I think your micron to inch conversion is off. 2.03 microns are equal to 0.0000799213" you may be using different notation, I just thought I would mention. It looks like it's saying .060" (as in close to 1/16th of an inch) when it is one thousand times smaller.
No dude, not in today's plastic engine components, the Ford EcoSport Fiesta Focus 1.0 GTDI EcoBoost Water Inlet Tube 2023617. This part sends coolant to head its 10mm ID thick and is a loose fit to the alloy cylinder head. This is much worse and fails long before the head gaskets, on average few months past the warranty date.
I have a 1976 Triumph Spitfire 1500 that the previous owner had ground the head down to increase the compression. It was so high that I couldn't get rid of the pinging with the highest gasoline available to me. I bought two stock head gaskets and I found some company that made me a copper one. I sandwiched the copper gasket in between the two stock ones ( I sprayed a copper sealer on them first) and bolted it down tight. That was around 25 years ago and it still purrs like a kitten.
Even as a former Subaru owner I never thought about head gaskets as being that high stress of an item, you've really out a whole new perspective onto things with this video for me
Hilariously I just diagnosed a buddies 2007 subbie legacy with failing head gaskets. He gon learn in a few weeks just "how bad could it be?" Ill make a car guy from him yet. Or maybe he'll start maintaining his shizniz a bit more betterer.
Many years ago a co-worker asked me to take a look at the engine of a boat he bought cheap. The engine did not run and upon disassembly, I showed him the head gasket was completely worn out. Due to the cost of a gasket for an outboard motor, he wanted assurance that it was the only problem. He did not want to spend money on a new gasket to only find out the motor had other issues so I took some common gasket material and made a temp head gasket and reassembled the engine. It started and ran nicely. He asked how long the temp gasket would work and I had no idea. It was the same type of material used for water pumps. I said, maybe a minute, maybe an hour. I really did not know. Just buy a proper gasket now that you know the engine is good. Well... he did not listen. That weekend he went to the lake and took off with his boat across to the farthest point when suddenly, the gasket failed. With no oars, he and his friends hand paddled the boat back. I laugh so hard when he told me what happened. 🤣🤣😁
I loved head gaskets as a mechanic. Good flat rate hours, easy to do, virtually no come backs, and a steady supply of them coming in. Especially older composite head gaskets with an MLS replacement.
Surely they can be a bit of a headache when due to overheats? i.e. having to make sure the deck/head are not warped, I'm sure customers don't like to have to pay variable amounts when you can't accurately quote before the job the cost of sending parts to machine shop
I work in healthcare and know next to nothing about engineering. I’m blown away by the complexities of mechanical engineering that are never learned by the average person who depends upon engineered machines in all aspects of life. Truly a joy to learn about these subjects.
@@MarkSmith-js2puwell, I'd say electric motors (at least brushless motors) are elegant due to their simplicity. Like Art or dresses, simplicity can be just as great as complexity. One is a physical marvel, the other an engineering marvel.
@@satunnainenkatselija4478 belt tensioners are not internal parts so that may be why. Although some belt tensioners (like toyota) seem to last forever and i doubt as much engineering has gone into them either.
I have replaced several head gaskets in my short time working with combustion engines, and I never stopped to actually truly appreciate how well engineered these parts have to be in order to survive hundreds of thousands of miles on the road. Thank you for this video! This has really given me a new perspective on a part of an engine that most people don't even know exists!
Engineering is really really fascinating, the small things we take for granted in everyday life that came from decades of research and trial and error, fantastic content!
Dude this channel is like a modern day "Modern Marvels" no BS just easy to understand and straight to the point explanations for very complex and complicated concepts. This channel has answered certain engineering, mechanica,l and material-science questions I've had for years answered within 20 minutes.
In 2005/2006 we were trying to build the 1st 1000whp e36 328 (m52 engine) The toughest/most aggravating part of the build was getting the headgasket to seal under high boost. Around 17psi the gasket would blow out in between cylinders. One reason why we went with the 2.8L m52 instead of the 3.2L s52 from the m3, m52 has a bore of 84mm and s52 is 86.4mm. Those extra mm's made all the difference. Even with the extra material we still o-ringed the block n head. That was the trick that put us for ahead of the competition and helped us have the world's 1st 1000whp m52. Also 1st in the 9s while still having full interior, heated seats and ac.Havnt been back to the track ever since we got kicked out and told we need a parachute lol. 16 years later and only like 2 others have made that much power. Truly were miles ahead of the competition.
TMS here in Stamford had a 1100 whp e36 m3 years ago. did see the car in person but never saw it on the dyno so not sure if that was accurate but it was a beast.
I have built many supercharged and high compression engines. I have always used plain soft copper with aviation quality sealer sprayed on both surfaces. It works far better than 90% of the "for boosted engine" commercially available gasket solutions.
@@borderwave2 made 715whp on the stock m52 in 2005. This was before e85 and the tuning options available today. Built 25 years later and specifically for boost is still barely better.
@@NewMind ahh.. 20 years that's good. Finally got back going again and continuing where I left off with the jet powered go-kart. I built everything and then I realized that the engine in my truck was blown. So I had to interrupt everything to rebuild the engine I have 4 broken main bearing bolts in the block now and 3 broken exhaust bolts in the head. Seems that for some reason the engine spun a bearing and has 1 bent valve, weird, only has 40,000 mi
I love how something so simple can become a fascinating video and something that I don't think I've ever really seen anyone else on TH-cam address like this. Can't wait to start sharing this with friends.
I work in heavy truck parts sales, and all of our parts are BIG, including head gaskets. We have a regular customer who constantly questioned the price of absolutely everything he'd try to buy from us. One day he came in looking for a head gasket for a Paccar MX-13, of course he was quite shocked at the $350+ price tag, but I told him we don't carry aftermarket options. So I went to go get the part, and when I came back, sure as hell he asked me "what does this part do anyway?" I was actually too stunned to speak...not because he didn't know what it does but because he was questioning me on price WITHOUT knowing what it does. I had to educate the guy on its function but to this day I was genuinely stunned that the owner of this truck, did not know what the part was, why it was important, and why it's so expensive. Don't friggin question me on the price of a part when you don't even know why it is probably the most important part of your truck you DUMB WALNUT. This video reminded me of that incident, tis a great vid.
I have only recently come to appreciate how critical this simple-looking component is to the efficient working of an engine. I have done two replacements already and looking to do another one later today and now I appreciate the precision engineering that has to be applied to keep compression, oil and coolant separate and contained.
EXCELLENT VIDEO! Me, ASE Certified Master Engine machinist for over 30 years. I have been working in the engine rebuilding industry for 55 years. Had my own shop for 20 which included a Comec wet surface grinder capable of accuracy of .001 per 12" of length which is what we used to surface both the heads and blocks. Back when I opened my engine shop in 1978, we saw a lot of Honda 1200 and Chevy Vega engines with blown head gaskets. The Honda was all aluminum while the Vega was Aluminum block and cast-iron head. Both used the "open deck" type of block. Both were composition gaskets "squishing" about .007-.008 when torqued. My thoughts were that the cylinders were "moving", and the gasket was not adequately being compressed on the cylinders. My solution was after machining the gasket surface of the block flat, I then went around the outer edge of the block and machined an additional .001-.0015. That resulted in the cylinders "standing proud" .001 compared to the edge of the block for a tighter clamp on the fire ring. This really helped the durability of the gaskets. But they still needed retorquing which in the case of the Honda meant removal of the rocker arm assembly since it sat over the head bolts, UGH! About this same time a LARGE gasket company (FP) announced their no-retorque head gaskets! We were jumping for joy thinking of all the time they would save and started installing them on our engines right away. Within WEEKS we started seeing problems! These engines started spitting out head gaskets some in as few as a couple of thousand miles! The VWs in particular would come back with actual pieces of the gasket hanging out from the edges of the head! We stopped using them and went back to OE type gaskets and the problems ended. The company asked me to send them back so I sent 1 of each, Honda, Toyota and VW. They called me and said they would warranty the gaskets. I said that was OK but did they want me to send them the REST of the failed gaskets we had? "How many more do you have?". I told them 32, SILENCE. Then he said "let me talk to someone". Another voice on the phone "Is there a major airport near you?" yes "A couple of reps are going to fly to your shop and see if we can tell what's happening". The next day the VP and head of Tech arrived at my shop. After examining my machines and procedures they could find nothing I was doing wrong and said they felt it was the area WATER that was the cause!. I was stunned but before I could open my mouth he said "BUT, we are prepared to offer to pay you parts & LABOR for all the failed gaskets PROVIDED you sign a release form and will make NO further claims against us. It was a LARGE CHECK so I took the offer. They must have sold a LOT of those gaskets, we continued to see failures of them that others had installed for YEARS after that!
What do you mean claims? Anyways very cool information. Have any other similar stories for other engine parts to non car layman like myself? I figured gaskets were an easy piece. Doesn't look too complicated. Love learning about the intricacies although I'll be never use the information. Don't even have a car haha.
