Q-jet

[NixVegaGT]

OK. After much internal deliberation I've decided to go old school on the induction. I was planning on building a MegaSqirt and running MPI on my Frankenstein engine but I've already got so much to do I have to simplify some things. This will allow me to stick with the simple wiring harness and fuel system.

I can upgrade after I drive it for a couple years.

OK so After thinking it over I might go with the old Q-jet. I've got a lead on a used JET built StageII. Some guys really like the Edelbrock/Carter. Some guys really like the Holley. I'm personally not so hot for the Holley design.

So what do you guys think?

[cosvega76]

Nic,

The experience I have had with Edelbrock carbs is pretty much plug-and-play. They don't particularly like a lot of overlap in cams, or at least I haven't studied them enough to know what to alter. Otherwise, they work well right out of the box.

Chuck

[ColinOpseth]

Nicolas,
I just did the exact same thing. Ditched the LT1 in favor of good ol' carburetion. Can't beat the simplicity.

If I swap anything in later it'll be a complete LS1/T56 powertrain. This powertrain would work great in a Nova.

My Dad told me to KISS. I see why, now.

I like Quadrajet. Once you set them they're pretty much a rock-solid carb. I have a 1406 I'm putting on my car. Can't turn down free.

[Sirshredalot]

IN my opinion the Q-Jet is the best carburetor on the street....they just get a bad rep because theyre always abuse and neglected because theyre "stock".

The Q-jet gets you great fuel economy and great WOT performance and JET makes a good one. Also ...Edelbrock has the casting rights to the rochesters and is making brand new ones.

The Q-jet is similar in design to the edelbrocks.

Bad thing isthat there are very few HIPO spreadbore manifolds to use.

They dont make a large plenum spread bore manifold anymore.
The older holley street avengers had a spread borepattern but I dont think that will be easy to find for the buick.

Good luck and God bless
-Shred

[NixVegaGT]

So does that mean I can't bolt it up to my Edelbrock performer manifold?

[HI WINDING MONZA]

I allways use Qjets ( heck , back in the day, my grandmother used to make them in Rochester NY)

Nick, Mr Gasket still makes the adapter to mount on the square bore manifold . Napa sells them for $16.

We used one on the Monaco 440 drag car with an adapter to replace the Carter AVS. It ran the quickest with it on.

Carter also made Qjets in the 70's.

Get the Rochester Carb book by Doug Roe. Tons of info .

www.recarbco.com/technical/rochester/qjet.html for
id info.

Doug in Az
.

[spyder_xlch]

Carter also made Qjets in the 70's.

I have one I plan to use. I think it says built by Carter for Rochester. Looks almost brand new, musta been rebuilt not long ago. Some people say Carter used cheaper metal on the Q-jets they built but others say they are fine. I think Rochester had a fire and contracted Carter to make them until Rochester got back up and running. Edelbrock bought the tooling from Rochester and were making a Q-jet but I think they stopped making them. The Carter AVS and the AFB were good carbs. But the good old Q-jet is my favorite. FYI, the Q-jet only came in 2 sizes. 750cfm and 850cfm. They only flow what is needed and that's why you can use a 750 on a V-6.

[HI WINDING MONZA]

Still got to love that rare Carter 1000cfm Thermoquad they had though! Doug in AZ

[SunbirdMan]

If you're like me, and love the Quadrajet, then I think you'll enjoy this page.


http://home.earthlink.net/~quadrajets/q ... atings.htm

[Sirshredalot]

Hey nick, I didnt know you had a performer...it will bolt to it if its not a square bore manifold....but even if it is you can still use a spacer/adapter.

I was refering to manifolds like the victor jr and the weiand team G.They just dont make em with a spread bore.

God bless
-Shred

[NixVegaGT]

I'm pretty sure it's a spread bore manifold because it's built to work with their carb. SO I think I'm good!

[spyder_xlch]

Nice find Roger. Looks like I was wrong about the 850. It was actually an 800.

[NixVegaGT]

That is a really good resource. I found another at:

http://www.florida4x4.com/tech/quadrajet/index.php

There are a couple really great tech papers you can download.

I did it. I bought a Q-jet for $20 off a '77 Olds 350. Reading more about the Q-jet has been interesting. There is A LOT of fine tuning that can be done. It's a pretty sophisticated carb. I'm looking forward to getting into it.

[HI WINDING MONZA]

Nic , if you have emission testing like here in AZ, the carb may be set up to run "super lean " to pass. I have found that out with a few rebuilt or reman carbs I've pulled off junkyard cars in the past. I find that alot out on the older cars on their last leg because of the strict testing out here. Just a heads up. Doug in AZ

[Sirshredalot]

If youre going to rebuild the carb...DO IT YOURSELF,and make sure its done right. Do yourself andfavorand NEVER buy a reman carb...theyve got a factory of nimrods making $7 an hour staring at a repair manual. At least thats my perceptions.

Only thing I ever buy reman'ed are calipers. only cause theyre rarely available new.

The Q-jet is probably one of themost sophistocated desgins out there, But not in a bad way. GM really over-engineered them. Theyre infinitely tuneable..if you can find the parts. Very similar in design to the carter AFB/edelbrocks. Only bad thing is that you cant fit two of them on a tunnel ram...lol!

Mak sure you puta new float in it...Its been awhile since I rebuilt one but i dont recall the kit coming with a new float...theyre available at all autozones for about $8.

Hold a flashlight upto the bottom of the butterflys and look into the side of the carb and check for throttle shaft wear...if you can see light they need to be honed and bushed....very common place for a vaccum leak.

God bless
-Shred

PS: I also am not fond of the holley design but they offer cheaper tunability than an Edelbrock...Just apain to keep pulling the bowls of the side and keep spilling gas all over my motor...not to mention the fortune youll spend in bowl gasket...cause even the "non-stick" ones stick and tear.