Dissecting an Engine, The Basic Parts and Their Functions - EricTheCarGuy

hi there car guy here today we are going to cover the basics the basic parts of an engine I get a lot of requests on engines and how they're put together and what the little parts are on the inside and what they do I plan to cover that today I'm not necessarily going to get into a lot of theory but I have this Integra engine which you may recognize from the oil pressure video that it's just kind of sitting here and I'm just kind of sitting here so rather than sitting here I thought man why don't I think about those people that watch my videos and give them something that they asked for so let's give you something you asked for we're just gonna point and name the parts how's that first we'll start with this this is a motor it's a starter motor motor this is a 1.8 liter Honda engine it was in a 1990 acura integra it is not a motor it is an engine of course if you use the word motor yeah people are gonna know what you're talking about but technically you would be wrong engine is actually short for ingenious device motor is actually something that represents an electrical component so this is not technically a motor this is an engine this is the valve cover under the valve cover we have the camshafts this is a dual overhead cam engine not every engine it's designed this way there are lots and lots of different engines designs everything from these traditional four-stroke types to let's say the rotary types that you might find in a Mazda those are fun that engines start down as a water pump with this dual overhead cam system you have two cam shafts each controlling a different function this one is the exhaust camshaft and this controls all of the exhaust valves this is the intake camshaft and it controls all of the intake valves we know this is the in tech because the intake manifold is on this side and we can see the flow of air into the engine we know this is the exhaust side because these are the exhaust valves and leads out to the exhaust manifold of the engine this is a camshaft or sometimes referred to as a bump stick why bumps these are the cam lobes now this really is everything because this says how this engine is gonna breathe this tells it when to open the valves how long to keep the valves open for and how far to open them that is huge because that is like I said directly proportional to how the engine breathes so if you want to change an engines behavior you want more horsepower less horsepower you want more torque you want more fuel economy all these things come down to this guy right here and they all have to happen at a given time hence the reason we have timing gears on them so that everything works together while editing this I believe I came up with an even better analogy for a camshaft think of the camshaft is a computer program a mechanical computer program for the engine so whenever you're thinking of camshafts think of them as mechanical computer programs because they dictate the behavior of the engine and how it breathes these cam lobes as they spin around push onto these followers on this particular and in turn they opened the valves this engine uses these followers so the camshaft pushes on this which takes its leverage from here and then pushes down this is actually the valve this is an exhaust valve so what this little thing does it sits down inside of here and every time the camshaft comes around it pushes down on these thus opening the exhaust valves you have them all the way across for each one of the exhaust valves on this this engine has two valves per cylinder on the exhaust side and two valves per cylinder on the intake side it's a four cylinder so four times four is 16 so it's a 16 valve dual overhead cam engine once again lots of different engine designs and a pushrod engine you have lifters so you'll have either solid or hydraulic lifters hydraulic lifters means that this guy's filled with oil and that this little thing in the middle here will squish down a little bit and these allow for quieter operation of the engine but with a solid valve train you actually have more accurate valve timing because this is like a squishy sponge a solid valve train is exactly that it's gonna open the valve precisely these are not so precise but mostly used in passenger cars to keep you know this the service is down because with solid valves you have to adjust them periodically with hydraulic lifters you do not this is a push rod and a push rod sits inside of that little cup there on the lifter and every time the cam comes around I realized this is not the cam for this car but every time the cam comes around what it does is it pushes up on that lifter and it opens the valve it doesn't a kind of a roundabout way that's why overhead cam engines came about this is the intake camshaft and this is the exhaust if you look at the bumps they're a little different ones a little higher than the other maybe a little fatter but the point is is these things are angled and put in just the right position so that they can activate the valves and we want to do this once again so that we make the engine breathe back of the intake camshaft has that little slot that does drives as a distributor so the distributor is mechanically connected to the camshaft so if the camshaft is out of time the distributor is to keep that in mind if you're doing timing belts and things aren't running right afterwards this is