Blown head gasket is still the most common engine failure you hear from people to this day, at least here. Unless you really mistreat your engine it's fairly unusual for any of the mechanical parts to fail. I've only had one engine fail really badly (i melted 3 of the 4 pistons), because I kept running it for over 100,000km with a blown turbo seal - it would lose oil pressure at idle, but as soon as you revved over 1000rpm the warning disappeared. Eventually it gave way completely, sucked all the oil through the intake, and I ran it dry at 200km/h until it cooked itself to death. The oil light never came on and coolant temp. was normal, I only noticed something was wrong because I tried accelerating and it was not responding. I stopped as soon as possible (less than 1km) but by that time when I opened the hood the turbo was glowing _orange._ After refilling with oil I still managed to turn it back on and drive 20km to the mechanic, surrounded by a cloud of oil. Absolute tank that engine.
For 100,000 km? What car was that lmao I had an oil Opel Astra F that we cracked the oil pan on when driving on a dirt road. Figured we'll just send it and try to go home - we drove like 15 kilometers and we were like 4 kilometers away from home before it gave in. I just saw a glowing red metal thingy fly away in my rear view mirror. Probably a connecting rod. Tried to find it but it was impossible. Looking back at it now, I wonder how that thing didn't cause a fire since it probably landed in grass. Well, the thing was a beater anyway and we already burnt the clutch a bit when trying to do burnouts so we were already somewhat detached from it. It took quite a beating from us tho lol Then we moved on to a Fiat Bravo HGT, which ended up with a.... you guessed it... blown head gasket. The thing was the most fun car I'll probably ever have though!
@@tabushka292 '97 Audi A4 B5, it had around 250,000km when I bought it and 356,000 when it blew. It wasn't dry the whole time though just to be clear lmao, it did use a bit of oil but not _that_ much. It leaked just enough oil through the turbo that after 15-20s at idle the low oil pressure warning would come on.
This explains a lot. If you had a Ford 3.8L V6 in the mid 80s to late 90s, it was virtually guaranteed to blow head gaskets. This problem was virtually eliminated in 99 when Ford started using the MLS head gasket for this engine, which you can now turbocharge in stock form up to around 420 hp with no reliability issues. I had read of the MLS gasket many times but never really understood the history until now.
@@ihadlunch8575 Well you know what to do! Repair that pushrod baby and put them MLS gaskets in there! It being pre-99 you might be able to put the supercharger on it that came stock on the SC Birds. 👍
Great video! One problem, in the first half of the video with the diagram of the head gasket the oil galleys and water ports are switched with eachother, since the coolant will need to be taking heat from around the cylinders and the oil usually just drips back through the head gasket down to the block
@jacobnelson2480 Surprisingly.. if you were to find parts in relation to them, they will all be labeled as "oil galley ___". While I agree gallery is the better choice, it seems that it is a galley for some bizarre reason.
Through my few years of school and experience I have always known them to be Galleys, but to each their own. I don't plan to change as that is always how I've known it, and this is what I do as a career.
Bugged me he used kilograms per square centimetre as a unit of pressure for half the video (nobody at all used that that I'm aware of) then switched to pascals for the last half which is at least SI and actually used.
First time ive ever seen your channel (im gonna rant for a sec forgive me my autocorrect doesnt work). Im a Hino Master tech, working on detroit side of Feeightliner (and I might as well be for Volvo) and man I gotta tell you not only did I learn something I learned lots of things. Im amazed by you. . Instantly subbed. Your vid got me going.
This was really fun. I have installed a lot of head gaskets over the years and have seen many of the designs shown. I hadn't thought about it at the time but I could definitely tell how things progressed over the years. Thanks for the excellent video!
As a recent graduate from a Automotive Technology program, I think this video would be a really good reference and history for in-class use. great job!
Your initial list of requirements doesn't include "cost" even though it is a primary driver in most engineering decisions (as seen in the rest of the video). I was wondering why they didn't get around to using crushable aluminum gaskets, but by the end of the video, the copper ones basically fill that niche.
One thing I would like to add about head lift and the use of a gasket - The gasket is compressed during installation, so even during extreme cases of head lift (0.001") there should be no separation occurring between the three components.
this video is just your typical "youtuber" reach, there is nothing special about head gaskets, any compression gasket can sustand high pressure with no effort.
There's lots of little wrong things like this in the video, those are just in the parts of it that I knew. Makes me wonder what wrong things were in the parts I didn't know.
For those curious, there is a major improvement to typical head gasket design, called "O ring," which places a steel ring in a groove shared by the block and head, and crushing a copper gasket between the two. This creates a much stronger seal, at the cost of a bit of engineering and of course the material cost of copper. This is what many drag cars use, and with it you're more likely to pull the studs out of the block or bend a rod than blow through it. Very well put together and informative video, though! I enjoyed watching.
I remember when I was young a lot of cars used to have the head gasket problem even without overheating or any issue, I wondered why I stopped hearing anyone have problem these days, thanks for the rich informative video
I remember replacing my first head gasket. Didn't know you had to turn them an additional 180 degrees after torquing. I found out after a few months...
Vintage Ferrari mechanic here. Old aluminum Italian engines, especially V12, really like to move around a bit. Using permatex Aviation Sealant ALL over the head gasket does the trick better than anything I’ve used. It does not ever fully cure meaning it changes none of the dynamic of an otherwise naked head gasket.
“The need to contain the power of reciprocating combustion will still exist for decades to come” gives me hope as a tech/ body shop mechanic. These motors will last a good while and someone needs to fix them!
the surface roughness conversion at 14:20 is off by 1000 - it looks like the um were treated as mm when calculating inches. As a side note, the SI unit mm should be written in lowercase.
eveything in this video is a far reach. This is just typical youtuber video for profit. Take a random topic and stretch it to the maximum, pretending head gasket is rocket science, that is quite ridiculous.
MMO oil additive truly does help lubricate the least lubricated but most important component in an engine, the piston rings! Sodium Silicate based head gasket sealers (blue devil) DO work when applied properly
@@OtherDalfite A huge problem is there is no direct oil contact on them other than secondary splashing from the crank shaft. Gunk naturally collects on the piston rings and seizes them. Many engines with blowby are permanently repaired with additives because the only problem was stuck rings. Additives are the only way to clean this.
@@termiterasin seems wild that there isn't. You'd think by now we'd have an oil passage just ever so lightly spraying/misting the bottom of the cylinder walls. But modern piston rings do run looser. It's part of the whole efficiency thing. My 2.4 ecotec has loose (not stuck) piston rings and they let oil by
This was very cool. On my air cooled VW's, it's generally agreed that you have to go in and re torque the head studs, since the sealing gasket is either copper, or simply cast iron on aluminum. Sealing torque is also only 18-21ft/lbs.
exactly the same torque and procedure for our older 2 stroke outboards:) service manual says to re-torque after 10 hrs of use, but i'm paranoid and do it after a heat cycle or 2, then 10 hrs after. i also use permatex 847 (just a tiny bit) around the fire ring surface to prevent the dreaded water intrusion. is that done with VW's/air cooled Porsche as well?
@@ct1762 Factory vw type 1 motors have no copper ring or sealer but some people add one, type 4 motors do have a copper ring. I'm not sure about the 6 cylinder Porsche motors I've never torn one apart. I haven't heard about the permatex sealer, usually you can see where there were leaking on teardown, and that's most often from other failures. Vanagon water cooled motors also have a copper ring and a very small o-ring for the combustion seal, and then a rubber seal around the perimeter for water sealing. Those have a bad rap but usually from corrosion that's coolant related.
@@curtislovrak5390 thanks Curtis great info. The 847 gasket adhesive was never recommended for outboards by the factory, but lots of guys use a tiny bit as the aluminum sealing surface for the cylinders is thin and all sorts of pitting/warpage tends to happen over time, especially with the heads themselves hence my curiosity about the equivalent with air cooled VW/Porsche. with outboards you get up to 30 psi of water pressure in the block, and i assume this can only increase the risk of water intrusion. the VW/Porsche motors seem to be more oil cooled than air cooled as they take what... 12 qts? at that volume and temp, it must act like a pure liquid so maybe additional sealing is necessary for vintage motors.
2:17 kg/cm² ist not a unit of pressure; kg represents mass not force. Use Pascal (Pa = N/m²) for pressure. Atmospheric pressure is around 100 kPa (~14.5 psi for non metric countries like Liberia). And check your calculation 1.5 bar may convert roughly into 20 psi, but 80 psi would be 6 bar not 50.6. 50 bar would be around 700 psi.
Wow, amazing job. Thanks for your effort to make this. One day I'm going to replace the headgasket on my Peugeot car. Fascinating to learn there has been so much engineering behind it.
