to 270 ( mid stroke ) is it not balanced just by the primary forces ??

[@thedominator8877]

basically every thing i know about cars and preformence parts are because me watching your videos so thank you've helped me alot

[@EngineeringExplained]

Very welcome, thanks for watching!

[@thedominator8877]

Engineering Explained and Im only 14 and you've given me a big boost in knowledge

[@Omar80533]

Thank you for explaining everything in such detail! Gladly appreciate it!

[@alexmaccity]

You did a good job explaining their use. But why would it be a reason to delete them? Only reasoning ive been told is for high rev application. Which makes more sense because having 30lbs of weight on the crank thats at its max or nearing its max. That extra weight is just going to cause more wear

[@joebidden4914]

Can you please make a video about balancing a 2 cylinder that is 180 degrees out from each other and what would be needed to remove a single balance shaft to make it all run smoother?

[@ayphool]

Hi, do i need to marking the balance shaft together with other parts like cranck shaft or timing shaft or its just enough to marking the balance shaft itself only?, Tq in advance

[@fabiodorigoni5848]

Thank you very much! I was struggling to understand how to install balancing shafts on a bmw m47 engine

[@mcanderson0]

“All the secondary forces are pointing up” I think what you mean to say is “the sum of all the secondary forces points up” since the secondary force of the down-pistons is actually down. Since its smaller than the up-piston’s secondary forces, the sum of those forces is up

[@intrepid_wandering]

Glad to see another video from here in my feed. I haveseen the two gears that drive the balance shafts on some Honda engines many times before but I have ever worked out their purpose. Thanks!

[@krutchiet]

I see that the same concept of the balancing shaft can be applied in the case of the yamaha R1 engine, which use a crossplane crankshaft but only a single balancing shaft. Can you explain why is it better with a single shaft in that case? Is it because of how they angled the engine instead of having it perpendicular like a B or K series honda?

[@milokicks6887]

Thanks for making these videos, I've learned a lot more about my car and cars in general

[@curvs4me]

The balance weight gram determination would be good to know. When people modify an engine with a lighter rotating assembly they delete the balance shaft because it will cause it's own secondary vibration being too heavy. If you want to rev like an R6 you need it in there and need it balanced to your new mass.

[@shafferjoe1962]

Hello, I have a 2009 Kawasaki KLR 650 that is a single cylinder and it vibrates really bad. My question is, how do they (The factory) determine the weight of the counterbalance weights?? I am guessing, they weight the wrist pin in the crank and the big end of the rod, add them together and make the CW the same weight to cancel out the forces going in the opposite direction. Am I wrong, right or not even close?? Thanks Joe

[@danielhayes6348]

May sound dumb, but whatever. Is there an obvious way to tell if an engine has a balancing shaft (s)? Or not? Your videos are always great! Thank you

[@chrismcadooak47]

Thanks for the video. I have a question I have a obsolete continental 4 cylinder engine I cannot find parts for. It spun a balencer shaft bearing. I tore it down to re-ring it. A piston and liner kit are no longer made. Then I found the shaft ruined. Shaft is no longer made and no salvage parts available. My question if I remove both shafts plug the oil ports to them how long will the engine last? It's in a tractor hi load on the engine sometimes but mostly half throttle using the hydraulics no engine load. Is it worth trying or a waste of time and money.

[@CossieMan]

Awesome video, man. Thanks! As informative as it gets(!). 👍🏻👍🏻

[@abhidk3126]

You explained very well, But i have a question, You explained in video 180 deg at TDC, 180 deg at mid & 180 deg at BDC, but as crank shaft rotates one cycle that is 360 deg, the balance shaft rotates twice that is 720 deg. So where is another 180 deg?? Kindly explain !!!

[@geneqco]

Thanks for another great video! When modifying an inline 4 cylinder engine, typically with lighter rods and pistons but also perhaps with increases to bore, stroke and rev limit, how important is it to also modify the balance shafts? I realise that technically, ideally, it should probably be done but imagine it may be a little complex to calculate and implement. Given that most I4 engines 2.0L and below don't even use balance shafts, is it acceptable to just leave them as they are? Secondly, I know that some delete them, especially for race applications, but is this a good idea for large capacities around say 3.3L? I know of some larger engines with balance shafts deletes that always seem to be cracking up and I wonder if the Balance shaft delete could possibly be a significant contributor to this problem? Thanks again for your excellent and very informative videos!

