Two stroke engine

[danieladamko]

waste of fuel: when air+fuel intake occur, small amount of useful gas will be wasted per cycle

pollution: especially burn oil particle because the fuel is a mixture of gasoline and motor oil, no real solution for lubrication

solve these and there will be better and more effective 2T constructions

[frank0067]

it appears that power may be lsot on downward stroke of combustion just as the piston passes exahust .. some of the pressure is released into the exhaust before the psiton gets all the way down.

[wangzaa1]

ชอบๆๆๆ ๆ

[racerwon2]

Sorry if your not mixing gasthan your not hulling ass

[racerwon2]

If yore mixing gas than your nut hullin ass

[foxeyfreddie]

0:20 why is the outside of the cilinder so spiky? To release heat away faster? 

[abcd19263]

@foxeyfreddie that's right. it gives the cylinder more surface area for air to absorb heat from.

[foxeyfreddie]

@abcd19263 thanks

[kelb53]

@foxeyfreddie Provides more surface area for air cooling.

[mi2tom]

Rode 2 stroke and 4 stroke of the same cc, 4 strokes are for pussy.

[joel80435]

a 2 stroke engine,fires every 360ºdegrees,rotation of the crankcshaft,while 4 stroke engine is 720ºdegrees rotation of the crankshaft,2 stroke consume more,compare to 4 stroke,,2stroke lessparts,lighter engine,4 stroke more parts,havier engine,2 stroke,morehorse power,better mechanical efficiency,4 stroke,lower hc emissions,cooler engine temp,more reliable,wide power band

[bayyagg]

@joel80435

The 2 stroke can be efficient if you put hardened alloy metals, the problem with 2 stroke is overheating, otherwise you put a water jacket in it!

[allturbo16]

Great vid

[nobodiesful]

best explanation ive seen yet

[bbcisrubbish]

Very clear and instructive.

[ROCKSOLID19]

Correction: The 4 stroke cycle engine does not necessarily need springs. Desmodromicvalve systems are springless, it uses a pushrod to lift and raise valves up.

[TheChickenlover93]

i dont get it... i like 2 strokes dont get me wrong but why not develop a oiling system to lubricate the piston instead of burning the oil which probably doesnt lubricate it very well? just got me thinking because 2 stroke motorcycle are not street legal because of the emissions?

[TheNoisePolluter]

They the port timing all screwed up at 2:00 in real life it would barely run.

[xXxDANMANxXx]

@tyywuk You didn't understand what I was asking. I know the combustion cycles and the difference between the two types of engines, I was wondering why not take 2 or even 3 "two stroke" engines to get more power because in a standard 4 stroke engine there's so many moving parts and more for the engine to overcome

[OSAMAxxxxxxxxxxyz]

Goood!

[HeatherK485]

They dont make the same amount of power, 2 strokes make nearly double at the same displacement.

[xXxDANMANxXx]

mmmm, would it be possible instead of a traditional 4 stroke engine, why not have two "2 stroke" engines to get 4 cylinders or would that just not be practical? Seems like there would be a lot less the engine would have to over come (cams, the springs the cams push against to open valves and all that)

[ShootAllQueers]

i still dont understand what happends at the bottom of the 2stoke engine

[shortyfocker]

The reason 2 stroke petrol engines are delivering less power is because just after the spark the power cycle last a less period of time cos the exhaust window opens too soon... in 4 strokes the power period lasts till the low position of the piston thus having more power.... in other words the gas transition influences a lot the 2 stroke engines... This is because the 2 stroke does not have a variable intake and exhaust. Look at the opposite piston 2 stroke engines which has a solution for that

[JETZcorp]

@shortyfocker A two-stroke engine does deliver more power per unit displacement than a four-stroke. Although each power-stroke produces less power, it is having more power-strokes and on the whole more power is produced as a result. The situations in which a two-stroke will seem less powerful usually involve it being compared with a four-stroke of twice its displacement through some convoluted logic. Two-strokes also usually have a narrow powerband, which can make them seem less powerful.

[barthoedemaker]

Most 2 stroke engine have horrible cilinder porting design/timing and engine design. I am a huge 2 stroke fan, it can deliver much more performance and the same reliabilty if set up correctly. 2 strokes don't pollute much more than a 4 stroke if you set the carburator setting correctly and even a good performance pipe ( which most factory 2 strokes don't ), can increase performance by up to 75%. Sadly most garages have no idea about 2 stroke, so the carburator settings are mostly always to rich.