I’ve always been told that connecting rod bolts are the single most highly stressed components in an internal combustion engine, in terms of pure mechanical stress over a given area / psi force through the component. Head gaskets have a tougher life overall but those combustion pressures are only exposed to a minuscule are of the head gasket when clamped properly.
oh thats a tricky one. I tend to think most of the force is experienced at or near TDC, meaning almost straight down onto the crank pins, and not laterally on the rod cap/screws. could be wrong and im sure they still experience thousands of PSI!
of course, you are on youtube and "creators" are up to anything to make profit, any ridiculous topic is widely streatched and sensationalized to the extreme for profit, even tho there is nothing special about head gaskets, a compression gasket can handle high pressure without much effort, it is not rocket science.
@@Nathan0A yes but the changing direction part would be the least stressful thing. the most would be the explosion of compressed fuel/air as it sends the piston down. the power stroke is what produces well...power.
I remember thinking "what a stupid component, why can't they make em better" after blowing a head gasket. I stand humbled by the mighty head gasket now
Head gasket replacement was my first diy, major engine repair. 18 years old, no idea what I was doing and terrified. But I was a young working man and paying $475 (in 1999) for a mechanic, vs $25 for a new gasket and fresh coolant was a no brainier. I had no help... There was no TH-cam or even a phone to watch it on lol. All I had was "the book" on my particular engine, Chevy inline 6, and a toolbox. 😁 After the 3 day struggle I not only understood how to change head gaskets but also had ascertained how to adjust valves and how rocker arms worked with pushrods and all that stuff. 👍 Lol I also learned to have sufficient antifreeze. 😊 It's funny how the head gasket can endure pressure and immense heat, but freezing water will quickly destroy one. Lucky that's all that happened.
My head gasket just blew on my 2005 Honda civic and it was not a fun time! A relatively expensive repair but this video is a good explanation of why it happened considering that it’s lasted all these years it was only a matter of time.
@@jayislander it’s a lot better! That was its most major of its issues. Still have a slight oil leak which I’m guessing is a VTech solenoid gasket due to the location. Shortly after getting my car back from the head gasket repair my car started revving weirdly and throwing codes so I used an OBD 2 reader and it was a cam positioning sensor that needed to be replaced. Other than that everything has been bulletproof. Thank you so much for checking in Jay :)
@@kmart625 that’s great hopefully you get everything fixed my headgasket also is bad just dropped it off yesterday waiting to get my vehicle back now watching some videos
Hi. Top notch video, thanks. It still pays today to recheck the torque on head bolts, even with modern "tighten-it-once" gaskets. I found that ensuring each bolt (or nut) ran freely on the thread with no trace of binding was the best way to get even clamping pressure over the whole head. A smear of H.T. grease on clean threads means the nuts don't seize after a few years of use. Copper was great because it only needed heat annealing to be used again. Cheers, PR.
noticed it aswell, also a pretty wacky unit, even as a metric user, it would make much more sense to use bar as a unit here. Or pascal as was done with the other pressures in the screen.
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@@owndampu1731 Yeah, we don't tend to use mass equivalents for forces and pressures. Newton and its derivatives is where it's at.
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@@owndampu1731 agree, bar would make more sense. He also made a mistake with temperature of the coolant at 2:55 - 140 degrees Celsius is not 220F, but something like 280F! - that's overheating!! :D
I would like to also nominate throw out bearing in manual transmission. It have to endure quite a lot of force and lots of cycles. Especially when sitting in traffic or at high revs. Plus no way to add lubricant after installation.
Also, thrust bearing. All that force the TOB has to handle has to push against something. So, don't ride the clutch sitting in traffic at idle with low oil pressure. It is annoying bouncing to neutral in traffic, but it's kinda important for a lot of reasons.
Hey bro, great video but some of your metric to freedom units conversations are off by a tad. Oil pressure early on (50.6kg/cm2), and then surface roughness about 2/3 through (80 though is 2mm not 2 micron)
Man ,it’s when they mess up these simple things then you start second guessing all the information and facts presented in the video. Hopefully OP knows the detrimental effects of these small mistakes.
I'd like to preface this with the fact that I am not a proffesional mechanic( never even touched a wrench before this job I have now) but I change oil, thats it. This was very useful to me as I always hear my coworkers letting the customer know 'hey, you have a head gasket leak'. Anyways this being the most common thing we see on arrival this was just very interesting.
This is a really interesting video so I hate to be a pedant, but there's loads of unit errors in here. You're inconsistently measuring pressure in Kg/cm^2 and Pascal (4:30), force in kgf rather than N (7:00), using the wrong capitalisation for milli and metres (14:10), rounding unit conversions with the wrong precision (12:20), using u rather than μ for micro and mistakenly using μm when you mean mm (14:20). It's difficult to follow your point through all of this.
Yeah, those micrometer to inch conversions are off by orders of magnitude, but it's the inch measure that's wrong. Those are millimeter equivalents, and a surface roughness of 1.5 to 2mm would be terrible. Interesting video anyways, but those need fixing.
Looked in the comments to see if anyone caught this too, The micron finish is correct, the imperial units should be corrected to 60-80 micro inches, which is a typical/industry standard roughness achieved from a finishing pass from milling.
Do you remember a while back when NASA lost a mars probe due to two teams working in completely different units? That's this video right now; I completely missed the errors. I can't really do much about it at this point without a complete re-upload.
An no mechanic electrical I understand have never seen before an explanation of head gaskets that live in motors (non mechanic here)..followed it and even down 2 how they are manufactured nice ....the micron tolerance rates as the pistons try to lift the bolts away under that amount of pressure ....next time I put key 2 ignition in my 4WD I will pause and think after watching this and yes I restarted and watched twice ,so much more lateral pressure in a diesel yes I paid attention but I digress I have been know 2 do that tk for the upload
@@angelgjr1999 Not really. Euro coolants are fairly similar, but are still different enough. Japanese coolant is still like the older Ford/universal specification. There's a rubber-softening polymer in Dexcool/Euro coolants that I wouldn't want in anything. I found it listed in the SDS some years ago.
@@angelgjr1999 There was a range of years where Ford and Chrysler were basically using Dexcool, but as their own branding/specs. It wasn't any individual engine, though.
There must be a graveyard somewhere of Mini head gaskets that is testament to your claim. I must have replaced at least a dozen on my Mini and my sister-in-law's in the space of a few years. Mini head gaskets were notorious for blowing due to the truly tiny web between pots 2 & 3! Apart from one, which was down to a different failure, ALL the ones I replaced went at exactly the same point. Until, that is, I was given a tip by a friend who rallied Minis and told me to use orange Hermetite as well as the gasket. Never had another one blow after that! 😎
Kind of feel the connecting rod is at least in the top 5. Personally would have given it the number 1 spot. It is a lever that is long, has to change vertical movement to horizonal rotation, and is usually under stress. It also bears the weight of uneven friction if the pistons want to not piston for any reason.
I had a plymouth acclaim, head went wompy and the gasket was able to keep the oil and coolent separate and it didn't let gasses out but it did burn about 1/2 gallon of coolent per oil change. I drove that car for years that way lol
It's the most "psychologically" stressed, with the most things to not screw up and lots of phones constantly ringing. The conrod just has to be a great powerlifter; having only one thing to concentrate on can be kinda relaxing if you're good at it 🤷🏻♂️
of course, its just your typical youtuber video, take a random topic, stretch it to the maximum for profit, serve hot to gullible "viewers". Reality is There is nothing special about head gaskets, any compression gasket can sustand high pressure, , the gasket does not get much stress at all considering how small the contact area is compare to cylinder heads for eaxmple. This video is just a big reach.
Please, PLEASE do a video on welding/brazing. It's a cornerstone of modern engineering with a rich history dating back to our discovery of metals, with major innovations in methodology and peripheral technology. It should be up there with the science of flatness and other machining techniques. There's a lot of molecular physics going on, creating structures that make good welds oftentimes stronger than the metal on the original part. There are also many unique aspects such as underwater welding and automated welding that can be covered
Toyota Camry is one of the most reliable cars on the planet. We have one identical to the one shown and it just keeps going and going, year after year, with maintenance of course. Love this series.
the most tortured part in a engine is definitely the oil. it gets whiplashed, burned and beaten till it has enough. when it has enough, you have to change it or it will get revenge and destroy your engine.
