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Old 05-03-2024, 06:11 AM   #1 (permalink)
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EGR

EGR, Engine Gas Returned, or more accurate, dead, spent burned exhaust gas returned to the engine can perform a number of things.

First it can displace part of the incoming air/fuel charge. There is just so much air/fuel the chamber can draw in, and adding dead spent exhaust gasses can thin out the incoming charge.

This can do also cools a lean burn, and partly helps makes it run lean, I know hot exhaust gases seems counterpoint, but it does lower the burn temp. of a lean burn allowing the engine to burn leaner and thus lowers the amount of NOx emissions.

And when added even in a larger volume, can if done correctly, can lower pumping losses but forcing the throttle more open lowing engine vacuum and thus lowing the effort needed to overcome that vacuum, which is funny as we are told for the best MPG we want the highest possible vacuum, which causes a drag on an engine which can in its self, lower MPG.

Luckily, I converted my brakes to a Hydro Boost system some time ago, so my power brakes are NOT depended of engine vacuum to operate.

This lack of engine vacuum and its drag is reported to be a feature of how diesel engine gets better MPG over a standard gas powered engine.

The one major down side is the gunk and crude that can build up in the EGR system.

I THINK I have two ideas of how I can stop the buildup:

First: idea is the use larger piping and no bottle necks and a combo of PCM and manual electronic controls.

Two: take my exhaust gasses from behind the last cat and before the muffler, this I hope will have the most cleaned gases and thanks to the cat, the deadest gasses having been father burned of Oxygen and fuel.

As I believe it is the back pressure of the exhaust system that helps force the EGR system gasses into the chamber VS the engine’s vacuum, I feel I need as much back pressure to back pressure I can get and as my understanding most late model Cats are free flowing so the muffler seems to last point of any back pressure.

And I plan on being able to clean and service this EGR system as needed, and I know it will not stay clean for 100K as car’s systems are required to do, which we all know they don’t.

I have noted that on my Ford Crown Vic's 4.6 engines they use a pipe and electric controlled valve to get the exhaust gasses into the cars throttle body, I am looking to add my EGR at the back of the Plumium of my Camaro TPI, and help in so doing is asked for.

Here is an article on this from: https://en.wikipedia.org/wiki/Lean-burn

"Lean-burn refers to the burning of fuel with an excess of air in an internal combustion engine. In lean-burn engines the air–fuel ratio may be as lean as 65:1 (by mass). The air / fuel ratio needed to stoichiometrically combust gasoline, by contrast, is 14.64:1. The excess of air in a lean-burn engine emits far less hydrocarbons. High air–fuel ratios can also be used to reduce losses caused by other engine power management systems such as throttling losses.

Principle
A lean burn mode is a way to reduce throttling losses. An engine in a typical vehicle is sized for providing the power desired for acceleration, but must operate well below that point in normal steady-speed operation. Ordinarily, the power is cut by partially closing a throttle. However, the extra work done in pumping air through the throttle reduces efficiency. If the fuel/air ratio is reduced, then lower power can be achieved with the throttle closer to fully open, and the efficiency during normal driving (below the maximum torque capability of the engine) can be higher.

The engines designed for lean-burning can employ higher compression ratios and thus provide better performance, efficient fuel use and low exhaust hydrocarbon emissions than those found in conventional gasoline engines. Ultra lean mixtures with very high air–fuel ratios can only be achieved by direct injection engines.

The main drawback of lean-burning is that a complex catalytic converter system is required to reduce NOx emissions. Lean-burn engines do not work well with modern 3-way catalytic converter—which require a pollutant balance at the exhaust port so they can carry out oxidation and reduction reactions—so most modern engines tend to cruise and coastdown at or near the stoichiometric point."

I have read adding EGR can lower NOx or my spraying some water mist as well.


“Thoughts?? Feedback??


