Marine Diesel Basics - an SV Tapatya Special

Closed Captions (CC):
[Music]

so we're not supposed to be here this

weekend we went off to do a sailing trip

proposals but it brings had a few issues

and the engine overheated and we ended

up going back to her home marina had to

order a couple of bits so here we are

and Hazen was asking about engines so I

thought why do a little marine diesel

101 and this is the utter basics of

marine diesels but but for people who

don't know anything and that may be

solid murmuring Diesel's 101 so we've

got this volvo penta there's an md 1b

single cylinder marine diesel they all

work on the same principle and basically

speaking you've got a piston attached to

a crankshaft crankshaft down in there

but she can't see but you should see the

piston here and as that as the crank

shaft rotates the piston as you can see

moves up and down okay that's the basic

principle what's that in that piston is

up and down that piston moves up and

down in the cylinder and just grab that

and in this case is assumed that that

piston will slide up and down in so what

we're going to do now is we're going to

get that piston in that similar what

you'll notice on the piston I hope here

is that you've got if you get in here

you got one two three four rings sprung

a cast iron rings that are sprung there

and they eat graph to compress those

squeeze them together so that we can get

it into that cylinder because that's

what seals the piston in the cylinder

we've talked about but more about that

in a minute I say this is a single sim

though it doesn't matter he's and this

just got his prints in the lighthouse

resistor just go to it

just pop these off so that we can get

that's in their own without too much

hassle

pop them offices mm-hmm yeah yeah do you

get too old yeah they were help but

after a very long time and you stopped

burning or when they when they want it

good you see that oil ring is different

this guy yes yes sorry first elbow

it's just a solid ring you understand

those rings are sealing it in there yeah

without the Rings and skills and then

but it compresses the air yes sir

Priscilla sighs so how we say it

so we've got the cylinder in position

and now when we rotate the fly or there

rotate the crankshaft you see the piston

going up in there

yeah yep so this is basically a pump or

a compressor on the top of here comes

this puppy

goes one way around that wherever there

is a good sorry now it's starting to

look like something

alright oh yeah yeah and bigger

well pretty tall so the the distance at

the piston moves from the bottom to the

top is called the stroke and because

this is a single cylinder engine it's

got fairly long stroke I with twin sons

you don't need such a long stroke and

benya now you'll see that that bit fits

on the top and seals the top of that

cylinder yeah if you're a piston rings

in position which we haven't we wouldn't

be out to turn that over now okay

because it's a very very hard yes we'd

be compressing here when the piston come

to the top and that would be a lot of

compression and we really struggle to

turn that around

okay so let's assume that and you pop on

your engine you got to it yeah

at the top here we've got two valves see

them they're coming again two valves

wanted to he's open and shut when we

look at the other side of the cylinder

head in it off again you'll see the two

girls there

one two I'm trying to get out of the

light there's your step

yeah so we've got two valves one take

they open enclosed and we've got another

thing in there that thing there is where

the diesel squirted in it's called the

injector that's corrosive easily when we

look at the other side that's in his we

see the tops of the two valves there and

the top of the injector there and these

are high pressure diesel pipes yeah and

the high pressure diesel squared alone

bumped along Goodson over put that back

on here so these two valves are opened

and shuts by a thing called a camshaft

the camshaft is down in the bottom of

the engine down here somewhere down

there it runs through there okay it's

down there and it's connected to the

other shaft the crank shafts that is one

end of the crankshaft all right

the crankshaft and we look at it look at

the crankshaft there and follow that

line through will notice that is in line

with the output end of the gearbox here

that pop out boy that's where the chaff

goes off to the propeller of the boat

yeah on there if I put it in gear when I

turn the crankshaft around you see the

propellers driving yeah take it outta

gear stop if I get it out of gear days

there we go

only to reverse now see ya oh it's out

yeah yeah yeah so there's a gear shift

see that got into reverse

yeah that forwards neutral yeah simple

so basically speaking what we've got to

do to get our propeller to turn round

remember the propellers fix to that yeah

solid fixing we've got to get out is

that the prop shaft we're gonna get that

crankshaft to turn around over me yeah

yeah easy enough yeah good so if we can

get our motor to turn the grain shop

around and we've got drive to a prop

shaft them yeah brother

yep so back to this we've got two shafts

