Mechanical secondary or vacuum secondary carb for daily driver

[fleming442]

Ok here goes nothin, I too have been down the Holley Highway to Hell. Same scenario, Small Block Chevy on the street, Vacuum then mechanical with no improvement and a lot more wasted fuel[mileage and fouled plugs] So I finally invested in a Holley Performance book and Wow did I learn a Bunch ! Specifically I learned that every model carb Holley or Quadrajet have their own idiosyncrasies [ engineered in problems]. It was enlightening to learn and fix my own carb , which by the way lead me to helping many others do the same. I wish I still had this book. Lent it to another Body man I worked with in Tampa and that was the last I saw of it. So if you have the time and want to learn some Good Stuff try buying the latest copy of the Guide to Holley Cards.
Best of Luck to you.

The biggest thing I learned about was the transfer slots and their relation to idle. It is a small finite adjustment that will make or break your tuning session QUICKLY! And, for Criminy's sake, don't drill any holes in the throttle blades!

 

[dickeymoore]

Okay Thanks ill try the street avenger

 

[vanrah]

Greetings Dick & all; Well I read most of this thread, some good advice. The 670 avenger should be Sweet if tuned properly. So get some books & read. Ask us specific questions & we'll try to give ya some tips from 55 years of experience. Not one of us knows all the answers, but together we know most of the answers, Ole' Bob.
Ps: Do NOT drill your blades!

Pss: I see your located just a few miles from the Bronze Brick's new home.

 

[dickeymoore]

I think the O-ring on the needle and seat is bad so I'm going to replace the whole needle and seat tomorrow and see what happens thanks

 

[vanrah]

Put a little oil on the ring before ya slide it in, slippery is good. I like Marvelous Mystery oil as it doesn't carbonize when it burns. You know how to set height? Take care Ole' Bob.

 

[dickeymoore]

10-4 on the oil yes I set it till it just dribble out the carburetor hole when you shake the car right

 

[57 Handyman]

DocG, did you say there was a good book for quadrajets that is worth buying? What is title and is it still available? My stock 305 '87 Elky has 2004r and Q-jet which doesn't seem to open up when I stomp on the gas. I can feel more power coming in after I let up slowly on the pedal. When I first got the EC, I rebuilt the carb with a kit and replaced the two computer controlled sensors on the carb. Unfortunately, that rebuild hasn't helped acceleration.

Could use some insights from all of you. Thanks in advance!

 

[CopperNick]

Don't blame the carb when there may be other issues at play. How much vacuum are you pulling at idle? Does that carb still have its original jets? What power valve and is it functioning or blown out? Is the cross-shaft for the butterfly plates in the base plate tight or are you sucking air 'cause the shaft bores have worn and need to be bushed? By way of research, what size carb got put on that mill by the factory? You running auto stick or manual and what gears do you have in the rear end?

+1 on the Holley Tuning Book.

Nick

 

[DocG G-edi Master]

Yes there is "How to Modify and Rebuild the Rochester Quadra Jet Carb, about $23.00 on Amazon. This may be the Most Misunderstood Carb ever. That is because it came Factory Installed on so many cars, and every year it was produced there was another minor problem engineered in, or so it seems if you have worked on a few.
DocG

 

[icr242005]

2x DocG. Great great carb WHEN and only when tunes correctly, but they were a B..... to tune.