What if "new CAFE requirements" ......

[gathermewool]

I want gas to be $1/gal and every car to only be required to get 20 MPG, max, downhill. The faster we burn up the crude we know about, the sooner we'll move onto something else. We keep buying ourselves the time needed to develop new techs to correct previously uneconomical (or less feasible) ways of sucking this stuff out of the Earth.

 

[Cujet]

https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3214199/1

The above link is a thread I participated in. Bottom line, a 20% reduction in fuel consumption is possible with a 20 to 1 air fuel ratio. When compared to a Stoichiometric mixture.

In a Ford 5.4L BSFC numbers are as follows:

1) Stoic 272 g/kwh
2) Lean burn 20/1 near unstable, 222 g/kwh

In the real world, this would translate into a change from 14.5 MPG to 17.5 MPG in my truck.

 

[SOHCman]

Originally Posted By: Cujet
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3214199/1

The above link is a thread I participated in. Bottom line, a 20% reduction in fuel consumption is possible with a 20 to 1 air fuel ratio. When compared to a Stoichiometric mixture.

In a Ford 5.4L BSFC numbers are as follows:

1) Stoic 272 g/kwh
2) Lean burn 20/1 near unstable, 222 g/kwh

In the real world, this would translate into a change from 14.5 MPG to 17.5 MPG in my truck.


Is this feasible, or would it just result in poor running pinging/detonating engines?

 

[Cujet]

Originally Posted By: SOHCman


Is this feasible, or would it just result in poor running pinging/detonating engines?


Completely feasible. However, some engine designs lend themselves to this better than others.

Consider what needs to happen in this example: during a highway drive at steady power, the mixture leans out to 20-1, the timing advances markedly and the throttle opens considerably more. The driver is unaware of the adjustments, his gas pedal position remains unchanged, only partially depressed, the engine RPM remains at 1700, and the transmission does not downshift despite the throttle plate being nearly fully open.

The amount of power the engine produces is unchanged. However, fuel use is reduced considerably.

Piston engine aircraft do this regularly. Especially if they are equipped with electronic ignition.

 

[nthach]

Originally Posted By: OneEyeJack
In 1970 I purchased a new E300 Ford Econoline van with a 302 V8, manual transmission and tuned up to factory spec's it passed California smog. I put larger main jets in the 2-barrel carb and carefully matched the porting on the carb to the manifold. I also advanced the static timing and changed the advance spring to allow the timing to advance quicker. The driveability improved a lot. It also blew better numbers in the smog test, too. A Ford mechanic wrote down exactly what I did including the P/N of the jets and springs. He used this method to satisfy customers that complained about stumbling acceleration in pickups and vans. He had to set the timing to stock and change the advance springs to make up for the retarded static setting.

I always wondered where Ford got the tune-up and carb settings.

And you did this at the beginning of the Malaise Era, way before I was born and when California was implementing the early parts of their clean air program as well the Clean Air Act. I take it your Econoline also had the early implentations of air injection, pellet-substrate cat but no EGR as well? I think Ford was one of the first to go EFI in the 1980s as well.

I thought the reason the Detroit 3 severely detuned their cars during the Malaise Era was to keep unburned HC emissions as low as possible given the state of the art at the time with carbs and mechanical advance distributors but it also forced things to run lean as well? Detroit was definitely coming off the euphoria of muscle cars back then and they didn't take Toyota or VW or even the Middle East as a threat seriously.

 

[OneEyeJack]

Originally Posted By: nthach
Originally Posted By: OneEyeJack
In 1970 I purchased a new E300 Ford Econoline van with a 302 V8, manual transmission and tuned up to factory spec's it passed California smog. I put larger main jets in the 2-barrel carb and carefully matched the porting on the carb to the manifold. I also advanced the static timing and changed the advance spring to allow the timing to advance quicker. The driveability improved a lot. It also blew better numbers in the smog test, too. A Ford mechanic wrote down exactly what I did including the P/N of the jets and springs. He used this method to satisfy customers that complained about stumbling acceleration in pickups and vans. He had to set the timing to stock and change the advance springs to make up for the retarded static setting.

I always wondered where Ford got the tune-up and carb settings.

And you did this at the beginning of the Malaise Era, way before I was born and when California was implementing the early parts of their clean air program as well the Clean Air Act. I take it your Econoline also had the early implentations of air injection, pellet-substrate cat but no EGR as well? I think Ford was one of the first to go EFI in the 1980s as well.

I thought the reason the Detroit 3 severely detuned their cars during the Malaise Era was to keep unburned HC emissions as low as possible given the state of the art at the time with carbs and mechanical advance distributors but it also forced things to run lean as well? Detroit was definitely coming off the euphoria of muscle cars back then and they didn't take Toyota or VW or even the Middle East as a threat seriously.