that one the crankshaft the other one is

called the camshaft yeah it's very thing

though you can't really say this is an

old pump on the end of the temperature

let me find your camshaft so you know

what one looks like

Oh God the camshaft kicking about here

somewhere

I've got a crankshaft and camshaft with

another look at it what is that well we

just put on the Pistons no the cylinders

and how many cylinders you two it's a

bit like your engine in many ways isn't

it

yeah you got to set this one the echo

with not water yeah okay

when we're doing something in a close it

something in exalt crankshaft okay

that's that's brilliant here not from

this engine but different engine okay so

in some of the crankshaft okay so this

would look like this just without one of

that exactly precisely don't you got

half of that so you've got that the

shaft that runs through in line there

you see ya and then you've got one of

those in there or in your boat you've

got - yeah

as this turns around from a heart the

holes down here as it turns around you

notice that they off-center aren't they

yeah

so our piston is connected to these oh

yeah so as that turns round moves up and

our Pistons moving up and down that's a

piston movement that we saw in there

completely simple yeah right the other

shaft we've got see that yeah cam shaft

so that camshaft is through yeah you

come around this way just mounted in

there in there it's not this isn't the

cam trial from this engine but

nonetheless is in there you can imagine

it being through that bump in the engine

there okay

as this one rotates you don't notice

these things are called cams for me I

believe just because the two cylinder

you've only got on this engine I've got

two of them does that rotate see the

cams

position got that when we look back in

that inside of here all right back in

there like that you'll notice that these

two buckets here but like that buckets

called a cam follower or sometimes

called a tap it it's not really they for

it name but a lot people and have it as

this turns around these are literally

sitting on those cams okay

as it turns around they go down and as

the cam comes around they're pushed up

mmm-hmm

if I now push those downwards and rotate

our crankshaft which is very difficult

do it up over at the piston can you see

them moving can you see this I get

around this side see that one going down

that one went down you see that now

that's it up see how that works

yeah wait a while before it moves again

here we go up see ya

and so on up right yeah good so that's

the camshaft in there moving those cam

followers good then uh once you got the

cylinder on you can spin it around no

trouble cuz the Pistons snegoff yeah

they're gone all back up good some of

the back together

do you remember down near our camp shall

force the cam followers right we can see

them down there the camel followers are

down in there yeah yeah Joe's dog yeah

so I'm gonna pull that back home there

now down in there then come follow yeah

good well up next is two rods called

push rods they sit in the cam follows

get rid of salad dust I don't really

mind about this engine normally it after

work cleaned this difference it the

movie like this

and there that goes that one yeah don't

move every time yeah so long word yeah

yeah they actually only move every two

times the piston comes up so they start

at the top lip stop first at the top

yeah yeah yeah piston goes down jumps to

the top again so that waved yeah there's

that one movie so now they're at a

position where if I go backwards that

one moves mmm before is that one those

yeah see that so we start there at

that's we call it on rock they're

rocking but you get in a position where

that one was there and that one lose it

in the rocking alright so they start

pissed at the top now we go down once

come up to the top once ever moved of a

mmm go down again next time we come to

the top they're gonna move that you just

sort of oh yeah all right

so they move every two times the piston

goes up in there Jeff

so now we're back together as you should

be this will pop here the balls they're

fitting them cups on the top of our push

rods he comes in there pusher up that

way he goes in there like that with them

two balls sitting in there push push

rods all right yeah yeah and that's

almost out for Derek screws go together

yes

step back together

that's it rupee see if it works

yeah going on then exactly just down

yeah yeah hey remember those valves yeah

they were innocent in the head don't lie

so so as we rotate our crankshaft our

push rods they're real is it clearly

happening now they're opening their

valves are they and the springs are

shutting the bells again do you see them

working yeah clear yet sorry

what we've got to imagine one of these

valves let's air inter send one of these

fellows let's exhaust gas Allison

okay do you know which does which nobody

speak I think I think that was in this

world we can work it out if we rotate

let's get them on to rock again

as Rob okay when they're on rock the

crankshaft

I should tell if the crankshaft always

turns clockwise at least in my

