Urban legend or not-high mileage carburetors

I've got an overdrive in it. My dad says its from a 57 chevy car and only the freewheel works; Anyone have any ideas on fixing that?

Rochester is rich all the time, and loads up w/ fuel when its parked for 5-10 minutes. Anyone know if Holley sells remanned 1 bbls? The economaster it had was on there 16+ years(8 sitting) and never needed a rebuild. I took it off cuz it was leaking-retarded huh?

 

if they were real they would be made in china and sold at walmart!

 

Our old shop teacher used to (illegally) sell plans to us poor schmuck students for those carbs, he coulda sold us gullible morons the Brooklyn Bridge several times over.

Pure myth.

 

http://victorylibrary.com/mopar/mileage.htm

 

There is a crazy old guy at my work that used to work at Chrysler as a mechanic. He claims he worked on a car with a strange looking carb. that got 80mpg or something like that , on a small block. He said that Chrysler got wind that their "secret" carb. got out, and they confiscated it back...

 

My first car, a '79 corolla got 42 mpg. Must have been something wrong with it.

 

dammit.

I hate it when every 6 months or so, this thread comes up.

Look. as far as super carbs go...it ain't gonna happen. I don't care if you figure out how to make dirt show the exact same charecteristics as gasoline, you still gotta mix it with the right amount of air or you get nothing. compression is part of the equasion there, too...and frankly, the inline, unless modified lacks that, too.
what you are facing-with mileage- is this. simple mechanical ineffefectiveness. Proof?

you're getting 12 miles per gallon. if you had a 305 v8, in stock trim, with a broken quadreject on it, you would make better than that.

overdrive is the easy way out...but don't expect any more stellar around town numbers.

Taller tires will have an effect...but not as dramatic.

easy way out?

PUT A SMALL BLOCK IN IT. it will be more fun any damn way.

 

yup. 4 of the cylinders fell off on the assembly line. Bet you picked up all the hot chicks in that sweet ride, Bro....

 

I've always wanted to see what two Hitachi DCH series progressive (ie: "staged") 2-bbl carbies would do with a progressive linkage on a V8...



You've probably seen these weird little 2-bbl carbs atop 70s and early to mid 80s Japanese cars (Subaru, Mazda, etc). They have a wicked cool sight glass in the side of the float bowl, and are a cinch to build.

 

Anybody have any experience with WW2 era tanks that ran Caddy engines with the fuel lines run through the exhaust manifolds?

 

To improve mileage...

Overdrive gearbox.
Higher geared diff.
Taller tyres.
Keep your lead foot OUT OF IT!

Cheers, Glen.

 

I think clifford engineering makes a 4 barrel intake for that engine.
Also whats the rearend?
Maybe switching it out to a 10-bolt or something with better gears.
TP
Oh yeah,
there is a solenoid on the tranny.
Not the governor it's the bigger one.
There should be 2 electrical connections,
One activates it the other don't worry about. (throw away all other wires & switches)
Test it you will hear it click if it works.
Hook up a hot switch to that connection, with a 30 amp fuse.
When it is in freewheel mode, flip the switch and let off the gas then accelerate.
It should click in to overdrive.
Remember to limit your engine braking with it on, and there is NO reverse.
TP

 

I think those lines were actually for the choke set-up. Similar to 50's and 60's Corvettes..

 

I've heard claims of up to 28 MPG with a Chevy 6.2 diesel in a half ton short cab pickup. Of course you have to draft 12" off a tractor trailer to get those last 4 or 5 MPG.... on the bright side, it's almost as underpowered as having a 153-ci 4 in it, so you won't need to pass him on all the uphills.

If I believe the guys on that board, a late 70's manual trans 6-cyl Nova can pull mid-20's. I don't, but maybe if you swapped for a T5 trans and a 3.08-3.23 rear gear, and put any other carb on it - Carter YF, that Holley, a piece of pipe with two butterflies and the fuel line just dumping out in the middle - okay maybe not the last one, but you should be able to pull somewhere in the 20-25 range on the highway with those changes.

The extra gear can help, but even if you keep your 3-speed OD, the key to economy is to get the engine in the 1800-2200 RPM range at crusing speed. It varies some depending on the torque curve of the motor itself.

Just as an example, the '60 Pontiac I've talked about so often would cruise around 1800 RPM in high gear.. and get around 18 MPG on the highway, out of a 389 with the dual-coupling 4-speed hydra-matic. Not bad for a 4000-lb car.

 

I see the Fish carbs on ebay from time to time. My buddy and I were just talking about this earlier tonight. They claim 100 miles per gallon in some cases. I know the technology is here and has been for close to 80 years. How good some of these items work, I don't know? A lot of bs stuff to get your money. But high milage carbs are very real! Why do you think you don't see them? The big oil companies own all the rights to most of them. Poor guy becames rich before it ever hits the market and oil companies charge billions more gallons of fuel! It's kind of a no brainer! My buddy is gonna try one out on his 66 Nova. Swap the Qudrajet out for a small ass one barrel and see what happens. We will see if they actually work? He just needs to get one now...

 

The basic idea is to get the energy out of the fuel...all of it. How many here realize that in 1970, an LT-1 Z28, with a 4spd, 3.73 gear, and 1 5/8" tubular headers was capable of 19-20mpg on the hiway? Bullshit you say? Look it up. Think of how efficient that engine was. High compression and just the right cam in a very well tuned condition, improved by the use of the headers. We already know what those do for us on both ends. The bottom line is always mechanical efficiency or effectiveness. There's so much more energy in the fuel we burn that we NEVER see.

