4-stroke internal combustion engine demonstration

[TheLionRichard]

How is the piston oiled?

[DrDaveBilliards]

@TheLionRichard

Oil is splashed around in the crank case to lubricate everything.

For more info, do a Google search for "lubrication in small engine"

[Greengun420]

Are those the only parts in a 4 stroke engine??

thanks in advance :)

[DrDaveBilliards]

@Greengun420

Obviously, in a modern and larger engine, there are more "details" to make everything work efficiently, but the 4 strokes are the same.

[starlitopensky1]

Very good job guys! The best explanation I've seen so far.

[DrDaveBilliards]

@starlitopensky1

Thank you.

[enkeibeloved]

thanks for this video--very concise and informative.

[DrDaveBilliards]

@enkeibeloved

You're welcome.

[surendarbaby]

sir, i have dought... except power stroke all 3 strokes are done by the stored energy of fly wheel.... at the very first begining how the suction stroke is done...?

[DrDaveBilliards]

@surendarbaby

An electric starter motor (or pull cord with lawn mower) is used to get the cycle started.

[sameer0403]

sir its one f d brilliant videos wich tell abt d wrkng f cam shaft...ie how d inlet valve open wth d hlp of spring..

i wnt to know mre abt it...as m persuing mechanical engineering

[DrDaveBilliards]

@sameer0403

The cams open both valves. The springs return the valves to the closed positions.

[himanshuhoney5]

very useful for a mechanical student like me......thanks for helping me sir...from india

[DrDaveBilliards]

@himanshuhoney5

You're welcome. Thanks for the comment.

[2617Saad]

it was very useful,ic engine described very well in a nutshell!

[thefunkyone247]

I'm studying about engines and this video was very helpful. Thank you. From uk

[DrDaveBilliards]

@thefunkyone247

You're welcome. Thanks for the comment.

[Thetrutv]

The cum short

[nonfatkibbles]

from knowing nothing about it this video was good and clear

[DrDaveBilliards]

@nonfatkibbles

Thanks!

[iiNaRcOtIkZz]

I'm still wondering how can a car go fasterr... They use mods or wut?

[DrDaveBilliards]

@iiNaRcOtIkZz

... bigger engine (more and larger cylinders and valves) and transmission.

[iiNaRcOtIkZz]

@DrDaveBilliards thank you

[DrDaveBilliards]

@iiNaRcOtIkZz

You're welcome.

[impromptuXpk]

Amazing demonstration, thank you so much for this. It was exactly what ive been looking for and helped me understand more clearly how the valves work

[DrDaveBilliards]

@impromptuXpk

Thank you ... and you're welcome.

[LordIllidan98]

Great demonastration. I copy-pasted every word you said on the 4-stroke cycle, on my essay..... at least it's not plagerism ;) Thx hope I get a great mark

[DrDaveBilliards]

@LordIllidan98

Actually, that is "plagiarism" unless you acknowledge the source in your essay.

Dr. Dave

[LordIllidan98]

@DrDaveBilliards yea yea anyways thx

[garfield9001]

@LordIllidan98 Hope you get an F you dip shit, who adnits to plagurrooosim, LOLZZ

[LordIllidan98]

@garfield9001 go check ur spelling, then u'll b decent enough to talk in the internet, not real life. go practise in microsoft word or notes

[debasissanjukta]

nice presentation......cleared some doubts...thanks a lot man...great vid

[debasissanjukta]

nice presentation.......u cleared my doubts about valve operation

[DrDaveBilliards]

Thanks. I'm glad you liked the vid.

[blazinloud]

great video, thanks

[DrDaveBilliards]

Thank you ... and you're welcome.

[dsrevo79]

i need to revive my scooter for summer,, it has old gas that need to be replaced,,,i don't know what else I need to clean besides the spark plug, and re charge battery...for it to start...any help? its four stroke 125 cc Piaggio Fly..

[bazzab0mg08]

Good video !!!!!!! uk

[visualxjinsei]

Thank you for the good video. It helped me figure out what's considered to be "one stroke".

~Kale.

[DrDaveBilliards]

@visualxjinsei You're welcome.

[rebelformetal]

awsome explanation of the 4 stroke cycle. you should make a vid of the 2 stroke cycle.

[DonHoraldo]

very nice vid. glad to see you didn't mangle your finger in the gears.

[DrDaveBilliards]

Thanks.

Luckily, there was a Plexiglas covering over the crank case ... so there wasn't much danger of finger mangling.