experience always turns clockwise hey

when the vowels are on rock as they are

now yeah they're on rock when we're

turning the crank shaft clockwise the

first one opens exhaust take one's inlet

good so now we know so let's watch what

watch what happens here

so good yeah the inlets about right

inlet valve air filter this is quite

similar to the one on your engine

exactly the same that fits on there yeah

it comes in here through the filter in

there

right okay good

piston that the moment is at the top I

think when we had it apart we noticed

that the valves are on rock when the

piston was at the top yeah it is any

I'll take you from me instance at the

top we rotate a crankshaft clockwise the

piston goes down all right

piston goes down and the inlet valve

opens so that air can now Florian is

sucked as the piston goes down it sucks

air in through layer into the cylinder

got it

yeah this thing gets to the bottom inlet

valve shuts you sit yup watch I'll do it

again

go Pistons go down in the boats gonna

shut now yeah Chuck Pistons at the

bottom cylinder is full of their own

yeah yeah piston comes up nothing's

gonna happen rid of elves let me just on

where that bottom is somewhere around

there it's gonna turn 180 degrees for

the piston to come up to the top one on

the right here degrees around their

piston is now at the top

nothing up and they're both fell stay

sharp yeah Pistons at the top or at air

there's now a finger press because if I

was a shotgun go anywhere you depressed

finger pressed a lot it's been

compressed by a ratio of approximately

20 to 1 yes yeah so you saw the size

that cylinder let's say half a liter

fits in here when it's full can't the

fire might be a bit more bring out the

top it's got a 20th of that volume yeah

all right it's very compressed does that

mean it's hot it means it's hot remember

our physics yeah compressing it with

increasing the pressure we increase the

temperature yeah it's very very hot our

ejector now squirts in diesel in 2000

into the cylinder into that very very

hot air and it squirts in a really fine

spray of diesel

how's it know when to do it you'll

notice these are the high pressure

diesel lines that you have on your

engine a you'll notice that they come

over here well I would do it for fear

properly there's not over here that one

screws on there oh yeah that one screws

on there that one comes on there these

are for this is the diesel pump a

high-pressure diesel pump under here

yeah under there is another little

plunger that goes up and down like the

listen just a bit like the bit like the

push rods and come house okay what do

you think moves out and down this

turning the crankshaft yeah which

particular part I see where it's mounted

is pretty much dead above the camshaft

on it yeah so the camshaft goes all the

way through there and has got another

cam on it okay that pumps this little

pump yeah so that's a high-pressure

diesel pump this time that's why the

camshaft when when that cam comes round

pumped increases the pressure a valve

opens in there and the precious flows up

this high pressure line into our

injector there's a valve in the injector

as well but it it opens and sprays in a

really fine really fine sprayer diesel

into a really hot air in there yeah if

it's hot enough diesel starts to burn

which it hopefully is on earth yeah Ezra

starts to burn and we increase it when

it's burning obviously we increase the

temperature in there more yeah when we

increase the temperature we increase the

pressure yeah

and because we've timed that burn just

right how a piston is actually just

after the very top just after the very

top Justin time down a little bit just

after the write-off

yeah that increase in pressure pushes

that piston Dale okay third just after

the very top it suddenly pulls down

right down by the pilot burning of the

diesel in there okay and that

but isn't it push down anyway because

the crank shaft rotates what's making

the crane shot rotate know this nothing

okay nothing to start the engine room

but we have to have an electric starter

that's get that's turning the crankshaft

round yeah you won't start by itself so

we have electric motor that turns the

screen shot well yeah yeah so we get all

that that would be looking at we get the

vowels moving and get the air going in

we get the diesel pumping we have a

little electric motor yeah

okay so increasing pressure then turns

yes exactly and now the motor is running

itself we can switch the starter motor

off did I pick my drove yeah and now all

that burning diesel in here pushes the

piston down there it goes

and then now the piston is and now

that's got enough umph about it it goes

down with such such force that we've got

this enormous heavy weight on the front

of the engine in this case on yours it's

somewhere on the back but you've got

enormous heavy one attached to the crank

Charles when we push that heavy weight

down it's got enough momentum it

character Turner lose it turn it's got

enough go about it this big every way to

bring the piston back up the top and as

the Pistons at the bottom and just about

starting to come up

