---
title: 'How Do Car Engines Work? A Close Look at The Intricate Details of an Engine'
source: 'https://youtube.com/watch?v=zYMzE4xnjtc'
video_id: 'zYMzE4xnjtc'
date: 2026-06-30
duration_sec: 3954
---

# How Do Car Engines Work? A Close Look at The Intricate Details of an Engine

> Source: [How Do Car Engines Work? A Close Look at The Intricate Details of an Engine](https://youtube.com/watch?v=zYMzE4xnjtc)

## Summary



## Transcript

the gasoline engine is one of the
greatest inventions in human history
that still propels us today but do you
ever wonder how it actually works behind
the scenes well in today's video we just
happen to stumble across this engine
which we will use to show you not only
how the operating theory is but how
things actually work behind the scenes
right after this
so before we dig into this engine and
find the how things work behind the
scenes let's talk about the very basics
of engine operation this is a fourstroke
gasoline engine every gasoline engine
needs four things to run you need
gasoline for the combustion you need air
or more importantly oxygen in the air
which is going to help that combustion
and then you need com something to
compress them and of course you need to
ignite that mixture using the spark plug
so they would combust and create that
power that propels this engine forward
so here is how things will will work in
theory get this is a four stroke engine
that means it has four strokes and those
Strokes are
intake
compression power and exhaust and the
way this works is intake is when the
mixture of fuel and air goes into the
engine and then the compression stroke
is when this mixture is going to get
compressed here we have the three things
that happen when you compress this
mixture of gasoline and and air or
specifically oxygen you're going to
create that combustion which is going to
create like kind of an gas that's going
to come out from that combustion that's
going to push and create that power
stroke and that's what's actually going
to start ranting this engine and then
all the combustion gases that are just
sitting there they exhaust in the four
stroke and then we repeat now this is
for one cylinder this particular engine
is a four cylinder engine so this cycle
is going to happen for for each
individual cylinder and that's how you
get that Continuous Flow so this is what
it's called the firing order cylinder
one's going to fire then four then two
then three and then we repeat it's just
going to keep going that way you don't
have one cylinder firing and then we
lose we kind of lose our momentum then
the second one then the third one the
fourth one no they're designed to
continuously run so you always have a
consistent power band that sounds all
great but how does this actually happen
behind the scenes is we're going to dig
into this motor and find out exactly how
that
works so before we dig into how it works
let's label the components understand
what are we looking at here cuz this is
not one piece this is multiple pieces
and some folks will say there's
thousands of parts to an engine not
thousands but there's a lot of parts
let's talk through
them this is the top of the engine this
is the front of the engine and that is
the back this part right here is called
the valve cover this is just a cover
that keeps the oil inside it's all it
does it has the oil fil C app has a few
other component that's all it does it
just covers things at the top then you
have the cylinder head this is one of
the most critical most delicate parts of
an engine this is what allows the
mixture to go in and go out the exhaust
we're going to dig into it and we're
going to take it apart and you'll see
every little part of
it this part is a cylinder block this is
where your compressor is this is where
the Pistons live
and this is what actually compresses
that mixture and then the mixture pushes
it down for the power stroke and then it
comes up again to push the exhaust and
then as it goes down it pulls the
mixture in this is not making sense
right now but when we take it apart
you'll see it how it how it does that
and it will all make sense but let's
just cover the part so you know what how
they look like this part of the bottom
is called a stiffening case it's
literally just an extend tension off the
engine just to have that area where the
oil sits and this very bottom piece is
the oil pan and this is what contains
the oil of the engine now let's start
peeling the layers and we'll see how
this
works let's start peeling our first
layer this is the valve train this is a
very simple Engine things get a lot more
complicated from here but we're going to
we chose this engine for a purpose this
is a dual overhead cam these are the cam
shafts and they are sitting on top of
the cylinder head that's the
identification of that style there is
multiple designations there's single
overhead there is not overhead there's a
lot of different configurations but this
particular one which is the most common
one in modern cars dual overhead cam so
what is a cam shaft all this does is it
synchronizes The Strokes of the engine
when are we going to allow that mix of
air and and gasoline into the engine and
when are we going to allow that exhaust
to come out so I'm going to turn it turn
this engine as if it was running and I
want you to watch what things are doing
here
do you notice this particular
Peak this is called a cam lobe and it is
kind of in a in a droplet shape and the
reason for that is every time this high
like pointy part goes down it opens
something called a valve every time a
round part goes over it it is closed now
these valves are what going to open to
let either let the gas mixture and air
mixture in or it's going to on the other
side is going to let the combustion
gases go out in the exhaust and when
they are both closed we are in the
compression stroke cuz you have already
the mixture inside this the combustion
chamber which we're going to look at in
a little bit and you are com compressing
it so if you have one of the valves open
it's just going to come out nothing will
happen so you have three stages of this
they're either open on one side closed
on the other open on one side closed on
the other or they're both closed now
there are cases we're not going to get
