Piston balancing - How to DIY

A step-by-step video tutorial showing you how to balance your pistons yourself. Done on a set of cast Toyota 4age smallport pistons. The same procedure can be applied to many other pistons.
A balanced engine runs smoother, produces less vibration, is capable of higher max rpms and copes better with higher power outputs and high rpms. Balancing is especially important for high revving naturally aspirated petrol engines such as the Toyota 4AGE.
They may be a thing of the past, but nothing beats a well-built, smooth, high revving naturally aspirated petrol engine in terms of responsiveness and sheer driving pleasure.
The crankshaft, flywheel, clutch pressure plate and crankshaft pulley are dynamically balanced - i.e. require special machinery.
Pistons and connecting rods are statically balanced - i.e. it can be done at home with some simple tools.
So why not give it a try and learn and save money in the process.
More MR2 and 4age stuff:
www.driving4ans...
An article on crankshaft, flywheel, clutch pressure plate and crankshaft pulley balancing: www.driving4ans...
#d4a #pistonbalancing #diy #pistons #4age #mr2 #ae86 #jdm #4age16v #aw11 #driving4answers #mr2mk1

[@d4a]

Precision scale to weigh the pistons: amzn.to/2MTiRMU A little update on this, these pistons have been installed, engine has been driven hard for more than a 1000 miles. Zero issues, runs great. Just thought I'd address all the criticism and comments how this approach will cause piston breakage and the implosion of space-time. Thank you everyone for watching and all the feedback.

[@telesniper2]

great troll, bro

[@thdmtr]

there were so many good explained answers like the David Dykes one, you could accept the criticism made to improve yourself, it's worse when we insist in the error, just sayin...

[@nonyadamnbusiness9887]

Call back at 50,000.

[@AbelCarden]

They work because your engine is not under high stress. removing material from the crown is the last thing you want to be doing in a performance engine, especially with a drill bit.

[@c41man]

@driving 4 answers On Engine Masters there is an episode that has them removing material from the top of the piston to achieve piston to valve clearance on a sbc. That leads me to believe that the piston mod you've shown to remove weight won't harm the piston at all.

[@huntlarry1]

As an expert calibrator on scales, I'd recommend if you have a scale not repeating within one count on every re-weighing, then use another scale. You can also check consistency by moving the piston around on the scale - it should repeat within one digit every time. Just thought I'd add that. I figured if someone would go through a lot of work like this they should have confidence in the scale they end up using.

[@johnmclachlan7337]

I have extensive experience building race engines and believe the best way to take ugly fat from pistons is to turn some aluminium from inside the lower skirt of the piston. OK if you have access to a lathe but if theres no access this method is fine just check how much meat you have in piston crown before going nuts :)

[@d4a]

Thank you so much! I made very shallow drills and measured crown thickness beforehand. I truly hope people read your comment before posting the same thing over and over. Thanks again.

[@briantracy1324]

Before you get all happy with the drill and die grinder you should match the heavy pistons with the light wrist pins to get the smallest amount of material to be removed ,, you might end up with nothing to grind.

[@briantracy1324]

On what planet is that true?

[@bluebanana6753]

ian volvo b230 dosent fucking care

[@jackass123455]

not the case with aftermarket pistons my 4 cp pistons came in a bow nicely packed in foam with 4 pins packed in arbitarily so the couldn't bang eachother

[@bluebanana6753]

if you have a good crankshaft with god precision berings you dont need to balance them but if it sucks you need to

[@SuperKONR]

Doesn't matter if you have 'god precision berings', if the rotating assembly isn't decently balanced it will shake itself apart.

[@SuperKONR]

This might have worked for a stock engine but piston manufacturers make certain areas a certain thickness for a reason. The correct way to lighten a piston is to take material off of the pin boss area. Thinning out any other areas are likely to turn the piece into a grenade, especially in a performance application. But if you want to go hacking into a set of pistons with a drill and not listen to anyone else then go for it.

[@warwickdean]

SuperKONR around the outer-underside of the piston boss 👍

[@1957f100]

I take my piston weight from the inside of the piston pin

[@DavidD-qr2vn]

Absolutely - 100% the incorrect way to weight balance pistons. (I'm a ME who is responsible for making a few million pistons a year and have for the last 25 years...so just a touch of experience / knowledge on this subject..) For Toyota pistons the weight balance area is lower window hoop, outside below pin. Do not remove material from lower pin boss, will cause hoop failure (pin breaking the lower pin boss hoop). Do not remove material from under crown, will cause burn-through of the crown - even in stock applications. There is a minimum amount of material under crown for weight savings and that is the highest temperature area of the piston and it is the structural "tension" point. Under load that area is in tension as the piston bends around the pin (in both directions) and is also the flex point - about the worst combination of loads at the point you are putting stress risers into with a drill. Please do some research on piston design and loading before you go posting a video that may cause others to waste hard earned money and time with a failed engine.

[@d4a]

Burn-through of the crown? How in heaven's name am I supposed to burn through the crown? Minimal material on the crown? I used the old pistons from the engine for testing, I drilled a hole through the crown just to measure it, and that is NOT minimal material. And that was the same piston without a dome. These are domed and people watching this video simply don't realize how shallow the drills I made are.

[@oh8wingman]

I second that. I used to do this kind of work and not once did I ever touch the crown of a piston.

[@buddhaman001]

You are removing material from the crown, what that is gonna do for you is create hot-spots and uneven heat distribution on the head of the piston leading to potential warping (however minor), and increased stress on the piston.

[@michaelkeyes3856]

David is 100% correct. the crown takes all the heat, You may have drilled all the way through your old one and thought you seen alot of material but you have to understand how the piston disipates that heat before you question someone else that knows what they are talking about. I also have been balancing rotating assy"s for 15 yrs and you just ruined them pistons. they may work for you but they are not working as they were designed to anymore. less efficiently on the heat transfer. good luck down the road with that engine bud. sorry i had to edit my spelling

[@davem5333]

The piston crown is designed for minimal thickness that will allow the heat of combustion that contacts the top of the piston to have an adequate path to conduct out of the crown to the sidewalls, down the piston skirts and into the cylinder walls. Those drill holes disrupt that path and impede heat flow.

