EVERYTHING about the CRANKSHAFT - Function | Manufacturing | Different types | Forged | Billet

Welcome to crankshaft 101. Once you're done watching this video you will know all the basics you need to know about crankshafts and more! We will cover the many different types of crankshafts and their advantages and disadvantages, all the terminology related to crankshafts like crank throw, crank radius, cross plane and flat plane, we're also going to talk about how crankshafts are made, the heat and surface treatments, lubrication and much much more.
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How it works? All internal combustion engine crankshafts have main journals and rod journals. Here are the main journals, these are what the crankshaft itself rotates on and are held in the engine block by the main bearing caps. Rod journals, a.k.a. crank pins or big end journals are where the big ends of the conrods are connected to. Rod journals are connected to main journals via crankshaft webs.
Now, the distance between the main journal center-line, and the rod journal centerline is called the crank throw, a.k.a. crankshaft radius. And this measure determines the stroke of the engine. The stroke of an engine will be 2 times the crank throw.
At the end of the crankshaft we are going to find a flywheel flange, this is where the flywheel is bolted onto. The flywheel with it's heavy round mass smooths out the pulsation of the combustion inside the engine occurring at different times. On the other end f the crankshaft is the nose. This is where the crankshaft pulley is attached.
These are the counterweights. The operation of an internal combustion engine generates strong rotational forces, and the mass of the piston, piston pin and rings and the connecting rod moving up and down at high speeds generates a very significant force that is exerted onto the crankshaft. The counterweights have the task of balancing out these forces. We will talk about counterweights in more detail later in the video. The holes you can find in the rod and main journals are oiling holes. Oil coming thorough the engine block into the crankshaft and out these. Another very important design element of the crankshaft is the radius fillet. Engineers take great care when designing this, because a proper radius fillet is key to a crankshaft not breaking apart. The radius fillet is key because it spreads the load and relieves the stress in what would otherwise be an extremely common point of stress fracture on any crankshaft.
Crankshaft manufacturing process
There three main manufacturing processes for crankshafts are Casting, forging and CNC machining. Casting is the most cost effective processes and in general results in the weakest art. Cast parts are often more brittle, that is to say they have a lower tensile strength and lower ductility compared to forged and machined billet parts.
Forged crankshafts - the forging process of a crankshaft involves a large crankshaft sized billet being heated up to about 2.500 -2.700 degrees Fahrenheit and then put into giant presses with dies in them that apply anywhere from 150 to 250 tonnes of pressure to shape the heated up billet into a rough forging. The rough forging is then machined and heat treated to create the finished crankshaft. You can tell a crankshaft has been forged by looking for wide parting lines and signs of grinding on those lines. The main difference when it comes to forged crankshaft vs cast is that the forging process compresses the grain structure of the metal into a much more confirm one compared to a cast part which results in greater strength and ductility.
Billet crankshafts - when it comes to billet crankshafts there's no casting, or forging or anything. You take a big billet and machine away material until you're left with a crankshaft, that's it. This takes a lot of time, and a lot of machining is needed to make a billet crankshaft which is why billet crankshafts are often very expensive and often reserved for racing and other extreme applications. The great thing when it comes to billet crankshafts vs forged is that there are infinite design possibilities for billet!
Crankshafts also often undergo heat and surface treatments such as induction hardening, tufftriding (tuftriding). When it comes to lubrication we have two different types. Cross drilled crankshafts and straight shot oiling crankshafts. To combat drag created by crankcase windage, crankshaft counterweights are sometimes knife-edged
Here's a summary of crossplane vs flatplane crankshafts: Crossplane cranks are usually larger and heavier so they have a lower max rpm, but they make the engine run smoother, generate more torque and sound different. Flatplane crankshafts engines are more prone to vibration, but are also more compact and capable of higher max rpms.
A very special thank you to my Patron:
Daniel
driving 4 answers is part of the Amazon Associates program.#d4a #crankshaft #enginebootcamp

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[@trumanhw]

Filet? or fillet..? It's ... _FILL•AY_ ... when describing the crank, only..? (I know little but sounds "unique" ..?)

[@trumanhw]

@7:31 ... will not the PSI be a function of torque or power ... irrespective forced vs NA..? It seems like it haaas to be related to absolute-power and less-so whether its NA or F.I. ..?