[djtekfour]

Nice video Dr. Dave!

[DrDaveBilliards]

Thanks.

[2S1D3]

wow nice video mate, I'm going to pick mechanical engineering next year in uni as i can't see myself doing a business course and i've always loved cars and physics in general, nice video again :)

[DrDaveBilliards]

Thanks, and good luck with your program.

Dr. Dave

[FliegenCockatiel]

I have a couple questions: one, why is the exhaust valve smaller than the intake? According to my (not-so-educated) understanding of thermodynamics and engine function, you want that the other way around, and also, how old is this engine?

[DrDaveBilliards]

I think the exhaust valve doesn't need to be as big because more pressure is available after combustion. I think the engine was about 10-20 years old.

[FliegenCockatiel]

Good vid! Earlier this afternoon I took apart a side valve engine like that one, and noticed that if you remove the cylinder head, you can see the valves opening and closing as well as the piston's movements at the same time, which explains it reallly well. I'm thinking of making a vid about it from such angle, using yours as a guide.

[DrDaveBilliards]

Sounds good. Please post a reply when your vid is available.

[twitchyring]

I'm considering moving into engineering after realising I can't be an office monkey anymore. This kind of video is brilliant for me. Lehman's terms and a great model being used for your instruction. Thanks.

[DrDaveBilliards]

I'm glad you like the video. I wish you luck with your "move" into engineering.

[nudistfla]

Thank you very much. Regardless of any comments, your video instuctions and info about engines is great. can you send me a link or tell me what others you've done. Also We've used this video at auto tech school as your basic conceptual model. keep em going thanks

[DrDaveBilliards]

The link to my video-demo website can be found in the video description text. Engine-related stuff is in the "Mechanisms" category.

Enjoy,

Dr. Dave

[kreidlermaniac]

its a briggs and stratton engine isnt it?;)

[DrDaveBilliards]

I think so, but I'm not sure.

[kreidlermaniac]

ow.. tnx mate;)

[highdeserthater]

it is. you can tell by the shape of the rod. briggs makes hevyer better rods than tecumseh, and honda never made flathead engines. other engines are much to valuable to be used as a demo.

[DrDaveBilliards]

Thanks for the info!

[KapRowMeat]

i think it is... i have a water pump from briggs and stratton really tough engines

[kreidlermaniac]

i've just made a generator(12V with a briggs and stratton:)

it works perfect, maybe i'm go for uploading a little movie on youtube,

;)

[curlyheadify]

Thank you, thank you so much:) And how about the first sentence I was refering to?

Thank you for your time and patience:)

[DrDaveBilliards]

See below.

Good luck with your studies,

Dr. Dave

[curlyheadify]

And then another one. You say: "Its a four-stroke engine" AND here comes a couple of words that I don't get but I do get what follows "the piston descends sucking the air and the rest that follows.

I would really appreciate your help

thank you for your time,

[DrDaveBilliards]

"This is a four-stroke engine, and the four strokes involved is (should be are): the first stroke ..."

Here, the language is a little awkward for writing, but it understandable in conversation.

[curlyheadify]

Hey Dr. Dave

I find your video very interesting. I'm a technical student and am trying to improve my technical English. There are 2 sentences in your video that I don't get and I'd really appreciate if you, or any of the users, would help me with these.

You say: "As it rotates around, it forces the piston to go up and down." And then comes one sentence that I don't really get. You continue with "The camshaft is what operates the valves and of course it has to be... " and it's ok with me.

[DrDaveBilliards]

The missing sentence is:

"It's also turning the gear over on this side, which is running the camshaft."

[desertgeologist]

Hey Dr. Dave, How is the air/fuel mixture compressed when there is a big hole in the side of the engine?

[DrDaveBilliards]

:) :) :) :)

[meanfazer]

Dr Dave ......oh Dr Dave!!!!! do you sometimes wonder why you bother'd to put this film on ....just to be bombarded with questions from fucknuts?????? hehehe,just finished sectioning my own 4 stroke single ....for sale on Ebay now,I shall video it and post just in case it does sell

[GrightGangBang]

counter weights and flywheel is what creat momentum which will pull the piston down in the intake stroke. That is why single piston engines arnt as efficient as 2 or more pistoned engines. Reason being is that when piston number 2 fires, it will crank piston number 1 in the following intake stroke...

The starter engages by a solinoid to the flywheel onto the sprockets, it will them crank the engine and eventually start on its own. Other than starting purposes started is to be maintained disegag

[rangerssteamtoys]

If you dont know how a 4 stroke works, then you have problems. If your going to work on it , know how it works, otherwise, you'll be ignorant alot of people.