an old-school distributor and this no rotor here but what this does is this is mechanically connected to the camshaft and driven by the king of shaft and what it does is it transfers the spark to each one of the cylinders as the cylinder comes up on its compression stroke so this is mechanically timed to the engine via that gear which is in many cases supplying to the camshaft this is not the correct cam shadow but this is what turns it so if you take one of these out you have to make sure you put it back in on the right place of your engines not gonna run right this is an old-school oil pump it bolts of the block and there's that little area right in here that is driven by a long shaft actually many times is R off the distributor so the distributor in the oil pump are often sort of tied together by this rod that connects the two so the camshaft also drives the oil pump something to keep in mind so your camshaft isn't running and you don't have oil pressure you may have a problem with the connection between these two here we have the exhaust manifold this is the dipstick for the oil goes down into the oil pan each one of these is a runner that comes out of each cylinder so each cylinder has its own runner they all collect inside of the manifold things that collect things are called manifolds you have the intake manifold in the back and then you have the exhaust manifold here these runners are all the same length reason for this is is as the engine runs it sends out pulses on each cylinder individually at different times and each pulse actually helps draw out the next pulse from the next cylinder so they all need to be the same length so that each cylinder can produce equal power you hear the term equal length headers it's kind of what they're talking about it's something that you need in the design of the engine if not it won't run smoothly so you want all these pieces of metal no matter how you bend them to be roughly the same like when they reach the point where they all come together there's your exhaust manifold you say all four of those holes collect down into that one big hole exhaust manifold in case you were wondering if you take that plug out it empties out the coolant inside the block I feel like I should have talked about this first but the camshafts sit up here and keep the top part of the engine in time the crankshaft is down here and this keeps the bottom half of the engine in time and these things are normally connected by a timing belt and the water pump lives here which is driven by the timing belt so and this this is the tension it keeps tension on the belt but there's a belt that connects the crankshaft with the camshafts it's called the timing belt because that's what it does it keeps the engine in time it keeps the valves opening and closing in time with the Pistons moving up and down which is the crankshaft which we're about to get to the water pump of course moves water throughout the engine other engines this is an older v8 setup use a timing chain and this upper big gear here would be connected to the camshaft and a lower one here will be connected to the crankshaft and the reason this gear is bigger for every one revolution of the camshaft you have two revolutions of the crankshaft and the reason for this is it's the four-stroke engine cycle so it's designed in such a way to where every time the camshaft goes around once the crankshaft has gone around twice kind of cool huh you may also hear the term double roller timing chain which refers to this which is too changed put together which is really stronger in addition to that you might hear of gear driven setups which are more accurate but also noisy you can put these in place of regular chains and some engines are just gear driven from the start I've seen a lot of diesels this way this is the intake manifold just like the exhaust manifold it has different runners going into each one of the cylinders that are all the same length air comes in here goes down through these runners each one of these goes down through each one of these runners into each corresponding cylinder intake manifolds I'm not going to get into the principles right now but intake manifolds that have long narrower runners are usually good for torque well are made for low end torque whereas likes a short runners that have big and fat that is made for higher rpm horsepower what happens with these long narrow runners is they help increase the velocity of the air going into the cylinder and an on a naturally aspirated engine it helps increase torque conversely when these are big open areas they allow the engine to draw in more air and a higher rpm which in turn gives it more power these cross here or all of your fuel injectors anyway these little fuel injectors sit underneath what is called fuel rail which supplies pressurized fuel behind the injectors themselves then what happens is each one of these injectors will spray into the individual cylinders at the correct time according to computer it uses all the different sensors on there such as cam and crank sensors to know exactly where the piston is to know that the intake valve is open and each one of these provides a little squirt so in this case in the case of a fuel-injected engine you have air all the way to this point then fuel is added at the last second while the intake valve is open a carbureted engine there's air and fuel in each one of these individual runners going down into