It's amazing to consider all the little things that go on right in front of your feet. Or in my case, as near as 4 inches from my right foot in my van. For anything to function properly, there has to be a long list of things with various degrees of acceptable tolerances, all happening hundreds to thousands of times per second. All in a meticulously orchestrated "dance" of fluids metals, composites, fire, electricity and so much more. It's a chain. Just one of those little things fail in even a small way, the entire thing suffers in performance or risks potential, permanent damage. A lot of young people think that their dad's, uncles, paps, or anyone else who preaches about vehicular maintenance, is just a blow-hard and likes to complain and worry. "Oh my oil was just changed last year! It can wait. - I' don't need to flush the coolant. My truck doesn't overheat. it's fine!" Sure, it's running fine, Now. But what they don't account for is those minute stresses,. forces and movements going on in their engines. It not just 4 to 8 chunks of metal bouncing around, and a spinny-ma-jig whirling around. No. As the host said, there is thermal expansion, temporary movements and many other unaccounted for actions going on outside of even the best of human eyes ability to perceive. So when dad says "Did you change your oil?" or "You may want to get a coolant flush." He's not nagging. he knows. It's called Maintenance. The car is a machine. Machines absolutely MUST have regular maintenance to operate properly. Any thing that slips, rubs, pivots, turns, or reciprocates, will eventually wear out. Proper maintenance can drastically prolong the life of those components. From the crankshaft bearings, right down to the hinges of the glove box. If it moves, keep it properly lubricated. Trust me, there are WAAAY more things moving in your car, than you think! So pay attention, read up on how things work. Put that cellphone to use, (NOT while driving!) and look up how-to's and other things about your car, instead of tick tocking and posting duck-lipped, or mindlessly screaming in vertical videos on isnta-scam.
Excellent comment. The more I learn about my vehicle the more I am amazed and neurotic about keeping on top of maintance, recording what and when something has been done
I've started my 1uz ls400 at negative temperature -30 with my foot flooring the gas. I'd say the timing components are more vulnerable or even piston rings and cylinder walls. The head gasket isn't really stressed when the torque force on the bolts are holding the head down are probably more stressed than the gasket.
I seen the title and automatically disagreed with it, finished the video and dont really have anything to disagree with. As a 20 year mechanic I hardly ever see head gasket failures these days, ingress due to the pretty amazing engineering. Building high performance engines we have to nail the details of the sealing surface, blocks and heads are a mirror finish, MLS headgaskets and arp headbolts usually does the trick. The main parts problems I see these days is running engines exponentially over there design capabilities and trying to pinch pennies and not replace every part inside the engine with the best stuff on the market. Right now I'm building a 60s engine that was originally 125 horsepower 7:1 compression and taking it to 500 horsepower 10:1 compression with 20 pounds a boost, not an easy feat. But feel like the head gasket is the least of my worries and rods and crank start becoming the weak point. Of course you can replace them with 1 off forged pieces, but where is the fun in that.
There is absolutely no way on earth that a 1960s engine designed for 125hp is going to handle 10:1 with 20psi, it'll snap the rods (and probably the crank) like a twig.
@@MattyEngland not my first rodeo. Plus it has been done by several people before. Cranks are very well designed and should hold quite a bit of power, I am pushing the limits of the rods but they have been worked over to be the best they can be. Should hold up fine, the boost controller is tunable, worst case scenerio.i turn the boost down with a knob and all is good. Also has knock sensors on it. And the pistons are some drastic amount lighter then the originals with much smaller lower friction rings. With a good set of rods people have been known to get 1k horsepower out of them. And I know well over 1k with a aftermarket crank. I have done alot of work to make sure it holds up.
@@townsendliving9750 They must have been the worlds most over engineered rods from the factory then lol....10:1@ 20psi gonna be some crazy cylinder pressures 😲 Best of luck. 👍
@@MattyEngland The over engineered rods are the modern ones. They know they'll bend like bananas at 200% of rated output power. Old stuff? Nah, just make it look like a conrod. If it breaks, we make it bigger.
I would argue to say that the head bolts are the parts under the most stress. Being under a mm thick and the small amount of surface area that's actually being subjected to the forces of combustion. The gasket in how it's designed is much stronger than the bolts that hold it together. The bolts are already under a lot of pressure at rest, then when you add heat, the head and block both expand. Which increases the pressure load on the bolts. And then when you accompany that with the pressure of combustion that are further trying to push on the bolts. Yes, the gaskets are exposed to more harmful conditions. But they're not under the most stress
The only exception is the MLS (multilayer steel) gaskets vs the aluminized cork style gasket. MLS gaskets will last at least double the life of the aluminized gasket. And in some cases, a MLS gaskets will outlast the bolts themselves
Its crazy how i understand all the scientific bits usually i would oversee all these numbers like the mega pascals or the anneling method, but because im currently studying engineering it just makes more sense and it starts to fit in. Thats pretty mind blowing
Bro i am not even 2 minutes in and this is already so cool. how've i never thought of the importance of the head gasket? I knew it, but its like one of those things that are designed so well you dont even think about it.
I still dont understand why the head gasket is needed. What happens if you dont use a headgasket and how does that happen chronological. Also if you would mold the whole engine head and box in one, would you need a head gasket?
▶ Visit brilliant.org/NewMind to get started learning STEM for free, and the first 200 people will get 20% off their annual premium subscription
I just spent the last week rebuilding my sisters Camaro that snapped a head bolt and blew the head gasket
I think your micron to inch conversion is off. 2.03 microns are equal to 0.0000799213" you may be using different notation, I just thought I would mention. It looks like it's saying .060" (as in close to 1/16th of an inch) when it is one thousand times smaller.
Backround music in the first minutes anyone?
Awesome video! :)))))
No dude, not in today's plastic engine components, the Ford EcoSport Fiesta Focus 1.0 GTDI EcoBoost Water Inlet Tube 2023617. This part sends coolant to head its 10mm ID thick and is a loose fit to the alloy cylinder head. This is much worse and fails long before the head gaskets, on average few months past the warranty date.
I have a 1976 Triumph Spitfire 1500 that the previous owner had ground the head down to increase the compression. It was so high that I couldn't get rid of the pinging with the highest gasoline available to me. I bought two stock head gaskets and I found some company that made me a copper one. I sandwiched the copper gasket in between the two stock ones ( I sprayed a copper sealer on them first) and bolted it down tight. That was around 25 years ago and it still purrs like a kitten.
I cringe every time I see a head gasket go on without being drowned in coppercoat
Add another head gasket and a blower lol.
Now that's amazing!
I hate to be that guy but I doubt it…
@@Lubbocksfinestwhats unbelievable about it?
Even as a former Subaru owner I never thought about head gaskets as being that high stress of an item, you've really out a whole new perspective onto things with this video for me
Makes me feel a bit better about dropping 3k replacing mine 😅
I see a subaru engine at 12:12 lol
Nothing blows a head gasket like an slightly tuned up boxer. I swear those engines eat head gaskets for breakfast
Hilariously I just diagnosed a buddies 2007 subbie legacy with failing head gaskets.
He gon learn in a few weeks just "how bad could it be?"
Ill make a car guy from him yet.
Or maybe he'll start maintaining his shizniz a bit more betterer.
Subaru should put spare head gaskets next to the spare tire.
Many years ago a co-worker asked me to take a look at the engine of a boat he bought cheap. The engine did not run and upon disassembly, I showed him the head gasket was completely worn out. Due to the cost of a gasket for an outboard motor, he wanted assurance that it was the only problem. He did not want to spend money on a new gasket to only find out the motor had other issues so I took some common gasket material and made a temp head gasket and reassembled the engine. It started and ran nicely.
He asked how long the temp gasket would work and I had no idea. It was the same type of material used for water pumps. I said, maybe a minute, maybe an hour. I really did not know. Just buy a proper gasket now that you know the engine is good. Well... he did not listen. That weekend he went to the lake and took off with his boat across to the farthest point when suddenly, the gasket failed. With no oars, he and his friends hand paddled the boat back. I laugh so hard when he told me what happened. 🤣🤣😁
How was he comfortable full sending on a busted head gasket? Ridiculous🤣🤣
@@furrycircuitry2378 Ridiculous is right! I would never have trusted it. Some people have to learn the hard way.
I loved head gaskets as a mechanic. Good flat rate hours, easy to do, virtually no come backs, and a steady supply of them coming in. Especially older composite head gaskets with an MLS replacement.
yeah, head gaskets are the same as engines now: obsolete
Surely they can be a bit of a headache when due to overheats? i.e. having to make sure the deck/head are not warped, I'm sure customers don't like to have to pay variable amounts when you can't accurately quote before the job the cost of sending parts to machine shop
Hey, I'm a future tech in training, any advice?
@@gamechip06 Ask more specific questions
@@gamechip06 start working on small engines. Take shit apart and put it back together
I work in healthcare and know next to nothing about engineering. I’m blown away by the complexities of mechanical engineering that are never learned by the average person who depends upon engineered machines in all aspects of life. Truly a joy to learn about these subjects.
The modern Internal Combustion Engine is a work of art unlike an electric motor.
@@MarkSmith-js2puwell, I'd say electric motors (at least brushless motors) are elegant due to their simplicity. Like Art or dresses, simplicity can be just as great as complexity. One is a physical marvel, the other an engineering marvel.
A minute of silence to those cars owners that got a call from their mechanic and ended up here to find out what a head gasket is
😣
Press F for Jay boys
@@kirilakmadjov8307 ?
I thought the belt tensioner was the most stressed part. Just look at it when it runs. Or try to, as you can barely see it.