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Old 05-03-2024, 01:14 PM   #2 (permalink)
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I have read adding EGR can lower NOx or my spraying some water mist as well.
I'm not trolling (he says) or a True Believer, but I'm hopeful that the Plasmoid Implosion stuff continues to be proven. It uses a water mist, but the water is ionized and then run through a bubbler to create microscopic air bubbles and then drawn through a convoluted reaction chamber (where they are imploded) and fed back into the engine.
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Old 05-03-2024, 01:49 PM   #3 (permalink)
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Lean burn at full throttle, like leaner than 12:1, can damage the engine.

But most engines run at a stoichiometric AFR when not warming up and when not being floored. Stoichiometric is the hottest AFR. I don't care what others believe, it is the point at when you are buring the most fuel per volume of air, therefore it is the hottest.

Leaning out the AFR leaner than stoichiometric actually causes the burn to be cooler. The leaner it is from there, the cooler it becomes. If you don't believe, the ones who have expirimented with this the most and have found this out are personal aircraft pilots. Running leaner caused their engines to run cooler and last longer. This was also my experience with my air cooled VW Beetle. I leaned out the low load jets so it would run at a 17:1 while cruising around, and then go up to a 12:1 when floored. The result was I had a hard time getting a warm engine, engine oil never would get to even 180°F and I got pretty good fuel mileage too.

Think about it, the extra air is innert because it doesn't have any fuel to react with. This is the same as EGR, inert gas that doesn't cause more heat. This is also why diesel engines run cooler inspite of running much leaner than their gasoline equivalents.

The main reason we've moved away from lean burn is emissions. Catalytic converters do a better job if they have very little oxygen. That way they can reduce NOx emissions, which need a reduced (low oxygen) environment in order to get the oxygen to separate from the nitrogen. This also why it is harder to reduce NOx emissions in diesel engines.

How lean, and when can make the ol' saying "lean is hot" either completely true or completely false. It's kind of like saying that rice is a high calorie food, then the go make those rice cakes that are sold as low calorie snacks. Go figure!
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Old 05-05-2024, 06:02 PM   #4 (permalink)
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Good information, @Isaac Zachary.

I'll add a few bits:

As you say, atmospheric air is effectively inert, though EGR has far less oxygen in it to combine with nitrogen, so it naturally produces less NOx. On the other hand, if you have less oxygen, you can have a harder time igniting a lean charge.

One of the major efficiency savings is reportedly in eliminating vacuum.

I'm most familiar with Honda's lean burn tactics. Their EGR systems tend to need manual cleaning every 100-150k miles. The G1 Insight runs around 25:1 AFR. Honda has a direct injection lean burn engine in the K20B, which is supposed to run as lean as 65:1 under certain circumstances (wikipedia, citation needed). Running much leaner than 19:1 or so needs combustion chamber tricks. E.g. The Insight uses a swirl tactic that passes a stream of fuel over a clocked spark plug, whereas the K20B based direct injection system ignites the fuel before it has a chance to spread out and get too diffuse to ignite - something you can't do without direct injection. Having an offset crankshaft helps in getting the crank angle optimal for the much slower burn rate of a lean burn engine, which can otherwise cause efficiency and power loss. Broadly speaking, a faster burn rate is more efficient, and lean burn slows it down, so it comes with downsides.

Atkinson cycle can also reduce vacuum, while also increasing the expansion ratio. Arguably it's better than lean burn, though you can probably use the two together.

Mazda published this helpful chart with regards to their experiments in Atkinson cycle and compression ignition:



Read further here: https://www.insidemazda.co.uk/2017/1...-x-technology/
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Old 05-05-2024, 06:25 PM   #5 (permalink)
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All well and good, but I am trying to do my best with a 93 Chevy 383, cast iron 193 swirl port heads, and a TPI Intake with port injection.

Pistons and chamber and valves faces Ceramic Coated for the lean burn which all of believed runs hotter.

I have run 16.5 on a 2000 Mercury Grand Marques 4.6 engine and gained 5MPG and got her up to 35MPG at 1700RPMs and 65MPH. The engine did not fall apart.