[@daleearnhardt817]

M

[@catatonia1]

I worked for a company that made and modified cranks for racing and tuftriding was only used on cast iron cranks and nitriding on steel cranks. Our forged non twist V8 cranks were CNC machined also. You are correct in saying that forging dies are expensive I believe it cost around $100,000 30 years ago for our one.

[@davelowets]

Those cheap "cast steel" crankshafts aren't really any better than the factory crank that it replaced. If you are into putting Chinese parts inside your engine, go ahead.. 🤷🏻

[@ViewThis.]

Here we go again. This guy showing up in my recommendations teaching me good, usable stuff.

[@sebastianherpst449]

He taught me to be sad for my crank shaft! Hang in there little guy!

[@mrsauce9307]

@@sebastianherpst449 Lmfaoo

[@tinolino58]

He needs a new haircut 😆 Maybe his subconscious believes he is a Grand mother?

[@chuckingram5966]

I know right guy is not only cool but awesome

[@D3M0N.5K1LL5]

this channel. I work on cars for the 2nd half of my living for many years. racing.experience rebuilding transmissions and modifying.engines. this channel.is half truths ill.be glad ig all my business competitions is fully educated by this channel.

[@5naxalotl]

this is brilliantly clear, comprehensive without being too long, and doesn't skimp on all those little details that people usually leave out because they assume you already know it. in short, you efficiently assemble all the information into a cohesive semantic network, like a knowledge bomb ready to be loaded into the human brain. ten out of effing ten

[@d4a]

This comment is what's ten out of effing ten! Thank you!

[@Justin-bz1dp]

@@d4a is race one

[@PetAmer599]

Finally a series dedicated to engine parts!

[@MrWilliam.Stewart]

I was feeling very cranky, then I saw this video, and now my head's spinning. The information is very eccentric, the big end is talking to the little end, the counter weight arguments are strong though. The forces are bearing down.

[@L-Noble.YT_Hi.Res-Soundminds]

Hope you zeroed in your head by this time and you got your crankiness balanced out dude.😁

[@JazzbLu]

I enjoy the analogies in this comment! Well done!

[@NCOGNTO]

Don't stroke out dude

[@gabrielgaranas]

When a petrolhead tries poetry...

[@dragonrider2.064]

You're a great teacher and you're amazing at focusing on thw details we actually want to know instead of taking a pointless class at school that teaches usless info. Thanks for your dedication and work on our behaf

[@zachfabbian1441]

Right. I'm going to school for auto mechanics and I'm learning more on KZbin than in school

[@billynomates920]

@@zachfabbian1441 that's how you do it. don't ask your teacher about stuff he's just taught you, ask him about stuff he hasn't taught you! i know that sounds dumb but trust me.

[@Devo491]

I've been a rev-head for 65 years, but I've learnt more in the last couple of years than decades of tinkering, thanks to your excellent videos. Thank you! Keep 'em coming...

[@holdmywetnutz]

All those thumbs down are those who think they know it all and could explain this manufacturing process better. Good video bro!!

[@loganpe427]

Every backyard mechanic's an expert, and nobody has any manners anymore, right? Besides it's too easy when nobody can punch you in the eye for being a jerk! 😂

[@NoName-tz5ji]

Wgat do mean by THINK? I know I know all. BOW TO ME YOUR GOD!

[@trumanhw]

Part of it is people don't appreciate what it takes to teach things... nor what goes in to creating anything and completing it. Normally indicating they've NEVER done either in their LIFE. (seriously)

[@joeschmoegaming3918]

Thumbs down might be for the 20-30 ads this video has.

[@jameshaulenbeek5931]

Years ago on a forum that I frequented, a member who had some basic knowledge of physics, but no practical knowledge of the workings of internal combustion engines proposed an idea: A solid tungsten crankshaft... He couldn't understand that, for one, you need an alloy to be able to withstand the forces on the crank, and two, the amount of power necessary to spin that mass would be astronomical. He also couldn't understand why you want a lightweight crank, thinking more mass meant more power - and while more mass does mean more *stored* energy, that stored energy wouldn't be useful in a street or race car scenario. It was a funny thread, it went on for a very long time and became quite a big joke, ultimately with ideas of cranks made from depleted uranium or even dark matter...😂 All that to say, fantastic video! I love how clearly and concisely you explain everything. It's a wonderful, easy to follow format. Thank you!

