Carb mod for better mileage?

[whitevette]

Originally Posted by Frank Lee

When anyone is ready to get serious about adjusting the mixture leaner, they'll rejet it.

Right on! Too many times (for too long) I have heard / seen people fiddle with the idle mixture screw(s) and expect miracles. The high speed jetting is built into the jets; don't think of drilling 'em out bigger, either. You'll only mess up the smooth bores.
Plugging the power valve(s) force the jet(s) to carry the full fuel load; power valves are a controlled leak....
Oh! One more "point": LaPoint isn't God. He & I have gone 'round & 'round before ... I'm not sure where he learned his flame front terms, but when it comes to gasoline chemistry, he is "old school". Pump gas is garbage. Not the same as yesteryear. There is wiggle room here, too. Lots.

[gone-ot]

...Chrysler and Honda learned a "lot" about LEAN-BURN techiques...both electronic and mechanical.

[afdhalatifftan]

Have y'all tried the 'Carburetor Enhancer' from Eagle-Research? I heard it works...

[suspectnumber961]

I've heard of the carb enhancer...but will be testing a FA2000 clone this summer.

This is basically an gas supply teed from after the fuel pump, that is run thru a sensitive valve so that just a trickle is allowed to get into a 3 foot long extended part of the PCV circuit...causing an amount of fuel vapor to be fed into the engine.

Along with adjusting the slight fuel flow thru this valve...they recommend adjusting the float level using this method:

* adjust the float level 1/16" lower...then take the car out on the highway at 60-65 mph and step on the pedal...if it bogs down...it is adjusted too low...if not...drop it another 1/16". Keep doing this till it bogs. Then with the TC2000...you are supposed to be able to turn it on and the "bog" effect will go away.

This same method could be used without the TC2000...adjust till it is CLOSE to bogging down.

[luvit]

is bogging the same as chugging?
i have an auto transmission. i have yet to look for my float.

[afdhalatifftan]

Can't wait to see the result...

[sc2dave]

what's a TC200?

[suspectnumber961]

Got that wrong...FA2000...they don't sell them anymore...you could easily make the equiv for not too much.



Had a recent tank come in at 36 mpg...which is a good gain...but this was mostly before the FA2000 was operational...seemed like a legit fill...but hard to say due to ahole issues...aholes that interfere with a fuel refill.

[sc2dave]

Originally Posted by suspectnumber961

Got that wrong...FA2000...they don't sell them anymore...you could easily make the equiv for not too much.



Had a recent tank come in at 36 mpg...which is a good gain...but this was mostly before the FA2000 was operational...seemed like a legit fill...but hard to say due to ahole issues...aholes that interfere with a fuel refill.

What are aholes? I can think of one meaning but i don;t think it pertains to this thread. Did you notice a difference with the fa2000?

[zoltanbod]

Originally Posted by suspectnumber961

Was trying to find the post by someone with an '82 Toyota 4x4 that had mpg issues....

"....also lower your floats to the lowest point possible without starving engine for fuel 1/4 to 3/8 of normal hight is a good start....carb manufacturers run 'just below flooding' fuel levels.

Try lowering your float in the carb to about 1/2 inch, as long as you don't keep your foot buried in the throttle you will see a major increse in MPG, my 73 f-100 (360 auto) went from grandma 6mpg to 2000
pound past capasity of 12.5 trip average from Washington state to Texas (2400 miles) and the truck burns(& leaks) 3 quarts of oil every 100 miles.

Your only limit is the floats hitting the bottom of the bowl. You may think 'The bowl will run out of fuel' if your that hard on the petal your not in the habit of getting good mpg anyway. Just use reason give your floats room to open the needle valve but not fill the bowl all the way up. The reason you get better mpg is greater levels of suction are needed to pull the fuel up the stem 'ripping' the fuel apart on the way up the high speed nozzle for more air contact (surface area)."

Fuel is not sucked up the jet nozzle,it is pushed by the atmospheric pressure above the fuel level in the float bowl.By lowering the fuel level you have reduced the volume and wieght of the fuel which is being acted on by the atmospheric pressure.So you have leaned out the a/f.Same affect as reducing the jet size or reducing the atmospheric pressure.