DIY CYLINDER BORE CHECK: How to measure OUT OF ROUND, TAPER, and REBORE size - STEP BY STEP GUIDE

0-150MM 0.01mm/0.0004 Inch Outside Micrometer set
ban.ggood.vip/WVod
50mm-160mm 0.01mm Digital Dial Bore Gauge Engine Cylinder Measure Gauge Measuring Tool Kit
bit.ly/36jYWQI
Today we're going to do an easy, step by step DIY guide that's going to show you how to inspect and measure your cylinder bores to see if they are out of round, or maybe tapered and to know for certain if they need reboring or not. We're also going to be working on our pistons to see how much to rebore an engine depending on piston size.
Now the first thing we'll be doing before measuring stuff is to clean and visually inspect our bores. During our visual inspection we're looking for two things: an absence of damage in the form of deep scratches and scoring and a presence of a cross-hatch hone pattern on our bores.
If there's an absence of damage and a presence of honing marks your engine has passed visual inspection. If there's an obvious presence of damage your bores have failed visual inspection and they will need boring.
Cylinder 1 of our block doesn't have serious rust and there's even some honing marks present. However there is increased wear on the thrust axis of the bore. Now increased wear on the thrust axis is normal and expected. During engine operation combustion forces act on the piston crown and because of the piston's position in relation to the conrod and crankshaft this part of the bore receives most of the load and therefore the most wear. This is also why pistons have more skirt material along their thrust axis. More skirt along the thrust axis helps better support the piston in the bore and helps distribute loads.
So cylinder 1 has an absence of serious damage and even some presence of honing marks which means that it passes visual inspection. But it does raise some concerns over increased wear.
In order to measure bores we're going to need two different measuring devices. A dial bore gauge and an outside micrometer. To measure bores we need to set our micrometer and bore gauge to the proper dimensions. The first thing we'll do is to zero our micrometer. To do this we need to set it in a vice. It's a good idea to use a soft jaw vice and/or some wood, and definitely don't tighten too hard as it's easy to distort the shape of the micrometer.If you distort a micrometer it's no longer usable for taking measurements.
Next we're going to consult our factory service manual or any other suitable source to see what kind of bore dimensions we should be seeing. This is a Toyota 4AGE engine block and the factory service manual tells us that our STD bore dimensions are between 81 and 81.3 mm. So we'll set our micrometer to 81mm exactly and lock it again. Now we're going to zero our dial bore gauge to 81mm. This is probably the trickiest part of this whole process and it requires a bit of patience sometimes. We're going to assemble our dial bore gauge by using an attachment of suitable length, and then we're going to insert the measuring end of the bore gauge into the micrometer. We will gently and slowly move the bore gauge inside the micrometer as we watch the needle.
Once you've zeroed the bore gauge we can proceed to the measuring. And we will be measuring at six different spots to get an accurate assessment of the condition of the bore. We will be measuring at the top, middle and bottom of both the thrust and the non-thrust axis of the bore. We're looking for two things - and out of round condition and a tapered condition of the bores. An out of round condition will reveal itself as a difference between dimensions of the thrust and non-thrust axis, and a tapered condition will be be present if there's a difference between dimensions at different bore depths. Our factory service manual tells us that the maximum allowable bore diameter is 81.23
How much should we rebore an engine? To learn that we need to measure our oversized pistons. When you rebore an engine, you need to get oversized pistons. To maintain a proper piston to wall clearance an increased bore dimater also calls for an increased piston diameter.
If we check our factory service manual we'll see that the piston is measured on the thrust side 42mm from the skirt bottom, which turns out to be just a few mm away from the oil ring groove.
Our factory service manual gives us a formula for determining the amount to rebore. Its' the piston diameter + piston to wall clearance - allowance for honing. In our case that's 81.38 + 0.13 (since these are supercharged 4AGZE pistons we're using) - 0.02 mm. The result is: 81.49, which is the new bore size that your engine would need to be bored out to.
A special thank you to my patrons:
Daniel
Peter Della Flora
Daniel Morgan
William
Richard Caldwell
Pepe
Brian Durning
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Brian Alvarez
Holset90
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#d4a​ #enginebootcamp

[@d4a]

0-150MM 0.01mm/0.0004 Inch Outside Micrometer set ban.ggood.vip/WVod​ 50mm-160mm 0.01mm Digital Dial Bore Gauge Engine Cylinder Measure Gauge Measuring Tool Kit bit.ly/36jYWQI

[@kylercarl3871]

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[@marvinanthony4545]

@Kyler Carl instablaster ;)

[@kylercarl3871]

@Marvin Anthony Thanks for your reply. I found the site thru google and Im in the hacking process atm. Seems to take quite some time so I will reply here later when my account password hopefully is recovered.

