200 MPG Carburetor Talk

[IamIan]

Originally Posted by mja1

It's not that you don't understand, you pick apart every sentence,

As I already wrote ... and you already knew:

Originally Posted by mja1

I respect this

When you post multiple things I see errors with or I disagree with I have pointed them out ... just as I previously posted and you previously acknowledged and and claimed you respected.

If it is correct ... it should make no difference how many parts I see errors with or I disagree with ... you should be able to explain why each part is correct ... if you can't explain the perceived errors and disagreements ... than they remain as open issues with the whole , and with any parts built on top of them.

Originally Posted by mja1

I tried to have a healthy discussion, your aim isn't worthy, it's to put down everything I write as if I were some fool who driveled bs with every keystroke.

You are incorrect.

That is not my aim ... I know my aim better than you do ... I have been straight forward and honest about my aim ... my posts have been honest to that aim ... an aim I already posted and you already acknowledged.

I suggest ... you avoid trying to tell other people what they are aiming for ... or what they are trying to do ... such efforts are highly prone to error... as in this example , you were wrong.

Originally Posted by mja1

I tried to continue a discussion in the PM as I sensed it was becoming more of a personal thing somehow. There's something more to the discussion than what we're talking about, I don't appreciate it, and I'm done with it.

I appreciate your effort. I didn't continue a PM thread, because it was just web links ... links that were relevant to the public threads discussion of the concept you were describing ... and sense you made no comments in that PM that indicated to me it was some kind of secret or personal information ... I saw no reason not to share the information you shared with the rest of the group , who may be following the discussion.

I am not apposed to a PM based discussion if you don't feel comfortable with an open public discussion ... if that's what you want , just say so ... but don't expect me not to point out errors and disagreements in PMs ... that part will remain the same, public or private discussion... no matter how many are stringed together ... they are all fair game.

[user removed]

A carbureted Opel could get 124 MPG in 1971, but it wasn't the carburetor that was responsible for the mileage increase.

It was radial tires, restricted throttle opening, and 15-45 MPH pulses followed by engine off glides where there was 0 fuel consumption. This method has been known since WW2 when gas rationing invited inventive driving techniques and no one was worried about radical fluctuations in vehicle speed. Their objective was to get to their destination without running out of their 2 gallon per week fuel rationing allotment.

If you have information that would prove that their is a 200 MPG carburetor, then that same Opel should get something like 800 MPG with your "miracle" carburetor using the same driving tactic.

My point is and this has been proven many times over decades. Operating the engine at peak efficiency in an all or nothing tactic has proven to increase mileage dramatically. The issue is not increasing mileage, whether it is a carburetor or fuel injection. The issue is how do you apply the pulse and glide technique, without the speed variation.

In order to do this you have to have two things. Capacitive on board energy storage and a variable ration transmission to apply that capacitive storage in the precise amounts it takes to maintain a constant velocity as the storage levels deplete. Once you have these two essential requirements then they have to be highly efficient or the total system losses make the system no more efficient than the status quo.

When done properly you can get the 120 MPG of the old Opel, without speed variations. The Opel averaged 26 MPH, about the same average speed as the EPA's city cycle.

Perfectly mixing (homogenous) the fuel and air will get you about 15-25% better efficiency, not even close to 500%.

regards
Mech

[WD40]

I think of it as "forum rage" not that far from "road rage" in my books .. it does not belong in a healthy forum .. I have left more then a few forums for this reason alone.
If your not happy with what someone has to say then ignore it, why get all bent out of shape over it.
We need a healthy forum full of constructive criticism.
Oh and BTW feel free to ignore this post.

[3-Wheeler]

Originally Posted by Old Tele man

The purpose of EFI is to more precisely 'control' both the quantity of fuel injected and the timing of its injection...two aspects of fuel economy (FE) and power (HP) that the common pressure-differential carburetor cannot match...perform reasonably well? Yes, but match or exceed, NO WAY!

First, the carburetor functions on pressure difference--vacuum--which means its susceptable to atmospheric and altitude changes...EFI is a VERY stable constant volume and pressure device, albeit a computer-controlled system. Typical, normal-aspiration engines only achieve about 14.7 psi differentials at best, whereas a pressure-differential of over 2000-2500 psi is possible/common with today's EFI high-pressure piezo-injector systems. It's like the HUGE difference between raindrops and weather's mist!