[@jacquespoirier9071]

it is all the recipocating assembly that must equalized on most OEM connecting rods, the weight difference is much more important. every minute spent on the balancing effort is rewarding even on a bone stockor a marine engine

[@chrisenright7003]

Good video. The first step is to pair wrist pins with pistons to get the best equal weight before any material removal. You put the heaviest pin with the lightest piston and so on. All the pins are ground to exactly the same OD so you're making your task more difficult by keeping them in the same pairs that they come out of the boxes.

[@ChineseSweatShoppe]

He didn't change the OD, he was removing material from the ID.

[@chrisenright7003]

You miss the point. The correct thing to do is to coarse-match the combined piston and wrist pin weights by pairing the heaviest wrist pins with the lightest pistons and so on. Only then MIGHT you need to start removing material to achieve perfect balance across all the piston and pin sets. Keeping the pins with the pistons they were shipped with is unnecessary and wrong.

[@ChineseSweatShoppe]

I feel like you miss the point, you were corrected and now you feel as if you should defend yourself even though you were wrong. You are right about your feeble try of subterfuge but you are still wrong about the original statement. What you did is consistent with a the classic "know-it-all".

[@RizoProduction]

Actually, you're wrong. Chris Enright never said that the OD was ever changed. His point was, the OD of the wrist pins are all equal, meaning any of the wrist pins can be swapped onto any of the pistons. So in turn, you could put the heavier wrist pins, in the lighter pistons, which in turn would mean that less material would have to be removed. How is that so hard for you to understand?

[@ChineseSweatShoppe]

RizoProduction It is not chris enrights car, so really has no say in how it is done. Things are done differently and if he wants to remove material he can do so. 1+8=9 & 4+5=9

[@enigmasvids9615]

Interesting method.I've done it myself with an obsolete V8 engine and a range of similarly obsolete mixed parts (various grades of standard size pistons). Weight had to be taken from other than 'usual' locations to gain a weight matched set. A damaged piston's crown was initially drilled through to gauge depth of material before dimpling was carried out on the selected batch. A benefit of the dimpling was the slightly increased under piston head surface area (cooling) from oil directed under there. Similarly on a Harley Davidson motor cycle engine the piston domes were reduced heavily (externally) to improve flame travel within the hemi cyl heads. Not all motors are built to be used at 9/10ths limits as in motor sport, nor are cheque books open ended for every individual. Look back at the early days of hot rodding to see what was done with limited resources.

[@AlexYeomans]

So this is close to being 7 years on. did this work? Later videos show a rebuild to a 4AFE, i am sure previous experience now counts. Well done for giving it a go. Keep it up and thank you for sharing.

[@d4a]

I removed this engine just a few days ago. These pistons did a bit over 5000km of hard driving and there were no issues. I compression tested the engine a few weeks before removing it and everything was spot on.

[@conservative-proud]

Why don't you weigh the pin with the piston together, then you only have to grind the piston and not the pin... But the pin and piston will have to be a matched set...

[@keithbaker1951]

Barry Johnston good question im interested in the answer because it would eliminate all the space time implosion theories from the piston design master builders i see in the comments..

[@docstruthers]

Even if you've had success with these pistons, removing material from the underside as you have is very risky. ESPECIALLY if the pistons are cast(usually stock). On an NA engine probably not a big deal unless you run nitrous. But on something that burns extra hot with a violent combustion stroke like turbo/supercharged. They won't last long. I'd offer alternate methods but each piston set is different.

[@mrdainase]

Matching piston and con rod weights does bring some good benefits but I can't agree with you on removing metal from the underside of the crown. Detonation in a cylinder places major stress on the piston crown, and removing metal from underneath it varies the thickness, creating a real chance of stress fracturing. This is even more important where you have crowns that are shaped (dish or dome) or have valve cutouts in the crown surface. It's more advisable to remove metal carefully from the gudgeon pin area, keeping away from directly underneath the pin hole itself and where it meets the skirt. Also, you have stated in the video that gudgeon pins must not be swapped between pistons. In many cases gudgeon pins can be swapped between pistons to get closer matching overall weights. You shouldn't do this however if your pins are an interference fit (mainly because it's a pain in the neck) or are custom machined to each piston. I'm assuming your pins are an interference fit, hence the comment you made.

[@d4a]

+mrdainase detonation? I hope you meant combustion. If you have detonation in your engine, uneven piston crown undersides will be the least of your worries. Now combustion, if we are talking about one capable of cracking a piston crown because the underside is uneven we are probably talking about a force fed drag strip racing engine, not a 1.6 liter four banger for street use. Take a look at the crown underside again, it was uneven to begin with. I appreciate your comment but stress fracturing really isnt an issue here. Everyone talks about it because its easy to understand and forums are full of it. And people just apply the same cookie cutter principle to all engines and applications. The piston crown is by far the toughest part of the engine. How many cracked piston crowns on street cars have you seen or heard of? I have already replied to comments similar to yours and will no longer repeat myself. I kindly urge all future commenters to read this before commenting. Please. Please stop obsessing over stress fracturing, i know its a fun concept and its easy to understand, but just because we think, "whoa this is a great opportunity to apply my Internet acquired knowledge", it doesnt make it the right opportunity or the relevant knowledge.

[@mrdainase]

+driving 4 answers (mr2 mk1 hero) Fine by me. Just thought I would try to be helpful, after all I've only been building engines for over 30 years. I won't bother in future.

[@RizoProduction]

Driving 4 Answers, you obviously have a large knowledge base, nad know how to do many things the correct way, but this. This is definately not the correct way... Vehicles have detonation all the time, it may only happen for a few RPMS untill the ECU corrects the issue, but those few times could still blow a hole right through your piston, and since you decided to remove material from the highest stress point on the entire piston, your likelihood of melting the piston is higher than if you wouldnt have. Pistons have certain areas for material remove, and none of them are from the crown.

[@stuartcookie133]

Tried this on my pistons, but took way to long to balance them to the same weight so I just drilled thru the tops to even them out. Downside is that the motor smokes-Upside is now I got a cool crack scale!!