[f50tube]

Petrol.

[ryanjaanusson]

if you want to see impressive new 2 stroke technology youtube or google 600etec engine or 800etec. these engines are direct injected, and use about 50% less gas and oil than traditional 2 stroke engines, its just something cool to check out

[engineering7777]

I think 2 strokes is best efficiency and good choise for motorbikes & small boat engine, but not frindly for inviroment and to much noisly and bad select in the hot country and more expensive maintenance.

[merdekamotor]

like this

[23spartanguy]

the timeing on the valves was wrong, on the anamoation. as u can clearly see, the piston was hitting it, also, that was a 4 stroke, not a 2. because 2 strokes have no valves!

[shittywilly]

@23spartanguy

there are many 2 stroke engines with disk valves , poppet valves and reed valves

[23spartanguy]

@shittywilly funny, cause 2 stroke motors only have 3 moveing parts. 1st- the rod 2nd, the crank, 3rd- the piston.

tell me, were do u see your "disk valves , poppet valves and reed valves" at in my words?

ill tell u what tho, if u can find me a motor with anyone of these valves, ill give u a "omg ur right!"

until then, please, dont tell me theres valves in 2 stroke motors.

[netefrog]

@23spartanguy

Modern 2-Stroke engines have both reed (intake) valves and exhaust valves. Look at the modern 2-stroke motors being produced by the OEM snowmobile manufactures. YVPS (Yamaha), R.A.V.E. (BRP/Ski-Doo) APV (Arctic Cat), and VES (polaris) are all examples of two stroke exhaust valve systems. Also, have you ever heard of V-Force reed valves? Reed "Valves" control the fuel/air mix coming into a 2-stroke engine.

[airmitch10]

@23spartanguy well, my 2007 yamaha yz250 has YPVS.... Yamaha Power VALVE system.

In fact most yami 2 bangers from 1988 onwards have rpm operated exhuast valves (banshee, RD250/350, TZ/R250) Also Orbital SC2.0, Honda cr250 and suzuki rm250 all have similar exhuast VALVE systems (some sliding, some disks)

[Mentorcase]

There are some big old 2 stroke Yamaha's in third world countries that have been running for 40 years without being rebuilt. Secret is make sure there is enough oil in the fuel mixture and don't thrash it.

[zenith828]

you can have a 2-stroke engine w/o a spark plug. Uses spontaneous combustion, caused by high pressure.

[lolwhat2]

The intake of fuel is usually controlled by Reed valves, not by the piston.

[aniket8747]

great explanation!!!!!!!!

[Wanted797]

This seems more efficiant then 4 stroke why do we use 4 stroke then??

[shiman6d]

4 stroke has more power.

[FastBoatsCanada]

@shiman6d

That is wrong, A 2 Stroke will have twice the power as equal Displacement 4 Strokes. Simple fact

[shiman6d]

proof?

[FastBoatsCanada]

@shiman6d

Where is your proof that 4 Strokes make more power huh?

A 2 stroke makes power on every stroke, It also it doesn't have A valve train. So power is not lost. 2 Stroke will naturally be lighter.

More power Strokes + Lighter Weight = Faster speeds, more hp and torque then equal Displacement 4 Strokes, Its a simple fact.

[shiman6d]

please hold your anger.

Mixing oil and petrol will reduce the explosive capabilities of the fuel, and the two stroke doesnt allow the exhaust to completely exit the cylinder resulting in a contaminated air/fuel mixture further hindering combustion rate. The exhaust port can also open before the fuel has completely burned, expending energy out of the exhaust port that couldve been used for the piston's down stroke.

[RM250D8rzr]

@FastBoatsCanada well not every stroke. ever second stroke bud. 1 stroke = from TDC to BDC or BDC to TDC on pass is one stroke. comon guys this is basic stuff

[FastBoatsCanada]

Yea my bad, That is what I meant to say.

[FastBoatsCanada]

Sorry for the typo, I meant to say 2 stroke makes power every 2nd stroke

[RM250D8rzr]

@FastBoatsCanada allmost. not equal

[FastBoatsCanada]

Why would it be equal? That doesn't make any sense. If A 2 stroke is completing the four cycles ( Intake, Compression, Power, Exhaust ) in two strokes then why would a 4 stroke that completes the four cycles in 4 strokes make more or equal power?