The trick as I see it is to run lean ONLY when in a light cruse at highway speeds with no hills and no wind.

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Old 05-06-2024, 02:43 AM   #6 (permalink)
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Quote:
Originally Posted by racprops View Post
swirl port heads
Contrary to popular belief, swirls are bad for fuel mileage. All they do is fling the gasoline out of the air causing separation of fuel and air, the exact oposite of what we think they do.

It's much more effective to blast the mix past a sharp edge (sharp edges in a combustion chamber are also contrary to popular belief). The air has to bend quickly but the fuel that collected on the walls shoots into the turning air causing it to atomize.





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Old 05-06-2024, 06:43 AM   #7 (permalink)
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I will take a deeper look, but I can see from the title: "De-atomization in intake tract in IC racing engines" That this is concerned with RACING!!

Almost every step of my way I have run into the Hot Rod view of my engine build.

The 193 heads do not breath well (disproven by a few people with flow bench testing)

The 193 heads will not run over 5 or 6K. Well I do not plan on a engine that can run up to 6K.

Now it is this. OK they are NOT racing heads….I do not need racing heads as I am not racing.

Damn near every hot rod/performance part I have every bought has NOT really improved over all driving.

The problem with Hot Rodding IS Hot Rodding, their aim is making more HP and going faster. And this can mean losing some of the everyday needs, such as cold weather driving, of MPG.

And often they go against what the factory built.

Granted a mass produced device will be a middle of the road design, and it tollance will be just good enough to do its job.

Even todays cars have room for some improvement, especially in higher HP and speed. It is fairly easy to Hop Up a PCM just add more fuel is mainly the answer…

GM spends millions even billions making their engines do a daily job, start, drive smoothly get fair MPG and last at least 100K.

THEY designed the 193s with a swirl port, ran them for a number of years then made their big brothers the Vortex Heads and they were and are still considered THE HOT HEAD.

And I have not checked into if these are still The Hot Heads…none the less they made them for at least a decade.

Here is a story how GM once tried to mount carbs with only three bolts…how it saved millions by using one less bolt, one less bolt to drill for, and tap for and put in during building.

It failed as three bolts did not keep a good seal. BUT the moral is if anything could be left off a modern car’s drive train it would be, so it has to be there for the car to do its job. So think very hard before changing anything…

I learned to keep my cars mainly stock, for overall best driving.

GM spent millions making these heads, for a good reason, for everyday driving, and keep making them as improved models.

I believe they know what they are doing for a good street engine and belive in them for my need over a racing engine.

Racing heads are Ported, Cleaned, and Polished and opened up.

I read a ton of reports that this porting and polishing is great for racing, BUT NOT good for MPG. For MPG I read a lot of reports to NOT polish the ports as it will lessen MPG.

So what good for racing is almost always bad for MPG.

On the other hand, many of hot rodding improvements can make for a longer stronger engine and transmissions, so many of these improvements I did use.

One especially is the Rhoads Variable Roller Lifters, which allow my engine to detune: lower the HP at low RPMS and then raise it at higher RPMs and again a bit of Hot Roding used to make MPG not HP. This lifters were invented to help tame a lopping hot rod cam and help make such an engine run almost normal at normal driving….

A kind of having a Good Tame MPG engine and the when needed a more of a performance higher RPM engine making good power all the way from1K to 4.5K.

I had a 2000 Mercury Grand Marques with a stock 4.6 engine making 200HP.

It got 30MPG at 65MPH.

I now have a 2003 Crown Vic with a 4.6, with the Performance improved heads and intake, it now makes 240HP.

Both engines have a REDLINE of 5500RPMs NOT 6000 or 7000, more or less 5000.

The 03 now gets ONLY 25MPG at 65MPH.

Everything is the same: Same transmission, 4 speed auto with .70 overdrive, same rear end a 3.27 rear gears.

SO 40 MORE HP = Less MPG.

This hot rod view runs on every step and nearly every main part of my build.

