[se428bandit]

Holley,Edelbrock or Demon carb for the Ventura. It's pretty much a street car that going to see alot of dragstrip racing. I'm having problems with the quadrajet flooding with my Robb Mc fuel pump even though i have a regulator set on 5 psi.
What do yall suggest,750 or 800 cfm,vacuum or mechanical secondaries?
I would like something simple and easy to tune.

1972 Ventura, car weighs 3315 by itself
455 .30 over
ported 6x heads 91cc
Torker 1 intake
crower 60919 470 lift 231/240 duration
long branch manifolds
turbo 350 2800 stall
3.23 gear

[Bruce Meyer]

my 2 cents- A Holley 750 double pumper.

[TinInjun]

Holley 750 DP with a 1 inch wilson 4 hole tapered spacer.

[Tom Vaught]

Agree, a Holley 750 DP would gave excellent response on the street and would be a good match for the Long Branch manifolds.

Tom Vaught

[se428bandit]

Thanks for the advice, i borrowed a Holley 750 vacuum sec carb from a friend and so far i like it. Only problem is i'm not getting full throttle but i'll deal with that tomorrow.
Is there any reason nobody has recommended a Demon? I use one before on my '75 Formula years ago and it worked fairly decent.

[72LuxuryLeMansLa.]

Originally Posted by se428bandit

Thanks for the advice, i borrowed a Holley 750 vacuum sec carb from a friend and so far i like it. Only problem is i'm not getting full throttle but i'll deal with that tomorrow.
Is there any reason nobody has recommended a Demon? I use one before on my '75 Formula years ago and it worked fairly decent.

Any reason you can't fix the problem with the Q-jet? I'm no expert but from what I understand this could be as simple as the fuel inlet seat leaking......

Karl

[se428bandit]

Originally Posted by 72LuxuryLeMansLa.

Any reason you can't fix the problem with the Q-jet? I'm no expert but from what I understand this could be as simple as the fuel inlet seat leaking......

Karl

I would like to have Cliff rebuild it but he has a 10 month wait. I guess i'll order a kit from him and have a friend of mine rebuild it and swap them around at the track to see what works better. If you look at my video below you will how bad it stumbles at the track.

[firebirdmi]

I have a 750cfm Speed Demon carb purchased in 2004 and have had the secondary float get stuck on me twice; flooding the motor. It's a shame because it's pretty easy to work on and tune.

[Tim Corcoran]

Added commentsThe Rochester Quadrajet is a great carburetor. GM used them for many years and put them as standard equipment on literally millions of vehicles. The design was improved over the years and they came with many different calibrations depending on engine size and vehicle type. They were used from around 1967 up until they were replaced by fuel injection. This should tell you that they are a good design. The Q-Jet can be calibrated to work on a variety of engine sizes on both granny cars with a 326 to HP vehicles with a 455. Even the Pontiac overcam six banger came with a Q-jet. On the downside they are old, worn out, complex and your average hobbiest does not want to mess with them or does not know how to modify/repair them to make them work properly. It's so easy to just toss it aside and put a Holley on it. To make a 40 plus year old Q-jet work properly it does need to be repaired, modified and calibrated to work with your combo. Once this task has been done correctly you will love your street machine with a Q-Jet. On a street or street strip car the Q-Jet will not bog, leak or otherwize fall short of your expectations. The Q-Jet (in proper repair and calibration) will run just as hard as a Holley at the dragstrip up to a certain performance level. I believe there is one exception as I believe the Q-Jet may not be as well suited for a HP manual shift car as a mechanical secondary Holley might be. But on the street the Q-Jet will have better fuel economy, produce fewer hydrocarbons and run just as hard as any Holley. Getting the 40 plus year old fuel mixer to perform like a swiss watch is a challange unless you happen to be Cliff Ruggles. If you like to tinker and you have the time you can get Cliff's book and the parts from him and do the repair/modifications and calibrations your self. It's not just a matter of installing a kit. You could stick a Holley on there for a year or so until you can get Cliff to does his magic, or you can just stick that Holley double pumper 750 on there and that should work great.

I didn't want anyone to think that Cliff is the only one who can build a great Q-Jet. There are others that can build a nice Q-Jet but there are so many out there building crap that it's a scary world. I believe carbking also knows his way around a Q-Jet and Holley and others for that matter.

[carbking]

To add to Tim's comment, you could post the number of the QJet you are using, and maybe someone here could help.

One issue many bring upon themselves is trying to use either too large an orifice in the fuel valve seat or too much fuel pressure.

Another issue is trying to use a "windowed" seat with the earlier float design.

Your issue might be very easy to correct.

And obtaining a copy of Cliff's book might be a good start. I have read a lot of books on carbs in the last 50 years, and Cliff's ranks in the top 3 regardless of brand, or cost.

Jon.

