Connecting Rod Balancing

[@jon4915]

I love how I can learn something new from a video that was uploaded 13 years ago

[@jesselambert9006]

Rest in peace John, You're a legend

[@timothyesmond7358]

He's passed away?

[@jesselambert9006]

@@timothyesmond7358 yes few years ago

[@HondaTurboToys]

I wish there was a machine shop locally to me that had the equipment and knowledge that you have. Always impressed with your videos

[@ROWB0AT]

This makes me want to work in a machine shop. Love this stuff.

[@Vore667]

The more I visit local shops the more I respect you.

[@GarageNation353]

Nice work. Curious to know, how come you don't have to balance the big end like you do the small in on the jig?

[@torchyboyz]

Dear John. Thanks for all of your vids, they are really informative. I am about to rebuild a Cummins 6bt diesel engine for a boat and want to lighten the rods. They are very rough cast and the casting flash is roughly ground off. Is there any value in grinding and sanding the rods all over to give them a smoother finish before balancing? Thanks john for your time and your expertise. Kind regards Paul (England)

[@normcameron2316]

40 years ago when I was a lowly apprentice a truck came in the shop, new factory rebuilt engine with a vibration. Felt like it was missing but every check indicated it was ok, vacuum, compression, ignition trace, cyl cut out. Didn't figure it out at the time but over the years I ran into different things causing weird vibration: casting flash in intake manifold blocking cylinder, wrong piston with wrong wrist pin height, wrong flywheel. 20 years ago my last personal service truck had a weird vibration, engine related but the newly factory rebuilt engine ran fine. I tore it down, checked everything and decided to weigh the rods. With the kindness of the local post office and later town store after the post office closed discovered the rods were not the same weights. After many trips back and forth from shop to post office or store, grinding on my part and weighing on theirs we came up with a set of rods that were reasonably balanced and that engine ran like a dream. In my mind a 20 year mystery solved. Re-builders: please ensure the rods in your engine are at least close enough together in weight to not cause vibration.

[@FatCokMcgee]

Cool story bruhhhhh. But it needs more dragons... 🤦🏼‍♂️

[@MonsterMadden12]

You taught me more in ten minutes than my teacher did all year

[@Vore667]

Great video, I will balance my rods myself thanks to this video. Thank you!

[@fiatnutz]

@burton402 - I've never heard of compressing the rods in a special fixture or heating them to do so. Shorter rods are sometimg necessary to stroke and engine, but I prefer to use a small and lighter wrist pin and move it up in the piston. Does require special pistons, but if you are going to stroke and engine you will need different pistons anyway.

[@fiatnutz]

@torchyboyz - Paul, you can certainly polish the beams, but be sure to check the balance. If you had a lathe big enough, you could reduce the bottom-end weight and some at the top woth a milling machine - again - rebalance rods.

[@CHIBA280CRV]

Nice work friend , enjoying your videos. You sure know your job! Thanks

[@mattcallahan5856]

Great simple explanation, thanks for taking the time to share this info. -Matt

[@sdold]

Thanks for posting. Aren't rods shot peened to prevent fatigue failure? If so, Do you re-shot peen the areas after you remove the peening?

[@tsifreak]

Thanks John I always wanted to know how this was done!! Love your videos!

[@fiatnutz]

The rods were well within the 10 gram tolerance that most manufacturers use, I've seen Lamborghini rods as much as 40 grams difference in the same V-12 set.

[@skarsnuten75]

Thanks for how to. Just did this also on Toyota 2TG rods and prefer to keep the ribs on bigend caps intact and grinded some material of excessive protrusions near trustflanges of bigend.

[@Jerrythenerdful]

The ribs add much of the strength. The ribs should not be the first place to grind.

[@PeggyParrow]

Years ago i did complete balance jobs in springfield missoui, we Always balance the Big end First because it is more critial because it is rotating, the small end is just going up and down !

[@AlexH33]

@DoriFord im pretty sure that is the integral part of the strength of the conrod changing that would make your piston weaker

[@larrydove3004]

Does the small end not get heavier after you remove weight behind the pivot point?