[@mariopic2625]

grinding pins is a bad idea also takeing off sides of inside of piston u throw the weight off on the sides of the piston its best to only take off from center of piston if sides are off weight u may cause odd ware on skirts due to it being unbalanced

[@rooftopcertifiedautorepair2012]

i take back what i said. i watched the video again and i noticed the man has on a wedding ring so he's under enough stress & he still finds time for his hobbies and films it all for our shared love of fine motor sports. actually, its a great video except for the music. and personally, i love the old 4a Toyota blocks. i had the 4a-c in my 1986' FWD Chevy Nova way back when. but i didnt balance my pistons, i just let it shake. i chopped all 4 counter weights off to lighten my crankshaft for added performance LOL. (i made up the part about chopping my crank.)

[@richardguilfoyle8276]

Doesnt this process weaken the piston?

[@thdmtr]

greatly

[@williamhughes3138]

buy a matched set of forged pistons and they will weight the same.besides cast pistons arnt worth the trouble get a set of h beam rods from eagle .and just have the crankshaft balanced unless it's cast iron too.

[@Folopolis]

Does this not remove weight symmetry with each individual piston? It seems like it should be better to grind off the bottom with a belt sander.

[@autom.d.8804]

Not going to get into any childish insults, nor am I going to chose anyone's comment as being factual, but I am researching balancing and will be doing my own from now on (except my crank for now) because the man that has balanced every engine I have built for the last 30 years ( I build around 25 engines a year) past away and he didn't leave behind a predecessor, I never actually paid attention to the method in which he removed the weight from the piston so for the hell of it I went and looked a three different sets of pistons that he did and not one of them did he remove metal from the crown but in fact he removed the metal from the flats just below the wrist pins, and there's only one to two small holes. From the look of it you removed more metal from one 4 cyl piston than he did from an entire set of forged stoker pistons with a 4.155 inch bore. personally I would have found a better set of pistons rather than remove that much metal. I have to agree with some of the comments tho my friend, I wouldn't have removed the metal from the crown of a stock engine ,much less the crown of the engines I build, "especially" on the engines I build knowing what they'll be used for. Don't take the comments to heart, if you see knowledge in them, note it, learn from them and move on.

[@legalman2891]

Just one big mistake budy Wen you went with the drill over the center of the under side of the piston You have create a hot spot !! Because the surface it's slimmer Than the rest and will provoke Preignition or a hole on the piston over a long trip or racing

[@d4a]

+lohengrin ballesteros Watch the video again, but more carefully. The big drilling on the underside of the piston was done only on my test piston. The pistons that are going into the engine got only very superficial drills, which is why I had to make a large number of tiny very shallow drills. I explain in more detail and suggest this in the video. I have consulted experienced 4age engine builders on various forums before and after doing this and they have told me it was done right. Also, preignition cant occur on the underside of the piston since there is no fuel there.

[@AsiAzzy]

+driving 4 answers (mr2 mk1 hero) That happens when people gain knowledge on forums. I'm sorry to inform you that removing metal from underneath the crown is a terrible mistake. It's a high stress area where careful calculations went and careful forging/casting went so it will have a smooth surface without stress risers. The removal of metal would start with casting marks and general imperfections and then on the inner part of the skirt, you thin it out with a lathe, file or die grinder. But don't take my word for it. Research other sources than forums as many times, forums are the cause of misconceptions and generate a number of adepts of a wrong procedure only because it is still working. An example of credible source is here www.pro-bal.com/tech_info/library/Precision_balancing_of_reciprocating_engines.pdf I'm a teacher (a small one) at a prestigious automotive engineering university. The more practical way to balance the piston is with the rings, clips and pins all at once. And you remove metal only from the piston! (the pin, if it's a floating pin is carefully unbalanced to control the rotation for even wear, also the hardened steel have a high polish even on the inside because of alternating loads and they are prone to fatigue cracking.. a random score with a grinder may initiate a point of entry to develop such a failure. Better not mess around the pin.

[@d4a]

Thank you for your comment. I have addressed almost everything you talk about in other comments. Please read the rest of the comments section. What you are speaking about is something that might be valid for a very different application. Why do you discredit knowledge from forums? Yes, there is nonsense on forums, but there are also people on the forums who built dozens of these engines (4age 16v bigport)., some of who do it for a living, and have a great reputation for their work. Forums are a great place for people to share knowledge and ideas. Just because the knowledge isn't shared in a regulated environment, let's say an university, doesn't make it less valid. Forums are like any other source of information, and are to be taken with a pinch of salt and require more research. Same goes for knowledge gained at universities from professors. I have seen, read about, and heard reputable professors say things that can be proven wrong easily. Information and knowledge is constantly evolving. Balancing the pistons together with the rings, clips and pins all at once is more practical? Are you sure about that? So I can move the pins from one piston to another? As far as I know each pin and piston are a set and shouldn't be switched around. If you're concerned about uneven wear, switching the pins around is probably a good way to achieve it. Moving the clips and rings has no effect at all. I weighed all my clips and rings. They weigh absolutely the same, down to .00 grams.

[@AsiAzzy]

+driving 4 answers (mr2 mk1 hero) The forums are great for some advanced users as there is valuable info in equal amount of garbage. It takes an experienced eye to distinguish the good info. I tend to watch closely forums and find research article on that matter if something is suspicious. And i agree with the fact that uni's are not the best source of info. I find the best info you can find is in research articles and international conferences where you find the most renown individuals on the exact matter you want to find. A more reasonable way to find quality info is by searching google with pdf files (as most of them are articles, abstracts, etc.. with an author and depending on the author it may turn up to be a really credible source) The ratio of good info vs bad info is greater than of the forums. Regarding the practical way I mentioned: Group the parts for each cylinder (1piston, 3 rings, 1 pin, clips, etc) and measure the whole group and remove metal only from the piston afterward. Depending on fit, the pin may not be adjusted to fit a certain piston.. if that is the case (and any pin would do the job), it's wise to do a quick weighting of the pistons and pins separately and match the heaviest piston with the lightest pin. That's how i teach my students. Of course we can continue the research and plot graphs of each part's weight maybe even figure the center of mass for each part and stuff like that. But as a minimum, this is it.