I made sure my van passed smog because of an experience driving into LA. I was on the freeway approaching Downey driving into a solid haze of smog. My eyes started to burn. I pulled over to a wide spot to get away from the traffic. A CHP officer on a bike pulled up and stopped. When I explained my problem he went back to his bike and handed me a small bottle of eyewash. He said to take my time and let the eyewash have a chance to work before driving on. I did and it really helped. In those days the smog sometimes blocked the sunlight and was so think you could almost cut it with a knife. Thankfully those days in LA are gone. It's not perfect now but much better.

 

[zorobabel]

Originally Posted By: OneEyeJack

I made sure my van passed smog because of an experience driving into LA. I was on the freeway approaching Downey driving into a solid haze of smog. My eyes started to burn. I pulled over to a wide spot to get away from the traffic. A CHP officer on a bike pulled up and stopped. When I explained my problem he went back to his bike and handed me a small bottle of eyewash. He said to take my time and let the eyewash have a chance to work before driving on. I did and it really helped. In those days the smog sometimes blocked the sunlight and was so think you could almost cut it with a knife. Thankfully those days in LA are gone. It's not perfect now but much better.

Is that how you lost an eye?

 

[nthach]

Originally Posted By: OneEyeJack
He said to take my time and let the eyewash have a chance to work before driving on. I did and it really helped. In those days the smog sometimes blocked the sunlight and was so think you could almost cut it with a knife. Thankfully those days in LA are gone. It's not perfect now but much better.

Oh wow, from reading about this in elementary school I had an idea it was bad, but if you had to pull over to wash your eyes out then it's really bad. The Bay Area can get bad, I can see the smog over SF/Oakland when I ride my bike up Mt. Diablo but I can picture it being much, much worse.

Things like emissions controls are needed in densely populated areas, much to the chagrin of people living in the country and other rural areas. Yes, it's a PITA to deal with fuel with EtOH and for the diesel guys EGR/DPF/SCR and to buy DEF every few hundred/thousand miles but it's what happens when you have a lot of people within certain geographical/geological confines. You can have a car or truck that gets great MPG but the emissions(CO/HC/NOx/PM50) are another story.

 

[SOHCman]

I don't know why I think up these silly things, but I thought you all might find this funny

 

[PimTac]

All this 20:1 mixture talk reminds me of Chrysler’s lean burn engines that pinged going downhill. All those cars of the 70’s and 80’s with newfangled air pumps and other emissions workarounds were a mess to keep up.

Hopefully this time around will be better.

 

[nthach]

I think Honda and Mitsu had more luck with CVCC and MCA-Jet even though it's a stratified charge design that puts the richer air/fuel mixture closer to the plugs as a whole. The Japanese didn't go all out with AIR and other things the Americans used.

 

[A_Harman]

Originally Posted By: Cujet
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3214199/1

The above link is a thread I participated in. Bottom line, a 20% reduction in fuel consumption is possible with a 20 to 1 air fuel ratio. When compared to a Stoichiometric mixture.

In a Ford 5.4L BSFC numbers are as follows:

1) Stoic 272 g/kwh
2) Lean burn 20/1 near unstable, 222 g/kwh

In the real world, this would translate into a change from 14.5 MPG to 17.5 MPG in my truck.


Yes, it can work. I worked on a lean-burn turbocharged natural gas engine in 1994-95 at Cummins that operated at 27:1 A/F at rated power. Cummins sold those engines in city bus applications. Those engines were premix charge, basically throttle body injection. But we fantasized about direct injection, stratified charge technology, even way back then. I think auto manufacturers are missing the boat after having developed DI gasoline technology, and not developing lean-burn stratified charge combustion modes.

 

[NYEngineer]

I was fifteen minutes into explaining why I totally buy into this theory and my computer did something odd and everything went blank.

Long story short, when I learned about quench height and combustion chamber design and all other related stuff, engines I built made more horsepower and had cleaner emissions.
Two examples were a 440 mopar that I originally had 1969 906 heads. Total junk. When I got some Edelbrock heads with kidney shaped chambers and dialed the quench to .038, it was a huge improvement in emissions and power.

I also built a 351W for my dad's 88 Bronco. By paying close attention to the quench, cam selection and very mild porting of the heads and efi intake, the guy who did the smog test on it at inspection time said you could breathe what was coming out of the tailpipe of that truck.

 

[ZeeOSix]

Originally Posted By: Linctex
No...... 15 years ago I rode in a Corvette that was getting 27 MPG.

Explain that?


Lots of low end torque keeping engine RPM way down at highway speeds and aerodynamics at play.

If you could magically take away all aerodynamic drag and only have rolling resistance, then cars would be getting very high gas mileage on the highways.