[@zildjian4life218]

Im looking at building a fixture like this. How critical is it to have the rod level between the big end fixture and the small end fixture that is on the scale? Does it matter if they are all done the same way? Also any recommendations on a scale to buy? Thanks again for all the videos you post. Very informative and awesome to see and learn from.

[@94vettelover2]

Are titanium connecting rods avaliable for the Lt-1 engine?Are titanium connecting rods cast,forged,or can come either way?Do they make billet rods that are lighter than titanium rods?When I rebuild the Lt-1 in my vette I would like light weight engine parts.What are some good cheap rods,cranks,pistons & bearings you would recommend for the Lt-1 engine?Same question is price isn't a concern?Thanks for your time & let me know these answers when you get a chance.You obviously know alot.

[@Ryknfjor]

the other 'floating jig' is very close to centerline of the small end rod holder and its in a fixed location to create accuracy and repeatability

[@wackedoutdude]

Awsome vids mate. I always wondered what went into this sort of mod. Great work.

[@tinoi30]

I would just like to say thank you for taking the time to make this video. This video inspired me to do my own balancing. I would feel confident to take them to you if I lived in your town, but I live in Laredo, TX. Nevertheless, I would just like to ask you one question. What affordable connecting rod balancing brand would you suggest for me to buy and from what vendor?

[@seymour86]

Awesome man! really strait forward looks like I will be doing this on my next 4AGE build thanks for the info man!

[@fiatnutz]

What kind of rods, what to you want to be done? You need to supply more info what asking a question. My crystal ball is in for repairs so I can't see or know what you are talking about.

[@drmatt357]

Well done sir. Question: If you were to now weigh the rods for balance front:rear after removing material from the cap, are they still balanced? I realize theoretically it still should be but have you checked just for the hell of it?

[@fiatnutz]

Yeah, measure the crank pin and look for scoring. Also measure the rod housing bore to make sure that it is on-size.

[@fiatnutz]

@reyftcossieR1 - Having a little trouble understanding your message, but lighten the three pistons that are 74,5 to the same weight at the 74. Ok?

[@fiatnutz]

I have found some older Lamborghini's with rods with nearly 40 grams mismatch.

[@ORego-em8yf]

fiatnutz Wow! In a Lamborghini where you expect it to be handcrafted fine machine work no less!

[@piwko4]

Do you do anything to finsh of the surface where you sanded? What i mean is do you bead blast or anything to prevent cracks from forming on the surface in the sanding marks.

[@Indicafatbud]

so if you get a set of new rods and they are all within 1 gram would you even mess with it?

[@Docv400]

Why do you have to match the little ends of the rods? The Big ends are rotating with the Crankshaft, so I understand the importance of doing those, but the little end is only travelling up and down (linearly) with the piston, so can't you just count it as part of the overall weight?

[@WAVETUBE84]

+John “Doc” Warner Equalizing the weight (end to end) equalizes the center of gravity of the rod. Unequal center of gravity, between rods, effects the balance when the rod swings between 90 degrees the 270 degrees (0 degrees being top dead center). It's not much, but does have an effect. Also unequal end weight effects the impulses upon the crank and causes harmonicis when running. An unequal weight small end will cause the rods with the heavier small ends to accellerate and decellerate at a different speed. So you will have the heavier rods slowing the crankshaft on it's portion of the crank causing it to flex a little more than the lighter pistons. That little amount of flexing is more pronounced at certain rpms and more or less pronounced if the motor is rev'ing up or down. That flexing, shaft twisting, and "ringing" back and forth puts a lot of internal stresses on the crank (which can lead to failure on high rev'ing, high performance, engines).

[@Docv400]

Ah, that makes sense, thanks.

[@deloran]

I thought you were not supposed to take from the cap due to a decrease in strength? Also would it matter if you weighed big side first?