Droplettes of gasoline don't burn very well nor very fast, resulting in less HP and even less fuel economy...while, the closer the gasoline volume within the air-fuel mixture is to a 'true' vapor, the more HP and better fuel economy...with LESS gasoline going out the tailpipe as emissions.

Hi Tele,

You make some very good points here!

Also, carburetors can run lean on high pressure days, and rich on low pressure days.

There was a very well known spark plug tuner namely Bobby Strahlman, who usually showed up at Daytona during Motorcycle Week back in the early 70's.

There were tuning issues with carburetors, where main jets were being changed in the morning, due to cool ambient temperatures, and then later in the day when the sun heated the surrounding air, again, main jets needed to be leaned back out.

With all this fine tuning going on during changes in temperature during the day, just imagine how "course" the tuning is on any old carbureted engine where the jets are never changed or optimized for best fuel economy. In fact, most of these carburetors are run on the rich side, to cover all the bases regarding worst case barometric/temperature swings during normal operation.

A fuel injected engine is vastly superior to this!

Jim.

[user removed]

Another point that can never be achieved with a carburetor. In some of the most advanced (in production cars today) fuel injection systems, with pressures of 2800 PSI (higher than combustion pressures) the individual injectors actually inject fuel into the combustion chamber in several smaller sequential events. This means instead of a single injection of fuel there are 5 separate mini injections for every cylinder's combustion cycle.

This allows for normally aspirated engines to run compression ratios of 14 to 1 with no chance of pre ignition, since the fuel is simply not there to ignite before TDC. The initial 1 of 5 mini injections is ignited, then additional injections occur when the piston is actually moving down in the power stroke, during combustion, which makes for a cooler longer duration burn with the pressure on top of the piston spread out over a longer period of time and a more consistent pressure for that longer time.

This is new stuff and is possible only with the better processing of modern computer controls and astoundingly fast data acquisition and electrical pulse generation. It would even work in a perfect vacuum if it was necessary. No carburetor will ever be capable of this type of fuel delivery, and the process of evolution is continuing to the point where it may actually become unnecessary to apply any after treatment of combustion byproducts, because the burn will be so clean that it becomes unnecessary.

regards
Mech

[aerohead]

I have a paperback from Lindsey(sp?) Publications from the 1980s which has a dozen or so 200-mpg carbs.
The crux of it is that you push the car up to 35-mph,start the engine and engage the transmission.The car will go down a straight,level road,under perfect weather conditions,at 35 mph and return 200 mpg.The engine won't idle.It won't race.It will only work in top gear at 35 mph.
Most folks can live with that,right?
I think there is a photo of the book's cover in aerohead's aerodynamic photos album archive.

[Grant-53]

Under those conditions engines are producing just enough power to overcome rolling resistance and wind resistance. Depending on the vehicle, only a small fraction of the engine's rated power is required, perhaps 10%. A Saab Sonnett V-4 would likely be more efficient than a Ford Cortina I-4 due to lower air drag. A Chrysler NewYorker or an Olds 98 might require roughly twice the power of the smaller cars. A fuel delivery system determines how much air/fuel mixture is available not how much is required.

[freebeard]

Uncle Tony talks about what works, what doesn't and why/how.

Extreme Fuel Economy And The Classic Car

....and promises to tell how to ecomod classic cars.

[oil pan 4]

Eco modding classic cars is easy.
Get a wide band O2 meter and a 4bbl carb. Tune the primary venturies for lean burn and tune the secondaries to be fuel dumps. Turn the timing on the vacuum advance up to all it's going to give, don't have a vacuum advance distro? You are wrong.
If a vehicle is running pig rich before tuning you can probably double the fuel economy.
If the carb is tuned properly 20% to 50% improvement could be seen.
If you have a fuel injected car, which should be perfectly tuned all the time lean burn will get you up to 20% more fuel economy.

[Grant-53]

If there were a miracle carb the Japanese would have used it decades ago. My 200 mpg carb is a Walbro in my 35cc two stroke 25 mph bike engine. The mileage competitions sponsored by Craig Vetter saw motorcycles using stock Japanese carbs. The Green Grand Prix had a 3 cyl. diesel kit car score 203 mpg at 45 mph years ago. Emission standards limit NOx so that lean burning above 18:1 is not allowed. Mass, drag, temperature, and emissions are issues we are well aware of in this forum. Drag reduction and driving technique have produced a doubling of fuel economy in most vehicles. The special Shell competitions have produced recumbent vehicles that can achieve 1000 mpg at 10 mph. I can go faster than that on my bicycle.