To burn it more completely you need to make mechanical changes. The reasons that tall gears and overdrives work is because it increases the mechanical load at cruising speeds, not because the RPMs are lower. Someone above mentioned compression. Again more burn. The newer versions of the venerable SBC run compression ratios of 10.5:1 and still burn unleaded fuel. They get away with that by reverse cooling (heads 1st) and aluminum heads to help eliminate detonation. There's way more tech to it but that's available info elsewhere.

Burn the fuel. Burn it as much as possible, as hot as possible, aid vaporization to the mechanical changes and you'll see better use of the fuel's energy. The hotter you can run an engine without boiling the coolant also works very well for a few reasons like tighter tolerances and aiding vaporization through the intake system.

It's more common sense than anything. Too often the basics get lost in singular ideas. How can we prove that any of what I've posted is true? 1st of all, try it. 2nd, think about why a powerglide bracket racer will 60' better(in specific combinations of course). It's not the launch ratio by itself...it's the load...the energy being extracted from the fuel. It's the basics.

 

I also heard wearing an aluminum foil hat will dramatically increase your mpg.

 

OK
The government owns all the high mileage carbs to keep the oil co. profitable? yes or no?
The girl at the nudie bar really does want to come home with you?
yes or no?
A stock rod 327 will turn 9000 all day long?
yes or no?
There really was a train car load of 55 chevies found in Kansas recently and the railroad is selling them at scrap price?
yes or no?

It's a pretty simple experiment,fuel has to be in the right mixture of atmosphere to ignite.
NOW take a can of gasoline in your garage,pour a tablespoon out on the floor and give it time to evaporate. Light a match and see what happens.
Nothing right?
Now pour about 10 gallons of the same gasoline on the floor of the garage and give it a couple of minutes to evaporate and then light a match.
See all it takes is the right mixture to burn,
The only way to increase mileage is to reduce weight, increase aerodynamics,or run the engine slower.

 

Dude..you forgot to tell him to close the door first....(pounding fist on table) IT'S ALL ABOUT COMPRESSION! We want "Boom!"...not "woosh."

 

A 6 cyl Nova with monojet certainly can get high mid twenties on the highway...but mine was seriously bad news at low speeds with powerglide...
12 MPG is sureashell not the carb's fault (unless it is badly screwed up...), and unless your car weighs 5,000 pounds you have other issues with both hardware and liveware.
Secret carburetors are currently like secret formulas for whale oil, since FI does the job so well, but there are things to ponder:
Simple carbs have to be too damn big for the engine most of the time in order to have sufficient capacity when full power is needed. This is a prob both for economy and emissions because at low flow (including much low speed cruise) the carb is actually running mostly on the very crudely regulated off-idle system rather than the venturis, which can do a pretty good metering job.
Likely progressive carburetion with tiny primary venturis could push venturi action down to low rpm levels...GM had to replace the Monojet in the last years of carburetion with a staged 2 barrel both for economy and for emissions because of this...a monojet is pretty big bore to enable decent power range on its 4--5 litre applications.
I remember once seeing a picture of one of the books on building super carbs at home...in the only pic I could actually see, the system seemed to involve a box holding a real carb...and a lawnmower carb! Obviously that guy was thinking just as I am now: Get a TINY venturi into the system and you can probably have good metering all the way down into idle speed.
For traditional purposes: Ford bulletins on Strombergs note the car is operating at least partly on off-idle system up past 20 MPH...off idle system is just a dribble out of a hole estimated to do the job, not truly metered to air flow...

 

Some years ago I had a chopped '34 Chevy sedan that ran a 292 six and a three speed. It got 12 mpg. You could start out in 3rd gear, it was a torque monster. Didn't really need 1st for anything. It ran fine, it was different, it had all the power of a 6 and the gas mileage of a badass big block. A really crappy engine for power or speed. Mine was stock, too. I know you can make some power with one, but for me it came down to "What's the point?" If you want a six that gets power and mileage, stick a Vortec V6 in it. Want nostalgia? Put in a nailhead or some similar mill. I think there is no cheap and easy fix for 292's poor mileage.

 

http://www.gofastnews.com/board/technical-articles/75-100-mpg-carb-does-really-exist.html

http://www.gassavers.org/

 

...'55 Chevies?

~Jason

 

If you want better mileage, I believe Offenhauser put out a 4bbl manifold (more street friendly than the Clifford, or so I'm told). Or perhaps you would prefer a multi carb manifold. Some of the people over on the inliner's board are having good luck with 2 carbs on an I6. They use the progressive 'Holley Webber' type carb. run on the primaries all the time (till ya homp on it) and claim beter economy, and some more power. It's a combination of the principles listed earlier. The smaller venturi's of the primaries in those carbs do a beter job of metering, and not having a single carb centered on the engine should get you better mixture distribution.

Of course if it's running as rich as you say, the two pipes and gas hose mentioned earlier should get better economy than you currently have.

As previously mentioned, taller tires and overdrive (fix yours if you can). A tune up sounds like it's in order (and a carb overhaul / replacement too). You should also run the tires to the highest inflation you can tollerate the ride at (without exceeding the cold inflation limit on the sidewall).

 

heh...that's neato!

the carb was straight off a briggs and stratton engine. So, I guess if you want to get mondo mileage, take off your bigass 4bbl carb, and put a lawnmower carb on it! might not go very fast though.

(I sure was good looking back then, eh?)

 

I thought you were hot.

Seriously though, that project was cool. I'm impressed.

 

Thanks, it was very educational too!

Having driven a 500 mpg car on a test track, I can quite honestly say I would never want to drive one in traffic....

 

I'm putting my money on cow magnets ducktaped to the fuel line. They align the molecules in the gasoline, ya know. Get at least 30 MPG!

 

smart car gets 75mpg, but it doesnt have a carb and runs on diesel, it does go 85mph and i think they would go 100 if the computer didnt limit the rpm's.