My cam is WRONG it will not make HP all the way to 6K+.

My using an 86 to 89 TPI Intake also will not run over 5K.

I had to keep saying: I am NOT building a racing hot rod engine, I am building a Low RPM Torque MPG engine.

Nearly everything I have read has shown my engine should make good to great MPG at 1500RPMs and with my use of a second overdrive do this at 75/80MPH.

I am trading high RPM HP for Low RPMs Torque.

I hope and plan on installing all of this by June, and hope to be running by July, there will be a breaking in of the rebuilt engine, 4L0e transmission and the NOS US Gear Dual Range overdrive.

Then I can begin MPG Testing and tuning.

Then we will see.

Anything better that the crappy 14MPG this van has gotten will be any improvement.

Rich
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Old 05-06-2024, 09:46 AM   #8 (permalink)
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So this month I hope to swap out the dead 350 and its 4L60e with my custom 383 and its 4L80e and dual range overdrive.

This dream and project has taken 26 years to do.

Frankly I am afraid to fire it up, and to have to wait until some 500 miles to break in a rebuilt engine, transmission and NOS (New) Dual Range Overdrive to start seeing if this is a great idea and the van gets 25MPG+ or a total waste of my dreams, time and money.

And the frustrating fact that when I started this quest, my ideas were still valuable for a fair number of Vans, trucks and cars might be able to use some of my ideas.

Vans, Trucks and cars have move so far from these systems that only 20+ older Vans, Trucks and cars might be able to use.

So I maybe one of the very few that can benefit from all of this.

As I am compiling the ECM (Engine Control Module) running the fueling systems and a PCM (Power Control Module) to control the transmission systems I am seeing how complex the control systems have become.

The ECM uses ONE O2 sensor, a throttle position sensor, a MAF air flow sensor, an incoming air temp sensor, an coolant temperature sensor, RPM readings, and a knock sensor, oil pressure sensor.

A new car now have: 4 O2 sensors, a crankshaft position sensor, cam shaft position sensors (one per cam) fuel pressure, a throttle position sensor, a MAF air flow sensor, and a MAP sensor, an incoming air temp sensor, an coolant temperature sensor, RPM readings, and a knock sensor, oil pressure sensor, and maybe more:

How many sensors are in a car engine?
There are around 15-30 sensors in a modern car engine if you don’t include the solenoids. You can find over 70 sensors in a modern car if you count every sensor in the whole car.

And ALL this stuff has barely made driving a car any better..not in MPG any way.

ALL this tech and cars still get about the same MPG.

And Trucks, Vans and SUVs still seem to get the same crappy MPG thay got with old carbs and no overdrive.

My 1974/78 Chevy G20 Vans running a 350s with 4 barrel carbs and simple 3 speed transmissions, and the same rear end a 3.43 gear: 14MPG.

My 1993 Chevy G20 Van, now with Fuel Injection, and a 4 speed transmission with a .70 overdrive into a 3.42 rear end gets…wait for it…14MPG…WTF??

Is this a fix?? Is my van PROGRAMED to get poor MPG??? Is this possible??


Well I have TWO Ford Explorers, one a 02 with a 4.0 V6, with a 5 speed transmission with a .70 overdrive and a 3.73 rear end.

And a 03 with a 4.6 V8, with a 5 speed transmission with a .70 overdrive and a 3.73 rear end.

Both get the about the same reported MPG, with the V6 getting 19MPG and the V8 18MPG at 65MPH.

As I have seen cars get great MPG at around 1500RPMs so I tested both SUVs at 1500MPH which is 50MPH.

And WOW both SUVs showed 28 to 32MPG at 1500RPMs…

But speed up to 60MPH and WTF now they are getting 18MPG…they both lose around 10MPG just going 10MPH faster.

But then things return to a normal loss of 1MPG per each 5MPH faster so they both get 16MPG at 75/80MPH…again WTF.