here this orange stuff here is all gasket that's the intake gasket it seals well what would be EGR here and coolant goes through here we'll check it out there's the valves these are the intake valves and they're both closed right now because there's no camshaft in there one on that side and one on that side notice how this darien here is all clean that's where the gasoline gets sprayed so the air goes in the everyplace else is kind of carving up the shape of this is very important because the air air moves like liquid so you want it to flow and here and as these valves open up into the cylinder they allow that air and fuel to pass into it and what you're looking at here at the top is actually the valve guide and that's the valve itself let's see if we can pop one of those out in a minute and here is the exhaust side which has kind of the same thing but instead of stuff coming in stuff's coming out just at the beginning of your exhaust system that brown crusty stuff that's burnt oil this is the cylinder head between the cylinder head and the block you have the head gasket these are dowels that guide where the head gasket goes but this head gaskets just fine there's nothing wrong with it what you'll see here is the combustion chamber or at least part of it these come in all different shapes and sizes some of you out there may be familiar with the term Hemi which actually stands for hemispherical this is what they call this a Penta drew f-- Penta roof design but the hemisphere design is like the inside of a sphere in here so this this is spherical inside the combustion chamber that's where that term Hemi comes from it's hemispherical this I believe is called a Penta roof design because it goes up and comes down at a sharp angle as you can see on each one of these the design of this the angle of these valves all these things weigh in to how the engine performs every little nuance every little measurement right down to the thousandth of a millimeter all of this comes into play with an engine so engineers spend a great deal of time designing the shape of this designing how big these valves are going to be everything else all to come together so that the engine works within a certain range certain parameters in the case of an automotive engine they're trying to balance between fuel economy and power it's that simple it's not an easy thing to do but the people that are good at it good for them this this is the top of the valve this is the valve spring and these are the keepers there's two of them that hold in the valve here is your valve spring here's the retainer and these are the keepers but these actually sit down inside of this groove and they're tapered as you can see I have a taper to them fatter at the top and they are at the bottom and they sit down inside here and grab on to the top of the valve so they sit in there and because this hole is tapered they're wedged in and they just they just wedge together and on the inside of these keepers there's a groove you see there and that groove sits in the top of the valve right here so that holds it all together it seems kind of cheesy but it stays together for the most part but what I just removed here is an exhaust valve and as you can see it's kind of crusty yeah a little bit of a little bit of oil on it so that valve seal may have been leaking a little bit but it's probably more likely that the rings on this engine are worn out because it's got quite a few miles on it now the shiny spot is called the seat or the shiny spot of the valve is where the valve contacts the valve seat which is here that's on the head so this area here needs to seal against this area of the valve whenever a valve job is done this seat is cleaned up sometimes at many different angles sometimes they grind in the seat up to five different angles five different sides of stones but they have a special tool that fits down in this valve guide and grinds this hole in such a way to where it will seat up against this valve sealing is very important in an engine especially in the combustion chamber any leaks cause compression loss and any compression loss causes power loss but that's the basics of how a valve stays inside of a head held on there by keepers now valve springs are also very important because after the camshaft compresses them and opens the valve it's the job of the valve spring to close the valve again and it's equally important that the valve closes as efficiently as it opens so valve springs are important in that they need to be able to combat the forces that are going against them and they need to rapidly re-expand to close the valve if not it's something called valve float to where the spring or the the speed of the valve overcomes the ability for the spring to close the valve in fact right here is probably the number one limiting factor of rpm high rpm engines have really good valve springs that are able to close the valves once they're open but you got to think if something is moving at 10,000 revolutions per minute which is really super fast if something is this spring has to compress and decompress in that amount of time which is milliseconds it's not able to keep up the stronger these are the more stress that's going to put on the cam in the and the whole valve train but the if they're too weak then what happens is they won't be able to close the valves and the valves will stay open and if the valve stays open then you lose compression you lose