Squish, mystery or not!?

[AKheathen]

no, you are still speaking out of your ass, and making me read a bunch of incorrent info. you still never want pre-ignition. pre-ignition, by definition, is unwanted ignition that occours before intended. a pre-power stroke/cumbustion effect that happens while intended is different. if you knew how a 2-stroke works, then, you should know that it has little to do with volumetric efficiency and will not run from natural piston aspiration. every single 2-stroke runs because the cylinder is stuffed.

 

"the entire point of the thread is for people who don't know better, blah blah blah" well, when the info written contains large amounts of incorrect info from another who "does not kinow better", then it starts people off in the wrong direction. some of us have literally spent years on this site daily, and other sites, and there are many like you who want to "educate before learning. i understand that teaching others is a good way for some people to learn themselfs, but i'm doing my due dilligence to curtail damage. what you do not realize that incorrect info, actually does cost many people large ammounts of money that they cannot aford. we have seen it hundreds of times. anyone not knowing better and taking all your info as total truth will be 10x the work to turn them around than what it would take to point them in the right direction in the first placce, or tell them nothing at all.

[sicivicdude]

no, you are still speaking out of your ass, and making me read a bunch of incorrent info. you still never want pre-ignition. pre-ignition, by definition, is unwanted ignition that occours before intended. a pre-power stroke/cumbustion effect that happens while intended is different. if you knew how a 2-stroke works, then, you should know that it has little to do with volumetric efficiency and will not run from natural piston aspiration. every single 2-stroke runs because the cylinder is stuffed.

 

"the entire point of the thread is for people who don't know better, blah blah blah" well, when the info written contains large amounts of incorrect info from another who "does not kinow better", then it starts people off in the wrong direction. some of us have literally spent years on this site daily, and other sites, and there are many like you who want to "educate before learning. i understand that teaching others is a good way for some people to learn themselfs, but i'm doing my due dilligence to curtail damage. what you do not realize that incorrect info, actually does cost many people large ammounts of money that they cannot aford. we have seen it hundreds of times. anyone not knowing better and taking all your info as total truth will be 10x the work to turn them around than what it would take to point them in the right direction in the first placce, or tell them nothing at all.

 

Check out 2 stroke engine designs before the 1961 grandprix when Suzuki got their hands on tuned pipe technology. They still ran.... Granted, not with nearly as much power output but they run just the same. In fact, if you took your banshee and put a straight pipe on it (no stuffing at all) it would still run (like shit, but run just the same).

 

If you'll read back through, this is for a general understanding of how the engine works and not specific information.

 

Go ahead, tear down the post because I used an incorrect term and not add anything at all about your understanding of how they work. Please, enlighten us as to how they work. I'm sure there are many members who would appreciate you straightening it all out.

[sheerider1026]

Bahahaha!!! Just what we needed!!! Someone from a blaster forum to come over here and school us on how 2 strokes work !!!

[BANSHEE HP]

squish is fake, no such thing. should be filed in the non fiction section at the library

[So Cal Suspension]

squish is fake, no such thing. should be filed in the non fiction section at the library

 

I can see you've spent a great deal of time in a library...

 

Fiction is fake, Non fiction is real.

[Finch]

Matt your pretty sharp!

[So Cal Suspension]

Matt your pretty sharp!

you're*

 

Haha, according to people who will say anything to try to make themselves not look completely ridiculous, I "dont look to sharp". Coming from a dude who gets a misspelled name of an animal on his arm.

[Finch]

[AKheathen]

Check out 2 stroke engine designs before the 1961 grandprix when Suzuki got their hands on tuned pipe technology. They still ran.... Granted, not with nearly as much power output but they run just the same. In fact, if you took your banshee and put a straight pipe on it (no stuffing at all) it would still run (like shit, but run just the same).

 

If you'll read back through, this is for a general understanding of how the engine works and not specific information.

 

Go ahead, tear down the post because I used an incorrect term and not add anything at all about your understanding of how they work. Please, enlighten us as to how they work. I'm sure there are many members who would appreciate you straightening it all out.

again, you still don't understant. tuned pipe, is an add-on to two stroke. detroit never even had a tuned pipe, just forced induction. every 2-stroke is forced induction, at least i have never seen one, but it would have to be something like that old tractor monstor 1cyl that red-lined at something like 40rpm, and would need an insane bore/stroke ratio, so it can compress that 14.7 good enough to burn good enough, while sitll getting good clean-out. i've run pipe-less 2-strokes. they sound pretty mean, and are fun for a couple min, but nothing like adding a pipe to them..... here, study this for a while. you might get some idea of how shit flows..... in fact it looks a lot like your blaster motor. actually, to be more specific, i have even rode my banshee with no exhaust at all 2x, amoung other things. even rode a 2004 liberty600 strait-piped (don't ask).....