Great video Dr.Dave

[aerozg]

Dr. Dave, i still don't understand, which force pushes the piston down during the intake? The air/fuel mixture when it is sucked in, along with the force of gravity, is that it? Or the electric starter, when we turn the key and it pumps some mixture in the cylinder? Please enlighten me. And which force pushes the piston up to TDC to compress the mixture? Is it the momentum, when the mixture is sucked in, and the piston moves TBC, then it "jumps" back to TDC to compress, (i don't think so :P ).

[aerozg]

Because in this video, a person is standing behind the engine and rotates that handle and the engine "works". I want to know, what "rotates" that handle when the real engine is working?

[DrDaveBilliards]

The electric starter motor helps get the engine started. Then, the combustion cycle takes over. When the engine is turning, the crank shaft has angular momentum, enhanced by the flywheel. The momentum pulls the pistons down during the intake strokes.

I hope that's clear,

Dr. Dave

[tokenchoke311]

aerozg how does a engine stay started... are you for real?? come on!!

[aerozg]

Yes i am for real tokenchoke311. Would you care to explain it? I wonder how that would come out. I understand how engines work, i simply wanted Dr. Dave to give a more thorough explanation. The detonation of the ignited fuel drives all the mechanic parts, otherwise it would all be just a pile of metal. That's the answer i was looking for.

[tokenchoke311]

aerozg for someone who knows how something works you sure ask some little kid questions.

[shadowhunter45s]

wow, the crank shaft dosent force the piston up the piston pull the crank up...

[DrDaveBilliards]

The crankshaft (and flywheel) momentum does push the piston up during the "compression" stroke. The piston pushes down on the crank during the "power stroke."

Dr. Dave

[k0ent]

haha, "dr. Dave"

you must be some hell of a professor to know the 4 cycles of a thumper!

[DrDaveBilliards]

Thanks (I think)?

Dr. Dave

[k0ent]

your welcome....

[corotor12345]

WHOAH!! are you new on engines? dont say that blasphemy about the crank... please, never again, you would be throwing all the tech behind F1 engines revving so high, out the window...

[wingking077]

thats kind of what I was thinking you were

[wingking077]

that guy has 3 hands

[DrDaveBilliards]

3 hands come in handy.

Actually, one person was turning the crank and holding the engine down while the other with gesturing and narrating.

[wingking077]

no im pretty sure that guy has 3 hands

[DrDaveBilliards]

I cannot lie any longer. I am an alien with 3 arms. :)

[pinchharmonics]

yup, no other possibility

[mickeymoose76]

you cant see the valves...

[DrDaveBilliards]

The valves are shown and explained starting at 1:37 in the video.

Dr. Dave

[sthalwille]

is it John Edwards ?

[dooley09]

You say the crank forces the piston to move, but it's the piston that provides the force.

[DrDaveBilliards]

Actually, the pressure from the expanding air-fuel mixture during combustion is what provides the force.

Dr. Dave

[Quarker99]

nice video,, i didn't know how the valves opened until i saw this vid... its a gear... great vid, this has aided me in my mechanical studies.

[9020powrmax]

In real life that engine won't last too long unless you put the DIPPER back on the rod...........

[vr00m123]

Gotta quick question if anyone would care to answer. Is the exhaust lobe of the camshaft usually smaller than the intake?

[sb6lb3]

im pretty sure theyre the same size. i dont get why the exhaust valve is smaller though.

[rudolphna54]

No, but the exhaust valve is usually smaller.

[CaptainFox91]

thanks

[respectzisha]

DrDaveBilliards your the best i was looking all over the web for hands on animation of a small engine thanks alot.....

[obamasux69]

sir do you know how to fix a engine sir please help me

[DrDaveBilliards]

It's easy to fix an engine. Just find what is wrong and make it right again. :)

[k0ent]

@obamasux69,

depends on whats broken, how are we supposed to tell you how you can fix your engine if we dont know whats wrong?

[alimiralimir]

where can i buy a dvd sir???

[shaz4real]

anybody got dvd or information about it

[alimiralimir]

sir you know how to modified the 4 stroke engine 110cc for dragracing???im from philippines...

[DrDaveBilliards]

Sorry, I can't help you. I'm not a motorsports or engines expert.