@@satunnainenkatselija4478 belt tensioners are not internal parts so that may be why. Although some belt tensioners (like toyota) seem to last forever and i doubt as much engineering has gone into them either.
I have replaced several head gaskets in my short time working with combustion engines, and I never stopped to actually truly appreciate how well engineered these parts have to be in order to survive hundreds of thousands of miles on the road. Thank you for this video! This has really given me a new perspective on a part of an engine that most people don't even know exists!
head gaskets are one of those things that people don't know exist until they are abruptly made aware of their existence
^ me a year ago. I now understand how to fully disassemble & re-assemble a Mitsubishi 3000gt. Dude wanted 3k to fix so I bought more tools instead 😂
Engineering is really really fascinating, the small things we take for granted in everyday life that came from decades of research and trial and error, fantastic content!
We stand on the shoulders of giants
Dude this channel is like a modern day "Modern Marvels" no BS just easy to understand and straight to the point explanations for very complex and complicated concepts. This channel has answered certain engineering, mechanica,l and material-science questions I've had for years answered within 20 minutes.
In 2005/2006 we were trying to build the 1st 1000whp e36 328 (m52 engine) The toughest/most aggravating part of the build was getting the headgasket to seal under high boost. Around 17psi the gasket would blow out in between cylinders. One reason why we went with the 2.8L m52 instead of the 3.2L s52 from the m3, m52 has a bore of 84mm and s52 is 86.4mm. Those extra mm's made all the difference. Even with the extra material we still o-ringed the block n head. That was the trick that put us for ahead of the competition and helped us have the world's 1st 1000whp m52. Also 1st in the 9s while still having full interior, heated seats and ac.Havnt been back to the track ever since we got kicked out and told we need a parachute lol. 16 years later and only like 2 others have made that much power. Truly were miles ahead of the competition.
TMS here in Stamford had a 1100 whp e36 m3 years ago. did see the car in person but never saw it on the dyno so not sure if that was accurate but it was a beast.
I have built many supercharged and high compression engines. I have always used plain soft copper with aviation quality sealer sprayed on both surfaces. It works far better than 90% of the "for boosted engine" commercially available gasket solutions.
Pretty crazy that you can make similar power on stock S58 these days.
@@borderwave2 made 715whp on the stock m52 in 2005. This was before e85 and the tuning options available today. Built 25 years later and specifically for boost is still barely better.
@@shifty1927 That's very impressive for a stock NA motor.
This was very interesting! Great timing I'm rebuilding an engine for my truck at this very moment.
Thanks! Haha, same! Doing my 4Runner 1/4 million mile service
Same nissan navara d22 😂
@@NewMind crazy! Is that how you had the idea to do the head gasket video?
Absolutely! I was impressed by the 22 years I got on the factory head gasket. What are you rebuilding?
@@NewMind ahh.. 20 years that's good. Finally got back going again and continuing where I left off with the jet powered go-kart. I built everything and then I realized that the engine in my truck was blown. So I had to interrupt everything to rebuild the engine I have 4 broken main bearing bolts in the block now and 3 broken exhaust bolts in the head. Seems that for some reason the engine spun a bearing and has 1 bent valve, weird, only has 40,000 mi
There's a reason TH-cam is still relevant today and it's because creators like you. Another great video!
I love how something so simple can become a fascinating video and something that I don't think I've ever really seen anyone else on TH-cam address like this. Can't wait to start sharing this with friends.
I work in heavy truck parts sales, and all of our parts are BIG, including head gaskets. We have a regular customer who constantly questioned the price of absolutely everything he'd try to buy from us. One day he came in looking for a head gasket for a Paccar MX-13, of course he was quite shocked at the $350+ price tag, but I told him we don't carry aftermarket options. So I went to go get the part, and when I came back, sure as hell he asked me "what does this part do anyway?"
I was actually too stunned to speak...not because he didn't know what it does but because he was questioning me on price WITHOUT knowing what it does. I had to educate the guy on its function but to this day I was genuinely stunned that the owner of this truck, did not know what the part was, why it was important, and why it's so expensive. Don't friggin question me on the price of a part when you don't even know why it is probably the most important part of your truck you DUMB WALNUT.
This video reminded me of that incident, tis a great vid.
I have only recently come to appreciate how critical this simple-looking component is to the efficient working of an engine. I have done two replacements already and looking to do another one later today and now I appreciate the precision engineering that has to be applied to keep compression, oil and coolant separate and contained.
Good video. No jokes, no annoying voice, no obnoxious music, no unnecessary cringe. Thank you.
People in comments tho get back with dumbest joke of them all... Subaru + Headgasket = humour.....
EXCELLENT VIDEO!
Me, ASE Certified Master Engine machinist for over 30 years. I have been working in the engine rebuilding industry for 55 years. Had my own shop for 20 which included a Comec wet surface grinder capable of accuracy of .001 per 12" of length which is what we used to surface both the heads and blocks.
Back when I opened my engine shop in 1978, we saw a lot of Honda 1200 and Chevy Vega engines with blown head gaskets. The Honda was all aluminum while the Vega was Aluminum block and cast-iron head. Both used the "open deck" type of block. Both were composition gaskets "squishing" about .007-.008 when torqued. My thoughts were that the cylinders were "moving", and the gasket was not adequately being compressed on the cylinders.
My solution was after machining the gasket surface of the block flat, I then went around the outer edge of the block and machined an additional .001-.0015. That resulted in the cylinders "standing proud" .001 compared to the edge of the block for a tighter clamp on the fire ring. This really helped the durability of the gaskets.
But they still needed retorquing which in the case of the Honda meant removal of the rocker arm assembly since it sat over the head bolts, UGH!
About this same time a LARGE gasket company (FP) announced their no-retorque head gaskets! We were jumping for joy thinking of all the time they would save and started installing them on our engines right away. Within WEEKS we started seeing problems! These engines started spitting out head gaskets some in as few as a couple of thousand miles! The VWs in particular would come back with actual pieces of the gasket hanging out from the edges of the head! We stopped using them and went back to OE type gaskets and the problems ended.
The company asked me to send them back so I sent 1 of each, Honda, Toyota and VW. They called me and said they would warranty the gaskets. I said that was OK but did they want me to send them the REST of the failed gaskets we had? "How many more do you have?". I told them 32, SILENCE. Then he said "let me talk to someone". Another voice on the phone "Is there a major airport near you?" yes "A couple of reps are going to fly to your shop and see if we can tell what's happening".
The next day the VP and head of Tech arrived at my shop. After examining my machines and procedures they could find nothing I was doing wrong and said they felt it was the area WATER that was the cause!. I was stunned but before I could open my mouth he said "BUT, we are prepared to offer to pay you parts & LABOR for all the failed gaskets PROVIDED you sign a release form and will make NO further claims against us. It was a LARGE CHECK so I took the offer.
They must have sold a LOT of those gaskets, we continued to see failures of them that others had installed for YEARS after that!
What do you mean claims?
Anyways very cool information. Have any other similar stories for other engine parts to non car layman like myself?
I figured gaskets were an easy piece. Doesn't look too complicated. Love learning about the intricacies although I'll be never use the information. Don't even have a car haha.
))) id be pissed if my newly rebuilt engine blew again
Bro. If you denied the money and made your own you could’ve owned a multi million dollar business by now.
Rule of thumb never take the check
@@nokturnal6146 I don't understand. Are you suggesting he could have invented better Head gaskets himself?
Blown head gasket is still the most common engine failure you hear from people to this day, at least here. Unless you really mistreat your engine it's fairly unusual for any of the mechanical parts to fail.
I've only had one engine fail really badly (i melted 3 of the 4 pistons), because I kept running it for over 100,000km with a blown turbo seal - it would lose oil pressure at idle, but as soon as you revved over 1000rpm the warning disappeared. Eventually it gave way completely, sucked all the oil through the intake, and I ran it dry at 200km/h until it cooked itself to death.
The oil light never came on and coolant temp. was normal, I only noticed something was wrong because I tried accelerating and it was not responding. I stopped as soon as possible (less than 1km) but by that time when I opened the hood the turbo was glowing _orange._
After refilling with oil I still managed to turn it back on and drive 20km to the mechanic, surrounded by a cloud of oil.
Absolute tank that engine.
For 100,000 km? What car was that lmao
I had an oil Opel Astra F that we cracked the oil pan on when driving on a dirt road. Figured we'll just send it and try to go home - we drove like 15 kilometers and we were like 4 kilometers away from home before it gave in. I just saw a glowing red metal thingy fly away in my rear view mirror. Probably a connecting rod. Tried to find it but it was impossible. Looking back at it now, I wonder how that thing didn't cause a fire since it probably landed in grass. Well, the thing was a beater anyway and we already burnt the clutch a bit when trying to do burnouts so we were already somewhat detached from it. It took quite a beating from us tho lol
Then we moved on to a Fiat Bravo HGT, which ended up with a.... you guessed it... blown head gasket. The thing was the most fun car I'll probably ever have though!