too complicated into there are cases
where this is delayed and that's delayed
we're not going to get into that we're
going to keep things simple because
they're actually a lot more complicated
so here's what's going on in this entire
picture each cylinder in this particular
engine it's 16 valve engine four
cylinder you have four valves per
cylinder in this this is the separation
of the
cylinder do you see how you have two
lobes here and two lobes here this is
the intake side and this is the exhaust
side the cam shaft will always
spin half the speed of the
crankshaft so if you're driving your
beautiful car at 1500
RPM this is spinning at
750 RPM this is how this works the
camshaft will always spin slower and
what this does
the way the Globes are orientated is
according to the firing order well we
did the four strokes here but at the
same time the four strokes are happen
somewhere else and somewhere else and
somewhere else they're in different
phases of each other but we're going to
actually focus on one cylinder only
right now both both of them are closed
and this is the beginning of the cycle
watch the cycle on the intake side first
this is the intake going to turn the
engine do you see how the intake is
opening the pointy part of the lobe is
down now that now we are taking in the
intake
mixture we're going to
continue this part is actually the
compression do you see how they're both
closed pointy part here pointy part here
the compression is happening and then
watch what's going to happen here we're
going to open the exhaust
valves now we're letting that gas out
and then as we let it out we're getting
ready to start the cycle all over again
do you see how that works but how is it
actually doing that see this part right
here this is called a timing chain you
have two Styles and engines you have
either a timing chain a metal chain that
synchronizes everything thing so all
these four cylinders would do what
they're supposed to do at the correct
time or you have a timing belt this
particular engine is a chain we're not
going to get too much into that part of
the design but let's see how does this
actually happen what is this pointy part
this pointy part what is it actually
pushing against and how is that
mechanism working and in order to do
that we're going to remove all the chain
we're going to remove the cam shaft
we're going to look at the cam shaft
outside and then we're going to remove
the cylinder head which contains the
valves that do this and see how that
works up close and personal so let's
take a look at the cam shafts up
close you see those slopes that's how
these look
like you see how they're not in the same
orientation because
each one corresponds to a certain phase
in that four stroke for that that
particular cylinder so they will not be
the same and they are engineered that
way to
work in that order now let's take these
out look at the area where they sit so
this cam shaft is just a piece of metal
that is spinning I mean if you're
driving your car at the highway 3,000
RPM this is spinning at, 1500
revolutions per minute that's a lot and
how do you not have this metal piece and
this metal piece get destroyed here's
how that
works this is called a
journal this part has a hole in it see
that little innocent looking hole that's
actually an oil hole so what's going to
happen is oil will come out to this tiny
little hole put a film of oil on top of
this which then is going to end up here
and on this little cam cabinet that sits
here that film of oil here will actually
prevent wear
between these two metals cuz they will
actually not be touching each other they
will be riding on a thin film of oil
here that keeps this lubricated cools it
down and and not allow this metal to
metal
contact that is pretty cool how that
works now we talked
about the cam Lo pushing down but what
is it pushing down on let's just take
this cam out of the way let's take a
look what is it pushing on cuz this just
looks like a flat
surface but see the thing with gasoline
enges is they warm up and they cool down
and what happens to metal when you warm
it up it expands you cool it down it
contracts so if we just put this
cam here here what's going to happen
when this metal surface heats up expands
this metal surface heats up and expands
and they're just going to be fighting
each other or when this metal surface
cools down significantly and this metal
surface cools down significantly and
they shrink well there's going to be a
giant Gap so how is that going to work
that is called valve
clearance it is something
precalculated by the Engineers that
designed it where we want this valve
cleaners not to be too tight where this
valve will potentially be pushed down
all the time and open and we can't have
our power stroke anymore where both of
them are
closed neither is going to be super
loose where we're not going to be able
to open our valve all the way and allow
that mix that beautiful gasoline and air
mixture to go in or the exhaust to go
out so they set it as specific clearance
that allows for both cases to
work this is called a manual valve
clearance engine and this particular
engine is that more modern engines and
more sophisticated engines will have
automatically
adjusting valve clearance what they'll
do there is they'll have a little
plunger that is oil pressured when the
Gap gets
smaller it'll e ease up to allow for
that expansion when the Gap gets big cuz
the engine is cold it's going to pump up
and take that gap between the cam low
and the valve but this is actually not
the
valve and this is a little bit of an
older design on this particular engine
this is called a bucket and the way you
adjust valve clearance on this
particular engine you see the inside of
this
bucket this is actually numbered bucket
so the distance between this inside and
the outside can be changed by the number
that is stamped on this bucket which is
just the distance you can see that
number I don't know if it's clear inside
there's a number corresponds to a
certain thickness of this but this is
the actual valve that this is pressing
which in turn the cam shaft lobe is
pushing on to open and close the valves
that that is the most basic operation
but wait a second what is this little
fancy looking thing here let us take the
cylinder head out of this engine take a