[@renancervi7954]

+EngineeringExplained , hello! Your videos are super helpful for my engine understanding! I would like to request new videos content: 1) explanation of knocking types from main and rod bearings; 2) the importance of thrust washer between the web and bearing; 3) radial and thrust load of crankshaft pins;

[@mohdsifat1789]

simply brilliant.......technology as well as your explanation

[@MrAllrounded]

Is additional torque from the crankshaft required to turn the balancing shaft? If so isn't this counter-productive as ur using power from piston to rotate heavy counterweights against itself

[@pitbulltrainingandmotorcyc1658]

What if I don’t care about the vibrations wouldn’t this balance shaft technically be working against the engine performance ?could it be removed safely also do all engines have this ?

[@zeyadsabbah2089]

I understood almost everything about the balancing, thanks to you, the four cylinder and the a one-cylinder engine, but what about the 3-cylinder engine, I know it's not a common thing, how do they eliminate the primary forces, if it's a 4 stroke engine with 3 cylinders? thanks in advance.

[@powersliding]

it would be interesting to tilt the engine 45 or more and run a single balancer shaft instead. this will make way for oil to crankshaft yet have a balancer shaft directly below crankshaft at the axis of piston movement. single balancer rotates against crank, would be cheaper with one balancer with similar outcome

[@lexonaire]

So basically these counter weights are causing the engine to exert itself more for the sake of balancing out vibrations and forces that normally would cause disruptions in the engine itself?

[@kenny6105]

please explain like i’m 5, with this in mind what’s the ramifications of a balancing shaft delete due to an engine swap? thank you in advance if you take the time to answer.

[@jt.124]

I watch all your videos! Love the work! Can't wait till I'm a mechanical engineer:)

[@gerrievanstaden3416]

Hey, are you one now?

[@christopherbrown5338]

I thought the counter weight on the crank-shaft balanced everything, so why is a balance shaft required at all?

[@EngineeringExplained]

+Christopher Brown Crankshaft balances first order vibrations, not second.

[@Charon-5582]

Could a pushrod 4 cylinder be made with the cams pulling double duty as balance shafts?

[@santanusircar1621]

Thankyou for the awesome simplified explanation...how is counterbalancing done in inline 3 or 5, 6 cylinder engines....also can you recommend a book or weblink for more understanding of this...thanks 👍

[@moto_rad]

Primary and secondary forces are balanced for those engines, so no shafts needed 👌🏼

[@liferider2089]

Great universal understanding thanks, will try on 2.2 D4EB Santafe.O' I think midstroke drawing would have weights on the side ?

[@mohammedalyaqout9038]

Thank you so much. Very good videos with drowing and explaining. I intened to translated to Arabic if you permit. Best wishes for you. And waiting for new videos from you

[@johnkavashjr.8550]

I have a 1999 Ford Explorer with a 4.0 liter single overhead cam 6cyl engine, this engine has a balance shaft in it and I was wondering if you could give an explanation! this vehicle is four wheel drive also

[@김동개미]

incredibly nice working explanation , thanks alot

[@NekroDart]

can you explain the Subaru AWD system!! your awd video is great but shows a layout where the engine is perpendicular to the driveshaft unlike subies!!

[@radoliz2]

I love balance shafts, and now with silent low friction chains, its all about smoothness.

[@Shumayal]

Can the balancing shafts run without the need for a pulley? Or is it the pulley which helps achieve the 2:1 ratio?

[@josephrajkumar5193]

Would removing the balancer shafts harm the engine,?

[@Unb3arablePain]

No balancing shafts is probably one of the greatest advantages of an Inline-6 engine.

[@EngineeringExplained]

Well, hardly any modern production vehicles use balancing shafts. Most either keep small enough engines that it's not necessary, or different layouts can cope in different ways. That said, I6's are terrifically balanced, I'll have a video on the subject soon.

[@NecessaryJerry]

Engineering Explained I remember when GM added balance shafts to the quad 4 engine. There was also a noticeable decrease in HP that year. Do balance shafts decrease engine HP?

[@nblax41]

JerryTheHeretic They do lower HP as they're extra mass the engine needs to turn over as well as losses through friction in the gearing and bearings needed to keep them turning and stable.

[@Mortalomena]

Engineering Explained My father in law bought a new 2.4 liter Honda straight 4 suv. It vibrates so much :D

[@roskataqv]

+Engineering Explained They are a mate has the well know bmw I6 well maintained you ca hardly notice its running!