@@tabushka292 '97 Audi A4 B5, it had around 250,000km when I bought it and 356,000 when it blew.
It wasn't dry the whole time though just to be clear lmao, it did use a bit of oil but not _that_ much. It leaked just enough oil through the turbo that after 15-20s at idle the low oil pressure warning would come on.
Imagine someone asking that question to this guy at a bar and then he drops this
imagine asking that question and the guy blows a head gasket and dies 😆
Oof that's hard to replace
Hats off to you my friend, what a great series so far. Can't wait to see what else you do.
This explains a lot. If you had a Ford 3.8L V6 in the mid 80s to late 90s, it was virtually guaranteed to blow head gaskets. This problem was virtually eliminated in 99 when Ford started using the MLS head gasket for this engine, which you can now turbocharge in stock form up to around 420 hp with no reliability issues.
I had read of the MLS gasket many times but never really understood the history until now.
I have a 97 thunderbird with that engine that has a blown head gasket.
@@ihadlunch8575 Well you know what to do! Repair that pushrod baby and put them MLS gaskets in there!
It being pre-99 you might be able to put the supercharger on it that came stock on the SC Birds. 👍
Great video! One problem, in the first half of the video with the diagram of the head gasket the oil galleys and water ports are switched with eachother, since the coolant will need to be taking heat from around the cylinders and the oil usually just drips back through the head gasket down to the block
Galleries not galleys. 😵
@@bat__bat No, it's definitely not "galleries." That's where you keep artwork.
@jacobnelson2480 Surprisingly.. if you were to find parts in relation to them, they will all be labeled as "oil galley ___". While I agree gallery is the better choice, it seems that it is a galley for some bizarre reason.
Through my few years of school and experience I have always known them to be Galleys, but to each their own. I don't plan to change as that is always how I've known it, and this is what I do as a career.
Bugged me he used kilograms per square centimetre as a unit of pressure for half the video (nobody at all used that that I'm aware of) then switched to pascals for the last half which is at least SI and actually used.
Oil pressure should have been up to 5,5 bar, not 50. The convertion from imperial went wrong
First time ive ever seen your channel (im gonna rant for a sec forgive me my autocorrect doesnt work).
Im a Hino Master tech, working on detroit side of Feeightliner (and I might as well be for Volvo) and man I gotta tell you not only did I learn something I learned lots of things. Im amazed by you. .
Instantly subbed. Your vid got me going.
Especially in mixed alloy head and block combinations... The thermodynamic coefficient of expansion rate differences are absolutely punishing...
Yes, they covered this at 6:50.
Reminds me of my mom's Chevy Lumina!
@@orangejjay to be fair the video kinda understated the problem. Like yes it was mentioned, but it's a hell of a problem.
The most highly stressed component in a race car is the nut that holds the steering wheel!
😂
This was really fun. I have installed a lot of head gaskets over the years and have seen many of the designs shown. I hadn't thought about it at the time but I could definitely tell how things progressed over the years. Thanks for the excellent video!
As a recent graduate from a Automotive Technology program, I think this video would be a really good reference and history for in-class use. great job!
Your initial list of requirements doesn't include "cost" even though it is a primary driver in most engineering decisions (as seen in the rest of the video). I was wondering why they didn't get around to using crushable aluminum gaskets, but by the end of the video, the copper ones basically fill that niche.
One thing I would like to add about head lift and the use of a gasket - The gasket is compressed during installation, so even during extreme cases of head lift (0.001") there should be no separation occurring between the three components.
Shout-out to all the head gaskets out there, we know your under a lot of pressure!
Love this channel. People don't consider edge cases and failure points in systems often enough.
this video is just your typical "youtuber" reach, there is nothing special about head gaskets, any compression gasket can sustand high pressure with no effort.
@@lo2740what about high temperature, high pressure, oil, water, temperature gradient, mechanical stress while maintanimg an almost perfect seal?
7:48 cooper is annealed when cooled fast, not slowly (it's the opposite of steel)
There's lots of little wrong things like this in the video, those are just in the parts of it that I knew. Makes me wonder what wrong things were in the parts I didn't know.
Learned something completely new AND PRACTICAL/APPLICABLE. Thank you newmind
For those curious, there is a major improvement to typical head gasket design, called "O ring," which places a steel ring in a groove shared by the block and head, and crushing a copper gasket between the two. This creates a much stronger seal, at the cost of a bit of engineering and of course the material cost of copper. This is what many drag cars use, and with it you're more likely to pull the studs out of the block or bend a rod than blow through it.
Very well put together and informative video, though! I enjoyed watching.
That was covered in the video at 16:30
Watch the video dude
I remember when I was young a lot of cars used to have the head gasket problem even without overheating or any issue, I wondered why I stopped hearing anyone have problem these days, thanks for the rich informative video
I remember replacing my first head gasket. Didn't know you had to turn them an additional 180 degrees after torquing. I found out after a few months...
Vintage Ferrari mechanic here. Old aluminum Italian engines, especially V12, really like to move around a bit. Using permatex Aviation Sealant ALL over the head gasket does the trick better than anything I’ve used. It does not ever fully cure meaning it changes none of the dynamic of an otherwise naked head gasket.
“The need to contain the power of reciprocating combustion will still exist for decades to come” gives me hope as a tech/ body shop mechanic. These motors will last a good while and someone needs to fix them!
the surface roughness conversion at 14:20 is off by 1000 - it looks like the um were treated as mm when calculating inches.
As a side note, the SI unit mm should be written in lowercase.
eveything in this video is a far reach. This is just typical youtuber video for profit. Take a random topic and stretch it to the maximum, pretending head gasket is rocket science, that is quite ridiculous.
MMO oil additive truly does help lubricate the least lubricated but most important component in an engine, the piston rings! Sodium Silicate based head gasket sealers (blue devil) DO work when applied properly
Modern piston rings usually run fairly loose compared to historical engines
@@OtherDalfite A huge problem is there is no direct oil contact on them other than secondary splashing from the crank shaft. Gunk naturally collects on the piston rings and seizes them. Many engines with blowby are permanently repaired with additives because the only problem was stuck rings. Additives are the only way to clean this.
@@termiterasin seems wild that there isn't. You'd think by now we'd have an oil passage just ever so lightly spraying/misting the bottom of the cylinder walls.
But modern piston rings do run looser. It's part of the whole efficiency thing. My 2.4 ecotec has loose (not stuck) piston rings and they let oil by
Engineering is so cool. There isn't a single person in the world that can actually dislike that.
This was very cool. On my air cooled VW's, it's generally agreed that you have to go in and re torque the head studs, since the sealing gasket is either copper, or simply cast iron on aluminum. Sealing torque is also only 18-21ft/lbs.
exactly the same torque and procedure for our older 2 stroke outboards:) service manual says to re-torque after 10 hrs of use, but i'm paranoid and do it after a heat cycle or 2, then 10 hrs after. i also use permatex 847 (just a tiny bit) around the fire ring surface to prevent the dreaded water intrusion. is that done with VW's/air cooled Porsche as well?
yes sir that is the way to do it
@@ct1762 Factory vw type 1 motors have no copper ring or sealer but some people add one, type 4 motors do have a copper ring. I'm not sure about the 6 cylinder Porsche motors I've never torn one apart. I haven't heard about the permatex sealer, usually you can see where there were leaking on teardown, and that's most often from other failures. Vanagon water cooled motors also have a copper ring and a very small o-ring for the combustion seal, and then a rubber seal around the perimeter for water sealing. Those have a bad rap but usually from corrosion that's coolant related.
@@curtislovrak5390 thanks Curtis great info. The 847 gasket adhesive was never recommended for outboards by the factory, but lots of guys use a tiny bit as the aluminum sealing surface for the cylinders is thin and all sorts of pitting/warpage tends to happen over time, especially with the heads themselves hence my curiosity about the equivalent with air cooled VW/Porsche. with outboards you get up to 30 psi of water pressure in the block, and i assume this can only increase the risk of water intrusion. the VW/Porsche motors seem to be more oil cooled than air cooled as they take what... 12 qts? at that volume and temp, it must act like a pure liquid so maybe additional sealing is necessary for vintage motors.
@@curtislovrak5390 Older 40HP bugs had copper sealing rings around where the cylinders met the heads I think as a form of secondary seal
There's a reason for this channel growing over 100K subs a year. It's been my favorite for over 4 years now. Thanks for sharing this great info.
2:17 kg/cm² ist not a unit of pressure; kg represents mass not force. Use Pascal (Pa = N/m²) for pressure. Atmospheric pressure is around 100 kPa (~14.5 psi for non metric countries like Liberia). And check your calculation 1.5 bar may convert roughly into 20 psi, but 80 psi would be 6 bar not 50.6. 50 bar would be around 700 psi.
kgf/cm² (kp/cm²) is. But yes, just use Pascal or Bar.