Dr. Dave

[k0ent]

@ alimiralimir,

why do you want to drag race with a 110cc? drag race bikes are more likely to have 2000+cc's, but if you want to you could get a bigger carb, akrapovic muffler (or leovince or something) wider expansion and you could get a big bore kit, theres tons of stuff you can do, but i think that your engine comes from a pitbike / dax/ monkey and those engines are not realy made for racing.. if you want to go faster i suggest you look for a propper 125 / 250 dirtbike

[alimiralimir]

dr,dave im from philippines you know how to modified the honda xrm 115cc 4 stroke???tnx and godbless

[DrDaveBilliards]

Sorry, but I don't understand your question.

Dr. Dave

[Mrboombastic50]

engines are amazing, yeah they do pollute but then again what else could you use that works like that and doesnt. and before anyone says hydrogen yes ok but.... im talking about something that is just as easy as petrol, diesel/bio diesel. but then agen i live in yorkshire where thier already developing hydrogen cars and stations to fuel up. 64p a litre woooo

[MoPar7055]

Females don't count since they don't know anything anyway. Cept cooking

[MoPar7055]

If you don't know how a four stroke works you're a retard

[DrDaveBilliards]

I guess 99.99% of the world's people are retards then.

Dr. Dave

[MoPar7055]

Somehow I doubt only 1 in 10,000 people know how a four stroke works

[DrDaveBilliards]

There are a lot of people in this world who are not educated and/or don't know much about cars or engines. Obviously, you and I are not in that group.

Dr. Dave

[MoPar7055]

Yes unfortunately, its like the ABCs intake compression power exhaust. Oh wait I thought it was compression then exhaust holy crap how retarded would you have to be.

[foxwhore]

yea dumbfuck not everyone is gear heads like me and you you god damn down syndrom.

[Add1cted2Fresh]

great explanation!!!

[mageac]

suck squeeze bang blow... excellent way to remember the strokes...

[MotoCrossCanada]

lol thanks!

[pierupower]

pretty crappy without valves...

[DrDaveBilliards]

I'm not sure what you mean. The valves are clearly shown.

Dr. Dave

[pierupower]

Oh right, sry I was blind for a second :D

[joness105639]

wow, no valve overlap. Thats not so good. You lose some volumetric efficiancy that way. I suppose its not really designed to get its peak power at the higher rev ranges.

[ze3mdahab]

great

[rjscott2007]

or is up and down two strokes?

[DrDaveBilliards]

At the website linked in "About This Video" I have more illustrations, animations, and videos explaining the 4 strokes (intake, compression, power, exhaust). Got to "Mechanisms" - "Internal Combustion Engine."

Dr. Dave

[rjscott2007]

why is it called 4 stroke if the piston only goes up and down twice B4 combustion again?

[sayedsayed55]

1 suction

2 compression

3 work ( explosion )

4 exhaust

that's why they called a 4 4 stronke cycle

[sobby36]

Its 4 strokes per cycle...basically it goes up and down twice to complete a cycle

First 2 strokes (or first round) = suction & compression

Second 2 strokes (or second round) = combustion & exhaust

[boneyardcreep]

also known as... Suck,Squeeze,Bang,Blow 4 strokes

[mustangguyy]

What is the guy turning the handle acting as, in other words what moves the crankshaft?

[DrDaveBilliards]

The combustion in the cylinder above the piston creates pressure which pushes the piston down to keep the crankshaft turning. If the go to the "Mechanisms" portion of the website linked in "About This Video," you can find many more illustrations and animations.

Dr. Dave

[roremster]

Thanks a lot for telling me all that info on 4-stroke engines. Do you know if a 4-stroke or a 2-stroke engine is more powerful?

[DrDaveBilliards]

I'm not an engine expert, but I think the answer is: "It depends."

Dr. Dave

[bmxer193]

if you have 2 of thesame size engines but one is a 4-stroke and the other is a 2-stroke, the 4 stroke will make more power but the 2 stroke will go faster. (remeber speend and power are 2 very differnt things)

[roremster]

thanks!

[SKarmytech]

well i'm sorry but your info is totally wrong, a 2 stroke engine those from Caterpillars or Detroit have conventional oil pumps, fuel injectors and valves like the 4 stroke engine, they have the same compression, they all get the same energy from the fuel, the correct statment is that 2 stroke have twice the power then the 4 stroke, do not compare a simple chainsaw engine that as been designed to be simple with a complex 4 stroke engine from an automobile

[AK47jt]

ummm...im a macanic..4 strokes have more torque and 2strokes have twice the power of 4strokes...