[@kylercarl3871]

@Marvin Anthony it did the trick and I finally got access to my account again. Im so happy:D Thanks so much, you really help me out!

[@marvinanthony4545]

@Kyler Carl No problem :D

[@TheRealTomLauda]

This channel is criminally underrated. Thanks for all the knowledge !

[@jonathanandrews1407]

I don't know how you can dislike this guys content...should be a crime

[@deciplesteve]

Nah, for this video, it's angry machinists trying to shut down the idea of checking to see if they're hosing you. Lol

[@gaspererjavec7108]

They are just angry serbians who cant get over the war :D

[@atlasintegrations4114]

Definitely not a boring video! Another production to help gauge your automotive knowledge, and thrust you to the next level of engine building. And for those leaving thumbs down, we know what you use your micrometers to measure.

[@benrodeheaver701]

I really liked your comment especially at the end ! I wonder how many readers picked up on that. God bless.

[@igorvashkov8821]

Those leaving thumbs down probably use bore gauges not micrometers.

[@atlasintegrations4114]

@@igorvashkov8821 sounds like you are an expert at all those bore gauges! 😂

[@igorvashkov8821]

@@atlasintegrations4114 Why would I be one? I always leave thumbs up on this channel!

[@jameshaulenbeek5931]

This is a fantastic video! I do occasionally use an outside micrometer at work, for measuring axle diameters when rebuilding traction motors. One day during a rebuild, the guy who was building the motor said the axle wasn't going to work - it wasn't cut properly. He wasn't familiar with zeroing out the mic. Found out the mic was out by nearly 0.008" due to misuse and abuse, so after adjusting it, we determined the axle was well within tolerance.

[@welltell.]

At this rate I will be able to build my very own MR2 Toyota motor in no time.

[@bobross6677]

Step one find a rustless mr2

[@welltell.]

@@bobross6677 step two find some rusty tools. lol

[@802Garage]

Everything you said in the first 2 minutes is exactly how I feel. Plus I'd rather save the money and do it myself. I've had a full set of budget engine measuring tools in my save for later cart for ages now. 😄

[@802Garage]

@Donovan Piko Thanks you too. 😁

[@1crazypj]

I did an 'Instructable' a few years ago on correct way of measuring cylinder bores. (on a two stroke motorcycle) There are a couple of things that can make life easier. Pistons are almost always measured around 3/8"~10mm from bottom as the crown is always a lot smaller diameter because it has more mass and expands further at operating temperature. Check micrometer with a STANDARD, a gauge block is a different piece of equipment. After you set micrometer to size, set it on a piece of foam rubber laying flat. It's a very easy way to set bore gauge without any balancing act or risk of changing dimensions from body heat. You also need to note the counter dial (the little one in the middle) I have seen people get a full 1mm out as block they were measuring was already bored to max

[@Projekt5.3]

Absolutely love the detail you go into. Far too many just glaze right over important things like thrust load direction etc. Top notch quality as always!

[@milenski_411x]

I really enjoy learning new stuff for the car so keep like that.

[@CodewortSchinken]

I have been following your channel for many years, but start to feel more and more spooked out. Doesn't matter what I do in my garage a new D4A video about pretty much the same topic gets released shortly after: - I rebulid the suspension of my car wit Poly bushes-> D4A video abou rebuilding suspensions with Poly bushes - I replaced the factory speaker on my car -> D4A video abou replacing blown out speakers - porting a cylinder head -> D4A video about porting cylinder heads -I finally decide to do something else, buy a clapped out motorbike, fail to make it run and have it sit in the back of my garage eating up space -> D4A miniseries on an old motorbike. Guess what I had in mind a month ago. I don't belive in telepathy, but I start to feel watched. Thank you for your very informative video though. I'd just have some doubts about the accuracy of those cheap no-name measuring instruments. I personally own a small collection of old japanese and german tools that I partially inherited or bought second hand. I just don't know if they are much better after being used for decades. At the end I decided to just bring the block to a trustworthy machine shop and have it checked.