valve out and let's just take a look at
it and see how that looks like now here
are the valves we were just looking
at these actually look like this
inside this is a spring so remember when
we were looking at the cams they push on
this well what's going to return it to
close it this this is called the valve
spring it's just a spring that has a
specific tension depends on the engine
so it would return the valve to the
closed part and speaking of the valve
this is a valve it's fully
assembled and here's what holds this
valve in
place if you look at the tip here
there's this retainer and then inside
this retainer there's actually two
little locks I'm get them out these tiny
little locks which are called Keepers
what these locks do if you look at the
tip of the valve you have this little
Groove these also have a tiny little
Groove that will go right
there and get locked in that Groove
where it's not going anywhere and then
this retainer will come up and lock it
in place and that's what you're looking
at here these are all locked in place
here is how that spring looks like
and here's how the valve looks like now
here's the interesting thing about these
valves this is the called the
stem this is the valve face this is
actually facing the combustion chamber
which we going to look at here the top
combustion
chamber in this
area you have oil in the combustion
chamber we do not have
oil so in order to keep that oil away
from going into the combustion chamber
through this around this stem there's
actually a seal that sits behind each
one of these valves and we'll show you a
little clip of that seal how it looks
like sitting down and then outside these
seals are called valve stem seal it's
the seal that seals the stem of the
valve to not allow oil to go into the
combustion chamber on top of the valve
valve now let's talk about valves intake
and exhaust valves are not the same
usually the intake is larger if you have
a car and in case you hear this that is
direct injected only and you have carbon
buildup on the valves they're actually
going to build up carbon here not here
that's a common misconception about cars
folks all engines will build up carbon
here including this one that's just
normal now not excessive amounts but you
this does have residue on it you cannot
clean this with a little can of magic
stuff that you put in the tank or the
shop chart you cannot clean this this is
normal the minute you run the engine
there will be some carbon that is
normal but when carbon builds up
here you're going to start obstructing
thing eventually this valve will stick
and won't be able to be closed by the
spring and we have issues or it'll be
completely plugged where you cannot no
longer allow that mixture to go through
I just thought I say this now some
carbon buildup here is normal excessive
carbon buildup here we have
problems why is this valve clean and why
do direct injection engines build up
carbon here see the way the port
injection work it actually sprays
gasoline in an area of the runner
leading up to this valve so G gasoline
and air will come together touch this
valve go around it into the combustion
chamber while direct injected engines
they will only have air passing through
here and then gasoline being sprayed
directly inside not before this guy so
what ends up happening over time there's
something called blowby that will build
up that carbon here because there's no
gasoline passing through here and
washing it off that's why direct
injection injected engines built carbon
welcome to the top combustion
chamber this is the other side of the
cylinder head these are the valves that
we were looking at that were basically
this this
sits right in
here this is when it's open and this is
when it's closed so every time this
comes up it allows either if it's this
side which is the intake side it'll
allow that gasoline and air mix to come
in if it is the exhaust side open it'll
allow things out and the what is
dictating what's coming in and out is a
part where we'll talk about in a little
bit I just want you to see this part now
one thing we will say right now this
just looks like to the average person
who is not into cars not into this stuff
this just looks like an oily mess just
random parts dirty oily greasy
gmy this is the most
delicate most highly precisely
engineered part of the entire engine
everything else is uh nuts and bolts
this is where the magic is cuz do you
see this
valve this valve actually has a surface
where it seals on because this needs to
seal
and the part right here is called a
valve
seat this is a very precisely machined
part so is this
one so when these two sit together like
so they're actually sealing the
combustion chamber so this is not an
oily mess and the other thing is this
surface
itself is a very precisely machined part
because wait a second we have this part
we have another part and the combustion
is happening here in this area for each
cylinder well how are we going to seal
this compression from going
outside this is where your head gasket
is you'll hear blown head gasket leaking
head gasket this car has a bad head
gasket most people talk about this they
don't even comprehend what the head
gasket does as the name
says the head gasket is just a
gasket
sits right
here and it seals between the cylinder
head and the cylinder block we're going
to talk about the cylinder Block in a
little bit but here's what usually
happens you overheat this engine for
example that's the most classic case
what's going to happen is this is a
precisely machined
surface this will heat
significantly and if you notice these
openings these are actually cooling
jackets they cool this area so coolant
will go out of
here into this area and then into the
block and that's how coolant is going
back and forth well when you superheat
this aluminum tends to warp when you
heat it meaning it's no longer flat so
this will open and then you will have
multiple of things will happen either
you will mix oil because there are oil
passages here as well some of these
passages are oil passages you will mix
oil with coolant that's the most common
thing that people will think it happen
but it's not always the case CU if you
actually break the area between two
cylinders you will have all kinds of
issue cuz you will bleed combustion from