Wow, amazing job. Thanks for your effort to make this. One day I'm going to replace the headgasket on my Peugeot car. Fascinating to learn there has been so much engineering behind it.
I’ve always been told that connecting rod bolts are the single most highly stressed components in an internal combustion engine, in terms of pure mechanical stress over a given area / psi force through the component. Head gaskets have a tougher life overall but those combustion pressures are only exposed to a minuscule are of the head gasket when clamped properly.
Yeah, this video is a reach. Can’t blame people for trying to make money tho. It’s still pretty cool
oh thats a tricky one. I tend to think most of the force is experienced at or near TDC, meaning almost straight down onto the crank pins, and not laterally on the rod cap/screws. could be wrong and im sure they still experience thousands of PSI!
of course, you are on youtube and "creators" are up to anything to make profit, any ridiculous topic is widely streatched and sensationalized to the extreme for profit, even tho there is nothing special about head gaskets, a compression gasket can handle high pressure without much effort, it is not rocket science.
@@ct1762 the inertia of the piston/rod assembly changing directions after TDC pulls on the bottom half of the rod cap through the rod bolts
@@Nathan0A yes but the changing direction part would be the least stressful thing. the most would be the explosion of compressed fuel/air as it sends the piston down. the power stroke is what produces well...power.
This video inspired me to change my headgaskets! Seriously though, you have a new subscriber.
I remember thinking "what a stupid component, why can't they make em better" after blowing a head gasket.
I stand humbled by the mighty head gasket now
Head gasket replacement was my first diy, major engine repair. 18 years old, no idea what I was doing and terrified. But I was a young working man and paying $475 (in 1999) for a mechanic, vs $25 for a new gasket and fresh coolant was a no brainier. I had no help... There was no TH-cam or even a phone to watch it on lol. All I had was "the book" on my particular engine, Chevy inline 6, and a toolbox.
😁 After the 3 day struggle I not only understood how to change head gaskets but also had ascertained how to adjust valves and how rocker arms worked with pushrods and all that stuff. 👍
Lol I also learned to have sufficient antifreeze. 😊 It's funny how the head gasket can endure pressure and immense heat, but freezing water will quickly destroy one. Lucky that's all that happened.
My head gasket just blew on my 2005 Honda civic and it was not a fun time! A relatively expensive repair but this video is a good explanation of why it happened considering that it’s lasted all these years it was only a matter of time.
How is it now
@@jayislander it’s a lot better! That was its most major of its issues. Still have a slight oil leak which I’m guessing is a VTech solenoid gasket due to the location. Shortly after getting my car back from the head gasket repair my car started revving weirdly and throwing codes so I used an OBD 2 reader and it was a cam positioning sensor that needed to be replaced. Other than that everything has been bulletproof. Thank you so much for checking in Jay :)
@@kmart625 that’s great hopefully you get everything fixed my headgasket also is bad just dropped it off yesterday waiting to get my vehicle back now watching some videos
Hi. Top notch video, thanks. It still pays today to recheck the torque on head bolts, even with modern "tighten-it-once" gaskets. I found that ensuring each bolt (or nut) ran freely on the thread with no trace of binding was the best way to get even clamping pressure over the whole head. A smear of H.T. grease on clean threads means the nuts don't seize after a few years of use. Copper was great because it only needed heat annealing to be used again. Cheers, PR.
2:19 fairly certain you meant 5.6 kg/cm², not 50.6, since that's what would actually correspond to the given 80 PSI equivalent conversion
More likely he dropped a zero and he meant 800 PSI
@@jaimepuig2258 hard to be certain, another possible explanation for sure though...that just seems like an implausibly huge range!
Informative! I'd always thought piston rings and exhaust valves were the most punished parts.
I discovered a mistake in the video: At 3:11, it should have said " 1.4 - *5.6* kg/cm^2 " instead of " 1.4 - 50.6 ".
noticed it aswell, also a pretty wacky unit, even as a metric user, it would make much more sense to use bar as a unit here. Or pascal as was done with the other pressures in the screen.
@@owndampu1731 Yeah, we don't tend to use mass equivalents for forces and pressures. Newton and its derivatives is where it's at.
@@owndampu1731 agree, bar would make more sense. He also made a mistake with temperature of the coolant at 2:55 - 140 degrees Celsius is not 220F, but something like 280F! - that's overheating!! :D
Isn't copper annealed when it's heated and cooled quickly(like in water),annealing and hardening is revers as steel.
I would like to also nominate throw out bearing in manual transmission. It have to endure quite a lot of force and lots of cycles. Especially when sitting in traffic or at high revs. Plus no way to add lubricant after installation.
Also, thrust bearing. All that force the TOB has to handle has to push against something.
So, don't ride the clutch sitting in traffic at idle with low oil pressure. It is annoying bouncing to neutral in traffic, but it's kinda important for a lot of reasons.
This was extremely informative and entertaining. I can't imagine how long it took for you to put it together. Subbed!!
What about piston rings? We've come a long way since the original hemp packing in steam engines.
Hey bro, great video but some of your metric to freedom units conversations are off by a tad. Oil pressure early on (50.6kg/cm2), and then surface roughness about 2/3 through (80 though is 2mm not 2 micron)
You definitely missed a lot of zeros when converting microns to inches on your ra values. 1.5 um (0.0015 mm) is 0.00006 inches, not 0.06"
#mathgod can you tutor me
I thought that seemed a little off too
Also, 80 PSI is ~5.6 kg/cm2, not 56 (as presented at 2:47).
Man ,it’s when they mess up these simple things then you start second guessing all the information and facts presented in the video. Hopefully OP knows the detrimental effects of these small mistakes.
@@ytf7608
Temperatures were also off at one point, when 135 deg C is 275 deg F, but 140 dec C is somehow 220 deg F. lol
Great video nonetheless.
I'd like to preface this with the fact that I am not a proffesional mechanic( never even touched a wrench before this job I have now) but I change oil, thats it. This was very useful to me as I always hear my coworkers letting the customer know 'hey, you have a head gasket leak'. Anyways this being the most common thing we see on arrival this was just very interesting.
This is a really interesting video so I hate to be a pedant, but there's loads of unit errors in here. You're inconsistently measuring pressure in Kg/cm^2 and Pascal (4:30), force in kgf rather than N (7:00), using the wrong capitalisation for milli and metres (14:10), rounding unit conversions with the wrong precision (12:20), using u rather than μ for micro and mistakenly using μm when you mean mm (14:20). It's difficult to follow your point through all of this.
at 14:20 He's talking about surface roughness which is always in μm and never in mm in the automotive industry. it's the honing tolerance.
Yeah, those micrometer to inch conversions are off by orders of magnitude, but it's the inch measure that's wrong. Those are millimeter equivalents, and a surface roughness of 1.5 to 2mm would be terrible.
Interesting video anyways, but those need fixing.
Looked in the comments to see if anyone caught this too,
The micron finish is correct, the imperial units should be corrected to 60-80 micro inches, which is a typical/industry standard roughness achieved from a finishing pass from milling.
Do you remember a while back when NASA lost a mars probe due to two teams working in completely different units? That's this video right now; I completely missed the errors. I can't really do much about it at this point without a complete re-upload.
An no mechanic electrical I understand have never seen before an explanation of head gaskets that live in motors (non mechanic here)..followed it and even down 2 how they are manufactured nice ....the micron tolerance rates as the pistons try to lift the bolts away under that amount of pressure ....next time I put key 2 ignition in my 4WD I will pause and think after watching this and yes I restarted and watched twice ,so much more lateral pressure in a diesel yes I paid attention but I digress I have been know 2 do that tk for the upload
3:04 you got engine coolant and oil mixed up but I mean it's the same idea
There's nothing more scary to car owners than hearing the phrase: "We have to replace the head gasket"
Ouch, thats $4000
I remember hearing that GM developed Dexcool instead of reengineering their head gaskets, as it can still act as coolant even with oil present.
That's a pretty nifty "cutting the knot" idea
Is dexcool compatible with all cars? I’ve seen it before, didn’t know what it was.
@@angelgjr1999 Not really. Euro coolants are fairly similar, but are still different enough. Japanese coolant is still like the older Ford/universal specification.
There's a rubber-softening polymer in Dexcool/Euro coolants that I wouldn't want in anything. I found it listed in the SDS some years ago.
@@veleriphon Is it compatible with ford 4.6?
@@angelgjr1999 There was a range of years where Ford and Chrysler were basically using Dexcool, but as their own branding/specs. It wasn't any individual engine, though.
There must be a graveyard somewhere of Mini head gaskets that is testament to your claim. I must have replaced at least a dozen on my Mini and my sister-in-law's in the space of a few years.