[@jets8991]

Dark matter crankshaft😂

[@foxman105]

Sounds like a fun idea until you realize that Tungsten is radioactive. It would add a whole different level of danger to an oil change lol.

[@electric7487]

@@foxman105 Some isotopes of tungsten are radioactive, but not all.

[@foxman105]

@@electric7487 oaky.and how do you plan to separate them?

[@electric7487]

@@foxman105 Dude, 99.8% of tungsten is stable. The four common isotopes, W-182, W-183, W-184, and W-186 make up 99.8% of naturally occurring tungsten and are all stable. The remainder is W-180, whose half-life is 1.8 quintillion years. There is zero risk because it emirs so little radiation that no one has to worry. Please take your tinfoil hat off.

[@JoaoZagoSJC]

As a Manufacturing Engineer from an automaker I can confirm that you videos are awesome! Brilliant job.

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I've randomly started getting tons of your videos in my recommendations. I think that means you're about to blow up. Keep it up, great content.

[@thomassalley7169]

This has become my favorite KZbin channel. You provide more technical information in short time, without getting confusing or tiresome, than any car channel I’ve found so far.

[@jeffwombold9167]

Just ran across your video, I've built engines since I was 12, and I have to give you a very good kudos for this video. It's just detailed enough for the common joe, and complete enough for people to get a reasonable grasp without being too complicated. Great job, keep it up, I think you'll do very well !!😉

[@MrGsteele]

1 minor language nit: the -et in fillet is pronounced like the -et in bet, rather than the -et in ballet. The counterpoint for an outside edge is called a round. It is exactly right that both are used to distribute the stresses more broadly, rather than to concentrate them at the inside or outside corner of a 90 degree intersection, thereby avoiding a stress riser that overtaxes the joining point, leading to failure of the material composing the joint (in this case, the cast iron or forged steel of the crank journal). Very well done presentation - thorough, and well-explained. Nice job!

[@robertsherman8887]

In welding when you fill a corner it's called a Fillet weld pronounced fill-it.

[@MrGsteele]

@@robertsherman8887 yes - fil-it, fil-et - that's just a small matter of accent. What isn't a small matter is pronouncing it fil-ay, which is what you do to a fish, or a reference to a cut of meat.

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I really like the content. Please keep it going.

[@JM-cg3ps]

You are single-handedly keeping me sane! Keep'em coming!

[@zf4hp24]

He's probably the best "educator" on YT. Seriously. Just facts, *concisely* explained. Great job.

[@flyfaen1]

A quick correction. Both cross- and flatplane V8s with a 90° bank-angle fires evenly four times per revolution, aka every 90° of rotation. Difference beeing the flatplane has even spaced power-pulses on each bank (so basicly two typical I-4s offset 90°) and the crossplane does not, it has an uneven distribution of pulses per bank. The total being the same. At short, the only thing the crossplane is better at is second-order vibrations. And no, the flat plane does not make less torque, displacement for displacement, all else being equal. Infact a flatplane makes more torque and power generally over the entire range, due to the even spaced (on each bank) pulses, giving better exhaust scavenging. (even exhaust scavange can be done on crossplane engines, but is very impractical due to exhaust header space constraints, and the runners becomes so long, that you get deminishing returns).

[@johnhunter7244]

This! Flat planes only typically make less torque because of the design of the engines that use them!

[@pawel_woloszyn]

Hello from POLAND, thhanks for every films you made.

[@gidovoskos1437]

I couldn't imagine that a chamfered hole will be so significant for an engine part. Excellent job!

[@cuttingedgecool7235]

The knowledge of why and how that's explained on your channel makes this "engine geek" very happy ☺️, thank you for the videos!

[@Jupiter__001_]

Thank you for this engaging lesson! I hope there will be many more videos in this bootcamp. Stay well and God bless!

[@Morphasella]

Thank you. The best engine crankshaft video I have ever watched

[@aussietaipan8700]

I've just come across your video's, this is the first one. Every apprentice mechanic should subscribe and watch content like this. Excellent tutorial . And just subscribed too.