this one into this one and this one is
not ready and it'll just become a mess
and the last thing that is
common this gasket corrodes and starts
leaking outside either oil or coolant or
both these are some of the things
with cylinder heads problems for modern
engines now if this is Warped you must
machine it or replace the cylinder head
if it's not if you're not able to
machine it due to
tolerances this needs to be a perfectly
flat surface and we're not talking oh I
passed my hand over it this is like
Machining style perfectly
flat having said that I'm going to put
one cam I'm going to turn it it's going
to be a little difficult so you can see
how these valve actually work when the
engine is running let's SW these valves
not open and close dance because this is
beautiful look at this
isn't that something beautiful so this
is actually cylinder number 1 2 3 4 I'm
going to go through an entire cycle
until we open four again see if you can
pick up the firing order from
this pretty cool right how these valves
open you notice they're both opening
together so if you do the math here real
quick these are 16 valves this is a 16
valve engine two valves for the exhaust
two valves for the intake so four valves
per cylinder and this opening right here
is actually where your spark plug is
that's what ignites the mixture so we
can create that beautiful combustion if
you had a direct injected engine you
will have a second hole just like this
one where the direct injector is
somewhere either here or
or sometimes it'll be right here and the
and the spark plug will be in a
different position but somewhere inside
this cavity right here now having met
the upper combustion chamber let's go
see the real magic of gasoline engines
which is the other part of the
combustion chamber cylinder
block welcome to the combustion chamber
which is actually actually this one it's
actually not the entire depth of this I
hope you can see this very clearly it is
just this
area and the top of the cylinder head
I'll remind you what that looks like let
me spin this and watch how this
works this is the Piston there's four
sters 1 2 3
4 here is what's going on here and the
best way I will be able to describe it
this is the compressor part of the
engine when this piston watch these two
when they go
up they are
compressing when they go
down they are
pulling so here's how this is going to
work for our four strokes let's start
with the first stroke which is the
intake we want to naturally pull that
mixture of air and gasoline into the
combustion chamber we're going to have
this piston go down so what it's doing
is creating a suction it's going to
pull the mixture
inside this
area then then we're going to want to
compress that mixture and ignite it with
the spark plug so what it's going to do
is it's going to come up and start
compressing as it reach its peak at a
specific position the spark plug will
will ignite this mixture so the mixture
will burn as it's burning it's going to
create like a a gas and it's going to
push
this piston down and then because we
have four cylinders let's talk about it
this
way this this piston has
ignition we have combustion it's going
to push this piston
down then this one has ignition it's
going to push it
down then this one has ignition it's
going to push it down then this one has
ignition it's going to push it down and
then this one is going to have ignition
again it's going to push it down and
that's how your engine will just keep
turning and turning and turning and
turning non-stop now this is the
beautiful part of
this this
piston is in the intake stroke it's
about to start pulling the components in
this one just had combustion so it's
going to get pushed
down now these two Pistons one of them
is in its ignition cycle one of them is
about to start the intake and that's how
these this firing order works it is
beautiful how this works you see how
this this is when you spin your engine
at 3,000 RPM or you are 18 years old you
just got your you are an adult and you
are racing your car down the street
which you shouldn't do that on public
streets and you're revving this engine
at 6,000 RPM all the
time every minute which is 60
seconds this crankshaft will do a full
rotation which the full rotation is this
piston going up and going down back to
the same position
6,000 times every 60
seconds this looks like how do engines
last this is the moment where we say
thank you engineer Engineers were
figuring this
out look mechanics and Engineers usually
don't get along but we have to be
truthful they know what they're doing
this is how these engines are designed
to run and run and
run here is the important things this
which we're going to take it out in a
little bit and you'll see it up close
and
personal is sealed there is three rings
or piston
rings that are sealing this
chamber and for you to get a better
understanding of really what's going on
like how does this effect work let me do
a small demonstration we are looking at
two cylinders I hope you can see the
outline of them we got them covered up
with tape just so we you can see how
they do this so you can picture
it every time the Piston goes up it's
going to create compression every time
it goes down it's going to create
suction so watch as I turn the engine
what the tape is going to
do see how this one came up this was
compression now it's coming
down this one is coming down now it's
coming
up funny sounds it makes this is
actually the compression watch this one
when I push it very
hard that is the compression and this is
the suction
effect actually it becomes comes really
difficult to turn this engine because of
the
obstruction eventually actually blew the
BW the tape That's How Strong this
compression is folks it needs to be
extremely strong to do this now that we
picture how this works let's talk about
a few nuts and bolts things
here this
round is the cylinder itself so the head
gasket sits here this is also a very
precisely machined surface so it would
seal on the gasket now in here there's
actually a liner cuz this is an aluminum
block if you create that combustion on
an aluminum block you will
immediately fire a hole through it and
it'll wear down with the with the piston
rings going up and down up down on it so
this is actually a steel liner now this