[@floydsparkman9347]

Very detailed, I really like the order of the information being presented. To the point, and very descriptive. Excellent

[@RoxyXie]

This is by far the most helpful video for us starter DIY engine builder.. thank you so much sensei.! 🤲

[@redyr6]

Just the video I needed after I took apart the smallport I bought. From the suspension videos to this, been a lot of help with my mr2!!!

[@almann101]

This is an excellent tutorial video and one I am very grateful for you posting and sharing your knowledge - I totally effed this up on my first try before seeing this video and ended up with the gauge going mental! Once I had zeroed the dial gauge properly using your video, I ended up with cylinders that were either near enough bang on or at most in the middle of the tolerance. Went from dire straits to happy days in one vid!

[@pierpaolosandrin3247]

I appreciate what you do and how you do that. "There is nothing more practical than a good theory". Would you do a video on the reasoning behind piston pin offset? Cheers

[@swfautoworkx5951]

This is an awesome channel and very solid accurate information ... Keep up the good content

[@itsdokko2990]

i don't know if i ever gonna need this knowledge in a possible future, but i'm glad i now have this knowledge

[@PRAD33PK]

Not a bad way to spend Valentine's Day, eh!? I was going to post a comment about how the cheap micrometers and bore gauges only have 10 micron gradations. I recently blew a significant amount for a 1 micron grade Mitutoyo dial gauge and micrometer. But just realised that I very rarely need to call upon that level of accuracy. And that the much cheaper 10 micron locally-made-cheap versions are the ones I use the most and that is the level that most factory manuals seem to need. Their ability to withstand wear and tear in carefully used home mechanic environment is quite acceptable too. Thank you for an important lesson in matching tools to needs, rather than always blowing the bank trying to buy the "best".

[@johannriedlberger4390]

Great Video but small Mistake When calibrating the micrometer do not clean the measuring surfaces with your finger. You always have a tiny amount of moisture on your skin (fingerprint). Use paper to clean the surfaces. Best is some printer paper that doesn't leave particles behind. The micrometer has shown 0.02 mm too much. That is typically the difference from clean to have a fingerprint there.

[@gaspererjavec7108]

I was looking at buying a bore gauge for a while now and im happy to buy it with your link :D

[@ibrahimqureshi2420]

you always come with so much knowledge thank you so much for educating me !

[@slightlyinsaneraf]

Very good guide! May come useful in future!

[@UncleKennysPlace]

I have a bore gauge, as I used to rebore motorcycle cylinders, back when that was a thing, in the seventies and eighties. Straight, round, and the right size, and everyone is happy, especially the piston.

[@d4a]

Especially the piston 😁

[@Gkitchens1]

Thank you for the info. Getting ready to rebuild my first engine on an extreme budget, an lt1. It’s low miles 81k) and overheated and popped at least one head gasket so I’m learning as much as I can. It was already torn down and coated in a nice coat of grease. I’m sure the cylinders are in great shape but don’t know if they are out of round. I’m probably gonna throw new bearing and rings in it since it’s already torn down and since I’m going that far I might as well make sure they aren’t out of round. Though if the bearings look good I might just button it back up clean it really well and leave the rings alone. My big concern is that the heads aren’t warped.

[@accordv6er]

Definitely doing my Miata spare block. See what happens. If it checks out good for the amount of overbore to clean pitting (looks a lot like this old 4agze) then I'll be doing some oddball mix and matching of factory parts if I can get the numbers right and without sky high compression. Cams will be custom grinds, Nissan valves and guides, far as I can tell, we'll see on base circle reduction when done, using zetec lifters, volvo or 4G63 valve springs, and doing most of the shimming on the valve stem if possible. Mild hand port, mostly just bowl blend, unshroud and radiusing. BP heads sorta just suck, as does the rod ratio. Should be able to get a 1.5mm over rebuild at the cost of OEM rebuild parts, with a healthy compression increase and hotter cams. I'm shooting for a 160whp N/A 1.8.... because we Mazda folk weren't blessed with 4ages, 3sge beams, or b series.

