225 drinking lots of fuel?

[DaisyDart]

Hey everyone,
I finally was able to do a test run this weekend since Ive noticed my dart has been taking a lot of fuel.
I filled her up, drove 117 miles (pure highway) and she drank 3 quarters of a tank.
I haven't had the chance to go fill her up yet but i wanted an idea on if anyone thinks this is normal for the 225 ( my gut is telling me no, its not normal ).
I leaned out the carb as much as i could, checked for leaks, tires are good... I Have the Pertronix kit on it, and her timing at the moment is 10 degrees, i gaped the plugs at 35 if my memory serves me right.
I'm wondering if i should invest in an air fuel gauge so i can see exactly whats going on with my mixture.
If anyone has any ideas or could even tell me if this is normal for this engine that would be great, please bare in mind i am fairly new to this engine and carburetor ( Holley 1920 ).
Thanks !

 

[Woods74]

What's the vacuum advance look like?

 

[NukeBass]

Unless your gauge is wrong, that's looking like around 11 mpg. Back when I had a slant six, I was getting 14-15 mpg around town. The first thing I'd do is put gas in it and see if the gauge is accurate. At 3/4 of a tank, you should be putting around 10-11 gallons in it. The one I had seemed to read 14 of 16 gallons (assuming a stock tank) from Full to Empty, but I guess that could vary, too.

 

[DaisyDart]

i just checked my gauge, unfortunately it's accurate, so something else is causing her fuel mileage problem, i cannot figure it out for the life of me..

 

[Woods74]

Check the vacuum advance bro. 12-16 is ideal. 48-52 total is best for mileage.

 

[AJ/FormS]

At what speed/rpm were you cruising? What % was steady-state? What kind of terrain?
Hows the engine mechanically? what cylinder pressure? Stock cam?Automatic? % TC slip? Loc-up? What rear gears? Tire size? Number of occupants? baggage? Oh yeah, and timings.Timing is very important.
Point is; theres too many unknowns to hazzard a guess.

My 70 Swinger 340-4spd was 3330 with me in it back in highschool. I was 140ish. With a slanty power-train, I wonder if she wouldnt be under 3000 pounds. You should be able to get some good numbers with that, if the engine is making good pressure.