particular engine is out of a Toyota
some engines this liner can be pulled
out and replaced this one cannot because
the way they cast this this aluminum
they put the
four steel liners and they cast the
thing around it and they are
mechanically bonded together so they
wouldn't come out so you cannot really
replace these but the wall of the
cylinder has a
specific Machining to it that is called
a cross hatch pattern and keep that in
mind cuz we're going to talk about this
once we talk about the piston rings this
area this cavity right here this is
where coolant is to cool these down CU
remember combustion creates a lot of
heat so you have coolant all the time
here cooling it and then you also have
oil passages around it because in
gasoline enges coolant cools oil cools
as well most people forget that part
haven't looked at all this and this
beautiful thing turning
how do this entire thing work and why do
these come up and these come up together
how does this work let us flip this
block and look how this this entire
thing works and then we will take one of
these pistons and tear it completely
apart so you can see exactly how this
creates this this compression or
pressure and the suction and how does
this exactly work welcome to the back of
the cylinder block this is where the
magic happens let me spin it so you can
actually see how this
goes so what we were looking at from the
from the other side you see that piston
right there see how it's going to come
down and go
up this part right
here this is called the crank shaft this
is actually what outputs the output of
the engine not the camshafts cuz
connected on the other side is the the
whether it's manual transmission
automatic transmission plane propeller
you name it it's connected on this side
this side is where your serpentine belt
or drive belt will be this is a harmonic
balance this is where the other side of
it is but this is what actually drives
your car this way it's the crankshaft
that drives the car cuz every time
remember that power stroke we talked
about where the Piston gets pushed up
it's going to push on this and turn it
and that's what's going to create that
output that's where the power of the
engine is transmitted out now you look
at this this just looks like a random
piece of metal looks like a museum piece
but let's take a look at at the finer
details of
this this is a crank shaft and it's
connected then it goes here then it
comes back then it goes here comes back
and comes back
here but
this is actually a separate
part and these are called the main caps
this is what bolts the crank to the
block and
these are called Rod caps this is what
actually bolts the Piston to the crank
not directly we're going to take one
apart and talk about it let me remove
one of these and we'll kind of examine
it and then we'll continue from there
this is actually how this piston looks
like this is called a connecting rod
this connects the Piston to the
crankshaft via this round opening which
goes on this this is called a crankshaft
Journal this is where this would ride on
kind of looks like this when it's
connected so do you notice that this one
has also a hole remember when we talked
about the cam this is the oil feed hole
and if we look at this we take this half
out it has actual rod
bearings these are little bearings and
you notice they also have that hole so
here's what's going to happen here if we
have this metal on metal surface just
going at 6,000 RPM as you're racing your
car well this is just going to wear out
and it's going to wear this out and then
everything will just
explode actually that's not how this
goes you have a thin film of oil that
comes out of here and coats the inside
of this and the other side so they're
actually not making contact
they're not supposed to make contact
there's supposed to be a film of oil
here that cools these and protects them
from wear these rod bearings and you'll
you'll hear the term rod
[Music]
knock the rod knock is the knocking
sound that the rods will make as they go
on the on the journal here when they are
when these completely wear out let's do
a small demonstration of that how that
sounds like now when I turn turn this
you hear no noise and this is solid it's
not going anywhere I'm going to remove
one of these
[Applause]
caps note do not do this on an actual
engine this engine is junk we are using
it for demonstration I'm going to remove
these cuz this is basically what happens
you see how thin this is if this wear is
down you basically have this is gone so
what I'm going to do here is I'm going
to remove
them and then reinstall
this never use power tool engine
remember this is a non-running
[Applause]
engine now watch this one this one is
solid it's not moving
hear that noise and watch when I turn
the
engine you hear that
noise that noise is a rod knock
basically your car will be idling you'll
hear
this now eventually what's going to
happen is
the bearing will be completely gone this
will start eating into this and
eventually either this will break and
this thing will come flying out and come
out of the side or this from the
hammering effect this will break in half
rip and go out side of the engine now
when you hear the term rod
knock you know exactly what that means
that means this ugly
sound now here's a cool thing
here you notice we talked about these
but we did not talk
about these caps these are called the
main caps this is what holds the crank
to the block and they also have bearings
because we also have an oil hole right
here that brings oil so we would not
have metal to metal contact now
something about gasoline
engines usually when you have oil
starvation when you run the engine low
in oil you have a o problem with the
pressure it's always the rod bearings
that will get destroyed before these I
mean if you destroy a main bearing we
are doing some serious stuff here
because the way the oil Flows In engines
it'll flow to the main caps first then
through the crank go here so it'll flow
from the Block into the into this then
into this so if you destroy this this is
long gone that's how it usually goes now
we talked about all this and you see
this journal this is on the crank itself
I'm going to pull this crank out so you
can actually see it in person and see