[@papaike2]

Why bother tiring to explain to this know-it-all he's an expert he has many years doing high performance race engines. HUH

[@onhawaii]

What about the set of piston rings???I would try first to put all parts together so they get as close as possible to each other in the total amount of the parts that will be assembled on every piston, and go from there. Because what real matters is the total amount of the moved mass of the assembled cylinder in the bore. Call me stupid but to make the piston head thinner just makes it weak to burn a hole inside and it is more alike to catch more oil under it with all that drill pits in it. This way will work but I do not think that it is the best way to do it.

[@coollasice4175]

Instead of drilling holes in the underside of the piston, it would have been better to drill 1/8 inch holes in the side, one at a time. This will promote good oil flow to the skirts. Better lubrication means less friction, lower temp of piston, longer life, and more hp.

[@codymoncrief2128]

You can also tig weld tiny beads inside the skirt to add weight to the pistons

[@rucasolo5021]

Drilling away at the crown of the piston is a great way to reduce engine life. All the BANG happens to the crown, better to shave the skirts if you (feel the) need to lose weight.

[@drumstyx6464]

Since the piston and pin move in the same way, why not just focus on the combined weight? Rather than taking .2g off the pins, you could just take an extra .2g off the piston.

[@d4a]

They move in the same way but are not a single unit.

[@drumstyx]

+driving 4 answers (mr2 mk1 hero) in practice though they operate as a single piece, no? The idea is to even the reciprocating mass, and they both are simply reciprocating mass. Technically the clips should also be included. That said, when you balance the pins individually, they're then interchangeable weight-wise.

[@kalhoon]

a few points to add. weight balance them with the rings on. dremel off imperfections first when changing weight.

[@d4a]

I weighed the rings before hand. All weighed exactly the same down to 0.1g.

[@nickmansfield1]

I think that there may be an issue if you are on the motorway, no lanes to pull to the side, no offramps near, you blow a water hose, and the motor starts pinking as the temperature rises to critical. The factory motor may take that strain for a while, until you can get to somewhere safe to pull over, the modified motor...? That's the question, eh.

[@neptunevibe]

I just discovered a new method of weight reduction and make a movie about it. Instead of making those shallow holes on the back of the piston you should make much deeper ones. This way you can distribute the weight loss more precise. The area made by those shallow holes is not precise. If you are making just 6 holes but way deep is easy to make a symmetry in the pattern.

[@mastermaxderguru]

THIS is so wrong on So many levels...

[@thdmtr]

hahahah so true

[@michaelhaiden6718]

I prefer to use a wheel cylinder hone to do entire length of w pins and a air wrench with cutter head to do pistons to remove other portions also and get a smoother more even cut and not making weakened division a bit like you would use for port polishing tetro machine will show you how thanks

[@johncunningham4820]

Completely have to Disagree with removing Material from under the Crown . And with using a DRILL . Use the DREMEL . After weighing , inspect and see if you can SEE the Extra material . Casting Flash etc . Clean them up and see if that improves things . Then remove material from the Buttress area behind the Thrust Surfaces tiny bit BOTH sides . Tiny bit at a time .

[@detroitbluesguy]

Pistons were very close to start with..JC@ Balance Technology Inc 1975.. you can see the skirt where it was machined.

[@corvettefever360]

Unfortunately there is a lot thats off with this, as are some of the comments on this video. I would advise extensive research on this subject. There is alot more to know in correctly balancing an engine, and a specific type of engine. I would explain but it would be too much for this post. So i will give some key words to look up & get a good understanding of. What is an "internal balanced"engine, or an "external balanced" engine, or using both. The "Bob weight", the "Rotating weight", the "Reciprocating weight", & the "Reciprocating factor". How this all applies to balancing an engine, & how this is achieved by taking rotating weight & dividing it by the reciprocating weight, using its reciprocating factor to get the bob weight. Understanding what /how the "counter weights" of the crankshaft, & the flywheel & harmonic balancer come in to play. Understanding your engine type. You can't balance an engine by just making the pistons the same weight, & in fact doing this, like this, sure it could technically work, it could also be, or become problematic. The weight of connecting rods, small end & big end, the bearings, the rings, the oil factor, etc also has to be considered/weighed. So while the pistons are all the same it can still throw off the balance, & possibly alot worse. An easy to understand "for instance" is; when the engine was originally balanced, they had a lighter rod attached to a heavier piston, So now you lightened that piston which greatly lightened them together. Thus throwing off the balance. To achieve optimal balance weight will be taken, or even be added to a specific area. So as in my example above, how does this come into play with that conn rod & piston, how will this now affect everything else. There's also something called "Allowances" & "Tolerances", which pretty much translates to "play room" or "acceptable". So depending upon how much in or out of these Allowances you are with something like this will greatly depend on the end result. You may get away with this, or maybe for a while even, but most likely will become problematic. Especially with true high performance engines. And not engines with a bunch of pep boys bolt ons, that make 200hp. Also, contrary to some of the comments here, weight can be & is at times taken from the back of the piston dome. Actually many pistons are made for this option. Notice the "cross-hatched" areas. BUT, again this depends on the specific piston, and its intended application. Also how it is taken is important. As a few said, you can't just drill into them guessing depth. Especially if you plan to boost or nos this engine. Again, the Allowances & Tolerances. Building an engines is a science & an art. My brother an i have been doing this for years & we still learn new things & techniques. I'm not knocking the guy who made this video. It's cool to see people into this & learning this versus smoking crack or worrying about how many likes they have on Facebook or Instagram, or what kim k is doing. I respect this, that he learned some new thats that many don't even know this much, so he's happy & proud to have learned what he did so far. But when making a video where as a teacher your instructing others, you got to get all the facts, and truely research the subject. Because just as your making this video without all the proper info, was probably how you learned this without all the proper info from another who did the same. This could possibly become a very experience mistake for someone, who also watch another video without all the facts & bolts on a massive turbo, & Nos, and then their engine pukes up all over the place.