[Blutarsky90]

With the same size the 2 stroke should be two times more powerful than the 4stroke,but it's much less efficient,so it needs more fuel...

[roremster]

thanks for the info!

[SKarmytech]

well i'm sorry but your info is totally wrong, a 2 stroke engine those from Caterpillars or Detroit have conventional oil pumps, fuel injectors and valves like the 4 stroke engine, they have the same compression, they all get the same energy from the fuel, the correct statment is that 2 stroke have twice the power then the 4 stroke, do not compare a simple chainsaw engine that as been designed to be simple with a complex 4 stroke engine from an automobile

[Blutarsky90]

ok,maybe its incorrect but its not TOTALLY WRONG.Anyway I was talking about 2 strokes from bikes,that usually have no valves neither electronic injection and are about 40-50 % more powerful using 100 % more fuel.I dont know much about those caterpillars you are talking about,but you are right,if they use valves and injection they should have the same fuel efficiency,and double volume efficiency(so they are lighter).Hope now i've been clear,it's quite hard to explain this in english!

[SKarmytech]

yes most 2 stroke bikes have less efficiency using inlet and outlet ports cause they lose alot of pressure with them, but these normally happens on the old classic engines, cause the new engine of the nowadays are super efficient ( i'm talking about those from bikes now ) for example most of the Yamaha DTs from 80 were smoky and had less pressure, but with the great refinations that Yamaha has made to their engine made the engines great, most of the 2 strokes aren't what most people think

[SKarmytech]

also the fact that these engines aren't so popular or in the public eye because of their smoky past lmao

[AK47jt]

ummm thats funny cause i have a ttr125 and a kx100 the kx gets beter mpg

[roremster]

Thanks!

[AK47jt]

2 stroke twice the power

[PHAEDRIDER]

not really .. twice the speed,yes, but under a load alot of energy is wasted. thats why 2strokes a re best suited for outboard motors and bikes and saws and stuff that can build momentum faster.. they can deliver alot of hp quicker, but not torque..

[AK47jt]

wrong...its not 2the speed its twice the power bsic mecanics

[PHAEDRIDER]

dammit.. my bad!!!duuuuuhhhhr . you're right..

same speed (actually, speed, shmeed engine only goes as fast as one makes it go), less strokes between combustion 2x the power per revolution. "basically".. now for the most embarassing part.. i've been a full time small engine mechanic for 12 years, and really do know (un modified) internal combustion engines very well. i'm good at it and it keeps me fed.

you're right i blew it on that one..

[Coasterbill42]

Thanks, I'm in an small gas engins class and this helps a lot.

[youfriend69]

isnt the big one the exhaust and the small one intake......

[DrDaveBilliards]

Watch the piston and valve timing in the video. The large valve is open during the intake stroke.

Dr. Dave

[marooncorsa]

no the other way around

[TheCottonTop]

This video reminds me of summer camp. LOL

[brownthug2b]

thx for the upload i was comparing rotary engines and normal 4 stroke engines an from this video i wonder...like this engine needs to make 4 strokes before it re-runs the cycle again but the Rotary engine does it all in one revolution...so shouldnt rotary engines be faster than 4 stroke engines???? i'd like sum feedback its really bothers me....

[EliteMadHornet]

rotary engines are faster than four stroke engines, they move at a much higher rpm but they dont make good torque until a relatively higher rpm also. basically, a four stroke engine in a Chevrolet Camaro's redline is at about 7500 whereas a rotary in a Mazda RX-7 is at about 9000. which actual car is faster depends on individual tuning specifications which we dont need to get into, but just making some real life references to make it a bit easier.

[LMF5000]

A two-stroke engine gives you one power stroke per revolution, and so generates more power, but it's not as clean and efficient as a four-stroke. Rotary engines have problems with maintaining perfect seals between the rotor and the engine wall. Rotary engines are also more polluting than 4-strokes, hence it's difficult to design one which meets emissions regulations and so not many manufacturers make them (as far as I know Mazda is the only one).

[Shandchem]

Excellent video, giving a very clear explanation of the 4-stroke cycle in an internal combustion engine. Suck, squeeze, bang, blow!

[serge933]

Very well done demonstration, how big is that engine? It seems very similar to my gokart engine lol

[DrDaveBilliards]

It is a small engine. I think it is from a riding lawn mower, but I'm not sure.

Dr. Dave

[rs4pro]

it looks like a 5 hp b&s

[Talatacus]

best i've seen so far in youtube..