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Engines & Misc
- Thread starter tsaw
- Start date
Yep, it's the strokes required to fire the piston.
AKA:
Intake (suck in fuel, piston on its way down, intake valve open)
Compression (compress it. Piston on it's way up and the spark lights the compressed fuel)
Power (bang. Piston forced back down due to exploded fuel)
Exhaust (piston on it's way back up, exhaust valve open)
go back to Intake
AKA:
Intake (suck in fuel, piston on its way down, intake valve open)
Compression (compress it. Piston on it's way up and the spark lights the compressed fuel)
Power (bang. Piston forced back down due to exploded fuel)
Exhaust (piston on it's way back up, exhaust valve open)
go back to Intake
You got it.
Bonus question:
Given the explanation you gave - (there are valves opening and closing) How can it be done without valves? IE: 2 cycle?
the disciption was was for a 4 cycle motor 2 cycle don't suck air naturaly they use a blower weather it's the crank case as in a small engine or a supercharger such as the blower in a detroit the 2 cycle combustion process is power and compression and power at the top of the cycle and intake and exhaust at the bottom of the cycle.
You say that a 2 cycle don't suck air naturally.
However, when the piston is on the upward stroke, there is a vacuum created under it - in the crankcase. Once the piston skirt raises above the intake port.. there is sucking going on. Right through the carburetor.. picking up air fuel.
So are you saying suck squeeze bang and blow is only for 4 cycle engines?
It surely must happen for a 2 cycle to run.
your description is partialy right but it's the forced induction unit doing the sucking in the case of a small engine the crank case is the blower on larger engines the blower is the intake with a carburator or throttle body on the intake side of the blower on the engine side of the blower it is all positive pressure as two strokes are un able to scavenge enough air to run with out forced induction if you had a constant vaccuum on a 2 cycle like a 4 cycle how would you exhaust combustion chamber gasses. i have seen the term you used in text books before describing the process of a 4 cycle engine and yes a 2 cycle also does suck and blow at the same time but it's the iron lung doing it for the engine itdoesnot happen naturaly like a 4 cycle engine.
Technically.. the rush of the air fuel mixture into the combustion chamber pushes out the burnt gasses through the exhaust.
Since we have a vacuum under the piston on the compression stroke, where air and fuel is sucked under the piston into the crankcase - on the power stroke - we have pressure in the crankcase. Then - that air fuel under pressure is forced into the combustion chamber. At the same time - the exhaust port opens. The gasses above the piston are pushed out by the incoming new air fuel mixture.
Since we have a vacuum under the piston on the compression stroke, where air and fuel is sucked under the piston into the crankcase - on the power stroke - we have pressure in the crankcase. Then - that air fuel under pressure is forced into the combustion chamber. At the same time - the exhaust port opens. The gasses above the piston are pushed out by the incoming new air fuel mixture.
this will be the last post i make on this subject you have obviously not worked on any thing more complex than a motor cycle engine i invite you to step up to a 53,71,or 92 detroit than you might under stand better. the crank case on a motor cycle engine is still a forced induction unit just like a blower if your piston skirts break or fail to seal the engine dies because a 2 cycle can not suck on its own or blow on its own .suzuki ued 2 cycle engines in their samuri's in the late 70's i'm not well versed on that engine they were only around a few years, and in the mid 80's chrysler experemented with a 2 cycle transverse motor but never put it into production that engine had a wet sump crank case and a roots blower.these facts come from 25 years of repairing engines from a small motorcycle engines up tp 16 cylinder detroit diesels i've spent countless hours in school learning therory and new technology i'm no lawyer i'm just stating the facts and will not try to argue or presuade any one further than this last post
I have no doubt you know a lot more than I do when it comes to engines.
However,
suck, squeeze, bang, and blow applies to a 2 cycle engine as well as a 4 cycle. If you disagree.. then you are saying this explanation (which is correct) is wrong. On the upward stroke of the piston there is a vacuum created under the piston. Then that vacuum is used to suck in air fuel. The piston squeezes the air fuel mixture - then the spark plug bangs. On the downward stroke, the crankcase has pressure instead of vacuum - and that pushes in a new air fuel mixture and blows out the burnt gasses - or exhaust.
[ame="http://www.youtube.com/watch?v=CLs4BOVYD7c"]YouTube- ~The Two Stroke Cycle Engine~[/ame]
Got to add this before I hit: "Submit Reply"
I just realized what you are saying.
You are saying that a 2 cycle does not "SUCK" air fuel - because in reality the downward stroke PUSHES the charge from the crankcase into the combustion chamber - and that in turn replaces the exhaust. That could be the technicality that makes you disagree.
However,
suck, squeeze, bang, and blow applies to a 2 cycle engine as well as a 4 cycle. If you disagree.. then you are saying this explanation (which is correct) is wrong. On the upward stroke of the piston there is a vacuum created under the piston. Then that vacuum is used to suck in air fuel. The piston squeezes the air fuel mixture - then the spark plug bangs. On the downward stroke, the crankcase has pressure instead of vacuum - and that pushes in a new air fuel mixture and blows out the burnt gasses - or exhaust.
[ame="http://www.youtube.com/watch?v=CLs4BOVYD7c"]YouTube- ~The Two Stroke Cycle Engine~[/ame]
Got to add this before I hit: "Submit Reply"
I just realized what you are saying.
You are saying that a 2 cycle does not "SUCK" air fuel - because in reality the downward stroke PUSHES the charge from the crankcase into the combustion chamber - and that in turn replaces the exhaust. That could be the technicality that makes you disagree.
that is kind of what i'm saying if you were in an engines class and you answered that question like you want to you would be wrong because what you are describing are the 4 cycles of of a 4 stroke motor the 2 cycle does the same thing but doubles up on the operations such as taking the f/a mix while blowing out the exhaust 2 cycle motors do suck but require a mechanical device to do it. in in your drawing it is using the crankcase as a simple super charger on a wet sump motor you have to have a blower to do the same thing. some 4 cycle motors like the p&w r2800 radials also used a supercharger as an altitude compensator to maintain horsepower at high altitudes but because the r2800 is a 4 cycle motor it will run with out its forced induction system they infact remove the superchargers off the r2800's for low altitude operations i don't wan't to cause h&d because all engines do need to inhale and exhaust to make power some just do it differently 4 strokes do it in 4 different operations and 2 cycles do it in 2 opps
please no more that are that friendly i'm not a lawyer so i don't try to interprate anything and i never participated in debate but i have worked on all types of engines turbines aircraft diesels 2 cycle and 4 cycle and gas powered from motor cycle to rotary style even worked on some vintage ford motors where i poured main bearings in to the block i know the theroy and am willing to share my years of knowlage with anybody willing to learn i didn't get where i'm at with out listening and learning.
you are correct before bearing inserts the bearingc were babbit poured into molds you than line bored them and the thrust was set with a file when the bearings got loose you removed a few shims and put it back to gether the oil pumps circulated the oil through main bearings and cam bearings no real pressure and the rods had little scoops on them to force oil into the rod babbots later on ford came out with the c block and that was the first true pressurised system as i remember right it was around 25 psi the c blocks also had larger rod and main bearings which made them highly coveted by the guys who like to tour around the us in their model-a's the c block was usualy found in later model trucks chevy also used babbit in their early engines.