[@josuegonzalez3375]

I have a 2006 Altima 2.5S . I want to know if this can be remove? Delete kit? Any option? Help! Thank u

[@samuelleite4045]

how do i calculate the mass needed for the balancing shafts?

[@markfoulkes4954]

Nice presentations. In fact, the best I've seen and I work in the auto industry. Great job. Question.... do you have a like for like on an i3 engine ? I imagine this poses some new challenges.

[@AnunnakiThe1]

I am Working on my GF's Daughter's 2006 QR25DE , discovered the unit is suffering from shattered testicles ( the drive gears are shattered , bearings shattered and housing unit bearing seats are destroyed ) , this is what I have in mind to fix this permanently : get a new unit , go to local machine shop and cut off the housing seats and install new cast Iron or bronze bearing seat blocks to house the shafts new bearings , I think the problem is in the housing unit not the shafts , the balancing shafts are made from steel and the housing unit is aluminum , too weak to handle 2-1 RPM and friction in ordination of Crankshaft RPM . besides I saw the engine block has those either cast Iron or Bronze made, that houses crank shaft bearings why not do the same to the balancing unit ? what do you think of my Idea ?

[@naveenyadav4298]

Hello everyone and thanks for this sweet video.

[@peterhermina656]

Can you do a video regarding "Why no one uses oval piston in a car engine"? I imagine a much more compact inline engine with oval pistons.

[@erinpalmer402]

honda built a motorbike v twin with oval bores a while back im not sure how sucessful it was though

[@jinstube5522]

I think you should have said that all those forces are inertial forces, I also read in a comment that every V6 doesn't need secondary forces balance. That is not true because only V6 60° are perfectly balanced, if you change the angle, those forces are no more balanced. And there is more: all engines that have a number of cylinders equal to 3, 6, 12, etc... can have a perfectly balanced configuration. Anyway I've never seen a car with those shafts. They're didactically valid but not practically... Cheers :D

[@edgartavares2353]

So in the mid stroke the secondary force points down because the piston is accelerating downward? While at bdc the piston is decelerating the downward motion hence the force would be up. Correct me if im wrong im a little comfused

[@lig1987]

i was overhauling a nissan ZD30 diesel engine and the balancing shaft bearings in the engine block are damaged very badly. There is no replacement part for that unless to change the whole engine block. The machinist helped me chop off the shafts n blocked the oil gallery. Its been 5 months now and the engine still running smoothly. Is this type of repair recommended? Will this type of repair damage the engine? Here in Malaysia is not easy to find parts.

[@khanyisomathe6750]

Thanks for the good work

[@Htm]

Was curious about this. Thanks for the upload! ... I wanted to make a suggestion for the next topic but i forgot about what it was, Damn my memory.

[@EngineeringExplained]

My memory is equally poor.

[@Htm]

i think that makes me feel a little bit better! Hhahah

Engineering Explained They have stuff you can take for that. I forget what it's called.

[@Htm]

looks like we both need it bud! Haha!

[@Striball]

What determines the weight of these counterweights? Does it need to have a particular weight or can it just be a random weight, assuming you have two shafts with the same weighted counterweights?

[@EngineeringExplained]

Definitely needs to have a specific weight, which would be dependent upon the mass and acceleration of the pistons.

[@rafa-qq7xm]

so if engine uses balancing shafts it is passible to use lighter flywheel, because balancing shafts accumulates some energy, and engine is not become so much less fuel efficient.

[@radoliz2]

I'm confused, in your video you state the shafts spin at twice the speed of the crankshaft. But your drawing showing mid engine position, looks like it is spinning four times the speed of the full revolution of a four cycle crankshaft revolution. Or 4 times the speed of the camshaft? Please help clarify. In other words, if the lobe on the balance shaft is in the upright position, at mid cylinder stroke, the the lobe would be spinning 4 times per complete revolution of the crankshaft through its one, complete four cycle revolution.

[@ibrahimabdullah7793]

Nice informative VIDEO.

[@ChrisKsan]

I'm trying to learn so my question is, how do the secondary affect the functioning and performance of the engine (with and without the secondary forces)?

[@EngineeringExplained]

The engine will have reduced vibration with balancing shafts. Performance will be slightly sacrificed as you're adding rotational mass.

