Re: Quadrajet problems
 

Tighten air flap spring just a hair and see if that helps.

Re: Quadrajet problems
 

x2!

Re: Quadrajet problems
 

How much fuel pressure do you guys suggest for a Quadrajet?
I spent a few race weekends this year struggling with the hesitation issue and couldn't find out what was the problem. So now I'm wondering if too high fuel pressure could cause this issue as we raised it a little during last summer.

Re: Quadrajet problems
 

Iv'e had more than one "carb guy" tell me that 5.5 lbs of fuel pressure is max.

Re: Quadrajet problems
 

I run mine a 6 lbs. low pressure and plenty of volume is what is needed on a Q Jet. one gallon in 30 seconds is about the minimum you can get away with.

Re: Quadrajet problems
 

Thanks guys, so it looks like I'll have to lower the fuel pressure when we can get to the track the next time. Now I was running with 7 lbs pressure, so it's interesting to see if that could fix the bog when launching.

Re: Quadrajet problems
 

I build quite a few Q-jets. . For the small block I recommend .135 needle and seat. Use a Y-block off the regulator to the carb for a supply of fuel volume and use 5.5 - 7 fuel pressure. 6.5 is more than enough for the Q-jet. Rear flaps may need adjusting, but really done at the track.They should open at 1.350 for most and tension is adjusted 1/8" of a turn tighter or looser. Your Accl. pump shot can also be modified as well. There is mods that can be done to the carb for better performance. WD-40 and Marvels Mystery oil is your best friend. Keep all shafts and linkage lubricated. Hope this helps.

Re: Quadrajet problems
 

Danny Ashley I believe started the slide plate for the secondary rods. But note that the air horn needs to be milled in the area that the slide plate goes
.