power and it starts to miss and have issues there now in this engine this is the valve seal and these are positive type valve seals meaning that they slip over the top of the valve guide itself and the valve guide is basically a metal sleeve that this is sitting on top of that the valve rides in and out of okay here's one of those valve seals and this is referred to as a positive type valve seal and the reason is is because it positively locks on to the top of the valve guide if you have bad valve seals a lot of times it will suck the oil well on the intake side mostly it will suck the oil from inside the cylinder head down inside the combustion chamber and this is not a good thing these positive type valve seals however are very good at keeping the oil out some valve seals are just what are called umbrella seals and they just sit on the inside of the valve and don't make a positive seal here at the valve stem they really look like an umbrella to help keep this out if a valve guide gets worn out and the space between the valve guide and the valve gets too big it will suck more oil in there which will cause you to burn more oil but I'm of the opinion that most of the oil consumption actually happens in the bottom of the engine because that's where most of the pressure is let's go there next all right now let's get a look at the correct shaft by the way this is a flywheel this is a manual transmission so when you have a manual transmission this is a weighted thing it's called a flywheel if this were an automatic transmission this is a thin plate and it's referred to as a flex plate not a flywheel fly wheels are on manual transmissions flex plates are on automatics this is a flex plate as you can see it's much thinner and lighter but these are for automatic transmissions the thick ones that are heavy or flywheels this is referred to as a flex plate so what does it look like is your engine runs all I'm doing is turning the flywheel 4-cylinder engine fires every 180 degrees so as both of these are up watch the four-stroke engine cycle to see more stuff on this but as both of these pistons are up one of them is on the compression stroke and about to fire and go on the power stroke and the other is on the exhaust stroke there's something called sister cylinders and it has to do with the crankshaft design and the way this whole system is set up that's what that means that's why two of these are always coming up at the same time same with these metal two sister cylinders cool huh okay now let's flip this guy or no dumping oil all over the place that's worried let's take the oil pan off this is the oil pickup so as the engine runs oil gets sucked up in here by the oil pump which is this assembly on the front of the crankshaft and it's driven by the crankshaft this metal plate is referred to as a windage tray so and some of these are actually designed to actually scrape a small amount of oil off of the crankshaft as it rotates to help it be more efficient oil pickup a little screen down in there something you know can help keep out any big chunks I'm getting sucked up in there but it goes to the oil filter also it's the reason why you have it on there so there's any dirt or anything in here it should get caught up by the oil filter or this screen it could be said that this is where the rubber meets the road because in essence what an internal combustion engine does is it turns the chemical engine it turns the chemical energy inside of the gasoline into mechanical energy and that happens right here at the crankshaft these are counter weights these are connecting rods these are directly connected to the Pistons in fact we're going to take one of those Pistons out of here now but as it rotates and with it with a four-cylinder engine it's hard to keep it balanced so what they often do is they have these harmonic balancers there's a little piece of rubber like it is in between the inside and outside of this pulley and the reason for that is because every time a piston pushes down and it causes this to rotate it creates a pulse but that pulse pretty much ends when it gets to the end of its travel then it has to compress something so it goes from accelerating to decelerating accelerating to decelerating and this creates pulses of power here at the flywheel in the crankshaft to help even that out so that it doesn't shatter itself because believe it or not those pulses are not good for the metal parts inside the engine this is called a harmonic balancer or a damper because that's exactly what it does is this helps dampen those accelerating and decelerating forces that happen at the crankshaft this guy right here is actually more important than you might think this is what it looks like rotating from below you got these the connecting rods that are connecting to the Pistons coming up and they're all transferring power to their respective journals and transferring it here to the back of the engine so when they say power at the flywheel like 140 horses at the flywheel this is what they mean that this has enough twisting force horsepower is actually derived from torque and torque is a twisting force so really torque tells you more about an engine than anything else but torque it quite smore torque equates to more twisting force more of the engines ability to push down bigger cylinders and other factors contribute to an engine that can have more torque camshaft design being one of them I'm not gonna