[@fiatnutz]

Have no recommendations for anyone in the LA area. Yes, the penny test is good. If you can feel any surface irregularities, the crank needs to be polished or ground.

[@HearGear]

I belive this will get the engine to be more responsive faster ?

[@etiliko81]

A question about small end weight measuring : the conrod must be parallel to the scales? How you check it?

[@fiatnutz]

We always check balance and make final adjustments after we are done with the lightening process.

[@botacarga]

it improves the vibration of the engine or it can be seen also in the running of the car?

[@U3erpru7ser]

So how would you balance pistons? They come in many shapes and forms were to grind away the material?

[@R5P205]

nice and simple really, thought it was harder! thanks john.

[@warwickdean]

Thanks for your video. Does it matter which was around the conrod sits when weighing the small ends?

[@mikldude]

great clip as always, just wondering John if there`s a particular engine that sits in your memory that you always found poorly balanced? ?

[@joshgroth]

What grit belt is that on the sander? I have access to a 'knife' style belt grinder. Would that work for this process? Also, what type of scale is that? Can different (cheaper, college priced) scales work as well? Ha

[@tinoi30]

Is there a rod balancing fixture you prefer?

[@fiatnutz]

We use 80 grit. Don't know what a 'kinfe' style belt sander looks like, but it may work. All you want to do it remove the weight - belt sander, file, grinder they all remove weight. That scale measures to .1 grams, you need a sacle that measures to a minimum of 1 gram. We aim for plus/minus .5 gram when balancing rods, etc.

[@DoriFord]

I've got a question! Is there a way to balance the rod between beams after it was lightened? Or beams balance isn't that crucial? Thanks in advance!

[@fiatnutz]

@tinoi30 - No preference, just get a scale that measures to .1 gram. Take a look on ebay.

[@fiatnutz]

I do this mod on all kings of rods and have not had any failures, so far. Most engines were built for racing.

[@SRT480]

is their a noticible difference in engine response from doing this?

[@partybridge]

how much would a set of 8 cost to be done

[@dougharper6144]

I have spent many hours attempting to replicate what you and others are doing to balance a set of rods. I have used electronic scales and a triple beam balance. My scales are accurate. My problem is if I take the same rod, mount it on the jig, I get a different weight, no repeatability. How is it that you have the big end floating in space and you get consistent readings to one decimal place ? I can't

[@Mozracing]

I'm having the same problem of yours, with several tests with the same rod I did not get repeatability. Did you solve this problem there?

[@wolftch]

Very interesting videos Sir! Good luck!

[@DestroyAllorNothing]

Very nice, thanks for the effort

[@DoriFord]

thank you for another great video! they are very helpful!

[@zapwatt]

This is so cool and if one had he proper scale setup, the guy at home could balance his rods fairly well.

[@Failandy]

yup they sell then for around a hundred bucks from some hot rod catalogs.

[@fiatnutz]

Been pretty busy and my video editing computer caught a nasty virus and had to be rebuilt. Plus I'm teaching 2 nights a week @ Golden West College. Have more stuff in the camera, but need my other computer to edit everything.

[@tomaszpl9902]

what is the weight of stock honda b16a2 rod?

[@bubster1981]

John im in the process of static balancing a home built single cylinder crank, for a little homebuilt engine. How is the rod leveled on your set up there and if you were building such an engine what balance factor would you use? i know they will never be perfect, but is 50% a good start point ? i would think so haha

[@fiatnutz]

Single cylinders like around 52-58%. I would start with 58, run the engine, them make corrections. Singles are the most difficult to balance because the percentage affects overall performance. Rod is leveled by eye. I have ball bearing on each end. Let me know when you post some video of your creation! John...