 

[PimTac]

Originally Posted By: A_Harman
Originally Posted By: Cujet
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3214199/1

The above link is a thread I participated in. Bottom line, a 20% reduction in fuel consumption is possible with a 20 to 1 air fuel ratio. When compared to a Stoichiometric mixture.

In a Ford 5.4L BSFC numbers are as follows:

1) Stoic 272 g/kwh
2) Lean burn 20/1 near unstable, 222 g/kwh

In the real world, this would translate into a change from 14.5 MPG to 17.5 MPG in my truck.


Yes, it can work. I worked on a lean-burn turbocharged natural gas engine in 1994-95 at Cummins that operated at 27:1 A/F at rated power. Cummins sold those engines in city bus applications. Those engines were premix charge, basically throttle body injection. But we fantasized about direct injection, stratified charge technology, even way back then. I think auto manufacturers are missing the boat after having developed DI gasoline technology, and not developing lean-burn stratified charge combustion modes.




This sounds similar to what Mazda is achieving with their SkyActiv X engines

http://autoweek.com/article/technology/7-things-you-need-know-about-mazdas-new-compression-engine

 

[Linctex]

Originally Posted By: nthach
Honda.... with CVCC ...stratified charge design that puts the richer air/fuel mixture closer to the plugs as a whole.


Such an amazing concept - These cars really made auto engineers sit up and take notice!

 

[ZeeOSix]

One reason a lot of car manufacturers are now going with small displacement turboed engines (ie, "Ecoboost") is to try and get very good gas mileage while not in boost, and then make decent power when in boost. Obviously, the CAFE tests that determine the MPG rating isn't going to be using any boost, so it's a "win-win".

I think the fuel efficiency of IC engines is pretty much approaching it's feasible maximum. Engineers are now trying to squeak out the last few percentage of efficiency with all kinds of friction and pumping loss cutting measures. If you could magically make a rotating engine totally frictionless you might get a hair more efficiency.

Next major step to increase fuel mileage is reduced vehicle mass and low aerodynamic drag. All those funky futuristic looking cars might just be the norm at some point in time, unless they have all those ugly spinning sensors all over it when they become self driving cars - puke!

 

[Shannow]

Originally Posted By: ZeeOSix
Next major step to increase fuel mileage is reduced vehicle mass and low aerodynamic drag. All those funky futuristic looking cars might just be the norm at some point in time.


I agree that we are at the end of the diminishing returns part.

Petrol engines now have DI and diesel like compression ratios. The other side of the equation is very very similar engines that run on diesel (they are nothing like "diesel engines" that we used to know.

Japanese OEMS are now increasing bearing sizes with the thinner oils, showing that they have nearly hit the minimum friction point, and are chasing piston friction, but need to hold the bottom end together.

Holden had 5 (or more) different steel specifications in the commodore depending on how it's used, Honda are leading Friction Stir Welding of Aluminium to steel.

I think that safety regs will provide a lower limit to the minimum mass

 

[VNTS]

Originally Posted By: Linctex
Originally Posted By: nthach
Honda.... with CVCC ...stratified charge design that puts the richer air/fuel mixture closer to the plugs as a whole.


Such an amazing concept - These cars really made auto engineers sit up and take notice!


no they didnt, they 70's early 80' Hondas with the CVCC engines were terrible engines, my whole family bought Accords from that time period with them, CVCC 1.8 with keihn 3bbl carbs. the rings were shot at 50k, head gaskets at 30k and valves on the CVCC were problematic, it was a dead end technology they abandonded for fuel injection.
the quality on these engines were terrible and to be truthful Honda should of been forced out of the market, those vintage cars were that bad.

 

[A_Harman]

Originally Posted By: ZeeOSix
One reason a lot of car manufacturers are now going with small displacement turboed engines (ie, "Ecoboost") is to try and get very good gas mileage while not in boost, and then make decent power when in boost. Obviously, the CAFE tests that determine the MPG rating isn't going to be using any boost, so it's a "win-win".

I think the fuel efficiency of IC engines is pretty much approaching it's feasible maximum. Engineers are now trying to squeak out the last few percentage of efficiency with all kinds of friction and pumping loss cutting measures.

Now see, right there you just described my last job at GM in one sentence! It was a grab-bag project of friction and parasitic loss reduction applied to the 5.3L small block, with the goal of achieving 31 mpg in a standard half-ton pickup.
The fuel economy gains we demonstrated were substantial, and we took advantage of a program of CO2 credits from the EPA where they had a list of technologies, that if we included them in our design, they would give us credit for reducing CO2 emissions, whether or not we could prove they actually saved fuel. The later we got into the Obama administration, the easier it was to get CO2 credits so they could tout great reductions in emissions...