Anyone have any experience with this type of carb? Are they any good? How hard/expensive to rebuild? I can get my hands on one or two for free but they will need to be rebuilt. Looking for something to top of my 5.0L with edelbrock vic jr heads and air gap intake. Cheers! Justin
When they are good they are really good, but I once went through 4 rebuilds in a 3 month period. Each time another issue popped up.
Had a quadrasuck on my '70 500" Caddy...one month I was getting 15 mpg...the next month it was flooding itself. Had it rebuilt, by a "pro" carb guy, told it was a good carb...got 9-10 mpg on the next trip. Knew that wasn't going to fly on our trip to Canada the end of July... Bought a 750 CFM Edelbrock and adapter kit...put it on and right out of the box, no adjustments necessary now get 16 mpg with it...as Fat47 sez...when they are good they are really good...otherwise they aren't worth the price of the fuel going thru them. Suggest you stick with Edelbrock carbs... R-
i like 'em. should run around $120 for a rebuild. maybe not for a 5.0 though. i second the edelbrock, summit has reman. for $200ish
We have had a couple done by Shaun Murphy....fantastic job....bolt it on and run. When properly set up, the gas mileage is good.
Provided you can now or willing to learn to speak quadrajet, they really can't be beat. They are infinetly tunable for just about any combination you could imagine. However I can't think of a more complicated carb because of this. They get bad mouthed by the crowd that doesnt understand them. For guys who don't want to tune a carb or fully understand what's happening, or are at the mercy of a rebuilder - quadrajet is probably not the best choice even though its a superior carb. If you can get them for free, they do make excellent trading stock.
I love them and they are pretty easy to work on.Rebuild it yourself, kits are cheap. I have had a lot of trouble with Q-jet carbs that have been bought from a rebuilder,they don't reject anything and will epoxy the fittings in the stripped threads.
I've had them on several near stock engines and absolutely loved them. I was lucky and had a mentor who loved Q-jets so I learned the language. If you wanna learn how to tune it they at wonderful. But for your application, I'm thinking you would be better off going with a new edlebrock... Posted using the Full Custom H.A.M.B. App!
Just about every GM car that came with a 4bbl came with one, so all these people that are having all these problems find someone else to do your work.They are great carbs, and if you know what you are doing very easy to work on. Look at some of the ET's of Super Stock cars running them.Now if it's a Ford 5.0 as said you may need an adapter unless the manifold is designed for a spread bore.in which case there are many other good carbs that will fit.
5.0 Ford, the only reason I was gonna grab these is cuz I can get em for so cheap.. I have heard they can be pretty good too, and I do know a guy who is good at tuning them etc.. but yeah the fact that they likely wont bolt right up means I will likely end up using something else.. I am trying to budget build as much as possible
I got two q-jets rebuilt by a pro and compared to a probuilt Holley i got the q-jets are better in every way. Posted using the Full Custom H.A.M.B. App!
Q-jet is a good carb. Your simply gonna have to factor in cost of adapter, and gaskets ect. That will tell you if it is cost effective.
I had the same problem on my O/T car a long time ago. Q-jets are "interesting" to work on, but work very well when set up right. If you want minimum fuss, go Edelbrock. If you like to tinker, go Q-jet.
There are a lot more parts in a Quadrajet than a Holley or Edelbrock/AFB and finding "over the counter" tuning parts for them is rare.If you are running a C4/C6 trans on your Ford there is no provision for the kickdown cable.You could slap this on it since you have a good set of heads and intake http://www.summitracing.com/parts/sum-m08750vs/overview/ it uses readily available Holley tuning parts.
They work great when they are setup to match your engine and application. Your heads and intake seem to be set for midrange and higher RPM usage so I would not use a Qjet, easier to tune a Holley with that head and intake setup IMO. Beauty of a Qjet is being to run off the small primaries to get good MPG and then have the huge secondaries for power at WOT. I only run them with short cams and dual plane intakes to maximize the balance of MPG and power.
Awesome carbs once they're tuned, but like a lot of guys have said, you need to understand what you're doing. Mike
X2, although if you are running Victor Jr heads, you should probably be using the 750 mech secondary unit. http://www.summitracing.com/parts/sum-m08750ms/overview/ But yea, I would take one of these HANDS DOWN over an Edelbrock.
Just like the real mechanics have said, q-jets are excellent if you take the time to truly understand them (this is true for any carb, ive seen every popular make and model carb horribly tuned by people who kinda hunt and peck their way around tuning them. If you do end up using one i recommend carefully inspecting the adapter. The transitions in the ports are rickety in some of them and need to be de-burred and smoothed out some otherwise they make a lot of noise on acceleration
Quadrajets are a bit of a black-art, that, it seems, the majority of folks out there just don't understand. They are an excellent carburetor, once tuned, and when in a good-state-of-repair. That said, with your setup, I would have to say no, for the reasons already mentioned. They are more of a low-mid biased carburetor (as this is how most folks with the OEM applications drive). I don't participate in carburetor brand debates. I work with Edelbrock carburators, because they are what I am most familiar with, and what I have had the best results with. Others say otherwise, but that is their own business.
I raced with them built or tune 100's for street cars great carb the best out there! but for your application I would use a 600-650 holley with vacuum secondaries
As far as not giving a shit about "matching numbers" and just wanting a Q-jet that works well, one from the 1969-74 era is best....at least those have been the ones that worked best for me.
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