[@bubster1981]

Ive heard those numbers more then once Thats what i'll shoot for.Its been an experience! Im about a year an 300 made parts into it now.Its a little 30cc ohv ohc 2 valve engine with a machined cylinder head (no castings atall). Ive made virtually the entire thing, you name it ... even fasteners. Its about 80 percent done and as it sits the only things i havnt built are a toothed timing belt of 5mm pitch, a sparkplug, 2 valve springs and 2 main ball bearings. I managed to off set turn a short length of stock that was was mounted on a rotary table off center in a 4 jaw to make a cam profile with symetrical lift and close profile as i have no mill! ( later soldered to a shaft)

[@АлександрЧернышов-ю8я]

Очень крутой способ взвешивания шатунов) Спасибо за видео. Все очень просто удобно и точно. В России не используют такой метод. (Я его никогда не встречал) В России тоже взвешивают и верхнюю и нижнюю часть шатуна, но все делают отдельно. получается не так точно и очень сложно в воплощение.

[@reyftcossieR1]

İ have to make balance different size pistons.!! (1 piece) 74mm and (3 piece) 74.50 mm pistons 3 piece piston be heavier can i do together piston&conrods gram adjust? Becouse conrod hard to take off.. How negative effect different size pistons and different heavier pistons!? U.K manchester Thanks

[@Gatorsrok]

does this affect the over all integrity of the rods?

[@PlayAClip]

Would you do the same thing for aluminum rods?

[@fiatnutz]

You need to call for questions like this.

[@Beretti112]

ZAJEBIOZA !! to jest super praca mechanika wie co robi ..... eeech w polandi mało takich ....

[@fiatnutz]

Quantify your question, 'few grams' what does that mean to you?

[@JohnDoe-go2fc]

Why would you want to weaken the piston end of the rod? It seems any material you take off will make the rod weaker. Why not just take off the crank end?

[@AlchemistHawk]

Balancing means you are making the center of gravity for every rod the same. So in a very basic sense, you need both the small and big ends of the rods to weigh exactly the same to be perfectly balanced. Some people argue over the tolerance, but the procedure involves removing material from both ends.

[@escargod]

Usually there is "extra" material available for removal. Sometimes a pad, sometimes a raised seam.

[@Nostradamus_Order33]

I know nothing about your job. I do know physics. I watched your video and I feel that you removing metal from the rod cap is problematic. There are two fulcrums. One in the center of the big end and another in the center of the small end. In your second step, by removing metal on the cap you then increase the small end weight in a two fulcrum system.

[@jjmccloud]

Anyone else agree with this? I'm about to do my own rods so trying to learn the do's and don't's

[@vwmountainman9701]

I would agree - I believe each end should be measured independent of each other. I not only match TOTAL wght - I have a similar hanging system - except I do both ends. Then double check total wght at the end. But you need a high/low to fall into as video states. Otherwise it would be never ending trying to match all 3. There has to be a GIVE - IN somewhere !!!!

[@tomassosaoconnor]

The procedure done is right; generally you measure the both ends individually. As a parallel forces system, you can calculate where the center of gravity is: the important thing when balancing the engine is that all centers of gravity are at the same distance from the crankshaft journals, so you can dinamically balance the crankshaft counterweights. The important part is that not just all the cg's are at the same distance, the total rod's weight have to be the same, especially in V engines.

[@fiatnutz]

Remove matal from the non-stressed ares of the piston.

[@MarioRamil]

Ramil - Balancing Act (check it out)

[@fiatnutz]

@sdold - We shotpeen them after we are done with the mods.

[@CrazyMonkeysGarage]

great video man I always wander how to do that

[@fiatnutz]

No, just smoother. Light weight rods will allow quicker acceleration.

[@lillamy9188]

I tried emailing you got this error back "The e-mail message could not be delivered because the user's mailfolder is full" tried calling but no one answered, are you still in business??!

[@mohamaditani451]

7mgte ? :)

[@itwTurbos]

Thank you man !

[@dougharper6144]

excellent

[@DoRiFutoS]

is really nice videos. congratulation.

[@incredibleplug89]

Thanks.

[@amf4591]

Trying to do the same Each time different readings from same rod🤦🏻‍♂️

[@erican442]

good video

[@mauricioalfredo83]

nice and easy to make...thnks ;)

[@eamh2002]

You know it's hard metal if theres sparkle! Try cutting a piston pin with a metal saw :D

[@sumjo]

great vid :)

[@jaydeebrickey9071]

Started on the wrong end....

