Q-jet Speed Secrets


Veteran Member
Jun 17, 2006
What you got for Q-jet speed secrets. My 1st.one is the 30° sec pickup mod for the base plate to pull the sec side open a ton sooner, it flat out works. Who else has anything?

jeff swisher

Veteran Member
Apr 26, 2018
Yukon Oklahoma
My engines liked the secondary air valve to come in quick and I did not run a vacuum pull off.
I was told by my uncle it would be quicker with it.
I let him hook it back up and tune it and after a couple hours he tossed in the towel and said my engine was odd and sure enough it liked it to come in soon as possible.

Now one little mod I like to do is not really anything special but it helps the secondary air door transition smoother.

That little rod with the spring on it that you can see when you turn the carb upside down.
That little rod will many times get a very "small worn notch" in it from the spring sitting in the same place for decades.

I polish that notch out with a small cratex roll.


Veteran Member
Nov 13, 2011
The tiny hole just above the leading edge of the air valve can be plugged and redrilled just BELOW the air valve to allow quicker response from the secondaries. It functions as a sort of passive "accelerator pump". Some factory carbs came this way.


Veteran Member
Jun 15, 2012
las vegas, NV
My tip would be buying high quality rebuild kits. The stuff from auto zone, advance, oreiliy and others is junk. Especially the needle and seat assembly.

My second tip would be check the top for warpage. You would not believe how bad some qjets warped from people tightening the front 2 carb to manifold bolts to tight.


Veteran Member
Lifetime Gold Member
Aug 29, 2007
Western, MA
I have several Qjets tucked away if anyone is interested. 2 would need to be rebuilt and one was rebuilt by a high end guy 20 years ago ( I can't remember the shop but at the time he was "the guy", I believe it was a "stage 2" rebuild but I never ended up running it on the car becasue the local guy I was using to help me set up my motor was more familair with the Edelbrock carb. After frustration with that I then went to a Holley 650 but found living in a colder it wasn't to my liking. I regret not sticking with the Q-jet...I switched over to a Holley Sniper now.


New Member
Feb 20, 2018
8pack, I interested in your Q-jets; the 2 that need to be rebuilt. Can you let me know models , prices and if you can ship them (to VA). Thanks.