EGR Valve Technical Question
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5th Wheeling
Joined: May 2019
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EGR Valve Technical Question
Hi All,
If this question has been addressed in a previous thread, I apologize that I couldn't locate the thread so pointing me in that direction will be appreciated.
I would like to know if the EGR circuit (piping) is closed off, or can be closed off, by the ECM (or some other) module during a regeneration on a 6.7 from the start to the finish or if the EGR circuit operates independently of what goes on with the DPF. Or, is the EGR circuit (piping) always open and venting into the intake?
I know exhaust gas goes through an intercooler to decrease the temperature before it enters the intake but I don't know if there is any control over when and/or how much exhaust gas is recirculated into the intake at any one time to satisfy some CARB/EPA requirement for emission control.
Thanks,
Joe
If this question has been addressed in a previous thread, I apologize that I couldn't locate the thread so pointing me in that direction will be appreciated.
I would like to know if the EGR circuit (piping) is closed off, or can be closed off, by the ECM (or some other) module during a regeneration on a 6.7 from the start to the finish or if the EGR circuit operates independently of what goes on with the DPF. Or, is the EGR circuit (piping) always open and venting into the intake?
I know exhaust gas goes through an intercooler to decrease the temperature before it enters the intake but I don't know if there is any control over when and/or how much exhaust gas is recirculated into the intake at any one time to satisfy some CARB/EPA requirement for emission control.
Thanks,
Joe
Cargo Master
Joined: Jul 2008
Posts: 2,566
Likes: 54
Joe - to my knowledge that is precisely what the EGR valve (bypass valve) is there regulating - the exhaust flow through the intercooler.
As to how much it closes down, or if it completely blocks the flow, during a regen - no idea.
If there are any changes in the way the EGR valve is to function it would have to be coded in the controllers.
For example - if you delete the EGR circuit/system entirely (deleting) there are kits to do that and ways to get the controllers to allow that operation. Otherwise, the controllers will know there is no EGR there and you'll have all kinds of codes thrown with a CEL.
If you keep the EGR circuit intact but you are wanting to change the way the EGR valve operates the controllers on the truck now would have to have some information that tells them the EGR system is "normal" while you are making "abnormal" changes to the function. So if you put a delete kit/programming in place, then control the EGR valve by auxiliary means that may be one way, or if you have Forescan and can figure out the engine controller programming that governs how the EGR valve is operated then you can change the program on the OEM controller.
Again, as to how the EGR valve is governed now - no idea.
As to how much it closes down, or if it completely blocks the flow, during a regen - no idea.
If there are any changes in the way the EGR valve is to function it would have to be coded in the controllers.
For example - if you delete the EGR circuit/system entirely (deleting) there are kits to do that and ways to get the controllers to allow that operation. Otherwise, the controllers will know there is no EGR there and you'll have all kinds of codes thrown with a CEL.
If you keep the EGR circuit intact but you are wanting to change the way the EGR valve operates the controllers on the truck now would have to have some information that tells them the EGR system is "normal" while you are making "abnormal" changes to the function. So if you put a delete kit/programming in place, then control the EGR valve by auxiliary means that may be one way, or if you have Forescan and can figure out the engine controller programming that governs how the EGR valve is operated then you can change the program on the OEM controller.
Again, as to how the EGR valve is governed now - no idea.
Thread Starter
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5th Wheeling
Joined: May 2019
Posts: 39
Likes: 0
If you keep the EGR circuit intact but you are wanting to change the way the EGR valve operates the controllers on the truck now would have to have some information that tells them the EGR system is "normal" while you are making "abnormal" changes to the function. So if you put a delete kit/programming in place, then control the EGR valve by auxiliary means that may be one way, or if you have Forescan and can figure out the engine controller programming that governs how the EGR valve is operated then you can change the program on the OEM controller.
Thank you for the reply, Steve.
I was curios because I didn't know if anyone (obviously not Ford engineers) or aftermarket tuners, had considered running the EGR gas through the through the DPF first then routing it back to the intake. That way, the dirty particulate that abrades the internal components and contaminates the engine oil would be pretty much removed, the "cleaned" exhaust gas moving through the long return pipe from a location past the DPF would be cooler than when it exits the engine but should still have (I think but not proven) the unburned fuel within it that is to be re-ignited in a fresh fuel burn compression cycle.