[@HC-ov2hh]

Doesn’t the heat in the center of the top part of the piston get the most heat? By drilling and making the center part of the piston weaker can lead to a cracked piston because it is thinner in that area???

[@specialized29er86]

This is an eye opener, I would have thought all the pistons would be equal in weight when being made at the same factory. What about the car manufactures are those engines balanced or no.

[@sartorig]

Don't you risk to weaking piston crown?

[@martincrabtree6704]

Yes it does. The correct way is to countersink the end of the pin only, you don't touch the piston.

[@manfredschmalbach9023]

Bodgering in an unexpectedly profuse amount is strong with this one.

[@harrismagnum04]

please dont do this folks its not the correct method, not even close.

[@d4a]

I won't even bother. I replied to this sort of comment too many times already. Just scroll down below, it's not that hard.

[@raptusgtoft6467]

Are you selling/supplying these services and and afraid compotition

[@Cloneufc]

Thats not the correct spot to drill. The piston boss area is thick, and the spot you want to drill.

[@d4a]

There is no "correct" spot to drill. I have checked this with professionals and had them inspect the pistons, they passed fine and can go in the car. This way of balancing is not what most people choose but that does not make it "wrong". As long as the drills are very superficial it is fine.

[@donavenable]

On small port cylinder head, which either 89kw or 96kw and when snap cam belt you will differently bend the valves on that cylinder, which leave crying to engineers. But, in big port cylinder head, which is 86kw standard from manufacturer. You never bend a values on cyclinder head, at any speed if snap cam belt. 1 and 3 piston are going weight the identical same weight, and 2 and 4 piston are going weight the identical same weight. Because that's way the motor was balanced from the manufacturer, before assembly and products of the car.

[@Cloneufc]

The Wrist pin balance is correct.

[@d4a]

Hey Anthony, For some reason I cant reply to your comment. I am really glad you like the video and find it useful. I am still alive and kicking :) I would love to work on the car more, but work and other obligations leave only so much time for it. I will definitely be balancing the connecting rods as well. Balancing the rods is a bit more complicated since I need to make a jig that will allow me to weigh the big and small ends of the rods independently. The rest of the rotating assembly can not be balanced by hand, since it needs to be spun at high rpms and needs a complicated expensive machine to determine where and how much weight should be removed. That's dynamic balancing. The pistons and rods are statically balanced and that can be done by hand. I actually drove to another country to have the crankshaft and other bits balanced, since where I live no one does it :)

[@thdmtr]

oh my god

[@4ujkdguy]

would have been better to match the lighter piston to the havier wrist pin, and take some weight of the skirt since there is no balancing pad on those pistons.

[@TheKutia]

seems like it would make it weaker?

[@d4a]

It's not that simple. The piston has an inner jacket and if the drills are shallow nothing is compromised.

[@thdmtr]

oh my god(2)

[@makemespin]

Not sure if i would dare to do this myself but i find this very facinating. But as for "polishing" down rough spots and cast marks would this do something similar?

[@d4a]

+Makeit Flip There many approaches to balancing, but the goal is always the same. To make all the components being balanced have the same weight. The way I have achieved it in this video looks extreme to many but I assure you I have made all the necessary research and precautions before doing this. I am not made of money and would never risk ruining a perfectly good set of pistons. As long as you are cautious and conservative and follow some basic common sense you will be fine. Polishing rough spots or removing weight on the underside of the piston skirts will of course help you shed some weight. Unfortunately there is often very very little weight in casting marks and even when you polish all of that down you might not remove enough weight to get the pistons to weigh the same as the lightest unit. The first thing you should do is weigh all of them and see how big the differences are and then you can plan for the appropriate method for weight removal. P.S. that spider on your profile pic is unbelievable. I have touched the monitor quite a few times trying to convince myself its not real. fun stuff.

[@rooftopcertifiedautorepair2012]

David Dykes is right. the material being removed is more critical as a thermal barrier and heat sink than it is detrimental to imbalance. unbelievable. has anybody even seen a model T crankshaft (or early crankshafts)? they didn't even have bob weights. not one. and there's not just one way to balance an engine. piston and bob weight are selected mathematically by engineers based on the desired power band. generally, they can over-balance or under-balance a crank. rods and pistons below target bob weight are good for lower power bands (1000-7000 rpm) while rods and pistons above target bob weight do better upstairs i.e. formula 1, motorcycles, Weed Eaters, NASCAR. NASCAR has articles discussing race teams trying different balance methods and they are not drilling the crowns of their pistons.

[@midgrave]

How will this still be beneficial once sutt gets on it and oils splashes everywhere?

[@d4a]

Oil doesn't stay on the pistons or any other engine internals. Soot i.e. Carbon deposits will be equal on all pistons if the engine has equal combustion in all cylinders, which a engine that runs ok will have.

[@Engineerboy100]

Very good video, thank you. I will be doing this as soon as my pistons get here :)

[@d4a]

Engineerboy100 Glad you like it and find it useful! Thank you

[@Engineerboy100]

Thanks ... I did organize my own way of doing the rebuild ... I am quite experienced and I actually am a mechanical engineer ... the project is complete and my Dad is enjoying the car ;)

[@TrgovacTrgovac]

Jao brate ti si kralj koja pedanterija u gram sve ... Ja planiram da uradim nesta na svom auto al nez odakle da krenem hocu malo tuninga

[@d4a]

Trgovac77 Trgovac77 Bitno je krenut :)

[@papaike2]

Why are the rings not included in the weight as well it is the total mass of the piston.

[@d4a]

they weigh exactly the same down to 0.1 gram in my case

[@blankpage1995]

would it be okay to do this with used pistons and or used pistons that are being used in a rebuild

[@d4a]

That-JDM-Fascination! As long as the pistons are good and within the required specifications I see no reason why it wouldn't be ok. Just keep in reasonable and don't drill to deep and you should be fine.

[@crpth1]

Nice video and all. But I totally disagree with your choice of where to start removing material. For balancing only is acceptable, but for performance build up leave the crown alone. Thanks for sharing.