[RM250D8rzr]

LOL when did i say this? two stroke makes more power per cc than a 4 four stroke. there allmost equal with the tech put into 4 strokes. there allmost on par. took a long time for 4 strokes to catch up. but most two strokes are more powerful then the same displacement 4 stroke. there RARLY twice as powerful. due to oil, not an effiecent cycle. some fuel is lost bla bla bla.... but are generaly (avarage)25 % more powerful.

[BigBadBadger1]

@FastBoatsCanada because the 4 strock burns the fuel more efficiently because there are no exhausts gas left in the cylinder so more air is available to burn also i would think that the octane value for the fuel in a 2 stroke is a lot worse because of the added oil i would also think that the fuel air mix is poorer and it is generally less precise and accurate also 4 stroke can make use of forced induction (turbo’s) 2 stroke can’t

[RadicakX]

@BigBadBadger1 also 2 stroke can especially on motorbikes

[wolfeman28]

@BigBadBadger1

There are plenty of forced induction 2 strokes. Only efficient in a small rpm range so it's kinda pointless for most applications, but they do exsist.

[homerunhita12]

@FastBoatsCanada more inertia in 4 strokes = more torque. generally, at least what I've come to believe is that 2 strokes with the same displacement as a 4 stroke counter part generally make more hp, but lack the over all torque, that's why it's necessary for higher rpm? correct me if I'm wrong. less moving parts = more high rpm reliability. They just wear out faster cause they're essentially doing double the work in half the time.

[LolzMan7756]

@FastBoatsCanada i say the same, let's take dirtbike as a example, i rode a 125cc 2 stroke and it was like a real powerhouse, then i tryed the 250cc 4 stroke and it was much more controllable power then the 2 stroke. wierd

[shittywilly]

@FastBoatsCanada

2 strokes actually have a better volumetric efficiency, if you take a look at major motorcycle competitions, you'll see that 2 stroke engines have been banned exactly for that reason. The other issue with them is that because of the overlap in intake and exhaust , a significant quantity of fuel goes unburnt through the exhaust thus creating emissions and fuel economy problems.

[23spartanguy]

@FastBoatsCanada there idiots. they watched this video, and thought they got smart enought from it to say "yea! i know everything now!"

[LeSatanicMechanic]

@FastBoatsCanada - with a four stroke engine you get one power stroke every four strokes of the engine. In a two stroke engine you get one power stroke every two strokes. A stroke is every time the piston moves from TDC to BDC (top dead centre to bottom dead centre) or vice-versa. It is not the number of times the crank turns 360 degrees.

[demonofrazgriz333]

@FastBoatsCanada well, if it helps, 2 strokes are more powerful for their weight and can reach substantially higher rpm ratings.

[etieditor]

@FastBoatsCanada

A 2 strioke engine is less efficient because as the piston starts moving up, before it covers the exhaust port, it pushes out some unburnt gas.

[bayyagg]

@etieditor

It could be efficient if you put a water jacket around the piston block and head, the problem is it got no oil filet nor filtering system upon inatke from w/in the block, thus small metal from crank bearing wearing down will be sucked into the combustion and scratches the piston/cylinder wall, affecting the compression of the piston and rings!

[KenMacMillan]

@FastBoatsCanada Because standard two strokes are less efficient than four strokes. They lose power through scavenging. Direct injected two strokes like Evinrude's & Murcury's overcome most of that though.

[floydstorm300]

@FastBoatsCanada because 4 stroke engine is more efficient than 2 stroke remember that 4 stroke engine pumps piston 2 times to inject fuel unlike 2 stroke who pump fuel with oil once every piston moves up. and 2 stoke burn fuel oil mixture is not good in creating power unlike 4 stroke who burned 100 percent of fuel which creates more power than 2 stroke

[Racketeerof89]

@FastBoatsCanada Less work for more results

[woodscritter]

@FastBoatsCanada Probably because of better volumetric efficiency, for one. In many situations, the big advantage of the 2-stroke is lighter weight/power output.

Don't confuse Briggs with serious 4-strokes.

[MrAlala911]

@FastBoatsCanada

4-stroke engine has better efficiency. In a 4-stroke engine the exhaust fumes and the fuel don't mix. The only downside is that a 4-stroke engine is heavier.