 

iff you will read what i said, "general understanding......" is what i have already addressed. do you have a paypal acount with large amonts of funds to support your "info" so vounerable members who scrap their motor on your info can live thier "learning experiences" that show how full of shit you are? bottom line, you do not know yet how a 2-stroke really works, even on the basic level, and should not be trying to teach others what you have learned while expanding your mind over a bowl.

 

it's not just that you used an incorrect term, it's that you defended it to the death, rather than just admitting the first, or secont time that you read/heard an incorrect term and refused to belive what people who actually know what is what was telling you. truth is, the "Term" is just a factor. your whole sum of information de-railed from trying to simply explain squish, to taking understanding 2-stroke operation down a whole different path from what is real/fact. by the way- it think einstine said it best: if you cannot explain something simply, you do not understand it well enough. so here is your simple explanation: air is drawn in dirrung an up-stroke to fill the case. reed, or crank interferance/air velocity combo helps to hold that air in the crank-case, where it is compressed and injected on the downstroke via the bottom of the piston. when the transfer port passages are clear of the piston, the compressed charge is forced to the top of the chamber and compressed quickly by the piston moving up and "closing" off all ports before the pressure can escape (higher exhaust pressure helps this). it is ignited for the big push, where it exits, and the begining process has alreay half-completed for the next cycle.

simple tuned pipe function: exhast exits, creating a wave, the length and volume of pipe sets the time for it to reach the rear of the chamber, where a portion "bounces" back to the cylinder. this timing, sets the rpm range that the pulse will reach the cylinder again, and, if the exhast port is clear, it will further stuff the cylinder with pressure.

 

simplest expanation of 2-stroke: air/fuel mixture enters crank, and bottom of piston pushes to top of piston. squish-bang, and bounce in exhaust to do it again.

 

i honstly did not want to tell you anything, because, i know you are going to want to keep posting every little thing like a tweet, as you learn it. and you will not put in the work to learn it as you "teach" it. by doing your research, even just this section, you could get a clue. i implore you: learn from us first. i think you can have the potential to be a helpfull entheusiastic member within a few months, but you are head-strong down the wrong path.

 

PUBLIC SERVICE ANNOUNCEMENT:

I have been fore-warned by a blaster forum mod, after my initial attempts, that this guy is basically another "SLORIDER" in training, and was run from the blaster forums. those who have been here a couple years or more know who i'm talking about. those who don't, well basically a crusader down the worst path, and eventually nothing but a plauge on the site. would be nice to see this turned around. we will see...

[Surfrjag]

This mod has a grudge against my friend here because he is not the almighty kor. Go for an easy target here or try looking at the big picture. I suspect this same mod is the reason kor will bei the only builder on bf..

[sicivicdude]

again, you still don't understant. tuned pipe, is an add-on to two stroke. detroit never even had a tuned pipe, just forced induction. every 2-stroke is forced induction, at least i have never seen one, but it would have to be something like that old tractor monstor 1cyl that red-lined at something like 40rpm, and would need an insane bore/stroke ratio, so it can compress that 14.7 good enough to burn good enough, while sitll getting good clean-out. i've run pipe-less 2-strokes. they sound pretty mean, and are fun for a couple min, but nothing like adding a pipe to them..... here, study this for a while. you might get some idea of how shit flows..... in fact it looks a lot like your blaster motor. actually, to be more specific, i have even rode my banshee with no exhaust at all 2x, amoung other things. even rode a 2004 liberty600 strait-piped (don't ask)....

 

iff you will read what i said, "general understanding......" is what i have already addressed. do you have a paypal acount with large amonts of funds to support your "info" so vounerable members who scrap their motor on your info can live thier "learning experiences" that show how full of shit you are? bottom line, you do not know yet how a 2-stroke really works, even on the basic level, and should not be trying to teach others what you have learned while expanding your mind over a bowl.

 

it's not just that you used an incorrect term, it's that you defended it to the death, rather than just admitting the first, or secont time that you read/heard an incorrect term and refused to belive what people who actually know what is what was telling you. truth is, the "Term" is just a factor. your whole sum of information de-railed from trying to simply explain squish, to taking understanding 2-stroke operation down a whole different path from what is real/fact. by the way- it think einstine said it best: if you cannot explain something simply, you do not understand it well enough. so here is your simple explanation: air is drawn in dirrung an up-stroke to fill the case. reed, or crank interferance/air velocity combo helps to hold that air in the crank-case, where it is compressed and injected on the downstroke via the bottom of the piston. when the transfer port passages are clear of the piston, the compressed charge is forced to the top of the chamber and compressed quickly by the piston moving up and "closing" off all ports before the pressure can escape (higher exhaust pressure helps this). it is ignited for the big push, where it exits, and the begining process has alreay half-completed for the next cycle.

simple tuned pipe function: exhast exits, creating a wave, the length and volume of pipe sets the time for it to reach the rear of the chamber, where a portion "bounces" back to the cylinder. this timing, sets the rpm range that the pulse will reach the cylinder again, and, if the exhast port is clear, it will further stuff the cylinder with pressure.