[@josephjablon8780]

Can you do some rods

[@hectorae86]

I bought a 0.001 g precision scale at a grow shop :P (that's a weed shop)

[@StepHop5]

hectorae86 same but for coke

[@hectorae86]

StepHop5 heheh, yeah... they can be used for both of course :P I live in the Netherlands though (Holland), we're known for legal weed so....

[@StepHop5]

oh im from columbia :D

[@hectorae86]

StepHop5 Hahahaha, ok ok, I get it :P

[@Tyschnei]

hectorae86 stoney right now bro

[@kalbi777]

does it matter where weight is removed on pistons ? i mean having less weight on top will influence crankshaft more than if you remove weight by the skirts or am i missing something

[@d4a]

Usually people remove from the skirt. I removed from under the crown, which many think was wrong, but no one seems to understand how shallow the drills were. As long as your cautious it doesn't matter where you remove it from, as long as it's not anywhere on the piston outer surface of course. The piston just moves up and down so wherever you take the weight from, it's the same. These have ran a few thousand miles so far and there is zero issues with them.

[@kalbi777]

driving 4 answers thanks mate

[@WhiteGravey]

what does this do for real world performance? does it make the motor quieter or last longer?

[@d4a]

+KoG GoK Here you go, copy pasted from the video description: A balanced engine runs smoother, produces less vibration, is capable of higher max rpms and copes better with higher power outputs and high rpms. Balancing is especially important for high revving naturally aspirated petrol engines such as the Toyota 4AGE. and yes it also improves longevity.

[@WhiteGravey]

driving 4 answers good info think i will balance my next block. thanks!

[@TheNorthsquad]

This procedure you developed is not necessary unless your in a very high performance engine, and the way you are doing it will likely cause a piston to fail.

[@alfonsocastellano1993]

nice job...j did the same with alfa boxer engine many years ago...

[@d4a]

Thank you! Alfa boxers are amazing.

[@jamesgullo8240]

Is there a website that sells this unbearable music that everyone seems to think is so hip for background music? I made it almost 30 seconds before leaving.

[@InstaltechCarAudio]

why would you need to balence them? theres sod all difference shaving a few grams off, better lightening the flywheel

[@tonyd7342]

THIS IS 100 PERCENT THE WRONG WAY TO BALANCE A PISTON! The top takes the heat and compression. First off, these are so close, that you could have let them be. Hey, why did you drill under the tops? You use the balancing pads on the side of the pistons. If they don't have pads, you can nip the ends of the skirt the debut. You can also drill out the sides of the piston above where the pads would be. This means on the pin side. Yeah, you can dtill and debur that area. Let me explain another mistake. After weighing the pistons and pins, do the math and carefully match to the pistons. Ok, something that you forgot. THE RING SET. Weigh them indivudually. By the time that you are done mixing pistons, pins and rings, you might find out that you don't have to balance a thing. Now a balance the rods. Heres a hint, you have to weigh and balance both ends. The small side is part of the pistons bob weight. The big end is part of the cranks weight. I've been a machines auto machinest for nearly 40 years. I didn't learn by watching an idiot on KZbin like you did the making my own video. I'm only writing this because I don't want to see anyone follow your mistake. By the way, you can also balance a piston side to side, but you haven't the sklll....

[@stevenjohnson4283]

Watching this video up to the point with the wobbly drill in the underside of the practice piston crown, I thought that doesn't look right, then he actually drills small amounts off of his new piston ......that can't be good. I'm not even a mechanic and I've never heard of pistons being balanced by drilling. I've seen flywheels with drill marks for balancing. Good thing that others below with engineering experience have clarified that 1 gram difference doesn't even matter, and that drilling under the crown is just plain bad. But the key is the cheap scale. I wouldn't buy a cheap kitchen scale to measure an engineering component which runs on button batteries. There are professional weighing instruments that are accurate to 100ths or millionths of a gram. Kitchen scales are probably accurate to + or - 1.5 grams. You could be grinding material off you actually didn't need to remove. Then all you are doing is sending the weight off even further. Wow, what a numb nuts!

[@janosgregor3844]

It's a big NO-NO ! Think twice before you use this method ! The cutting edge of the drill always makes microscopic cracks on the inner surface of the piston right where it takes the most stress under combustion. Just think of a plasterboard what you cut from behind and push from the front.

[@d4a]

These pistons have already been installed. 500 miles on them so far. Zero issues. I will make a video update after a few thousand miles and more hard driving.

[@janosgregor3844]

Car parts are over-designed to be able taking nearly twice as much abuse as they normally should. If your engine is not highly modified, it will go for a long time, but this method becomes very risky in case of increasing the horsepower. Weakening the pistons with drilling them is pointless anyway, because all of the alternating masses must be balanced together. So it's just a lot more beneficial if you start to remove the casting burrs from the side of your con rods. Lengthwise direction is a must and stop micro-cracks with a nice surface polish.

[@d4a]

Conrods and pistons should be balanced separately because they move in a different manner. Anyway, there's no single correct way to balance an engine, it's best if we leave it at that.

[@janosgregor3844]

I agree. They should, but the biggest difference is only 1 gramm. So if you take it off from the rod, it's gonna be perfect and most importantly risk less. These are cast pistons, so it's even better to smooth out the casing edges inside the piston. It takes away mass from the right places without weakening it. Your method has a chance to work trouble free in a stock engine, but the theory behind it becomes counter productive when trying to achieve some higher performance.

[@truthinadvertising2702]

Exactly how NASCAR does it only they use a hole saw instead of a drill bit.

[@andibogat3129]

I really dont understand what is going on...is that the right method to do it?

[@d4a]

Andi Bogat There is no "right" method. This one works fine if you are careful and keep the drilling shallow. I ran these positions and the engine ran fine. It failed because of blast media that came into the oil pump. I took it apart and there are zero signs of any trouble on the pistons.

[@thdmtr]

OH MY GOD(3)

[@MVanDii]

Very VERY helpful. Thanks!

[@d4a]

VanDii Motorsports Thank you, glad you found it useful.

[@flamespirit1]

@driving for answers can you give me the link where to buy the scale?