However, to accomplish this, I'm thinking the EGR should be closed just prior to & a minute or so after the regeneration cycle so none of the fine ash from the regen would be picked up & sent into the intake. Not sure how abrasive that fine ash might be but if it is abrasive, it defeats the whole "no dirty exhaust gas in the intake" concept.
I would think a method like this will not be considered a D by the EPA since the EGR sysem is still intact and accomplish the extra burn they want to decrease the unburned fuel, NOx and other crap they are so concerned with.
BTW, is your KC8QVO like my KF7LPY only obtained at an earlier date than mine? You don't have to answer this question if you don't want to. I'm just curious.
Joe
Thank you for the reply, Steve.
I was curios because I didn't know if anyone (obviously not Ford engineers) or aftermarket tuners, had considered running the EGR gas through the through the DPF first then routing it back to the intake. That way, the dirty particulate that abrades the internal components and contaminates the engine oil would be pretty much removed, the "cleaned" exhaust gas moving through the long return pipe from a location past the DPF would be cooler than when it exits the engine but should still have (I think but not proven) the unburned fuel within it that is to be re-ignited in a fresh fuel burn compression cycle.
However, to accomplish this, I'm thinking the EGR should be closed just prior to & a minute or so after the regeneration cycle so none of the fine ash from the regen would be picked up & sent into the intake. Not sure how abrasive that fine ash might be but if it is abrasive, it defeats the whole "no dirty exhaust gas in the intake" concept.
I would think a method like this will not be considered a D by the EPA since the EGR sysem is still intact and accomplish the extra burn they want to decrease the unburned fuel, NOx and other crap they are so concerned with.
BTW, is your KC8QVO like my KF7LPY only obtained at an earlier date than mine? You don't have to answer this question if you don't want to. I'm just curious.
Joe
Cargo Master
Joined: Jul 2008
Posts: 2,566
Likes: 54
You lost the html for the quotation. For example - when I quote your post it starts with (remove colons) :[QUOTE=CJ01;18914961: and ends with :[/QUOTE]:
In any event:
Interesting idea.
I've been around a lot of diesel engines and watched the EPA regs and manufacturers go through the different tiers over the past 8-9 years (mostly off-road equipment, but some on-road also in the lighter duty truck market - obviously having owned/driven 3 generations now myself) and I have never seen any schematic or functional pictorial or instructional/sales video of any kind that has that theory you describe.
That having been said, the EGR circuit on engines is just that - onboard to the engines. A DPF (and DOC, the diesel oxidation catalyst, and SCR - Selective Catalytic Reduction, DEF injection) are external to the engine - they are outboard functions that solely affect the exhaust stream post-engine.
What you are suggesting is to take an outboard process and re-route it back to the inboard processes of the engine. Could it be done? I suppose. It is an interesting idea. Would it work? No idea.
As to the unburnt fuel - I would be curious to see the test results from a lab test on it. There may be such data out there. There is a lot of testing etc that goes in to engines and facilities exist to run engines for thousands of hours. I would venture to say somewhere along the lines a group somewhere has tried your idea. The questions are - how practical of a design is it, can adequate production practices be put in place for it, is it reliable, and is it serviceable?
On edit here - you may need 2 exhaust streams - one post-DPF and one pre-DPF (as in the way the EGR runs today), or perhaps just delete the regular one. When the DPF is in regen mode it is burning out the soot. What's the point of pushing unburnt fuel through the DPF to be burnt? Then again, and what I don't know, is how much of the unburnt fuel would accumulate in the DPF? In that case - it wouldn't make it back to the intake to be burnt in the engine anyway and would just go up in smoke in a regen. With the "second" exhaust stream to function like the EGR does today you can keep the unburnt fuel out of the regen.
Just a hunch - but I suspect the complexity of rerouting an outboard solution to an inboard process to an engine is too foreign of a concept for any industry to "accept". Maybe in today's day in age it isn't, given the past decade or more of EPA regs crunching down on manufacturers. For example - today society is more accepting of DPF/DOC/SCR-equipped engines (the DPF/DOC/SCR are outboard solutions already) than society was in the early 2000's, or before. The crowd that insists on 7.3L or earlier engines (pre-emissions) is getting smaller every year - and if you look at the market the availability of those older trucks that are still on the road, driveable, and serviceable is getting fewer by the year. We have a market flood of emissions-equipped trucks now (6.0 with the EGR, 6.4 with the EGR and DPF, and 6.7, now the 3.0 also, with EGR, DPF, and SCR - just on the Ford side). The "generations" of model years and engines are replacing the usable market of vehicles still on the road with engines that have outboard emissions solutions. So I think, again, that opens up the possibility of the market today accepting the idea of rerouting the exhaust post-after-treatment (what we call after-treatment today) back to the intake.