how it looks like we got our crank ready
to come out one thing I'll say about the
crank this seal you see this seal I pop
it out
this is your rear main seal that when it
leaks you have to pull the transmission
out to pull the engine out because it
literally sits between the engine and
this is where the transmission would be
on that side so this is how that looks
like and with that
out pull this out and are you ready to
say hello to the crankshaft very heavy
part that noise we'll talk about in a
second
this is how this crankshaft looks like
isn't this a
beautiful piece engineering that other
piece that fell off we'll also talk
about isn't this a beautiful piece of
engineering just look at this I would
put this in my dining room as a as like
a
decoration I'm a car guy maybe maybe my
wife will not think so as well but this
is a
crankshaft you notice how it's stepped
in a specific way these are the
mains that hold it to the block which by
the way here's that other bearing on the
other side you notice these are much
heavier Duty bearings that they have a
much larger oil Passage through
them and then the rods much
smaller there's four of them this is how
a crankshaft is and this other side of
the
crankshaft is where your if you have a
manual transmission where your flywheel
will connect if you have an automatic
transmission this is where your flex
plate will connect that the torque
converter will connect to and that's
where the output of the engine
is now when we took this crank
out we had these two very innocent
looking washers come out see how much
wear they have on
them these are called thrust washers
now as you load this crank every time
you see how it has a little bit of
movement and it's specifically designed
for that every time you put like you
push the P piston down and you have like
lateral movement these are actually
going to limit that or hold the crank in
in place they are wearable they do wear
with time
but you will rarely see these go out
some
engines and this is another thing we'll
talk about some engines these actually
sit right here we've seen cases where
one of these or both fall out and
they'll end up in the oil
pan and here's what ends up happening
you'll have a very strange knocking
sounds that sounds like
this and people will think it's broad
knock they'll take the engine apart
they'll freak out about it they'll think
it's a tensioner they think it's a heat
shield it's actually one of these fell
out or wore
off this could tear up the engine very
quickly now that we've talked about this
I'm going to remove
this I want you to observe something let
me turn this a little bit do you see
these four four jets that are
facing the piston this is where the
Piston would be right
here these four jets are vital to engine
operation folks did you know that
coolant is not the only thing that cools
down engines it's actually oil you
remember the old engines they were air
cooled but it's actually the oil that
cooled it and the air helped cool the
oil so these jets are spraying oil
directly at the back of the of the
Piston to cool it down because the
combustion is happening right on top of
it they are
vital to the life of the engine some
engines will have two Jets not just one
and they're precisely positioned where
they spray a specific amount to cool
that
piston just so it would not
overheat speaking of the Piston let's go
look at at that closely and see how that
is a huge important part of this of this
beautiful piece of machine here's a
piston let's talk about this cuz this to
me is the magic part
so this is the Piston itself and it does
have multiple components to it now this
is an assembled one let me bring one
that we took apart so you can
see this is how this actually looks like
so you have a wrist pin which looks like
this that's completely worn
down this goes through
here goes through
here and then comes out the other side
and then there's two little rings that
lock it in
place normally they will do
this they have a little bit of movement
that is normal people have taken engines
apart they have no of doing so and they
look at this they're like well this is
making a lot of noise that is
normal what this allows the Piston to do
as it's going up and then the crankshaft
turns direction to come down it allows
it to
swing back and
forth this is just a beautiful thing
this is a rod and the bearing is here
piston on this end now here's what
can cause issues with these
rods usually the rods believe it or not
are sacrificial in an engine same thing
with a bearing on it CU you want to
protect the crank if for example you
drive your car through a giant puddle of
water and the engine takes in
water that water is going to come here
now you can compress air you cannot
compress liquid and if you get large
amount of liquid here this will try to
compress it and it'll just dead stop so
what's going to happen is this let's
think it's going to do what this does
it's going to literally Bend and when
this
bends it's no longer going to make it
all the way up and you'll have all kinds
of problems or if this seizes all of a
sudden and this try and push on it this
will literally break in half
that's what this does so when an engine
threw a rod that's a term you will hear
this broke and just went sideways broke
the cylinder and just came out of the
side of the engine that's what an engine
that threw a rod through
this but let's get the distraction out
of the way and let's focus on the most
delicate part of an
engine the piston
Rings which did you notice that this one
just broke that's actually one of the
problems of this particular
engine these piston rings there's three
of them one two three the top
two and take them
out these are the compression Rings this
is what SEALs
this this piston as it goes up and down
in the in the cylinder to create create
that
compression second one is also a second
one that does the same
thing the third one is called an oil
control ring I think this one will not
come in one piece I we just rip it out
and that's okay cuz it's
broken this all this third ring which
now is in two
pieces does do you remember that jet
that was sprad here all the time well
that oil eventually going to Splash and
want to stay on the cylinder walls
this scrapes it down as we
go so we would not have oil inside the