we see our exhaust valve opening okay so

that releases is that pressure order oh

yeah

it pumps the burnt yep these will ania

out the exhaust yeah yeah

so piston comes back up to the top

pushes all that burnt stuff out the

exhaust oh yeah yeah comes out there use

that finger a little bit deploy and

there's our piston back at the top yeah

starts again inlet valve opens it's

still got enough weight here

nothing not from a Minton from not that

way to turn it around okay in that Bell

so still turn around from from the force

of that one big push down on this heavy

weights got enough to turn it around

twice yeah that's good piston sucks in

here gets down to the bottom up it comes

still from that white turn around

at the top spraying diesel off we go

again pressure off you go down we go

down we go down we go up we come open

his or self out so it's called the

four-stroke cycle you've got four

strikes a stroke remember as a movement

of the piston either up or down or up is

one stroke let's look at it Pistons at

the top stroke one move down inlet valve

opens types in here alright just fun my

top pocket mark for the top isn't it

okay yeah good down ego sucks in here

down to the bottom stroke one hold it in

let intake intake

piston comes up compression yeah yeah

snakes don't know pistons at the top

again it's run fuel squirted in starts

burning combustion yeah combustion

combustion engine or commercial me no

okay

pistons at the bottom into the

combustion thoughts come up exhaust

exhaust yeah yeah so and then starts on

in legging hmm intake compression power

or combustion exhaust and it just keeps

going around like that yeah sometimes

called suck squeeze bang blow something

squeezes it bang down she goes blow it

out again mmm yeah there you go yes

that's how it works okay

it obviously generates a lot of heat

yeah that Bernhard Eisel makes

everything really really hot too hot we

need to keep it cold we need we're not

cold we need to keep in a safe operating

temperature range it gets hot but we're

not ridiculously hot so things start

melting and they would so we need to

pump water around here so all of this

has got we're not look at I've got

another cylinder here see that's another

there mm-hmm

you see those those are our water flows

okay I was in there flows all the way

around that cylinder it's all hollow in

there or froze all the way around it

okay it's in Russell here from water

these puppies generally saltwater called

you've got two options you've already

got pure sorta cord or you got a to

recruiting system which you're in yeah

yeah this one we simply pump we have a

pump somewhere with an impeller in it

mm-hm the pumps this one's a water

around all of their this comes up around

the cylinder head as well keeps you cool

out the exhaust comes out the exhaust

okay okay you see so I always hear my

left there that's the exhaust gas and

the result

what comes out there I think okay yeah

in fact this is a water cooling way here

force in the head on your one you've got

a closed system of water in here okay

with a pump that pumps it around in this

closed system yeah

so it's in there it comes out of there

into a thing called a heat exchanger

that's that mounted on the side here

yeah

heat exchanger so guys out of here

through the heat exchanger back in there

it's keep through come to keep circling

it around from pump through the cylinder

through the exchanger back down to the

pots off yeah the same water you've got

another system that pumps the seawater

through the heat exchanger heat

exchangers got two tubes in it basically

one in the middle that the closed

systems going through and around the

outside of that salt water pumps yeah

the two never mix okay but the source

cold saltwater flying around the outside

of that should be a lot of tubes with it

with this closed system croonin water in

it cause it down yeah yeah that's salt

water for you is thing joins into the

exhaust and goes out the exhaust yeah

all right okay you've got a fuel filter

yeah yeah yeah that's I recognize yes

no where - on your system you've

probably got more fuel filters but you

always always almost always have one on

the engine somewhere okay you see this

is filtering you see what it's doing

this is fuel in here yeah coming into

the filter and he's coming out of the

filter and going into a diesel pump hmm

yep so we've got clean diesel going into

POC the arrows on this is oh yeah

flow direction and what does it filter

out any miles in diesel any money okay

but this one doesn't have like a water

no I had a trap somewhere else this one

doesn't this pure filter is for making

when it's filtered enough mark out of

the diesel the filter gets blong it

bummed up gets blocked so if these will

come flow through it anymore yeah yeah

in Gemara

yeah physical gain in diesel it's not

rocket science

yeah you have to change the few other

basically exchangeable some of them some

of the old ones a clean of all most of

you do take the filter out throw it away

but in your world okay all right

when that is eat that's not there

they're remarkably simple

there's no electrics needed apart from

for the electric motor to get it started