On a bit of a parallel - if you look at self-driving cars - 15 years ago society would have had a hard time acclimating to idea of someone not holding the steering wheel of a car going down the road. Yet, here we are with Teslas all over the place now. So all seeds of technology and advancement planted earlier as "concepts" or "prototypes" can lead to mainstream acceptance, however "far out" they may seem at the time of their inception. It just takes an idea to be put out there then society to mold to gravitate to the acceptance of it.
Yep. Been a ham radio operator since 2001, Extra since '07. For what it is worth, also, I've done a lot of mobile operating. I currently run 2 screwdrivers on my F350 - a Little Tarheel II on a mount off the hood for higher bands and a Tarheeel Model 400 off the side of the trailer hitch in the back with a 102" whip for low bands. The 400 doesn't normally come off of 75m. The Little Tarheel II I'll run 20 and 17 on. I lost the high bands on the 400 when I put the longer whip on, but thats OK. The Little Tarheel II is my "portable" mobile antenna also. It uses an SO-239 lip mount so I can put it on other vehicles - rental cars, my semi when I was over-the-road, etc. I've been running a Yaesu FT-991A as my dedicated mobile rig - HF/VHF/UHF (and does Fusion also - havent run that much, but it does it). Any questions on the radio side/integrating with the truck just PM me. I have had a radio in my truck since the day I bought it and had it bonded within the first few months once I figured out the mount for the big screwdriver. I did just have the coax to my big screw driver give up the ghost on my travels this summer - on the start out on a ~2000 mile trip. I replaced it with a temporary run at a rest stop. I still have to pull the old cable out and tie it all back up nice again.
In any event:
If you keep the EGR circuit intact but you are wanting to change the way the EGR valve operates the controllers on the truck now would have to have some information that tells them the EGR system is "normal" while you are making "abnormal" changes to the function. So if you put a delete kit/programming in place, then control the EGR valve by auxiliary means that may be one way, or if you have Forescan and can figure out the engine controller programming that governs how the EGR valve is operated then you can change the program on the OEM controller.
Thank you for the reply, Steve.
I was curios because I didn't know if anyone (obviously not Ford engineers) or aftermarket tuners, had considered running the EGR gas through the through the DPF first then routing it back to the intake. That way, the dirty particulate that abrades the internal components and contaminates the engine oil would be pretty much removed, the "cleaned" exhaust gas moving through the long return pipe from a location past the DPF would be cooler than when it exits the engine but should still have (I think but not proven) the unburned fuel within it that is to be re-ignited in a fresh fuel burn compression cycle.
However, to accomplish this, I'm thinking the EGR should be closed just prior to & a minute or so after the regeneration cycle so none of the fine ash from the regen would be picked up & sent into the intake. Not sure how abrasive that fine ash might be but if it is abrasive, it defeats the whole "no dirty exhaust gas in the intake" concept.
Thank you for the reply, Steve.
I was curios because I didn't know if anyone (obviously not Ford engineers) or aftermarket tuners, had considered running the EGR gas through the through the DPF first then routing it back to the intake. That way, the dirty particulate that abrades the internal components and contaminates the engine oil would be pretty much removed, the "cleaned" exhaust gas moving through the long return pipe from a location past the DPF would be cooler than when it exits the engine but should still have (I think but not proven) the unburned fuel within it that is to be re-ignited in a fresh fuel burn compression cycle.
However, to accomplish this, I'm thinking the EGR should be closed just prior to & a minute or so after the regeneration cycle so none of the fine ash from the regen would be picked up & sent into the intake. Not sure how abrasive that fine ash might be but if it is abrasive, it defeats the whole "no dirty exhaust gas in the intake" concept.
I've been around a lot of diesel engines and watched the EPA regs and manufacturers go through the different tiers over the past 8-9 years (mostly off-road equipment, but some on-road also in the lighter duty truck market - obviously having owned/driven 3 generations now myself) and I have never seen any schematic or functional pictorial or instructional/sales video of any kind that has that theory you describe.