Mini head gaskets were notorious for blowing due to the truly tiny web between pots 2 & 3! Apart from one, which was down to a different failure, ALL the ones I replaced went at exactly the same point. Until, that is, I was given a tip by a friend who rallied Minis and told me to use orange Hermetite as well as the gasket. Never had another one blow after that! 😎
The man is the head gasket of the family. Tough, serves many purposes and exposed to unfathomable stresses.
true
Outstanding video. Great work @new mind #how2wrench fans will love this, so we added it to our playlists "just plain cool". TY
It always amazes me how flimsy head gaskets are, especially when you feel how heavy the cylinder head and block are.
I loved and learned so much from your video!
Kind of feel the connecting rod is at least in the top 5. Personally would have given it the number 1 spot. It is a lever that is long, has to change vertical movement to horizonal rotation, and is usually under stress. It also bears the weight of uneven friction if the pistons want to not piston for any reason.
Top of piston pretty stressed as well
And rod bearings, the whole valvetrain in push rod engines, etc etc
Why do I need Brilliant when there are youtubers like you?
50kg/sq cm is 711 psi, not 80
I just discovered this page today. I love the smell of newly discovered TH-cam page in the morning!
Subaru has left the chat…
I had a plymouth acclaim, head went wompy and the gasket was able to keep the oil and coolent separate and it didn't let gasses out but it did burn about 1/2 gallon of coolent per oil change. I drove that car for years that way lol
The conrod, hands down the most tortured part. The headgasket has more then one function, but its not the most stressed part by far.
It's the most "psychologically" stressed, with the most things to not screw up and lots of phones constantly ringing.
The conrod just has to be a great powerlifter; having only one thing to concentrate on can be kinda relaxing if you're good at it
🤷🏻♂️
I guess the conrods can be easily engineered with physical capabilities to endure the stress they undergo.
you spelled compression rings wrong
of course, its just your typical youtuber video, take a random topic, stretch it to the maximum for profit, serve hot to gullible "viewers". Reality is There is nothing special about head gaskets, any compression gasket can sustand high pressure, , the gasket does not get much stress at all considering how small the contact area is compare to cylinder heads for eaxmple. This video is just a big reach.
Please, PLEASE do a video on welding/brazing. It's a cornerstone of modern engineering with a rich history dating back to our discovery of metals, with major innovations in methodology and peripheral technology. It should be up there with the science of flatness and other machining techniques. There's a lot of molecular physics going on, creating structures that make good welds oftentimes stronger than the metal on the original part.
There are also many unique aspects such as underwater welding and automated welding that can be covered
Toyota Camry is one of the most reliable cars on the planet. We have one identical to the one shown and it just keeps going and going, year after year, with maintenance of course.
Love this series.
Misspoke at 2:56 - 140c is about 285f, not 220f.
The most tortured part of engines are the piston rings in my opinion.
Exhaust valves..
the most tortured part in a engine is definitely the oil. it gets whiplashed, burned and beaten till it has enough. when it has enough, you have to change it or it will get revenge and destroy your engine.
That’s not a part
@@skylerstone7885 Its a liquid part
It's amazing to consider all the little things that go on right in front of your feet. Or in my case, as near as 4 inches from my right foot in my van. For anything to function properly, there has to be a long list of things with various degrees of acceptable tolerances, all happening hundreds to thousands of times per second. All in a meticulously orchestrated "dance" of fluids metals, composites, fire, electricity and so much more. It's a chain. Just one of those little things fail in even a small way, the entire thing suffers in performance or risks potential, permanent damage.
A lot of young people think that their dad's, uncles, paps, or anyone else who preaches about vehicular maintenance, is just a blow-hard and likes to complain and worry. "Oh my oil was just changed last year! It can wait. - I' don't need to flush the coolant. My truck doesn't overheat. it's fine!" Sure, it's running fine, Now. But what they don't account for is those minute stresses,. forces and movements going on in their engines. It not just 4 to 8 chunks of metal bouncing around, and a spinny-ma-jig whirling around. No. As the host said, there is thermal expansion, temporary movements and many other unaccounted for actions going on outside of even the best of human eyes ability to perceive.
So when dad says "Did you change your oil?" or "You may want to get a coolant flush." He's not nagging. he knows. It's called Maintenance.
The car is a machine. Machines absolutely MUST have regular maintenance to operate properly. Any thing that slips, rubs, pivots, turns, or reciprocates, will eventually wear out. Proper maintenance can drastically prolong the life of those components. From the crankshaft bearings, right down to the hinges of the glove box. If it moves, keep it properly lubricated. Trust me, there are WAAAY more things moving in your car, than you think! So pay attention, read up on how things work. Put that cellphone to use, (NOT while driving!) and look up how-to's and other things about your car, instead of tick tocking and posting duck-lipped, or mindlessly screaming in vertical videos on isnta-scam.
Excellent comment. The more I learn about my vehicle the more I am amazed and neurotic about keeping on top of maintance, recording what and when something has been done
I've started my 1uz ls400 at negative temperature -30 with my foot flooring the gas. I'd say the timing components are more vulnerable or even piston rings and cylinder walls. The head gasket isn't really stressed when the torque force on the bolts are holding the head down are probably more stressed than the gasket.
I agree the headbolts are whats getting the stress and what stretches. The gasket is just smashed under the head.
@@xxxxxxxx183 Hence studded heads for higher compression cars.
I seen the title and automatically disagreed with it, finished the video and dont really have anything to disagree with. As a 20 year mechanic I hardly ever see head gasket failures these days, ingress due to the pretty amazing engineering. Building high performance engines we have to nail the details of the sealing surface, blocks and heads are a mirror finish, MLS headgaskets and arp headbolts usually does the trick. The main parts problems I see these days is running engines exponentially over there design capabilities and trying to pinch pennies and not replace every part inside the engine with the best stuff on the market. Right now I'm building a 60s engine that was originally 125 horsepower 7:1 compression and taking it to 500 horsepower 10:1 compression with 20 pounds a boost, not an easy feat. But feel like the head gasket is the least of my worries and rods and crank start becoming the weak point. Of course you can replace them with 1 off forged pieces, but where is the fun in that.
There is absolutely no way on earth that a 1960s engine designed for 125hp is going to handle 10:1 with 20psi, it'll snap the rods (and probably the crank) like a twig.
@@MattyEngland not my first rodeo. Plus it has been done by several people before. Cranks are very well designed and should hold quite a bit of power, I am pushing the limits of the rods but they have been worked over to be the best they can be. Should hold up fine, the boost controller is tunable, worst case scenerio.i turn the boost down with a knob and all is good. Also has knock sensors on it. And the pistons are some drastic amount lighter then the originals with much smaller lower friction rings. With a good set of rods people have been known to get 1k horsepower out of them. And I know well over 1k with a aftermarket crank. I have done alot of work to make sure it holds up.
@@townsendliving9750 They must have been the worlds most over engineered rods from the factory then lol....10:1@ 20psi gonna be some crazy cylinder pressures 😲 Best of luck. 👍
@@MattyEngland The over engineered rods are the modern ones. They know they'll bend like bananas at 200% of rated output power.
Old stuff? Nah, just make it look like a conrod. If it breaks, we make it bigger.
I would argue to say that the head bolts are the parts under the most stress. Being under a mm thick and the small amount of surface area that's actually being subjected to the forces of combustion. The gasket in how it's designed is much stronger than the bolts that hold it together. The bolts are already under a lot of pressure at rest, then when you add heat, the head and block both expand. Which increases the pressure load on the bolts. And then when you accompany that with the pressure of combustion that are further trying to push on the bolts. Yes, the gaskets are exposed to more harmful conditions. But they're not under the most stress
The only exception is the MLS (multilayer steel) gaskets vs the aluminized cork style gasket. MLS gaskets will last at least double the life of the aluminized gasket. And in some cases, a MLS gaskets will outlast the bolts themselves
Seeing kg/cm² being used a unit of pressure made me die inside.
Gotta love the Metric system my 👶.
@@anim8dideas849 not sure if joking actually.
Sittin here watching this with my Landcruiser like "see boy? It's not your fault! It happens often!"
any British manufactured car always has garbage head gaskets and transmissions.
There there, just blame volkswagen it's ok now
Its crazy how i understand all the scientific bits usually i would oversee all these numbers like the mega pascals or the anneling method, but because im currently studying engineering it just makes more sense and it starts to fit in. Thats pretty mind blowing
Really well put together presentation. Nice job.
Bro i am not even 2 minutes in and this is already so cool. how've i never thought of the importance of the head gasket? I knew it, but its like one of those things that are designed so well you dont even think about it.
Just fyi the micron to inch conversion was substantially off. Great video
When my wife drives, the most stressed part would be the clutch.
And my ears when she screams back
I still dont understand why the head gasket is needed. What happens if you dont use a headgasket and how does that happen chronological. Also if you would mold the whole engine head and box in one, would you need a head gasket?
This channel is criminally underrated!
A lot of modern engines produced by Honda and Toyota have high compression ratios. That must make the importance of head gasket even more important
This channel is so underrated.