[@ChrisKsan]

Engineering Explained Thank you.

[@jameswalker2116]

Good video except you have one point wrong The counterbalance shaft run at One to one Gear ratio to the crankshaft not to 2 to 1 as you explained as that would put The balance weights back into the same position after the piston had done one stroke 180° of the crankshaft 360° on the balance shaft all other points are correct

[@sterlingsilver9003]

Clear and concise-Thank you!

[@MattWilson-nl4zk]

Thank you for a great video!

[@799chirag]

Doesn't the crankshaft play any role in countering the secondary forces in the cylinder?

[@xdan87]

Some In-line 4s engine like those used in motorcycles don't have balancing shafts. I am wondering how those engines deal with these secondary vibrations. I have a CBR600RR crankshaft, and it seems to have more counterweight than needed for basic static balance (counter the rotating crank arm). Should in-line 4s be using 0% balance ratio since they are already in perfect primary balance and any extra counterweight would not help reduce the secondary balance?

[@yyalbert4756]

So, by derive the moving formula of the piston, I found that the movement of piston has harmonics of high order, like third, fourth, it that right? If so, are they negligible?

[@vicosee4439]

Ok I understand but I own an audi 2.0t that broke balance shaft I see that its a common issue and I see that the balance shafts are being deleted and even raced what do you think?

[@samsmith977]

If this is so how come all four cylinder engines doesn't have a balance shaft? Just trying to get a greater understanding.

[@nayaranantes3380]

Hi bro, I desperate need to know if my 4 cyl engine needs bobshaft to balance, or just balance the crankshaft without using bobshaft to lightweight counter weight ? Or just need to assembly pistons and con rods weight?

[@tomk9134]

My older four cylinder engine without balance shafts will vibrate more at 3,000 rpm's and also at 6,000 rpm's. I know this is due to resonant frequencies which will exaggerate the secondary forces at certain rpm's. How can I change the rpm that this occurs?

[@fujimo70]

O have never worked on an engine with balancing shafts so forgive me if this is a dumb question. Can the balancing shafts be out of balance? like installed wrong or out of sync with the crank?

[@EngineeringExplained]

Absolutely. If they were installed slightly out of sync with the crank, you'd get noticeable vibration.

[@rajeshpillai9001]

Well explained bro

[@DarkAxi0m]

Are Balancing Shafts just a comfort thing, or is there any/noticeably performance gain? I have a small (Just for fun) 3 cylinder track car, thinking of not putting the balance shaft back in to see what difference it makes

[@EngineeringExplained]

Well technically you're using more power to have them in, however an engine with less vibration will usually last longer, and won't fatigue other components of the car as much with vibration either, along with the added comfort.

[@BrianChappie]

Great explanation!

[@franksavignac2788]

Hi i cant figure out every ting, so here is my question for you. I did a transmission wit a ninja 250 motoe. removing the piston and rods. keeping the gearing.. but as i spin the motor 500 600 700 rpm, it shake left to right.. there is balancer shaft in there. shoud i remove them also ?? Tk

[@paulcamalin5236]

Simple and to the point. Thanks!

[@SirXyloid]

I'm going to be going to college for mechanical engineering soon, I wish you were my tutor

[@EngineeringExplained]

Expect a lot of math! But seriously.

[@mohammadhoseinrivandi5657]

@@EngineeringExplained studying dynamics right now...😭😥 U know how i feel😂

[@christopherelrod8788]

Do they ever need to be replaced? If so how do you know?

[@metodraginii]

Man, are you gonna do some videos on other types of suspensions, apart from the ones u already have (e.g. air, hydraulic) at some future point ? (:

[@amitkrupal1234]

will an Parallel Twin engine with no balancing shaft but compounding gearbox with weight included in gears works best.

[@MrRoboshark]

great video man thank you!

[@ronniefoster9467]

Thanks, Great explanation.

[@ΘανάσηςΓκαζόζας]

Won't the crankshaft lose energy, as it has now to spin those 2 balancing shafts also? Won't we have less energy to transfer to the wheels ?

[@markflierl1624]

Those balancing shafts will use some power but not much. I wouldn't be surprised if they use less power than the alternator.

[@mikegillean]

What would be the benefit or downside to eliminating balance shafts in, say, an h22a out of a 97 prelude?

[@TheFlacker99]

More power, but more vibrations (which cause damage). I'd go onto forums and ask around.