[@d4a]

Flame Spirit I bought it on eBay ages ago. Just type in 0.01g scale.

[@flamespirit1]

Thank you

[@nicholaswieczorek4971]

If I were to do this, should I have my drill holes symmetrical to make sure the weight is even?

[@d4a]

Nicholas Wieczorek The way I see it that the piston is a single piece of mass and you are removing weight from that single piece of mass. To get it out of balance would require removing A LOT of weight from the far end of just one side. What is far more important is to make the holes as shallow as possible. What you are talking about MIGHT be required for some insane 20k rpm racing engine that is running on the very brink of self-destruction where every little bit matters. Each of these holes I made is placed in the piston-crown and each hole removes 0.1 - 0.2 grams so being symmetrical wouldn't really add anything to it. I don't know what you are building, but I am pretty sure that as long as you put the holes in a common sense manner and not all on just one side of the piston that they don't need to be symmetrical at all.

[@nicholaswieczorek4971]

Ok thanks

[@Engineerboy100]

mr2 mk1 hero I agree with the single piece of mass theory. why not weigh all of the parts for each piston together then just remove material from the piston instead of trying to balance the pins separately, introduce and accumulate tolerance rounding errors every time an item is weighed separately.

[@d4a]

Engineerboy100 When I first thought about doing this I also was of the opinion that balancing the pins and pistons as one made the most sense. But people with far more knowledge and experience than I have told me that the pistons and pins are not one single piece of mass. They are two separate units. The piston and the pin are exposed to different stresses and aren't fused/welded together. When you think about it makes sense. For a mild street application such as mine this might have been unnecessary, and balancing the piston and pin as one might have been "adequate", but I had the time and the tools to balance them separately so I did. Doing more cant hurt, right? :)

[@Engineerboy100]

mr2 mk1 hero Well I did mine this weekend. Will post video in a couple days. All my pins weighed the same ... go figure. I was hoping they would weigh a little different then I would have switched them around. But thanks for the vid anyway, I would not have even thought to balance the pistons at all! As it turned out I have to drill 3 ... sucked a little but car runs great.

[@christopherkapelczak3446]

Match heavy pistons to light pins, then balance from the correct area. Aka not what you did.

[@ArcadeJason]

1 gram is approximately the weight of a small paperclip even at high rpm you will never notice a difference this is not the "correct" method but judging the video i doubt any actual harm was done. seems people get so upset when things are done incorrectly that they never stop to think if it will actually work. that being said i wouldn't put those in my engine

[@TrojanHorse1959]

Great video, thank you for your time and efforts.

[@AB-ng7zc]

omg engineering is not for every one find something u can do

[@thdmtr]

HAHAHAHAH

[@e36racer44]

Never realised how many professional piston engineers there were on the planet

[@justinhutchinson9507]

I'm not a music guy, but I like your style

[@d4a]

I used this song mostly because it's free. I like future funk and 80s Japanese city pop :)

[@javierbroger2635]

Hello nice video ! I was wondering if you could help me, my question is if I can put a 11.8:1 CR piston ( wiseco piston 82 mm bore and 18 mm pin) on my mr2 with a bluetop 4age and running stock cams and stock fuel pump , pretty much just change my stock low comp pistons for those high comp piston? I will really appreciate your help!

[@d4a]

+Javier Broger I hesitate to use the redtop bluetop terminology, this is an old engine and valve covers have been exchanged and there have been engines with bluetop covers and redtop internals and vice versa. So first of all, if you haven't already, take your engine apart and measure everything before you order. Now, if you have done that, in terms of those pistons, you can put whatever you want in your engine. The stock compression ratio of the 4age is 9.4:1 i believe. What you have to do is determine what will the end compression ratio be, taking into account your head gasket thickness, bore, how much the head and the block will be decked, etc. etc. The 9.4:1 cr is by today's standards very low, but it was done then taking into account the fuel quality and other factors that were present 20-30 years ago. Here's an article that is a very good start for you. www.driving4answers.com/compression-ratio-calculate/ It explains everything about compression ratio, provides a compression ratio calculator and an example calculation. You will need to get some data on those wiseco pistons to get an accurate calculation. I will be aiming for a final compression ratio of 10.5:1, which I will achieve by putting in smallport pistons, decking the head and block a bit and using a OEM head gasket. I assume you will end up with a higher compression ratio with those pistons, which means a higher risk of ping (pre-detonation). Higher compression ratio goes hand in hand with higher lift of the camshafts, so if you don't intend to change the cams, like me, i wouldn't go for those wiseco pistons, because that might result in a too high final cr, Those pistons would go great with some 8.1mm lift 264 duration tomei cams I believe.

[@javierbroger2635]

+driving 4 answers (mr2 mk1 hero) really appreciate your help, I haven't opened the engine to measure every components , but reading all you taught me i think its a better idea to put some small port pistons but this means I have to change the crank and the con rods right? or there is another way ? assuming my engine has a bluetop internals? because I really want to increase my CR of my aw11 :) I think when I do it I will also put a thinner Head gasket all these trying no to pass the 11.5 CR mark you mention on your page ( excuse me for bad English)

[@d4a]

+Javier Broger That page is nice, but its better for learning about cr then being a definitive guide what you should do. Doing 11.5 cr without installing different cams is a waste. If you wont change cams, don't go for 11.5. Where do you live? What's the highest octane (ron or pon) fuel you can get? That will also influence the cr you can go for. I'm in Europe and I can get 100 octane fuel (European ron standard) which is pretty good. Elsewhere in the world you can't get that. I also suggest looking into some form of knock monitoring. Also install adjustable cam gears, they can help advance the spark timing and prevent knock, etc. This all is a pretty complex subject and requires a lot of research on your own. Since i wrote that article i gave up on tomei poncams and 11.2 cr. This is my first 4age so I decided to settle for a much more reasonable 10.3-10.5 cr, just to be safe and sure. If this is also your first 4age, or maybe even first engine you're rebuilding, go more conservative to be safe. Even with just 120 or so horses the 4age is still good fun.