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One of the best KZbinr of the world..... knowledge... humour... unbelievable explaining most difficult things in the most easy way ..nice way to speak..no music that is distracting.. unbelievable various subjects of videos.. pictures videos that help understanding.... for the best for car subjects ... Hope you have enough time and money to give your fire...like Prometheus...

[@beaches2mountains230]

Hell yeah! I was aware of these different styles of crankshafts but to see the manufacturing take place was super cool! I love to see how the oil flows through the engine and it would be super cool to see more diagrams or illustrations showing the oiling system at work. Keep up the great videos and I cant thank you enough for the free content and I sincerely appreciate You taking time to inform the masses! Stay strong and healthy. Oh yeah don't forget to burn some rubber!!!

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this is the greatest video I've ever seen on youtube.

[@d4a]

That's a bit much, but thank you 😊

[@davidproffitt1101]

Brilliant! That is one hell of a lot of information with examples and animations in such away everyone can understand. That shows you have great knowledge and I like your sence if humor. Thank you. 😊

[@polloloci21]

The only KZbin channel that I have my notebook ready to take notes. 😀

[@brudevold62]

Great reference to fighters these machines need to be respected with that sheer force of energy the create. Your analysis on all of your videos are spot on keep up the good work.

[@eugeneleroux1842]

Thank you once again for a really informative presentation, so well presented, and supported by great video material.

[@diplonik8174]

don't get me wrong, I'm not writig because I think youre chanel is bad, but because it is one of the best for explanation of engine tecnology which I found on you tube. Crank shafts don’t care a lot about forces, but a lot about torsion. The primary and secondary mass forces are important for NVH but not directly for crank shaft stresses. What really matters is the Eigenfrequency of torsion and the combined torsional frequencies of all mass and gas forces. If the match, the crank shaft will be stressed to the maximum. To reduce this stresses, dampers are necessary for more than 3 cylinders (I could write much more about it...) Casting vs. forging: Like I said before about connecting rods: In modern engines you will find much more casted crank shafts and connecting like 30 years before. Mercedes for example changed the crank shaft of the A-Class Diesel engine from forging to casting without changing the bearing dimensions. Casting is becomming better and better and reducing cost is a strong dringing force.... Forced induction on gasoline engine doesn’t increase the peak pressure a lot, because it is limited by knocking. Even modern boosted gasoline engines are operated with a peak pressure of about 100 bar. Cross drilling the main bearings enable undivided lower bearing surfaces (180° oil groove) and so, much higher resistance to gas pressure, that’s why all Diesel engines are equipped with cross drilled main bearings. For really high rpm (like in Formula 1 engines) the oil is center feed from one end and flowing longitudal through the whole crank shaft. Knife edging crank shafts is kind of woodo to me, I never seen any knife edged crank shaft from an serious racing application or OEM. In contrast, sharpening the leading edges of the counterweights gives a small benefit (with almost no cost) and can indeed be found by some OEM (Opel). Crossplanes and flatplane crank shafts for four cylinder and eight cylinder have a totally different background and pros/cons, therefor no general rule can be given. For eight cylinders, crossplane crank shafts offer perfect mass balancing, but uneven firing on each bank. If the exhaust system is on the outside of the engine, this will hinder the gas exchange effectivity. To avoid these drawbacks, the exhaust system can be placed inside the V (like in modern BMW V8 engines) so, that even exhaust pulses to the Turbocharger can be realized. Also some Formula 1 engines in the sixties had a central exhaust system with combining 4 cylinders from 2 cylinders of each side. Flatplane for eight cylinders have free mass forces of the second order and run much rougher. The advantage is the even firing order on each bank which offers more power and torque compared to the conventional crossplane V8 with side mounted exhaust system. In four cylinder inline engines, Yamaha is the only example of a cross plane crank shaft to me. Here, the cross plane enable a nearly constant kinetic energy of the reciproting masses, which shall result in a smoother run at very high rpm. In a conventional four cylinder, all pistons reach the maximum and minimum value of kinetic energy at the same time, thus giving uneven rotational speed of the crank shaft. The drawback of the crossplane design is the free mass moment of the first order and the uneven firing, that’s why these shafts are very uncommon.