[RM250D8rzr]

@shiman6d oh yeah, what ur backing on that? LOL cuz ur so wrong its retared. a two stoke fires ever second time it has a stroke,. a 4 stroke needs to have 3 strokes befor it has a power stoke. witch is the only power stoke. happens once in ever 4 strokes. on a two stroke ur makeing power ever second pass

[shiman6d]

@RM250D8rzr

please read this.

Mixing oil and petrol will reduce the explosive capabilities of the fuel, and the two stroke doesnt allow the exhaust to completely exit the cylinder resulting in a contaminated air/fuel mixture further hindering combustion rate. The exhaust port can also open before the fuel has completely burned, expending energy out of the exhaust port that couldve been used for the piston's down stroke.

and stop being an ass.

[RM250D8rzr]

@shiman6d Lol? yeah. what are u trying to tell me? never asked. i am quite aware how a two stoke works and its performace and function. and its pros and cons

[shiman6d]

then you are fully aware that the fuel delivery system and the lubrication system are integrated with each other and causes a loss in expansion rate of the fuel resulting in slower explosion and decreased power. The exhaust system allows for unspent fuel to shoot out of the exhaust port.

You cannot say that a 2 stroke has more power than a 4 stroke.

[6Camel6Finger6]

has more power?-no

has more acceleration? - fuck yes

[lolwhat2]

@shiman6d A 2 stroke has more power than a 4 stroke.

[guccamain]

@lolwhat2 no its lighter runs hotter runs at twice the rpms with less moving parts

[shiman6d]

it also seems you could lose some fuel/air mixture during the downstroke.

[thefumanchew]

emissions. 2 stroke is dirtier than 4 stroke because yoyu have to mix oil and gas.

I like 2 strokes. I have a YZ125

[timsrandomvideos]

2 stroke has more power, but are going absolute due to emissions. 2 stroke puts out more gasses in the atomosphere do to a power stroke every revolution (360 degrees) and its harder to cut down on emissions with 2 stroke. a 4 stroke has a revolution every 720 degrees which doesn't have as much gasses going into the atmosphere. a matter of years 2 stroke will probably be very hard to find in new stuff due to admissions and there regulations.

[Frederik19951995]

@Wanted797 Because the 4 stroke live longer, and you dont have to mix oil and gasoline (in some 2 stroke you dont do it either), and 4 stroke dont pollute that much. And 4 stroke dont run at high rpm's. If you did use a 4 stroke in a chainsaw, it couldnt cut any trees because its dont run in high rpm's.

I hope it dit help. and sorry for my bad english

[Colt041]

@Wanted797

as Frederik mentioned, 4 strokes also burn less fuel, therefore they are more suitable for longer trips, you don't have to mix oil with fuel because there is one already in oil pan below, wich also reduces danger that engine will seize up (unless your oil leaks out), they are also more quiet (in most cases) than 2 stroke, etc.

However 2 stroke have their advantages, they are lighter (they can be used to power ex. a weed whacker). It all depends on what do you want to use them

[robinhooodvsyou]

I meant scavenge port.

[robinhooodvsyou]

The exhaust port position is fucked-up, and also the "coasting port", this is not a well made animation, well, it looks clear but stupid to me.

[2stroke1971]

Remember kiddies, a proper chamber will create waves that will serve to push some of the unburnt mixture back into the combustion chamber. Simpler, more power per displacement.

[metalx1234]

alot of gas is wasted in two-strokes because the way the valve works

[ilmuhaq]

i download this video. thank you.

i take this video and knowledge only.

[Cringle84]

Well they did not cover the part how the expansion chamber works, it plays part in compression as well.

[robinhooodvsyou]

That is seriously a fucked-up animation....

[manoftnuva]

...And there is no any unfired gasoline with fired yet, while it exhausts?

[xSQU1RR3Lx]

maybe, maybe not. but keep in mind the piston is moving faster than hell lol.

[TatesMan]

same questione here lol

[disndat11]

manoftnuva

Of course there is! That is the inherent fault of the 2 stroke engine, some gas always escapes with the exhaust when the piston moves down. That is why, despite the fact that the engine is so simple and economical to make, we don't see a lot of applications of the 2 stroke engine.

[STUDENTOFARNIS]

Nice job. Actually one of the better ones out there. Jolly good show. Bloody high quality I always say.

[aittri]

nice presentation

[christc102387]

this guy is very dry

[marter71]

how true...

i use 1/2 E85 and 1/2 87 octane gasoline in my weed wacker