take the crankshaft out and I'm sorry to say but I will this is the your last thing I'm really I'm gonna take one of the connecting rods out and here is the bearing cap you might remember this from the oil pressure video and bearing is lookin so great but see the bearings have these little tabs on them and they fit down under these little slots here on the caps so you just slide and down into place like this say they fit in there all nice this journal right here has to be completely round it's really important it also has to be nice and shiny and smooth because this is where the power is transferred you want it to happen smoothly okay see a piston being born all right tada we have our hands hey mister this is the hole that was left by the cylinder now this normally should have a crosshatch pattern on the inside of it because that helps the Rings seal and the oil control rings work but there is the crankshaft journal now think of the crankshaft like petals on a bicycle in each one of the Pistons are like legs peddling the crankshaft so it works in a very similar way here is piston it's fairly light actually this one's still nice and stiff but that's it for these that make up the displacement so when you hear a 1.8 liter like in the case of this engine that means the volume between all four of these cylinders and pistons comes out to be 1.8 liters of displacement that's how much air this displaces shiny spot right here is called the skirt three little grooves up here the first one with a little wavy played in it that is the oil control ring then you have to compression rings you have this compression ring and this compression ring so an engine or a piston normally has these two compression rings and an oil control ring so when people say they're re-ring in the engine or putting your rings in that's what they're talking about as those piston rings because these guys are the things that seal against the inside of the cylinder this right here is the wrist pin and this allows the connecting rod which is this part to pivot power is transferred as this piston comes down to C it has to change direction as it moves up and down on the crankshaft a little dents in the top for the valves when they come down so sometimes the valve is really that close when it opens up and the piston is all the way up so that's what those little grooves are for so the Pistons all the way up those little valves come in like that and that that's pretty much your engine and then there's these little holes once again remember the whole oil pressure thing that has actually forced out this other little hole which lubricates the bottom of this area in here so this will squirt up throw oil up under the bottom of the piston which helps one keep it cool because you got to think it's really hot on this side of the piston in the combustion chamber it's like over 2,000 degrees in some cases but they're getting rid of that heat with the cooling system that's why the cooling system is so important and engine turns the chemical energy from your gasoline into mechanical energy here at the piston and the crankshaft that's what it does one of the really scary part it's only 20% efficient 80% of the heat that's generated by the chemical energy of the gasoline is lost through friction and other things other loss of motion it's not very efficient to take a piston and move it up and down three times in order to get one thing of power out of it it's really not that efficient but the internal combustion engine is not really that great we've got it to a point where it's about as good as I think it's gonna be because we've got combustion down to a science but still you can't fight physics at the end of the day this is an extremely efficient what inefficient way to make power it works it's common it's cheap efficient no not so much I'm gonna cover more specifics of this stuff at some point time but this once again just a general video just a video to say these are the parts inside the engine this is what they do if I miss something or if you have something to add feel free and the comments but come on be nice so are you out there kind of uptight I'm here to learn just like you and I am learning just like you but this is what I know are the internal components of the engine and how they work and I hope this information was helpful to you you can always visit me at eric the car guy comm or you can visit me at facebook and twitter oh yeah and then I'm also doing podcast on Sundays at noon Eastern Standard Time which you can find a link to that also on my website so feel free to do all those things if you so desire thank you for subscribing and if you haven't subscribed hey why not be safe have fun and of course stay dirty see you people

Channel: EricTheCarGuy

Views: 3,700,948

Keywords: engine, internal combustion, motor, engine dissection, engine tear down, motor dissection, motor tear down, piston, rings, valves, cylinder heat, cylinder block, engine block, connecting rod, crankshaft, counterweight, intake manifold, exhaust manifold, cam shaft, rocker, pushrod, lifter, solid lifter, hydraulic lifter, piston rings, compression rings, oil rings, automotive education, ericthecarguy, eric the car guy, etcg

Id: saPGX-1qC4M

Length: 32min 26sec (1946 seconds)

Published: Sun Jan 30 2011

Reddit Comments

[u/[deleted]]

What a fantastic resource. Thanks.

[u/TheBestArlabuNakti]

One good way how to kill engine: https://youtu.be/2JSutzns27k