 

simplest expanation of 2-stroke: air/fuel mixture enters crank, and bottom of piston pushes to top of piston. squish-bang, and bounce in exhaust to do it again.

 

i honstly did not want to tell you anything, because, i know you are going to want to keep posting every little thing like a tweet, as you learn it. and you will not put in the work to learn it as you "teach" it. by doing your research, even just this section, you could get a clue. i implore you: learn from us first. i think you can have the potential to be a helpfull entheusiastic member within a few months, but you are head-strong down the wrong path.

 

PUBLIC SERVICE ANNOUNCEMENT:

I have been fore-warned by a blaster forum mod, after my initial attempts, that this guy is basically another "SLORIDER" in training, and was run from the blaster forums. those who have been here a couple years or more know who i'm talking about. those who don't, well basically a crusader down the worst path, and eventually nothing but a plauge on the site. would be nice to see this turned around. we will see...

 

You cannot even begin to compare a 2 stroke "Jimmy" to a schneurle ported 2 stroke gasoline engine. The supercharger HAS to be there or the engine will not operate (not, will not operate properly, just flat out will not run).

 

In a TRUE schneurle ported engine (weedeater for instance) the process you are describing DOES take place (the charge is slightly pressurized by the falling piston) HOWEVER this process does not explain how the engine continues to operate with a boost port or boyesen ports (direct pathways backwards into the intake tract) or how it doesn't pass the entire charge out of the engine while the exhaust port is open.

 

"Higher exhaust pressure"? Do you mean the exhaust wave pulse returning from the tuned pipe? Because again, a scheurle ported 2 stroke engine will still operate without a tuned pipe (chainsaws and weedeaters are fine examples of this) just not to the same tune level as an engine with a tuned pipe.

 

The incorrect term was explained well enough. Pre-ignition or detonation.

 

einstine (Einstein actually) did say that, however, there is very little "simple" about what is going on inside a combustion chamber, even a "simple" 2 stroke engine. The entire point of the thread was to give everyone who don't know any better a little "primer" on how certain parameters effect power output. For someone who knows NOTHING, this is a relatively simple (uh oh, there we go with simple again) method to understand something relatively complicated.

 

Just so there is no confusion, the moderator you all are getting your "information" from is Awk08, the single largest cheerleader for Ken O'Connor Racing out there. The "nut hugging", is 95% him and he does have a chip on his shoulder against me because of some off hand comment made to a fellow KOR groupie.

[AKheathen]

"higher exhaust pressure" does not have to come from the wave pulse. it simply means that the pressure in the exhaust is high. just about any engine can see 20-50psi exhaust pressure naturally, at some ppoint/level of operation. just like you've heard the saying that you loose bottom end stuffing/tq/drivablity/whatever running strait dumps on a v8.

 

yes, you can compare all 2-strokes. they all are working on the same principals. forced induction IS taking place and simotaneous/asyncronis with the squish-bang cycles. a "jimmy" would be like replacing the crank chamber and related with a turbo, or super charger. wormholes/boost ports/boysesn ports, or whatever you want to call them work for a few reasons. first, you have to remember the most obvious point is that THERE ARE FREAKIN REEDS! i could go into mapping the effects of those ports, but i'll keep it simple and tell you that it basically ballances the pressure of the reed chamber, so it can work with the crank chamber together more effectively, mostly at higher rpm's. a great deal of 2-stroke understanding comes from a good grasp of the fluid dynamics, and understanding the timing of waves/pressures, and such, and experience in working with effecting this (i.e. experienced porting)

 

for the upm-teenth time, your "basic explanation" is wrong, and flawed, to say the least. i wish you would accept that and move foreward. i am not going to say that my shit don't stink either. in fact, years back, i did not have a correct understanding of the 2-stroke slide carb, having a vast amount of experience only in automotive crbeuration and fuel injection. once pointed out, i quickly apologised and moved on to studying and learning every thing i can about the matter. i'm not really one to toot my own horn much, but many can attest to my exceptional knowledge and experience in the stock, and other mikuni round slide carbs, and stock jetting. this has a huge part to do with the mentioned mistake. i did not defend to the death what i said, rather learned from it. so, no, i am not picking an easy target, as this is in no way easy, and yes, i know what it's like to be in your shoes... oh, and i think the therm you are looking for is having a "hard-on" for you, or something to that effect. "a chip on his shoulder" is a better description for the way you have been.

