[Mr Anonymous]

Every vehicle I've ever had, if driven long enough, was determined to have a "sweet spot" where it just wanted to be. Above or below that speed just wasnt as pleasant. For my Cummins dually, its 63-64. A 2.14 geared G-body that we had with a 400ci, its spot was over 80 and the mpg was over 25. I can remember ones that had two happy places, and they were almost 20mph apart - and that place in the middle wasnt nearly as good. Carb/EFI, gas vs diesel, they all seem to have a certain speed/rpm/aero combo that is their happy place.

[carbking]

Off-topic vehicle, but on topic fuel mileage:

Before I was bit by the "buy American" bug, in 1973 special ordered a Toyota Corolla 1600 to use for rallying purposes, as well as daily driver.

Reworked the distributor to have the Japanese advance curve, and reworked the carburetor. Several other modifications as well. Had both speedometer and odometer calibrated.

Kept exact records. At 74 MPH (Arkansas had a 75 MPH limit at the time), car got 39.4 MPG in 5th gear.

In 1975, national speed limit was set at 55 MPH. First 400 mile flat interstate trip, found could not maintain 55 MPH in 5th gear, and had to run in 4th. Result: 32.3 MPG!

After that, used it in town, and used our older vehicle with larger engine for trips.

Gearing matters, keeping the engine in the peak of the torque curve!

Jon

[JJDeville]

We had a local guy who was the head of an IT Department install a hydrogen generator on his Trailblazer and was supposedly getting unreal fuel mileage. This was when fuel went up back in 2009 or 2010 or so. I always thought that guy had it together until that bull****, I lost a lot of respect for him after that!

[Tom Vaught]

Hope he had the Hydrogen container figured out.
We had to buy the Hydrogen Gas EVERY TEN DAYS for testing as it leaked thru every
known container in that period of time.

Example:

Day one: fuel container (say 1000 liters of Hydrogen) is fully charged with Hydrogen gas.

Day 5: half of the gas (500 liters is gone even though we never used a liter of it in
those 5 days

Day 10 the container with FORMERLY 1000 liters of hydrogen is now EMPTY even though
we never used even one liter in testing.

The key is developing a CONTAINER that can trap the hydrogen gas for weeks and not have it disappear. Not there yet.

Do the math: deepest ocean is about 36,000 feet of Water: Hydrogen and oxygen and
some other chemicals based on water contamination.

36,000 times 1 cubic foot of water = 36,000 cubic feet of hydrogen and oxygen.

Think about how many cubic feet of Hydrogen and Oxygen are in the Pacific Ocean by
itself. Too many zeros to post 1,000000000000000000000000000000000000---------

Lots of volume but expensive to convert to oxygen and hydrogen gases.

Tom V.

Hydrogen gets about 1/2 the fuel mileage of conventional fuels so he was full of beans.

[SRR]

Originally Posted by fiedlerh

I always get a kick out of the "magic carburetor" stories. It's always an uncle or former co-worker with a "secret carburetor" that was "accidentally installed" on their car. Having the government/dealer/big oil confiscate the carburetor adds to the BS factor.
Basic physics say there isn't enough energy in gasoline and not enough mechanical efficiency in a 1960's production engine to get 60-200 mpg.

Speaking of a humorous MPG story*...
Two Sun Electric engineers teamed up to compete in one of those fuel economy contests that the oil companies ran in the 60's or 70's. They ran a Corvette. They narrowly missed finishing first. Being engineers they calculated the cause of their narrow loss was because of the extra weight of a celebratory 12 pack of beer they stowed on the car.

*For you historians, I could not find details on past contestants, so I believe this was a local event and not one of the well-known nationwide contests.

Heard those stories when I worked at Balch Pontiac back in the 70's.

[mgarblik]

I bought a Geo Metro during the last "gas Crisis" with a blown engine for $75.00. Remember those? 1.0L 3-cyl fuel injected. Rebuilt the engine and installed it. It was an auto trans, 3-speed. Lock-up converter but no overdrive. I drove it for about 6 months. Tracked every tank of gas. It never broke 40 MPG. Best was 39.7 MPG. That was not using the AC and not driving over 60 MPH. The engine was too small and it ran too fast to get any real MPG. It ran at 3800 RPM's at 70 MPH. It was screaming for mercy. Had a friend with the identical car with a 5-speed, manual. It routinely got 50 MPG from the lower engine speed. All about that sweet spot.

[carbking]

The "experimental carburetor that was removed by the dealer" ACTUALLY HAPPENED!

In 1933, Ford Motor Company was using a Detroit Lubricator carburetor on their V-8. As everyone who knows any Ford history knows, Henry and George were buddies; and Ford was always trying to use Holley carburetors. There is a great story about the Ford Model A carbs, but nothing to do with this thread.

In late 1933, Ford installed Bracke (a division of Holley) experimental carbs on 1000 1933 Ford V-8's and the dealers WERE INSTRUCTED TO REPLACE THEM WITH THE DETROITS AT THE FIRST SERVICE, so at least this much of the stories is true! I have never seen any test data on the efficiency of the Bracke (the super mileage claims of others may have been embellishments), but this is documented in Ford Motor Company documents.

I have a picture of the Bracke in the virtual carburetor museum section of my website:

https://www.thecarburetorshop.com/Ca...eum.htm#Holley

EDIT: if you look around on that site, you will also see pictures of the "Pogue" and "Fish" carburetors.

Jon

[NeighborsComplaint]

I run two of these positioned directly over the secondaries of my Holley Spreadbore. I can tell it really saves on gas. Every time I mash the gas pedal the car stalls.

[Tom Vaught]

Originally Posted by NeighborsComplaint

I run two of these positioned directly over the secondaries of my Holley Spreadbore. I can tell it really saves on gas. Every time I mash the gas pedal the car stalls.

Normally I would not say anything against other Engineers BUT in this case they deserve it:

These three 'Gentleman' suggested that to increase power to the 4 cylinder engine you could plumb the heater/A/C box to feed the Air Intake Throttle Body. They asked what I thought and I said you would never have a Warranty Complaint as you would kill the people inside the vehicle with the reversion pulses from the engine first.

Management People but clearly did not understand the consequences of their suggestion.

Tom V.

[sdbob]

I remember back 72-74 era I guy I knew that was into Chevies put a home made water Injection using a electric water pump to spray your windows. It did not work very well.

[fiedlerh]

I ran an Edelbrock Vara-jection Water Injection System on my 68 Firebird after premium gas went away in the late 70's. They used a variable speed pump and a vacuum sensor to meter the water spray into the carb. It worked very well except during single digit winter weather. Even alcohol couldn't keep the carb from icing up. I still have it in a box.

[Formulabruce]

1981 YENKO Z-28 Camaro had Water injection. Saw one run in person when new, and again in 1994.

[jerry455]

Wasn't the 1981 Yenko turbocharged? I remember in the late 70's and 80's, water injection was popular on boosted cars to control detonation.

[firechicken]

It's still popular on my car.