[@GMan-ym9xl]

Thanks for the Great videos that you put out. Most people do not realize just how much effort and time goes into making something like this.

[@H33t3Speaks]

Absolutely fantastic content! Supremely illuminating, you've done a great service!

[@superbirden57]

Good I found your series. Easy to understand for beginners. Interesting and in depth for the gearheads. High school auto shop ought to show your content. Kudos!

[@the496elcamino3]

The video clips with explanations make these really easy to understand and retain, well done 👍

[@shawnclyne1904]

Great to see the parts other than rims, radios and add ons. Any info on your rotating assembly is vital not just to making power but longevity the most important part of any automobile. Great post.

[@ntag411]

Really straight forward explanation. Good deal of thought went into the making.

[@d.haroldangel241]

Excellent exposition. So much to learn and understand. 100 thumbs up !!!

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Have never seen a short video yet more detailed than I could imagine 🤗

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I've watched 2 of these so far. Fantastic.

[@FierceMotorworks]

These videos are amazing. Perfect amount of detail and simple explanations make it easy to understand. Thanks

[@joshuachandra6677]

Thank you for taking the time to explain this!

[@wojtekdobrowolski8084]

I love those videos, they help to reinforce knowledge, I have read books about internal combustion engines which are great but they contain quite a lot of information which you might forget after reading a book, those videos really help to revise and ground all that info.

[@Ozgrade3]

Geez, what a brilliant video, actually series of videos.

[@Mmdg634]

This was one of the most engaging and easy to understand video I have watched, thank you so so much!!

[@phlodel]

I know most of this stuff, certainly enough for my purpose, You explained it so well and clearly, I watched the whole video and found it very interesting.

[@MrTech1210]

This is very well presented 👍🏻 very well put, in the most simple and basic way. Excellent, very good! I’m really enjoying your videos, they’re very educational 😊👍🏻👌🏻🤙🏻

[@autobodyspecialistsinc.4397]

especially enjoyed the portion of the video in which you explained tufftriding and nitriding .... another great job!

[@hyacinthbucket3803]

How does one become so knowledgeable? It’s impressive.

[@paxdriver]

Your channel is a feather in KZbin's cap. New sub, thanks for all your hard work!

[@MrSparker95]

I could listen to you for hours, you are so good at explaining everything. Thanks a lot!

[@brianhind6149]

Bravo! Well explained & described & accurate. Your supporting drawings etc. were all first rate. Thank you for a job well done.

[@berkayozfidan5066]

You are the man no doubts ! i ll use your video as a reference for my presentation You are the savior man !..

[@yesnomaybe3372]

Hey yamaha r1 features cross plane cranks! They even call their 3 cylinders cross plane even though they technically aren't! Loving all the new content, been a sub for a few years!

[@bensiok]

Love the video. Thank you for your time invested in this video kind Sir!! Good info :)

[@goranEE9]

Awesome video! Great knowledge and explaining technique. All the best to you and your YT channel.

[@jerichomelvincentazarcon8030]

Very clear and concise explanation.. thank you for the information.. Genuine.

[@ilham7345]

5:52 my lifetime question on how crank get it's oil has been answered

[@BigUriel]

Same thing for the small ends, and turbo engines usually have a squirter end to to spray oil under the piston to cool it.

[@paul_109]

Learning is genuinely fun with your videos

[@SE45CX]

Wow, such a fantastic lesson on crankshaft design aspects!

[@damnationswarhead8005]

Nice vid mate,very informative and understandable😀

[@gepisar]

THAT! Was an AWESOME video!!! Brilliant explanations!

[@M0nsieurX]

Learned a lot, thanks! Looking forward to the next videos!

[@AL-HITLR]

Thanx bro u increased my knowledge and only a teacher can increase someone's knowledge by the way love your work keep it up

[@troychampion]

Excellent video.. well put together well thought out and well executed. Thanks... because of the quality of this video i liked and subscribed.

[@zachfabbian1441]

Very great information. Much more enthusiasm and better explanation than my instructor at School. Great explanation. Thank you

[@lorenzovonmatterhorn1230]

Great factual explanations as always. Thanks!