[@ronnybharati678]

Wished you were my instructor during My engineering years !! Hats off sir !!

[@craazyy22]

You should always check if the measuring rods that came with the cheap micrometer sett is accurate with a good caliper if you have one.

[@jameshaulenbeek5931]

Depending on their size, you may need to take the rods to a shop to have them checked. Generally though, as long as you are the one doing the measuring and assembly, even if your measurements are off by 0.001" or so, everything you're measuring is, and it will all work out in the end. When you use the same tools to calibrate everything, all the measurements will match each other and you won't have odd discrepancies.

[@rezakheradmand5341]

that was AWESOME ! simple comprehensible and perfect many thanks to U

[@stavrique]

Perfect video and perfect explanation....as always

[@aromero9243]

Theses videos are awesome thanks! 👍

[@oscarmazur5552]

Amazing channel!! I really want to thank you for sharing your knowledge!

[@vanhap]

Thank you for sharing such great and helpful info for us. If someone cant borrow and want to only buy one of the two tools. Get the Dial Bore Gauge Engine Cylinder Measure Gauge. you can see and measure these points' measurement differences.

[@adriandiez3728]

Very well explained,nice video thanks very much

[@marujo100]

thank's or this video! all the best from Brazil!

[@SirCavemaninthewest]

Currently assembling my new pistons. How ironic! Will double check those bores.

[@flyonbyya]

As always...great content !

[@BackmansGarage]

Very good guide 👍

[@JohnSmith-ok9sn]

Excellent video. Thank You!

[@maximolopezsr9399]

Very good explanation

[@AMGTOM]

Thanks a lot for all those explanations

[@cibimbox9195]

I always done this job with an angle grinder. So probably this is why my engine still has some issues.

[@anthonysaoulidis6340]

Thank you for the educational video

[@tomheater6149]

Very good information. Thank you!

[@valentinuiliqnow6198]

best day ever ! ! !

[@jozsefizsak]

Great stuff,. Very informative, and I appreciate the stressing of zeroing the instruments. One quibble: I was taught to say "decimal three eight" as opposed to thirty-eight because thirty-eight is a whole number whereas the aforementioned decimal or point three eight is, of course, a fraction of one. This was stressed so much that even decades later it's painful to hear anyone mixing whole numbers and fractions in that way. A pity for me since it's a rather common mistake!

[@802Garage]

Very interesting. I've never heard of that stressed so much. Though I'm not professional machinist. American as well. I would usually say "point three eight" or "point thirty-eight" comfortably. Now that I say it out loud, I think I would usually prefer the former when measuring. We might of course say "thirty-eight thou" for 0.0038 though. Which adds a layer of confusion. However, I would rarely say the whole number in a decimal unless it's in the tenths place. I wouldn't say "point zero thirty-eight" for 0.038 I would say "point zero three eight" so perhaps it's pretty standard across the board, but with the tenths exception? Would make sense to keep it uniform. Just rambling as I think about your post. :D

[@jozsefizsak]

@@802Garage It was mathematics class and that's not a profession that looks kindly on imprecision!. Thirty-eight thou is absolutely correct terminology since we're counting thousandths and there are thirty eight of them.

[@d4a]

I'm self taught on all of this 😅. Saying 38 thou is really hard for me as it comes out super weird and unnatural. Decimal three eight I never even heard as I had math in my mother tongue and we said it like I say it, I just translate to English in my head. But videos are great because you can put actual numbers on the screen 😊

[@LoneStarMini]

Outstanding.. the best out there I believe!!

[@pantelis241]

Great video , many thanks 🙏🙏🙏

[@kirtonvincent]

Yes it is I agree with you 100% so much valuable information that they provide is helping me a lot learn so much thank you guys do you guys are killing it easy to understand Keep it up guys

[@lavina58]

Awesome video 👍👍😊

[@golammustafa662]

Really it's a great helpful video.

[@krystaltholen9736]

this has been so helpful, when I pass my ase I will drink to you :)

[@ashaphter9738]

Bang good that's what she said. Joking aside good stuff to put out sir.

[@piotrprobala4808]

Great video

[@donperryautomotive]

IF a torque plate is used to bore the block, wouldn't it make some cylinders out of round when not bolted?