How odd is this?? My 2000 Grand Marques and 03 Crown Vic with a 4.6 V8 only does the normal loss of 1MPG per each 5MPH faster…so they have a steady loss of MPG with faster speeds.

There is NO drop of 10MPGs at any speed change of any 10MPH.

I believe instead of using the computers to make as much MPG in cars and Trucks, Vans and SUVs especially are using the computers against us.

I hope to show that we can get better MPG.

I rest my case.

Rich
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Old 05-06-2024, 11:37 AM   #9 (permalink)
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Quote:
Originally Posted by racprops View Post
I will take a deeper look, but I can see from the title: "De-atomization in intake tract in IC racing engines" That this is concerned with RACING!!
And your point?

Yes, I get that you're trying to make a fuel sipper, not a fuel guzzler. But getting the most power from the least amount of fuel helps both worlds. And you can still build an engine that gets as good of fuel mileage as possible and let the power fall wherever it falls, even if it's pretty puny.

In some instances power and fuel mileage are at odds with each other.
  • A bigger engine will run with the throttle more closed running less efficiently.
  • More boost means more enrichment, which also isn't good for fuel mileage.
  • Large, open, unrestrictive intake tracts don't help fuel mileage any more than keeping the throttle valve large, open, and unrestrictive (unless maybe it's a diesel, but then it would need to be sized for the lower RPMs you're likely going to be targeting, which again would be smaller than what a performance expert would recomend).

But you will find pretty much zero ecomodders who can compare themselves to racers when it comes to testing. Racers can do dozens, hundreds or perhaps thousands of complete engines with all their systems, whereas most of us ecomodders have built maybe a couple of engines.

And so when it comes to things like:
  • More fuel atomization,
  • More compression in general,
  • Less restrictive exhaust, or at least understading how exhaust and intakes actually flow instead of just slapping on big tubes thinking that's going to solve everything.
These are the things that get you more power from less fuel, those things help with people striving for either goal. Some of the most fuel efficient car engines in the world are F1 race cars, being around 50% efficient, they've got a lot more testing, trial and error, experience, whatever you want to call it, it's much more solid knowledge than some internet myth floating around that if you put on a big open intake you'll somehow miraculously get better fuel mileage.
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Old 05-06-2024, 01:25 PM   #10 (permalink)
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Yes, I get that you're trying to make a fuel sipper, not a fuel guzzler. But getting the most power from the least amount of fuel helps both worlds. And you can still build an engine that gets as good of fuel mileage as possible and let the power fall wherever it falls, even if it's pretty puny.

I have read many books that say tune your engine and drive train so that your engine is at or near your engines Torque Peek for best MPG at your preferred Speed.

BUT a torque peak of 2800 RPMs mean cruse below 2500RPMs will not give good MPG…



In some instances power and fuel mileage are at odds with each other.
* A bigger engine will run with the throttle more closed running less efficiently.

Yes, thus my looking into EGR to cause a more open throttle to cut “pumping losses”

* More boost means more enrichment, which also isn't good for fuel mileage.

I have NO boost of any kind.

* Large, open, unrestrictive intake tracts don't help fuel mileage any more than keeping the throttle valve large, open, and unrestrictive (unless maybe it's a diesel, but then it would need to be sized for the lower RPMs you're likely going to be targeting, which again would be smaller than what a performance expert would recomend).

Small low performance heads and valves are reported better for MPG.


But when it comes to things like:
* More fuel atomization,
* More compression in general,
* Less restrictive exhaust, or at least understading how exhaust and intakes actually flow instead of just slapping on big tubes thinking that's going to solve everything.

WHICH is why I am running a STOCK TPI, no big tubes, stock 193 Heads with stock valves, and a stock cast iron exhaust manifold into low restrtive cats and mufflers.

These are the things that get you more power from less fuel, those things help with people striving for either goal. Some of the most fuel efficient car engines in the world are F1 race cars, being around 50% efficient.


Yes, at full throttle and max RPMS, but will them do 35 to 50MPG???


Yes efficient in their world…


Rich

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