Fuel economy and egr questions

[Tinbender59]

I may be overthinking this? need some assistance or clarification.

My thoughts; however crazy that they sound?? When cruising at highway speeds most of the time we need only about 75 ftlb torque and under 100 HP, normally 40 to 50, as it has been explained to me??? So, the manufactures know that we can’t drop the fuel content without lowering the O2 content, as the result would be a severe Lean out, and motor go boom!! The Manufactures have created the EGR to "inject" inert gasses (burnt O2) into the combustion cylinder to allow the "burnable" O2 levels down so that we can lower the fuel content needed to keep the reduced power output at a safe operating temp. With this basic operation we can increase our fuel millage significantly. My question now is can we push the EGR farther, for more increase, or do we need to supplement it with ethanol, or is there a different way to do this?

This theory has only been presented to one other person on this planet, so I hope you all can follow along. I had hopes of getting rich off of this idea, but I am getting older and no money richer, lol. So you younger braineyacks here’s your claim to fame.

P.S. I do not know if anyone else has figured Stanley Meyer's “spark plug” out yet? So here it is.

One method that I have been ”think tanking” for almost 35 years, is an internal combustion steam engine. That is how Stanley Meyer's VW was operating; Look at his injector, inject HHO in the top, ignite it (super-Hot Flame. Play with it you will see) then injecting a water mist into the flame; which turns the water mist into Steam. 1 gallon of water will make 1860 cubic feet of steam (i believe that is correct) and port it into the cylinder through the spark plug hole. "Important point to understand"; Also a fact of physics - liquids draw heat like a brawny towel draws moisture. How much power does steam have? I’m glad you asked; well let’s just say catapults operate on less pressure than it takes to blow up an acid/aluminum/plastic bottle.
So next logical next question; can we go ahead and lean out our AFR, then inject a water mist in the cylinder to absorb the extra heat, and the mist then will be converted into steam to assist with pushing the piston down?? Thus; Increasing fuel millage exponentially

As I said, I maybe crazy, but these are my thoughts??

So This is the end equation.

With the 411, can we substitute a water mist for the inert gas???

[Tinbender59]

uh!!! am I to far out on this??

[ccreddell]

Isnt this somewhat like what we did back in the 70s with water injection? Or maybe like what theyve been doing lately with Hydrogen bubblers?

[RADustin]

there are significant gains to be had with timing and a leaner AFR at lower load. I gained ~3mpg by a timing increase of 4° alone.

direct injection and ultra finite timing control seems to be the wave of the future.

I do see where you are going. By eliminating manifold vacuum without the use of forced induction(going WOT), the BSFC will drop as efficiency is gained if RPMs/Load held the same(BMEP would increase). Basically have the otto cycle mimic the diesel cycle here and control RPM(needed HP) by fuel/spark input alone while using EGR to reduce free oxygen available(richen mixture). Sounds tricky but seems completely possible. You would certainly need to keep MAF so you know how to fuel as MAP would be nearly useless. Seems like this would work tuning wise very similar to diesels.

You'd need a roadrunner and ton of dyno time. Not to mention CHT,EGT, and WBO2 to know when to quit.

I don't know about the water injection but I've seen it before. Crowler built one a while back. The power potential of water-> steam is very hard to control. https://en.wikipedia.org/wiki/Six-stroke_engine

[joecar]

Interesting thread... :cheers:

[Tinbender59]

The power potential of water-> steam is very hard to control. https://en.wikipedia.org/wiki/Six-stroke_engine

Yes you are correct,



there are significant gains to be had with timing and a leaner AFR at lower load. I gained ~3mpg by a timing increase of 4° alone.

direct injection and ultra finite timing control seems to be the wave of the future.

I do see where you are going. By eliminating manifold vacuum without the use of forced induction(going WOT), the BSFC will drop as efficiency is gained if RPMs/Load held the same(BMEP would increase). Basically have the otto cycle mimic the diesel cycle here and control RPM(needed HP) by fuel/spark input alone while using EGR to reduce free oxygen available(richen mixture). Sounds tricky but seems completely possible. You would certainly need to keep MAF so you know how to fuel as MAP would be nearly useless. Seems like this would work tuning wise very similar to diesels.

You'd need a roadrunner and ton of dyno time. Not to mention CHT,EGT, and WBO2 to know when to quit. [/url]

Sometimes I think that I am totally insane, the crazzy sh--stuff that My mind ponders at times.

