Cliff's Quadrajet Parts and Rebuild Kits

General Category => Quadrajet Carb Talk and Tips => Topic started by: Brian B. on February 26, 2022, 03:21:58 PM

Title: #7044270 1974 SD Auto Float Level Setting
Post by: Brian B. on February 26, 2022, 03:21:58 PM

Hello.  Could someone kindly confirm that the correct stock float level setting for #7044270 is .390"?  Thank you!

Title: Re: #7044270 1974 SD Auto Float Level Setting
Post by: Cliff Ruggles on February 26, 2022, 04:56:07 PM

Are you using the stock size float and .135" fuel inlet seat?...

Title: Re: #7044270 1974 SD Auto Float Level Setting
Post by: Brian B. on February 26, 2022, 05:09:58 PM

I'm now using the small size float with .135 N/S trying determine next setting before road testing.

Title: Re: #7044270 1974 SD Auto Float Level Setting
Post by: Kenth on February 27, 2022, 12:58:57 AM

Factory settings:

Title: Re: #7044270 1974 SD Auto Float Level Setting
Post by: Cliff Ruggles on February 27, 2022, 03:41:32 AM

I set those at 9/32"......Cliff

Title: Re: #7044270 1974 SD Auto Float Level Setting
Post by: Kenth on February 27, 2022, 09:08:03 AM

With today's volatile ethanol blended fuel, I have found that there is a nozzle drip in my 7040270 at idle in gear with the float set to 9/32 and 7 psi fuel pressure. No such tendencies with the float adjusted to 13/32. No disadvantages with this measure for min .030 "drilled 455, possibly a slightly lower consumption on long-distance driving.

FWIW

Title: Re: #7044270 1974 SD Auto Float Level Setting
Post by: Brian B. on February 27, 2022, 10:34:55 AM

Thank you Kenth and Cliff for your feedback!  I've got some great input to try out.

Title: Re: #7044270 1974 SD Auto Float Level Setting
Post by: Cliff Ruggles on February 27, 2022, 04:33:22 PM

Have never once experienced "nozzle drip" running 9/32" float height with a small float, .145" fuel inlet seat and 7.5 psi fuel pressure.  Not a Super Duty carb but I've street, dyno and drag strip tested plenty of them w/o any issues.   

One has to realize that fuel pressure, fuel inlet size, and float level all determine the fuel level.  The fuel level has an impact on the tune.  Pressure differential is what pulls fuel from the bowl, when there is more of it in there you'll get a little more out without changing anything else.......