 

fyi- quoting typos are not going to have much bearing on me, or my posts. i correct what i can see, but still don't look at the screen while typing, and can't seem to get spell-check to work on this site anymore. i'll be leaving firefox beta feed-back on that matter, if it helps you feel better.

[sicivicdude]

"So let's walk through a combustion cycle in a MSV designed head..... It all starts when the transfer ports close (piston coming up)"

 

From the very first post of this thread excluding all of the events that have taken place up to then to get us to the start of the actual compression for the point of explaining how varying squish or quench parameters will affect the combustion process.

 

None the less, I'll indulge. The crankcase on a either reed valved or rotary disced two stroke engine DOES act as the intial "air pump" to get the process started. The reeds also act as the one way check valve in the system to keep it from back flushing. I am agreeing with you there. However, your "simple" explanation that the crankcase does all of the "work" is as flawed as my "simple" explanation of the operation of squish while excluding the operation of the rest of the engine. The point was to explain is as simple terms as possible how changing squish (without changing combustion chamber volume, crankcase volume, port timing, port size, carburetor size, or reed choices) can "tune" how an engine responds to those changes.

 

Internal combustion engines operate as gigantic air pumps. Whether they be 4 stroke engines that open a poppet valve and increase internal displacement (piston falling on the intake stroke), schneurle ported 2 strokes that operate by using the crankcase as their initial air pump, crossflow 2 strokes that operate without the aid of a true tuned pipe (some would argue that the "loop scavenging" of the crossflows acts as a tune pipe but they're not truly balanced so we'll exclude those), Screaming "jimmies" detroit diesel supercharged 2 strokes, or even opposed piston 2 strokes (look up Junkers Jumo 204 or Napier Deltic engines) they ALL operate on pressure differential.

 

Ambient air pressure at sea level is 14.7psi, 1 bar, 760 mmHg nominally. We'll exclude slighty pressure changes due to weather events (although if you want to get REALLLLLLY technical, you should consider rejetting for storms) and call it "nominal". No matter the induction style, pressure differential is how they induct air by moving the air and fuel mixture (except in the case of the diesel!) into the combustion chamber, compressing it, using the force of the explosion to drive the piston down, and exhausting the old mixture. The old "suck, squish, bang, blow" is the really simple version of how it's done.

 

All engine operations are fighting this initial starting pressure (whether they are ultimately forced induction or not) from the moment the air enters the low pressure area around the inlet to the engine (whether that the air filter, airbox inlet, air horn, carburetor horn, turbo inlet, whatever) everything that happens from that point on is a function of restriction versus actual flow.

 

Volumetric efficiency is that measure. That's what I was talking about when I mentioned 14.7 psi as being the starting point. The ability of the engine to actually fill the volume of the combustion chamber to the swept volume of the engine is the "hard fight" on a naturally aspirated engine. Tuned pipes can overstuff the cylinder at their peak operating range but at all others, they don't help.

 

When you leakdown test your engine, how much pressure do you put in there? 7psi. If you apply a lot more than that, you will blow those crank seals out. When the piston is at BDC, both the exhaust port and transfer ports are open. If the exhaust actually operated at 20-50 psi, you would blow crank seals out every time you got on the pipe.

 

I will agree with you that the pipe operates at greatly elevated pressure HOWEVER, only for a brief section and even then only in certain parts of the pipe. During blowdown, the pressure wave from the cylinder passes through the headpipe and divergent section. While that pressure wave is passing, there is a greatly elevated pressure (I doubt 50 psi but definitely higher than ambient) however once the pressure wave enters the divergent section, the relative pressure (pipe pressure to combustion chamber pressure) swings violently back to vaccum! While the transfer ports are open, the pipe begins to actually "draw" charge through the engine directly which is why boyesen ports and the boost port, properly designed, work as well as they do.

 

This is why I say, your "simple" explanation that the crankcase does all of the work is as flawed as mine about squish parameters without including the rest of the operation. That process can actually continue to draw charge directly through all the way until we get back to the start of this thread. That's why I started this thread at that point instead of "muddying" the conversation with what you are discussing.

 

Now, back to the original purpose, do you have any specific information to add about squish or quench areas?

[possum]

you're*

 

Haha, according to people who will say anything to try to make themselves not look completely ridiculous, I "dont look to sharp". Coming from a dude who gets a misspelled name of an animal on his arm. http://bansheehq.com/forums/public/style_emoticons/#EMO_DIR#/clap.gif

 

like i said, "you dont look to sharp".

 

http://grammarist.com/spelling/opossum-possum/

[Dicklez]

penis