But there is a lot of fuel wasted inside our motors. has anyone heard of "fuel cooling" or "fuel dumping"?? This is a reality my friends. the manufactures dump excess fuel into the motors. why do you think we have Cat converters, they burn the unburnt "Hydrocorbons" fancy word for unburnt fuel. How ever there is a reason that they dump fuel, it is the easest Liquid to use, and it is readilly available on board an automobile. It is the easest to use, as the delivery system is already in place.

the purpose of Fuel dumping is to remove excess heat. a fuel flame at optimum AFR is between 1200 to 2400 degrees depending on the air and fuel delivery method. (I work with thermal processes that can get up to 2200 in a controlled situation). Ok back to excess heat, pistons will melt down around 600 deg F, if our fuel mixture was optimal, we would have a problem before we went a mile. If you remember
"Important point to understand"; Also a fact of physics - liquids draw heat like a brawny towel draws moisture" so the briliant engineeres (yes spelled it wrong on purpose) figured that they would dump extra "LIQUID" fuel into the combustion chamber knowing that there is not enough air to burn it up. With the sole purpose of "scrubbing" the excess heat out of the cylinder before it could move into the piston or block. In aircraft that is refered to as Heat soak. The excess fuel absorbs the "free heat" meaning the heat in the open mass of the cylinder, sorta grabs it, turns most of the fuel into a hot vapor. then before it can leach into the engine components it is pushed out the exaust port. there are a hundred other things going on at the same time, such as both valves opening at the right time to add air as the exhaust valve opens to aid in the burning of the unused fuel, also to help push exhaust gasses out.... bla bla bla

Then they have a Cat to burn the excess unburnt fuel.

then they came up with the idea of the EGR, it helps elieveate the fuel dumping, but it does not eliminate it completely, as the flame temp is still an issue.

there is a lot more to this theory, but it is late.

More next time. please ask questions, helps my archive retreaval system.

[Tinbender59]

Interesting thread... :cheers:

Thanks, and please join in I would like to hear from your expearience Joe.

[joecar]

I hate EGR, it is the antithesis of performance... sure it was developed to help reduce formation of NOx compounds (which cause brown colored smog pollution) by lowering combustion temperatures (which also helps to prevent ignition knock)... but there are other ways to achieve all the same results as was seen by the disappearance of the EGR subsystem from the 2001-2002 F-car and Y-car... since 2001, no GM LS1 derived cars have had EGR (I don't know about trucks).

Fuel dumping is a very common combustion chamber cooling method and has been used for as long as the liquid fuel carburetor has been in existence (for example, have you ever followed behind an original VW beetle for a few seconds, your eyes will weep gasoline tears). In the modern era of the PCM/ECM, algorithms calculate combustion chamber and catalysts temperatures based on current operating conditions (and short term running history) allowing the detection of impending disasters (like imminent melting of piston tops and catalysts) so the PCM/ECM can then take protective measures by dumping fuel and adjusting ignition timing to avert such disasters.

When fuel/air charge is ignited, the flame front that proceeds across the combustion chamber has a shockwave in front of it, it is this shockwave that isolates and protects the combustion chamber (aluminum pistion tops and heads) from the flame's heat (which like was said above burns at a temperature higher than aluminum's melting point)... a knock event is an explosion (a very short duration very very intense spike in pressure) which breaches the flame front and allows the flame's heat to damage the combustion chamber... even the lightest continual knock causes cumulative damage... EGR helps prevent knock (in those cases where the PCM can predict it), but there are ways other than EGR to do this.

Catalysts work properly when the running AFR (I prefer to say Lambda instead of AFR) is such that HC/CO and NOx are minimized (which is approximately at stoich AFR)... fuel dumping with late ignition timing causes the cats to heat up significantly, so the PCM has to advance ignition timing to allow the fuel burn completely (as much as is possible) before it leaves the combustion chamber... I don't fully understand the complete relationship between cat temperature and CC temperature, but I know ignition timing plays a key role (which I'm studying up to learn more about).

Underlying all this is the EPA/CARB mandate to reduce emissions (NOx, HC, CO), so all the subsystems are supposedly designed to work with each other, which means we'll always be screwed up.