[@benrodeheaver701]

Excellent amigo. Want to share about cylinders that get catalyst in them from excessive valve lap. The middle of the liner can be up to .040 over but cannot be seen by your eye. I found out the hard way after honing and new rings/valves with no increase in compression. It was my fault for not using an inside micrometer !

[@terjejohnsen3651]

Thank you for the education its good to know.

[@roadtuned1416]

Excellent info, just about to start making a hybrid engine from m54b30 and m52b28tu to m54b28 :) Will definitely use this knowledge now.

[@zorg1396]

What's the advantage of this? :)

[@roadtuned1416]

@@zorg1396 Currently i am trying to film the rebuild and make series out of it but briefly will mention whats the main differences: B30 vs other engines b25/b28 etc. B30 has more displacement , it has better intake cam. The other ones especially b28 can be build to have similar or more horsepower with the intake cam from b30 or better (Schrick for example, and other goodies too long to write) All m54 have issues with pistons rings wearing and letting a lot of blow by and high oil consumption, with the m52b28tu you dont have these issues. B30 has longer stroke and has huge harmonic dis-balance after 6,5k rpm which ends up ripping the oil pump and not letting you rev the car safely past 6,8k(unless you spend shit tons of money) B28 has square cylinder design 84x84mm and is excellent for high revving. I am sending mine to 7,3k with custom camshafts and other goodies. It will have close to 100hp/L . So it is a hybrid as it will use management system and mostly of fuel system from M54 but remain 2,8l to avoid the harmonic issues. Hope that helps ;)

[@ryanscanlan9875]

Great channel

[@RestorationApprentice]

Odlican info, hvala!

[@clintonhayes670]

Good job.

[@saibabupodala6297]

Good information

[@wanderider321]

When you are doing these measurements how are you reading the guage (Inside bore Thrust and non-thrust). When I was looking at the gauges I read the dial as pointing to between the 90 and 0. How did that give you 81.01 to 81.04? Was it subtraction, or perhaps tilt of the guage dial?

[@alainprefontaine1909]

4:35 Thank you for showing how to zero the micrometer with the 75mm calibration block.

[@Limeayy]

5:51, what you mean by that is when the needle goes clockwise all the way to the furthest direction, correct? Not CCW? I love the pictures really beautiful knowledge, keep it up D4A

[@findvoltage]

Hay, what about the dial gauge? how do I set the indicator plunger into the extension for the bore value?

[@majestic1120]

have a question, i was given a 08 colbalt 2.2L had a spun bearing on connecting rod cylinder 1. alot of score markes i was able to hone out. problem now is cylinder one if I put a oil ring in has a slight gap between ring and wall. if the cylinder is oiled you would never see it. without oil and a flash light you can see the slightest light right along one skirt side wall I mean slight. starts approx an inch from top to two inches from bottom. would this be a major issue requiring a rebore...thanks

[@pigeonsil240sx]

can you use those telescoping T measuring tools for this and micrometer or is it just not accurate enough? i ask just because how easy they are to use

[@SayaAmirulSyamim]

Hi , i’m just wondering why does the bore gauge goes anti clockwise instead of clockwise when measuring?

[@Stiefe300]

Thats a really Good video about how to messure the bore. Maybe but i think you already did that, you can also do videos about the main and connecting rod bearing.

[@d4a]

Will do bearing clearances for sure 👍

[@edward9862]

Great vid! THX!

[@johnh1001]

Nice Video ; Try using a "Dial Bore Setting Fixture" . If folks use a micrometer to set their dial bores , it's not what you would need for such . Try using a digital type "Sunnen" dial bore gauge . They also come with a calibrated Sunnen setting fixture . The method shown in the video could easily become a tricky/dicey thing for some of the machinists 101 type folks . To plug in quality assurance in a finished machined cylinder , anyone would be better off with a three fingered digital dial bore gauge . Try , you will like it !

[@solanimanamela2494]

Hi there, Please help, I've got a Nissan NP200 & recently repaired the cylinder head & replaced the intake manifold. I noticed that whenever I change gears, the engine revs a little bit higher than usual. What may be the cause for this?