[@gmmza03]

its preferred to balance big end first.

[@mitropoulosilias]

5 grams???? looks lot to me!!

[@RPP_Motores]

Great job man! I'm your brazilian fan! take a look in my videos about Ford Galaxies engine maintenance at roolders channel. tks!

[@HearGear]

Yes ok.. thats what i thought.. :D

[@jonathanohare7035]

This is not right... You balance the big ends " FIRST " then you weigh the total rod and remove it off the small end...

[@Airmanmx1]

Jonathan O'Hare According to UTI the Top Automotive school in the country there is no actual sequence but "suggest" to do the smaller end first, weight the rods then shave off the big ends avoiding the center of the top.

[@WAVETUBE84]

+Jonathan O'Hare Since the big end is supported by the jig it doesn't matter. Or visa versa. The end resutl is identical, whichever end you begin with.

[@escargod]

I check the total weight of all rods, then each end and sort them by whether I will take material off one end or both. I am balancing to +/- .3 grams

[@АлександрЧернышов-ю8я]

WAVETUBE84 Не совсем так. В начале нужно снимать металл на верхней шейки шатуна! Как показано на видео. А уже позже подгонять вес на нижней шейке! Как показано на видео. Почему именно так? Дело в том что на первом этапе мы практически идеально уравновешиваем верхнюю часть шатуна. Да в противовес верхней шейке шатуна идет нижняя, но этим можно пренебречь. Так как плече на которое воздействует сила противодействующая весу верхней части шатуна сильно меньше плечу на котором взвешивается верхняя часть шатуна. Таким образом мы получаем практически идеальный вес верхней части шатуна. Второй очень важный момент это подбор веса нижней части шатуна и веса всего шатуна. Если взвешивать только нижнюю часть шатуна, то не будет учитываться разность веса крепежного элемента.поэтому все делается в сборе. И если делать именно как показано на видео, то мы получаем идеальный баланс между весом нижней части шатуна, крепежа и весом всего шатуна. Если кому то вдруг не хватит точности балансировки таким способом, повторите процедуру 2-3 раза и вы получите идеальный результат.

[@ahmadshah4248]

Dear bor Please don't writing to face of screen . Cus we become confuse

[@fiatnutz]

BAD teacher!

[@guycroft318]

this is a nonsense. No way can you balance rods like this.

[@MattsMotorz]

+Guy Croft He just did.....

[@guycroft318]

no, you cannot assume mass removal by this means assures same C of G position on each rod. Removal must be done incrementally at each end. Very time consuming. If you don't get the C of G in the same place you won't get optimum reciprocating balance. Sure, you might be able to assess the V imbalance factor for crank balance but that is all you will achieve. I've done this so I can assure you I am right about what I say.

[@MattsMotorz]

Guy Croft But he did one side at a time. If his point of support is on the bottom end, and the weight on the scale is only from the top end, then ensuring all of the top end weight is the same means that the top end of the rods are all the same weight (because the bottom end is being supported in the fixture). Therefore when he weighs each connecting rod on the scale after that, all of the extra weight is only on the back end. I am not arguing with you I am genuinely questioning why this method isn't correct according to you, because to me it does seem like it would make the COG the same in each rod.

[@АлександрЧернышов-ю8я]

Этот метод очень простой и удобный. Если делать этим методом, то вес шатунов будет в допуске и даже во много раз меньше допуска. Вы конечно правы, что вес будет не идеальным во всех шатунах, но он будет более чем в допуске.

[@АлександрЧернышов-ю8я]

Если у кого то возникнут проблемы с весом шатунов по этому методу, можно повторить процедуру 2-3 раза и я ручаюсь, что для измерения веса не хватит точности измерительного прибора. ( весов )

[@DumbCarGuy]

Boy, people that don't get it sure like to complain. Are you a democrat or a liberal?