Engine Braking?

[BansheeJerry]

Now,now lets play nice.. No name calling..

I have an idea... My uncle has been a diesel mechanic for over 20 years and I can find out everything you all need to know. Just make a list and I will ask him and reply. Sound fair to everybody?? We can settle this shit once and for all..??

[boonman]

Alright. Now that I have finished up a couple things in the shop, I have some time here to break down your post and add a reply.

 

Ok, first off your right you dont deserve to be sworn at. I'm sorry for my foul language.

Thanks chief. I appreciate it, even though you go at it again later. I'll point that out, just keep reading.

 

Secondly your still wrong, and I cant even to begin to scratch the surface in the aeras where you are worng.

Well, I am not wrong. I have proven it with every post. Time and time again. SO, I don't understand where exactly you keep running with your nonsense.

 

The reason I wrote "from what I understand" is because this is how I understand it to work. UNLIKE YOU I dont go shooting my mouth off acting like I am an expert

I am not shooting my mouth off. I am speaking from persojnal experience, and knowledge. I have been involved with diesel engines long before I got a banshee.

 

because I know there is a chance that I may be wrong.

Ding fries are done!!!!!! You are wrong!!!!!!

 

I keep an open mind, you should try this. If you had I wouldn't have been so harsh on you. I cannot stand Iragont people like yourself who think they know everything, then prove to you that they don't.

You are not keeping an open mind here. You have been nowhere near harsh. If you had, you would have known it. Believe me, I can take it. You, on the other hand, don't seem to take well to things when you are flat out wrong.

 

You on the other hand claim that you "know" how engine breaking works, however your theory is wrong.

 

You said that a diesel engine has little engine breaking because it has an unrestricted intake, thats why I thought you understood engine breaking to have something to do with the intake. So thats where I was going with that whole blowing vacuume lines off thing. think about it if your compressing the air from the engine back through the intake, would't that happen?

I would like to know where I said it would blow compressed air BACK through the intake. What I said was that a Diesel has an unrestricted air intake. What this means, to me and every other person on the planet is that there is no butterfly to control the amount of air that flows into the engine. It may behoove you to understand this for a moment. If you had read any of my posts, or the ones I asked you to re-read, (I even quoted them for you so you wouldn't have to scroll, I know how this must be hard, because you obviously haven't read them) you would have understood this. I said that on the intake stroke, a diesel can suck in as much air as it wants. What part of that don't you understand?

What vehicle has a plastic intake?? holey crist for someone who is such an "expert in engines you should be able to rattle a few dozzen.. Since I know nothing, heres a few that have plastic intakes My 2003 F150 5.4L has one, so does my 1998 Ford Crown Vic 4.6L. Ever open the hood of a Taurus they all have plastic intakes. How about a windstar, freestar, ranger, mustang and a Focus, they all have plastic intakes. You never heard of any of these cars? Oh thats right you only speek on factual knolwedge right? So you MUST not have ever head of any of these cars.

 

Already been cleared up. Scroll up, and you will see my reply to that. Thanks. And I do not only speak on factual things.

 

DAMM YOUR SOME KIND OF AN EXPERT ALLRIGHT.

Nope. Never said I was. YOU were the one who laid that one out there.

 

*side note. I work at a ford dealer and rarly see under the hoods of other vehicles but I believe the dodge neon has a plastic intake (I had a friend who had one)

REALLY???? I hope that you are a service writer. No, on second thought, I do not hope that. Perhaps the cashier. Because you are not a people person. Maybe the janitor??? You for sure can't be any sort of mechanic. I know SEVERAL people that work at Ford dealerships. I know several people that work at every manufacturer dealerships. Some close friends, some are just acquaintances. So what does that have to do with the difference between diesel and gasoline engine braking.

 

ok heres another good one from boonman "With your theories, these vehicles should stop on a dime every time you let off the go pedal" Yeah thats what my theory proves... right. At which point did I say engine breaking will stop you on a dime?

You didn't say that, I made that inference from the jargon you posted. Sorry if you didn't mean that. it was more so of a comical line, I didn't think it would get ya all hyped up like that.

 

But to answer your question, YES engine breaking does occour when you let your foot off the gas. you normally dont feel it because you probably have an automatic transmission.

Hrmmmmmmmmmmm At which point did I ay that it wouldn't??? None. Of course it will. Any time you take the combustible material out of the equation you will get some sort of engine braking. That is common knowledge. I was explaining ORIGINALLY in this post that diesels differ from gasoline engines.