[@javierbroger2635]

+driving 4 answers (mr2 mk1 hero) i am from Guatemala unfortunately here the most you can get I think is 91 or 95 Ron booo

[@javierbroger2635]

+driving 4 answers (mr2 mk1 hero) after a little research I have found that the best fuel you can get here is 98 octane Ron

[@MrTaylorTexas]

Thanks for the captions, I had to mute this due to the shit music.

[@d4a]

It is horrible isn't it 🤣

[@danielcsoka2878]

Piston balancing - Level Ricer

[@abccba3903]

Another, I haven't got a clue how to do something so I'll make a video for KZbin proving it

[@d4a]

Abc Cba Please read my pinned comment.

[@VolksTrieb]

Iam not an enginebuilder okay... I did build engines with my father okay... Balancing is very cool and good and the engine runs smoother. BUT drilling out is certainly not the way to do it. It leaves sharp edges which can result in cracks. No thanks, either you take the time and grind/sand out of the whole area or just leave it...maaan

[@covid-20lit41]

Some things can't be unseen

[@mraaaaaaa]

Clown Pound like your profile picture?

[@rassoulsaliou9950]

I have a formula for better piston.

[@martinw9425]

I did put a thumb down for the very loud and annoying music and some content information...no offense though.

[@OpenLogicEFI]

! I would not recommend this Ballance approach.. why not Ballance by removing casting leftover from assembled rod of your should be assembled piston, wrist pin, and !rings!.. you forgot the rings btw..

[@d4a]

Detonation Rings all weigh exactly the same. Pistons and rods have been balanced separately. These pistons have been installed, engine driven hard, feels smooth and runs great.

[@martind349]

This is good music to get _____ and ____ ___ ___ to.

[@terrya450]

not the center that's where the hot spot is holly crap

[@anthonywatson3130]

Cool video! I haven't checked for updates in a while, so I'm glad to see you're still working on this. Are you planning on balancing the connecting rods by hand as well? If so, I can't wait to see the video! Finally, it looks like you didn't balance the rest of the rotating assembly by hand, right? www.driving4answers.com/crankshaft-crank-pulley-flywheel-and-clutch-pressure-plate-balancing/

[@martiniman34]

that was a lot of material removal for 1.2g reduction o_0

[@mt-bp9ei]

Aluminium is light. I think it was made of an Al alloy.

[@daleolson3506]

Music sucks

[@leninjusto8263]

Dale olson which is the nome of the music? Pleace

[@cubanob247]

you are probably enjoying the hell out of ur car and in the end thats all that matters. YOLO bro. Its about living life to the fullest. Fuck up 100 pistons & 100 motors. Who cares!🤷🏻‍♂️💣

[@pornokid333]

holy crap...that doesnt look good or safe for a high compression setup. id rather leave the pistons as is and rev to 8200 with peace of mind that the piston isnt going to disintegrate

[@Joopsmann]

This is unnecessary on a four banger. They are never in “balance” because of the inherent nature of the engine. Think about it...

[@mpfoote]

For a 1 gram difference.... I wouldn't even bother. That's .33% (1/3rd of 1%) on a 300 gram piston. Within 1% is fine.

[@cdoublejj]

it's all the little mods added together. you also balance the rods and crank and drop the combined weight of the rotating assembly.

[@maxschulz8007]

At the end that 1% will make a difference between 9000 and 12000 RPM. Some difference are more fatal than others. For example when the front of your car is heavier than your rear part. In a Engine it's more crytical.. because it moves at ultimate speed and the spark plug is in ms.

[@enlightendbel]

Depends, I've had some Golfs who's engine vibration completely changed going that extra .1 gram. But I've also had pistons on a Megan Cup car that did better with the left most piston being .5 heavier then the rest. Balancing a car engine is literally a balancing act. Small "features" in any part can change how all the other parts behave.

[@chriswest5360]

Damian Toczek 9-12,000 rpm??!!! Wtf kind of engine with cast pistons are you spinning over 5500ish, much less 12 grand??? A cast piston like this one would come apart LONG before it reached that kind of rpm

[@ReinaldoGonzalezreix2x]

Thanks pal! nice tuto

[@de.davids196]

Horrible synthetic music

[@masoodkarami9897]

چه کاریه؟!!! خوب پین سنگینترو بزاره برای پیستون سبکتر پین سبکترو بزاره برای پیستون سنگین تر.اگرم میخواد تراش بده فقط پینو باید تراش بده.

[@lpmorgan90]

This technique would be so bad to use on a bike... The thermal differences alone would cause problems... The real issue is that this is a car engine, this technique may or may not work I'm unsure, but if you ever go near the internals of a performance bike, I suggest you leave it alone and get a professional to do it... Take the material from the skirt, not the crown hence why they make the skirts bigger than they really need to be...

[@jdtv...9134]

The horrible music screwed up a good video

[@pauldenson5287]

wow I read almost all the comments and all of them are rubbish in fact you theory of balancing a 4 cylinder is to . I manufactured my own race engines for my father's company in new Zealand Denco Speedway engines we made every component . Firstly balancing a 4 age is okay but really a waste of time as 2 pistons are up and 2 are down its newton's law guys equal and opposite say no more as for 6 or 8 cylinders a little more tricky the ballance factor is done thru crank counter weigh and total piston and rod assembly weight . thinking such a small amount of weight on the piston would matter is crazy the total difference is less than 1 percent over 330 grams . although it is common practice amongst racers it does nothing . as for taking material off the crown that is a no no removing a small amount from the skirt or off wrist pin is the way to do it . if you like wasting time .

[@jamest.5001]

it just looks wrong. the factory most likely makes the pistons thin as possible. while maintaining enough strength to be just durable enough. and how much could they differ any way. the way we have always done balancing is heavy piston on light rod. heavy pin in light piston . and weigh the rings in sets. and light set on heavy piston. and most of the time its so close. there was no need for grinding. unless you wanted more than 98% perfect. the different amounts of oil and carbon would make the same amount of different weights. the major vibration comes from the crank and the big end of the rods. I have used completely different pistons. same style. from another manufacturer. and ran it hard for years. with no vibration. but if a odd rod got thrown in. it would likely fly to bits! just my view.