combustion chamber which now is going to
basically your car is going to start
burning
oil see we've talked about oil
consumption in a video detailing why
they do that why engines burn oil it's
not these two these two if you have no
compression in the cylinder because of
the Rings these two will be to blame but
if you burn oil it's actually the third
one that does this so This has a spring
see if I can get it out so you can see
it this
spring sits these are actually two now
these are no longer two but these are
actually two rings and this one sits in
between them and it pushes so if
you look here it's extremely difficult
to see it because this is why this this
engine is used as a demo there are holes
here every time the Piston is going down
it's actually going to create pressure
downwards and when you have that oil
pushed in here it's actually going to
push this ring out and scrape the oil
down from the cylinder wall so we
wouldn't leave it there and then burn it
when this gets seized
from many
reasons is one of them this will no
longer be able to scrape the oil down
and then another thing Could Happen
these little passages here will get
clogged and then they will no longer
push this out and then nothing
happens now let's talk about other
things with pistons
we're not get too much into it but you
remember that mixture that we talked
about of a perfect amount of fuel and a
perfect amount of air which has oxygen
in it the per perfect mixture let's call
it in the
middle you can go either way when you go
more fuel less
air you go to a mixture that's called
Rich what the rich mixture is going to
do is you're going to dump so much fuel
here that it's too much for the spark
block to ignite all of it so some of it
will actually trickle down and come out
of the exhaust that is called a rich
mixture Rich mixtures lower the
temperature of the of the Piston so have
you ever have gasoline in your hand I
don't encourage you to do so but if you
ever had that experience it's actually
has a cooling
effect and that's what it does when you
have a rich mixture you're going to cool
things down but at the same time you're
going to build up some carbon cuz all
that unburned fuel is just going to
linger and the next cycle is going to
get burned but it's too much and it'll
leave deposits and now we have all kinds
of
problems the
second kind of edge of the
spectrum too much air too little
fuel that is a dangerous mix because
when you have two little fuel too much
oxygen you're actually going to cause a
lean condition lean conditions in an
engine are like a torch that's the best
way I can explain it if you ever used an
oxy aylin torch you know exactly what
I'm talking about too much oxygen in a
combustion will create a a very hot
flame that will actually melt the Piston
now we're not talking about you got a
code small code for system lean and that
that's we're talking extreme cases where
the computer cannot control it it will
literally melt this piston like some of
these pictures you see here it will melt
this piston because this piston is
aluminum special kind of aluminum but
it's still aluminum it's designed to run
at Optimum operating conditions not the
torch of Lan
condition let's talk about a few few
things with gasoline engines that you
should know
about the pattern is that is called
cross hatch if it is
lost
the oil rings will no longer be able to
clean that surface they're that's one
thing about them and the best part is
what wears down the crosshatch is the
oil control ring when it seizes it's
supposed to move as we go and when it
doesn't it starts wearing in one area
and you have loss of cros hatch and we
no longer
have the ability to scrape that oil down
and the engine starts burning oil oil by
the way of course oil is derived from
the same place crude oil so you start to
have elevated levels of hydrocarbons and
eventually this caused all kinds of
issues Believe It or Not engines that
burn oil actually run slightly cooler
than engines that don't and the way you
know an engine Burns oil if you like
take the spark plugs and send the camera
in easiest way to know of course if you
have cylinder whale damage well you know
that that engine potentially Burns oil
but there's one Telltale
sign which
is reading the Piston see this one has
so much carbon that this is a different
case but if you look at a piston you
look like a four CER
engine if you have a coolant issue
getting in here see coolant is a mixture
of
water and ethylin glycol in most cases
ethylin glycol is the part that causes
the antifreeze part and water is just
water it's to cool things
down if you have water here or coolant
in that case that water will steam up
it'll become like a pressure washer
it'll wash the face of this piston
perfectly
clean and if you look at all this the
Pistons one of them looks very clean and
the rest of them look dirty or not dirty
just like this you know that you have
cooling going into a cylinder and if you
have I wish we had a better example this
particular engine has a lot of issues if
you have only the edges are clean but
the rest of it is not that is actually
the same effect but of oil oil will
actually start steaming this and just
washing the edge of it that is called
ring wash that's when the ring is not
able to scrape the oil down and it's
evaporating here and kind of cleaning
this Edge only if you see that this
engine Burns oil 100% now how much that
is the question but if you see that
edges are clean but the rest of it is
normal you're burning oil now let's talk
about a few other little things with
engines this is the most basic form of
of how an engine works but let's talk
about the things you will run into as an
average o driving your car every day now
that you know more about this engine
occasionally you'll drive your car and
you accelerate you hear
this just strange rattling noise and
then it'll go away sometimes accompanied
by smoke that is called knock ignition
knock
or predestination could be either way
let talk about the most basic form of
that so we want now that we understand
how this whole thing works we want that
mixture to be ignited for our combustion
to start at a specific
point no later no before exactly at the
right time as the Piston is coming up we
want to ignite that mixture and then
push that piston