[Nicks67GTO]

Originally Posted by se428bandit

Holley,Edelbrock or Demon carb for the Ventura. It's pretty much a street car that going to see alot of dragstrip racing. I'm having problems with the quadrajet flooding with my Robb Mc fuel pump even though i have a regulator set on 5 psi.
What do yall suggest,750 or 800 cfm,vacuum or mechanical secondaries?
I would like something simple and easy to tune.

1972 Ventura, car weighs 3315 by itself
455 .30 over
ported 6x heads 91cc
Torker 1 intake
crower 60919 470 lift 231/240 duration
long branch manifolds
turbo 350 2800 stall
3.23 gear

Iv'e got a 750 mighty demon with idle-eze laying around I might be willing to part with if you're interested.

[Greg Reid]

Russ, I just finished going through Cliff's book and rebuilt a spare carb using his recipe. It turned out great. Just put it on my car and started it today. Not that difficult but there is a learning curve involved. Cliff was very accessible to answer my questions.
I'm going to do it again for my '68's carb. Personally, I really like Q-Jets.

[se428bandit]

Originally Posted by carbking

To add to Tim's comment, you could post the number of the QJet you are using, and maybe someone here could help.

Jon.

The carb # is 17057274 off of a 1977 Firebird. It ran fine on the 350 i had in the Ventura. With the 455 i bought a Robb Mc 550hp and that when the flooding started. On a gauge it had 8 psi at idle so i put a regulator in between the pump and carb and set it on 5 psi. When you get into the thottle,cracking the 4 bbl thru the gears and let off that when it floods.

Greg,i have always like quadrajets until reasonally,this one is drving me crazy. On the original 350 it ran great,no bogging issues or starting problems at all.

[Greg Reid]

Russ, that just tells me that it was set up right for the 350...but not for this engine. As for flooding, sounds like something that could be figured out. Maybe dial the pump down to 4 pounds?

[lust4speed]

Use another gauge to measure the pressure after the regulator. It sounds like there is still more than 5psi getting to the carb.

Why all this love for double pumpers on the street? A vacuum secondary carb is going to have better manners, better fuel economy, and likely will produce quicker times off the line. Size becomes much more important with mechanical secondaries. A vacuum carb will simply only open up the secondaries as far as needed, so you can easily get away with going large.

[A.W.Dille]

With the ethanonal that is in todays gas can have an effect on the tip of the needle valve, not letting it seal right and contribute to the flooding problem also. But do get Cliff's book and read it (and have your carb man read it also) before you just buy a kit and rebuild the carb. The larger engine, headwork, cam and exhaust all have an effect on carb performance.

[69FIREBIRD76MM]

Originally Posted by se428bandit

Thanks for the advice, i borrowed a Holley 750 vacuum sec carb from a friend and so far i like it. Only problem is i'm not getting full throttle but i'll deal with that tomorrow.
Is there any reason nobody has recommended a Demon? I use one before on my '75 Formula years ago and it worked fairly decent.

I run a mighty demon, new out of the box 850 cfm it performed flawlessly...my car pull 1.60+ 60ft...with a fairly stock 455..trw....I still have my carb, it looks awesome..i like holleys too though...my 2c.

[Brent Flynn]

Nothing wrong with a holley( i have one on the '62), but, If thats the only problem you are having, you should call Cliff, order his complete kit, get his book and redo your carb. If its idling and driving around just fine, and it only does it, after you are in the throttle, it could be that the secondary flap is sticking open, or you are running too big needle valve... i'd run the .135 Needle and seat... You will feel better about your car, if , you use what you have.... I believe , if done correctly, it'll out perform the holley(with your 3.23 gears and stall)... and its more impressive when you open the hood If i can do it, anybody can do it. I just did an 800cfm Buick for my Wagon...did the whole Cliff treatlment to it...and i love it... Cant wait til SPring!!!

[Cliff R]

The carb # is 17057274 off of a 1977 Firebird.

Same exact number I use on my 455. It has over 1200 drag strip runs on it with zero issues, and 4 trips to the final round at Norwalk in the Stock Class.

I run 7.5 psi fuel pressure on it, from a Comp 140gph electric pump and 8AN lines. Here's a clip from Norwalk, timing retarded 4 degrees and shifting at 5000rpm's to stay roll bar legal:

http://www.youtube.com/watch?v=6zVdoLR-VzM

I also have an electric choke on it for instant cold weather starts and fast idle while it warms up.

When you get time, contact the shop and I'll set you up with a custom kit and tuning parts, so it's basically just "plug and play" for your builder.....Cliff

[old66tiger]

Damn Cliff...my car is faster than that! LOL. Nice run. How's that 400 build coming?

I would tinker with the Q-Jet before going the Holley route. My second choice for carbs would be a quick fuel or pro systems mainly because I have heard the customer support is awesome for either of these companies. Plan to spend $500 - $700