yeah and a petrol engine you need

electrics for the hinge in the run but

not not on the diesel once you get

started you don't know any latex but not

on this one of these man modern car they

was a bit more technical bang yeah

so you can switch the electrics off and

the diesel engine once is running we'll

carry on running yeah you could take the

battery out throw it overboard if it's

running it will carry on running doesn't

need any electricity to us um sometimes

you've got an electric fuel pump which

is a silly darn idea because often this

one was gravity fed so the fuel tank was

above snows came and elbow gravity very

often you have a little fuel pump

somewhere on the side you have on this

side at the front here somebody ran

through a pump that's pumping the fuel

up out of your tank and that's also run

off of the camshaft okay so I don't know

in fact you've got four can know you've

got two cylinders so so you've got six

guys I'm here for four the push for ya

one for the DS upon one Philip but the

high pressure diesel pump one for the

low pressure diesel no yeah okay you've

got a list pump yeah

the low pressure diesel pumper stays on

this side of your engine left

yeah pressure diesel yeah just to get it

yeah and on your boat is that with

gravity pump on it at the moment and I

will I will use your finger stuff yeah

yeah gravity feed is beautifully simple

we can't go wrong into social flow down

is that like gravity

your mother always works there's a

little pump and we've got a couple of

little filters in the pump cover just

wire mesh yeah I can block up a pump can

break it happens but sometimes you have

to put a new lift on them they're not

very expensive but listen of these three

yes you're filming a lot yeah yeah yeah

no but that's it this is really as

simple as that there's nothing to it

yeah off your crankshaft you're running

an alter later some engines to

alternators you've got a belt on Nick

off the front of your crankshaft yeah

you got on your front of your crane so

have you got two belts yeah one runs to

see your bump

yep yeah one that runs the fresh water

pump yeah and an alternator where does

that alternator to the alternator makes

electricity ah

it's called an alternator because it

makes alternating current

IEC uh yeah but because of boat runs on

DC entirely in the back of an alternator

you've got a set of diodes that convert

that AC into diesel

okay mm-hmm yeah we took yeah so it's

you know it's really nothing to it

really nothing to it

you got an electric start a motor

mounted over here your alternator

mounted over here

with obviously wires coming to it yeah

but the wires aren't there it's like the

engine run apart from actually start it

one thing you running remember you could

switch all electrics off the thing you

carry on running yeah so I think I know

what's the turning crank crank shaft

yeah well I think I know which one it

but mine's really small yeah well you

haven't got this big flower on the front

yeah you've got yours follows in the

back here somewhere

it's hidden in this casing yeah okay so

that they're somehow connected

the floor was faulty to the crankshaft

oh okay really look at these

this is why we'll in the middle of it

yeah so yeah sure

yeah so it doesn't matter where the

flywheel is it will be somewhere bolted

to the crankshaft it can be on either

end or in the middle yeah it's got bad

flow because it that's the mass that

stores the momentum to keep that piston

going up and down remember only fires

you only get burning one once every four

strokes you've gotta get it round yellow

three strokes purely from all that

weight being yeah just keeps it moving

all that way she got that floral mmm

Ramadan flow and is that do you think

that's reckon that serious part of that

engine is one of the reasons why they're

so early yeah also you remember that

that it compresses twenty to one roughly

speaking ratio

yeah is the engine itself has to all

quite heavily built yes stand that

pressure yeah and you said with if it

just has sorta cooling then it needs to

be more do you understand that's all

recruiting yeah this is all crossed on

this one was slowly exhaust on pushes up

to the task up to the water it moves it

rusts a little baby so we rust in there

yeah it lasts a long time

okay guy says his her the basic

principle of brain teasers and you know

glue won't go into a lot more detail

there but I said the fundamentals of how

they work in Heerlen gets the boat

prepping the hull at the moment so it's

a lot of and it's very hot time if he

hit very sweaty

dusty work going on in here but it's

looking great and nearly ready for some

paint on the hull will leave it for that

and leave it there for this weekend

thanks for watching we'll be back on the

boat next week see it

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she was kissed by her son

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by taking it in a new day has begun

still going steady

she stopped by number one

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to turn and strike as the day got right

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