[@avahrintmurth1159]

I would love to get more in depth especially in the formula and if possible where to search its. Thanks in advance your fan from Algeria

[@billy6690]

It would make an interesting video on how accurate the Chinese measiring tools are compared to quality ones. I was thinking of buying the same ones a few months ago as you used, but changed my mind for accuracy concerns.

[@MikeSmith-nu9wt]

For measuring taper and out of round, it could be set wrong, but you will still see a problem in different measurements. Accuracy is important, but even if they are off its still a useful tool

[@ParsMaker]

nice video

[@nicoleibundgut534]

Where did you learn all these things you are explain us here? Follow you quite some time now and watched most of your vids. Would love to know where you got those infos from. Greetings from switzerland

[@richardmarkham8369]

The Land Rover V8 4.6L manual doesn't give a max diameter. The bore is just secified as 94.000mm to 94.015mm. It only says max out of round of 0.013mm. Clearance is specified at 0.015mm to 0.045mm, so pretty tight. How much wear is allowable? Your MR2 seems to allow 0.2mm, sounds like a lot!

[@laurenmartinez55]

Still waiting on that video of the RB26 or the Ford FE series or Chevy small block. Also, where is your accent from? I can't for the life of me figure it out

[@blinkyd4952]

Man what are you qualified in, because you know so much about engines , like are you a professional mechanic ? or an Engineer? I'm a student in Mechanical Engineering

[@Validaty]

Hi brother. Thank you for your explaining. Good luck. Answer my questions please... Does a cylinder block metal type affect these values formula, that you explain end of the video? (Cast iron, aluminium)

[@d4a]

The formula is based on piston to wall clearance which needs to be checked for each individual engine. The piston to wall clearance depends on many factors and there's no universal formula. The allowance for honing is usually similar for most engines, but double check that too.

[@juancruzmarquez5502]

mans out here teaching us how to work at a machine shop FOR FREE

[@Irfansaqi-mx4ds]

One thing not understood many 81.04 end piston size 81.49 how,??

[@zakhu4971]

hello from iraq with you well done

[@porterarthur659]

In my experience it is also good to check after machining.

[@d4a]

True! Can't check enough

[@ernestdamo677]

Please i don't have that equipment, please is there another way to check the cylinder bore because is not all of us who will have that special tools

[@Bubutankita]

mantap bos,i like

[@JackBWatkins]

Are you going to take us through the whole process in future videos?

[@d4a]

I will do more hands on videos like this in the future. Bearing clearances, ring gaps etc. If that's what you meant?

[@pumpmancatiwalaangaudiano7101]

Can i rebore only 1 cylinder in multiple cyclinder?

[@abijithsnair6300]

ഡേയ് പിള്ളേരെ വായോ ഇബിടെ കാമോൺ💥 MMV💥

[@iuse9646]

Fuck yeah this is the exact guide I've needed to see

[@tudor3874]

Fa20 pls?

[@gregorymiller343]

Hey how can i get my hands on some legit Service manual (Mainly Asian Vehicles)

[@noahtoombs9351]

Is it possibly to have iron sleeves installed on an iron block? That way you can indefinitely rebuild it?

[@d4a]

Sure, you can do sleeves into cast iron blocks... But nothing can be infinitely rebuilt 😉

[@jameshaulenbeek5931]

@@d4a con rods DO make interesting viewing windows. 😂

[@d4a]

🤣 🤣 🤣 Though I've seen people muggyweld fist sized holes.. So maybe it IS infinitely rebuildable 😂

[@noahtoombs9351]

@@d4a that poor block 😂😂👏👏

[@beerandgames5380]

So did i look at it wrong or did he zero it on 70 instead of 75?

[@noahbartlett2832]

rb26 video?

[@ovalwingnut]

Yeah baby! Better than a 3rd date.. (if I ever get to one)

[@drogo21]

An actualization about your Seicane Autoradio please?

[@d4a]

Sold the car 8 months ago. Worked ok until the end. I had some Bluetooth issues, but it was generally ok.

[@stefanlynch3210]

Yes we do take stuff to the machine shop until we get everything back together and find out all cylinders are pushing 70psi max compression.

[@theloord5118]

When the piston diameter is 78.40, mm how to adjust the dial bore gauge , set 78 mm or set 78+ 0.50 mm

[@vikrammalviya7917]

78.65 bore size.