:)

[Tinbender59]

I hate EGR, it is the antithesis of performance... sure it was developed to help reduce formation of NOx compounds (which cause brown colored smog pollution) by lowering combustion temperatures (which also helps to prevent ignition knock)... but there are other ways to achieve all the same results as was seen by the disappearance of the EGR subsystem from the 2001-2002 F-car and Y-car... since 2001, no GM LS1 derived cars have had EGR (I don't know about trucks).

Fuel dumping is a very common combustion chamber cooling method and has been used for as long as the liquid fuel carburetor has been in existence (for example, have you ever followed behind an original VW beetle for a few seconds, your eyes will weep gasoline tears). In the modern era of the PCM/ECM, algorithms calculate combustion chamber and catalysts temperatures based on current operating conditions (and short term running history) allowing the detection of impending disasters (like imminent melting of piston tops and catalysts) so the PCM/ECM can then take protective measures by dumping fuel and adjusting ignition timing to avert such disasters.

When fuel/air charge is ignited, the flame front that proceeds across the combustion chamber has a shockwave in front of it, it is this shockwave that isolates and protects the combustion chamber (aluminum pistion tops and heads) from the flame's heat (which like was said above burns at a temperature higher than aluminum's melting point)... a knock event is an explosion (a very short duration very very intense spike in pressure) which breaches the flame front and allows the flame's heat to damage the combustion chamber... even the lightest continual knock causes cumulative damage... EGR helps prevent knock (in those cases where the PCM can predict it), but there are ways other than EGR to do this.

Catalysts work properly when the running AFR (I prefer to say Lambda instead of AFR) is such that HC/CO and NOx are minimized (which is approximately at stoich AFR)... fuel dumping with late ignition timing causes the cats to heat up significantly, so the PCM has to advance ignition timing to allow the fuel burn completely (as much as is possible) before it leaves the combustion chamber... I don't fully understand the complete relationship between cat temperature and CC temperature, but I know ignition timing plays a key role (which I'm studying up to learn more about).

Underlying all this is the EPA/CARB mandate to reduce emissions (NOx, HC, CO), so all the subsystems are supposedly designed to work with each other, which means we'll always be screwed up.

:)

Heh Heh, I was hopeing that you would impart some of your wisdom Joecar, thanks for the input. The idea of this thread is to "think Tank" this issue of economy to see if we can colectively come up with a plausable theory.

[joecar]

I don't like economy by itself (i.e. for the sake of economy)...

I do like economy achieved by means of engine being correctly fueled at all condtions (rather than being gratuitosly overfueled everywhere because this was simpler/safer)... i.e. economy as a by-product of efficient performance... it will not be as high, but engine is always happy.

[greasess]

I like this idea. I was already thinking of using water injection under boost using the shift light function to activate, IAT ignition offset table to adjust timing and the distilled water that drips out of the AC system to fill the water tank. Even if the AC drip didn't keep up with use durring cruising it would extend the time between refills. The only thing I would be worried about with using the egr table alone to activate water injection in the lower rpms would be that your tune would depend on the water injection completely unless you're thinking of something I'm not.

[joecar]

I don't know much about water injection...

[greasess]

I watched some customers experiment with water injection on a turbocharged k20. They went from around 550 with 11/1 AFR on 93 to just over 600 and 12 - 12.5/1 AFR. I know they were using more timing too but idk how much. I'll try to dig up the Dyno graphs from this and post if anyone wants to see.

[joecar]

I read the Wikipedia article on water injection... interesting, a balance between cooling the intake charge and displacing incoming air... the cooling allows more timing advance and/or higher CR (as always) and the instant steam keeps combustion chambers clean.

[greasess]

I really want to start playing around with this on my wife's Saturn L200. It's on the supported list and I pulled the tune file off the PCM (P11) but EFI live won't let me open it... Does anyone have some kinda clue where to start as far as an air to water ratio? I was thinking of pulling the fuel pump out of anything flex fuel at the junk yard to use as a water pump and make or buy a spray nozzle. I found a few videos on youtube claiming economy gains as well.

[Level2]

It seems to make sense NOW to me to use the EGR solenoids wiring to directly control a water injection system instead. If ever I don't have to work again, I might explore this, if no one else has already.

Years ago, I had a 3.8L Turbo 6 in a Buick Riviera... the luxury version of the Regal. With a quadrajet no less. Stock from GM.

Water injection allowed me to keep the monster knock sensor from retarding timing, run 4-8 degrees advance, and rip CV joints apart every 20k miles. I was young and knew everything then... man I have learned so much since. :-)