DO THIS put the trans in 1 (thats past Drive and 2) take off, get going to like 20-25mph....let off the gas, what happens? HOLEY SHIT ENGINE BREAKING.

Wow!!!! How long did it take you to discover that????? Probably a damn long time. And yes, I do drive vehicles with automatics. In these vehicles, I have them equipped with manual locking torque convertors. But, I wouldn't expect you to understand that. And I have driven plenty of trucks that are standard and towed alot with them. No biggie.

 

You can do this in a manual transmission too.

Really???? You mean I can downshift with a manual transmission vehicle???? The manual in Grand Theft Auto never told me that........ But, thanks for pointing that out and clearing it up.

 

Perhaps you dont know what the 4 strokes in a 4 stroke engine are.

1Intake (sucks in air from the intake, which also creates vacuume in the intake)

2Comresson (this is what your running aginst in engine breaking)

3Combustion (when the air/gas mixture explode sending the piston down)

4Exaust (exaust valve opens and the piston traveline up pushes the gas out)

No kidding. You're right. I had no idea what all that 4 stroke stuff meant. But, once again, you have set me straight and "proved me wrong". LMMFAO!!!!! But, which vehicle does this apply to??? Because, in #2 stroke there, you have listed that this is where you get engine braking. Well, in a diesel, yes. In a gas motor, NO. You actualy get you're engine braking on the #1 stroke. Intake stroke. But, you REFUSE to address this FACT. There you have it folks. Diesel engines provide COMPRESSION braking when you refer to engine braking. Gasoline engines provide Vacuum braking when referred to engine braking. Yep. Plain and smple. (or so I thought)

 

Take away fuel and air (so there is less combustion) and push the engine (from the driveline) and what do you get...engine breaking. 

indeed. You are correct. I don't know why you are so hung up on this. We already went over this. It is an undeniable fact.

 

So during the compression stroke how in the hell is air going to be pushed back into the intake? Lets see....with both valves closed, it wouldn't. SO WTF DOES THE INTAKE DESIGN HAVE TO DO WITH ENGINE BREAKING?????

NO WAY MAN!!!!!!! Holy crap batman!!!! Both valves close on the compression stroke???? WOW. You must be the re-incarnate of Jesus. I NEVER said that diesels don't have valves. Where you get this nonsense from, I don't know. Perhaps it comes from your "open mind". Which, by the way, isn't very open. Of course the engine has valves. You CANNOT have an internal combustion without one. What I meant by the unrestricted AIR intake is that there is no butterfly to stop the air flow IN. Why don't you understand that? This is where diesels and gas engines differ. Do this, take the butterfly off of your '03 F-150 with the "mighty" 5.4. DOn't worry. Your computer will still make it run. What happens? When you drive it, do your little "engine braking test"

But to answer your question, YES engine breaking does occour when you let your foot off the gas. you normally dont feel it because you probably have an automatic transmission. DO THIS put the trans in 1 (thats past Drive and 2) take off, get going to like 20-25mph....let off the gas, what happens? HOLEY SHIT ENGINE BREAKING.

and see what happens. Oops!!! Meltdown!!!! Can't do that on a gas engine. AND, that engine braking wold be compareable now to that of a diesel. (except for the firing of the plugs to ignite the air in the cylinders that is now pesent because there is no butterfly to restrict the airflow) On a serious note, I wouldn't do that. It would make the Ford service peeps blow their fuse to figure out what happened when you take it in for warranty. Anyways,

NOTHING YOU IRROGANT JACKASS!!!

Remember when I said I was going to point out when you started getting the foul language going? Well, there it is. No need to call me a jackass. I am not a donkey.

Just to clairify I do not dissagree the fact that diesels have unrestricted intake air flow. my point is that the Intake side of the enigne has little if anything to do with enigne breaking.

THANK YOU for finally noticing this. WOW. I can't believe it took this long.

 

Which makes perfect sence, since the intake is only exposed to the volume inside the cylinder during the intake stroke and at that time the exaust valce is closed and the pistion is traveling DOWN.

Yes, you just explained the intake stroke. Yeeeehaw. And the unrestricted AIR intake has nothing to do with engine braking???? Ok. You're right. Go throw a butterfly on your diesel's intake mouth. Why the hell not? Being that you say it has nothing to do with engine braking. Well, it has EVERYTHING to do with what manner the engine brakes.

 

It just baffels me that you dont understand this.

Just how is it that I don't understand this???? hrmmmmmmmm Seems I am NOT the one who doesn't understand it.

 

How can I deny that your bs is BS? because it is, retard.

You cannot call it BS. It is fact. The way the engine operates cannot be changed. And there you go again with the language.