[@82swapped97]

Really been enjoying the videos! Keep up the good work👍

[@pedersterll5007]

Great video as always !! The stuff presented here must be considered Chapter 1, Page 1 in the "Handbook for petrolheads" Looking forward to a video on Flatplane vs. crossplane cranks

[@michaelcramer8794]

Awesome video. You are teaching my high school auto class. Thanks for a great video!

[@MrMini500]

Love your videos man. Great work, I always retain what you teach.

[@TheAirsunyie]

From this video you control how I learn and think. Thank You.

[@mattscott5254]

brilliant video I've heard the terms cross plane and flat plane crank but never new the difference.

[@trevnerdhubbabubba6230]

Very informative and helpful vids!

[@johntulloch1430]

Just loved this presentation....good stuff everything you needed to know .... without knowing you needed it.

[@rudyfluit9546]

What a great video, totally explained everything in terms easily understood. Thank you

[@LarryisControversial3000]

Great video, highly informative. I personally like the sound of the cross plane crank more, especially at idle

[@mr_mon-eye]

Superb video fella and look forward to the next one. Keep up the good work

[@edwardm9227]

Very useful videos, I have a bike engine to build with alloy rods and now feel armed to make decisions after watching several of your videos, many thanks 👍

[@Engineersoldinterstingstuff]

Hi, Thanks for your videos. One remark about grain flow and its effect on the strength of the component. It's actually much better to have the grain flow follow a radius than to cut the flow lines. This is a big advantage for forged components as compared to machined ones. There is roughly a 30 % reduction in fatigue limit of the steel if the flow lines are not aligned properly. A forging with this defect (likely due to improper design of the forging tool) will fail. Stresses in a forged component are relieved during heat treatment and are not present in the final component. Forged compenents, given that the geometry makes it possible to forge properly will always be stronger than a machined part. In a forging you have the possible to "align the strength of the steel" in the direction that best handles the design stresses.

[@catatonia1]

What you say is correct the company I spent 15 years as a machinist with a company that made non twist V8 crankshafts for racing for that reason the grain runs the length of the crank unlike billet stop start grain or the normal forging process where the pins are twisted into position as is the grain.

[@erniemathews5085]

A a fairly well-informed person, your content pushes my frontiers further and tells me things I never heard of: it keeps me humble.

[@Garage35Racing]

Awesome video mate. Well done.

[@ppsor329]

Big thank you for creating useful content for everyone

[@GarageKing]

Great vid, you certainly put a lot of effort into it!!

[@cobrajeff96]

This presentation was great. Bravo, sir.

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Such amazing videos. Easy to understand, well thought out. Sir, you are a blessing. I have learned more from your videos than any others. Thank you very much for sharing your knowledge with us.

[@Israelfx-ty8rj]

I'm outside the building about to take my ASE A1 ENGINE REPAIR great review video for the crankshaft!!!!

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You sir push content that all channels should wtrive to achieve. Thank you yet again for a great video.

[@ABC-td4rg]

Answers to questions I didn't know I needed to ask.... Thanks!

[@henkm9905]

Very well done. Very much in depth.

[@TurboHappyCar]

Really good stuff man! These videos are killin' it.

[@WhiteFeather1x]

Heck yea. Cool video on crankshafts. I learned a lot

[@williampetsch1244]

He explains very well, easy to listen to

[@L-Noble.YT_Hi.Res-Soundminds]

I love these videos. Learning so much is great so thank you.

[@bicyclist2]

This was very educational. I know Ferrari uses flat plane cranks in there V8s. Keep up the good work. Thank you.

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Excellent lesson well explained and very useful information keep up the good work

[@Francisco-sx7th]

Extremely clear, thanks!

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One of the best video on crank on youtube

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Great video! Love your presentations.

[@1crazypj]

Fun fact, 'The Daily Grind' as referenced to work, comes from the fact that it took a few hours every day to grind enough cereal (wheat, barley, corn, whatever) to make bread. Most small capacity motorcycles (and a few large ones) have multi piece built up cranks. It was only relatively recently (208 ish?) that Harley Davidson stopped using a 5 piece crankshaft and switched to 3 pieces pressed together at around 50 tons. Majority of single cylinder bikes used a pressed up crank, particularly two stroke motors where they have needle roller big end bearings