That having been said, the EGR circuit on engines is just that - onboard to the engines. A DPF (and DOC, the diesel oxidation catalyst, and SCR - Selective Catalytic Reduction, DEF injection) are external to the engine - they are outboard functions that solely affect the exhaust stream post-engine.
What you are suggesting is to take an outboard process and re-route it back to the inboard processes of the engine. Could it be done? I suppose. It is an interesting idea. Would it work? No idea.
As to the unburnt fuel - I would be curious to see the test results from a lab test on it. There may be such data out there. There is a lot of testing etc that goes in to engines and facilities exist to run engines for thousands of hours. I would venture to say somewhere along the lines a group somewhere has tried your idea. The questions are - how practical of a design is it, can adequate production practices be put in place for it, is it reliable, and is it serviceable?
On edit here - you may need 2 exhaust streams - one post-DPF and one pre-DPF (as in the way the EGR runs today), or perhaps just delete the regular one. When the DPF is in regen mode it is burning out the soot. What's the point of pushing unburnt fuel through the DPF to be burnt? Then again, and what I don't know, is how much of the unburnt fuel would accumulate in the DPF? In that case - it wouldn't make it back to the intake to be burnt in the engine anyway and would just go up in smoke in a regen. With the "second" exhaust stream to function like the EGR does today you can keep the unburnt fuel out of the regen.
Just a hunch - but I suspect the complexity of rerouting an outboard solution to an inboard process to an engine is too foreign of a concept for any industry to "accept". Maybe in today's day in age it isn't, given the past decade or more of EPA regs crunching down on manufacturers. For example - today society is more accepting of DPF/DOC/SCR-equipped engines (the DPF/DOC/SCR are outboard solutions already) than society was in the early 2000's, or before. The crowd that insists on 7.3L or earlier engines (pre-emissions) is getting smaller every year - and if you look at the market the availability of those older trucks that are still on the road, driveable, and serviceable is getting fewer by the year. We have a market flood of emissions-equipped trucks now (6.0 with the EGR, 6.4 with the EGR and DPF, and 6.7, now the 3.0 also, with EGR, DPF, and SCR - just on the Ford side). The "generations" of model years and engines are replacing the usable market of vehicles still on the road with engines that have outboard emissions solutions. So I think, again, that opens up the possibility of the market today accepting the idea of rerouting the exhaust post-after-treatment (what we call after-treatment today) back to the intake.
On a bit of a parallel - if you look at self-driving cars - 15 years ago society would have had a hard time acclimating to idea of someone not holding the steering wheel of a car going down the road. Yet, here we are with Teslas all over the place now. So all seeds of technology and advancement planted earlier as "concepts" or "prototypes" can lead to mainstream acceptance, however "far out" they may seem at the time of their inception. It just takes an idea to be put out there then society to mold to gravitate to the acceptance of it.
Yep. Been a ham radio operator since 2001, Extra since '07. For what it is worth, also, I've done a lot of mobile operating. I currently run 2 screwdrivers on my F350 - a Little Tarheel II on a mount off the hood for higher bands and a Tarheeel Model 400 off the side of the trailer hitch in the back with a 102" whip for low bands. The 400 doesn't normally come off of 75m. The Little Tarheel II I'll run 20 and 17 on. I lost the high bands on the 400 when I put the longer whip on, but thats OK. The Little Tarheel II is my "portable" mobile antenna also. It uses an SO-239 lip mount so I can put it on other vehicles - rental cars, my semi when I was over-the-road, etc. I've been running a Yaesu FT-991A as my dedicated mobile rig - HF/VHF/UHF (and does Fusion also - havent run that much, but it does it). Any questions on the radio side/integrating with the truck just PM me. I have had a radio in my truck since the day I bought it and had it bonded within the first few months once I figured out the mount for the big screwdriver. I did just have the coax to my big screw driver give up the ghost on my travels this summer - on the start out on a ~2000 mile trip. I replaced it with a temporary run at a rest stop. I still have to pull the old cable out and tie it all back up nice again.
Last edited by KC8QVO; Oct 24, 2019 at 12:04 PM. Reason: Afterthought on unburnt fuel in exhaust through DPF
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