 

by the way what sort of mechanical background do you have? just wondering where you get your "factual information" from.

My mechanical background isn't in question here. but, since you must know, I design and build precision automated production machinery. From the ground up. From designing on ACAD, to constructing framework, to machining all the parts, to designing electrical, to installing electrical, to programming. I also do the maintenance on these machines. I own my own company desinging and building suspensions for vehicles. I do many things. However, they never get questioned. Why do you? I help out ALOT of people with engine work. I build and see alot of vehicles. My factual information comes from alot of places. I already quoted a couple. You must have overlooked them.

 

 

 

 

I will start another paragraph here. O.K. Hrre we go. Summary time. Perhaps I used too harsh a word when I said that diesels provide "little" engine braking. They do provide engine braking as so generously explained by P8121 in

But to answer your question, YES engine breaking does occour when you let your foot off the gas. you normally dont feel it because you probably have an automatic transmission. DO THIS put the trans in 1 (thats past Drive and 2) take off, get going to like 20-25mph....let off the gas, what happens? HOLEY SHIT ENGINE BREAKING.

Folks, there you have it. "Holey shit engine braking". Alright. NOWHERE did I say that diesels do not provide engine braking. They do. IMHO not as good as a Gas engine does. Stock for stock. It is something that I have tested. Now, Trav said that he found the opposite. This is good. Scenarios may have been different in his tests. I used the same trailer, and the same brand truck. Anyways, here is where I will explain the difference between gasoline engines and diesel engines where engine braking is concerned.

 

Diesel engines use compression braking. They do this because they have an unrestricted air intake. I do not mean that they don't have valves, I mean that they have no butterfly, (or slide) to restrict the air flow entering the engine. What this means is that on any given intake stroke, the engine can suck in as much air as the cylinder(s) can hold. It then compresses it, which provides a certain amount of resistance to "brake" the motor. This, of course is all with respect to the operator "backing out" of the throttle. Or, providing no fuel into the equation with the motor remaining at higher than idle revs. Such as would occur with a loaded trailer on the back, and going downhill. So, we have diesel engines incorporating compression braking. I have explained that I don't know how many times, but some peeps neglected to soak that in.

 

Now that we have covered the diesel engine braking, I will move to Gasoline engine braking. Gas engines differ from diesels in that they have a restricted air intake. They do this via a butterfly style valve, or a slide. They have to, because there is an ignition which will fire off a spark. This would ignite a lean mixture, and burn up the motor if there wasn't a restriction placed on the air intake. I explained this with the F-150 butterfly removal analogy. now, when you back out of the throttle on a gas engine, you effectively shut off the fuel (in a fuel injected vehicle, the computer stops firing the injectors, and in a carb vehicle, there is no air moving across the jets to pull out the fuel) and you shut off the air. So, the engine has nothing to pump anymore. So, on the intake stroke, it is trying to suck air in through the intake (wow, and I remember someone asking WTF the intake had to do with engine braking, and seemingly, it has EVERYTHING to do with it, but, I am a moron, or a jackass, or retard. take your pick) but the intake has been close off via the butterfly or slide. So, this creates an extreme level of vacuum inside the engine. THis is what brakes the gasoline motor. So, a gasoline engine utilizes vacuum braking. This is the mainstay of the discussion. This is where they differ. (with respect to engine braking) they differ in many other places. But, we shouldn't get into that untill other people understand this simple rule. So, tell me how I'm wrong here? Please. Pretty please? I would realy like to see it done. Because if, and that's a very big if, I'm wrong about the way diesels and gasoline engines brake, I will never come the the HQ again. Class is over

[fixitrod]

damn, bet you didn't think you're question would lead to this.

[Travis's Banshee]

Please let me know when class will be beack in session Boonman. I have a couple more questions.

[boonman]

Class can be back in session. But this time, homework is a must!!! And dammit all, pay attention!!!!!!

[Cooker]

Good job Boon, I don't know how you have a patience.

[BansheeJerry]

LOL Damn Boon. I bet that one took a few mins to type.. Ding..fries are done...

[boonman]

LOL Damn Boon. I bet that one took a few mins to type..  Ding..fries are done...

'Bout a half hour. And I love that song!!! I have some cool remixes of it!! I play it through the paging system at work!!!

[bigboybanshee]

I have some cool remixes of it!!  I play it through the paging system at work!!!   

Whoever it was that made it seems to be updating it yearly!!! Last one I heard it wasn't just the retarded Burger King rep it was a whole choir singing!! Muchos props to the creator!!! That song is hysterical!!!