down then the the power is
throat if you for example have a piece
of carbon that got too hot and that was
hot enough to ignite your mixture before
time that's called preignition you're
going to pre- ignite the mixture at the
wrong time so what that's going to do is
it's going to cause something like this
is going to rock that piston as it's
going up because it's ignited at the
wrong
time and this is where we're slightly
going to go into the fuel compensation
see engines have a compression
ratio usually high performance engines
will have a higher compression ratio so
they can have more power that's how you
make more power out of an engine give it
more compression more air more fuel
either or or combination of that's how
you make an engine make more power
so high compression engines things are
elevated you have more compression you
have more fuel going in you have kind of
a more aggressive thing is happening
so the temperatures are much higher in a
high compression engine on top of the
piston and in the combustion chamber
than that of a lazy family car that is
just meant to drive at normal speeds and
we're good so when you have all that
extra heat
and you send that gasoline in here well
if it's too hot that gasoline will just
combust whenever it feels like it
because it's simply too hot this is
where you put premium
fuel so premium fuel let's talk about it
for really quickly here premium fuel
it's a more stable fuel so it will not
ignite only from a little bit of higher
temperature you have to have an ignition
Source it's more stable less volatile is
the word for it so when you have these
extreme temperatures because of this
high compression and things are on high
alert that fuel will be more stable be
like no I will not ignite from this
little high temperature I will wait for
that spark plug but all of a sudden you
put regular gas in a car that's designed
to run on premium fuel and you will have
detonation all day long and what's going
to happen is this will keep rocking and
rocking and rocking and rocking
eventually you're going to wear your
cylinder walls
and we're going to have major problems
but equally if you put premium fuel in a
regular car while the temperatures are
low so fuel will come in we ignite with
the spark plug and the same thing will
happen I just wanted you to understand
why putting premium fuel in a regular
car does absolutely nothing but cost you
more so now you know that part
now engines do have a protection for
this modern engines something called a
knock sensor it's a little microphone
actually it's nothing fancy it's
literally a microphone sits right here
it's actually the place for it in this
particular engine it's listening for a
specific
frequency that this piston will make
when it starts rocking back and forth
when it hears that it's going to send a
signal to the computer the computer
knows ooh we have things are happening
at the wrong time is going to
either back off the ignition timing
which will calm things down which we now
we're going to kind of ignite later cool
things down try to lower the
temperatures to control this rocking
before it destroys thing and this
happens for a little bit it's okay but
if it happens all day long we have a
problem and some cars you'll notice when
they do that strange sound you'll hear
for a little bit and it'll go away but
you need to feel a car kind of
underpowered but why does that know
happen to begin
with carbon on the Pistons and the
valves and in the combustion chamber or
poor quality fuel is usually what does
that poor spark plugs spark plugs have a
lot of carbon on them and you haven't
changed them in a very long time there's
many reasons but bottom line is you hear
that
sound this is not good you should look
into it sometimes you it's inevitable
and it will happen as engines age and
everything but if it's continuous and it
doesn't stop something is terribly wrong
and you should look into it and lastly I
want to clarify one thing there are two
types of things that will rock your
piston back and forth I just want to
clarify this because the language can be
confusing you have knocking and you have
pre-ignition
pre-ignition is when the Piston is still
coming up and you have ignition before
it's supposed to happen that's called
pre-ignition
knocking is
when the spark plug ignites the mixture
and all of a sudden you have a second
ignition from the side either it's a
piece of carbon that got loaded with
fuel or whatever the case may be that is
knocking now the knock sensor can pick
both of them but it's really meant to
detect the secondary ignition cuz we're
not supposed to pre- ignite on a normal
healthy engine but sometimes you will
have that secondary explosion that kind
of rocks everything as the Piston now is
coming down you don't want more more
combustion all of a sudden that
combustion comes up and rocks the Piston
as it's coming down we don't want that
just wanted to clarify the two cuz
they're often confused and they have
multiple names with mechanics so these
are the two terms for them and this is
what they mean and this is how a
gasoline engine works pretty fastc fting
isn't it I've had the absolute privilege
of being able to work on these engines
for a very long time and experience them
and after some time of working on them
it becomes kind of like the norm you're
just used to it but every once in a
while we just stop as a new engine it
comes out we looking into it we stop and
just wow things have come a long way
with gasoline engine folks and it's
always fascinating to me as many
thousands of engines that I've been into
and working on it's still fascinating to
me and I hope now you have a better
understanding of how exactly these four
strokes happen and how this beautiful
piece of engineering Works folks I hope
this video was helpful informative I
hope you learned something new if you
like it consider giving a thumbs up if
you're not a subscriber consider
subscribing to the channel check out
some of my other videos until the next
video folks may the Lord bless you and
keep you and you have yourself wonderful
day
and in case you are wondering what will
we do with this engine after we're done
with this video which is basically a
junker we're going to turn it into a
bongo listen to
this there you go
[Music]