Thought I would post a poll about this to see what most of us like on the board. For me, its the Q-Jet. Need it for a street car and to keep good mileage. Lets see what everyone else likes.
I know I will probably get flammed for saying so, but I really like the Holley Carbs. I owned several GM products of the years and the first thing I would do is remove the Q-jet and bolt on a Holley. But that is only my .02.
Q JET. just a good all around carb, once you get it set up right you shouldnt have to touch it till it need rebuilt, around 100,000 miles. those racing carbs look cool thought!
I used to have a Q-jet on my 425. I really liked the way it ran, nearly perfect. On the down side, these are prone to leakage on the bottom, but that can be fixed with a special kit. Also, the fuel filter threads strip easily if you are not careful, and the air horn will warp if you overtighten the 2 long front mounting bolts. I upgraded to the dual Carter set up a few years ago, and I like those better by design, there is no welch plugs on the bottom to leak, and it bolts to the intake with 4 short bolts through the throttle body. It would be very hard to warp the air horn on one of these. The motor has a lot more top end power with the dual 4's, but the cold driveability is not as good as it was with the Q-jet. It seems to hesitate a little until it's warmed up and no matter what I do, I can't get it to run as good cold as the Q-jet did. Just a footnote here, I used to have a holley 600 w/ vac. secondaries that I bought new on my old Ford 351w, and I had more trouble with that carb than I care to remember. Needle and seat flooding problems required me to install a pressure regulator and different float springs. On damp days, it would smoke and run rich on startup. On dry days, it would stall a few times and need re-starting when first started in the morning. There was no compromise adjustment on that choke pull off, which was very difficult to set. On the lighter side, it got better gas mileage than the Ford spreadbore carb, but had a little less power. Only god thing was being able to adjust the float level from the outside:bglasses: I don't race (most of the time:grin: ) and I guess I like the Carter AFB's the most. Too bad there is no choice for AFB's on your poll. They look the same as the edelbrock, so I voted for that.:Brow:
Q-Jet but not just any..... one calibrated and set up by John Osborne. Worth the bucks IMHO. I once had a Holley on the GS (4160 if I remember right?) that ran very smooth at any speeds other than WOT. Something about those vacuum secondaries that never really opened like they should? I drove the car from GA to Ohio in '99 for the Nats there that year and got 14 MPG overall with the AC on with this carb!
edelbrock I like the edelbrock carbs I have on on my 430 in my riv and my brother has one on his chevy 350 different sizes of course! They perform flawlessly right out of the box just a couple adjustments with the A/F mixture and I was ready to go. And there much easier to work on than Holleys. will
IMO, the best 'fix' for the stripped threads problem is simple - don't use that little filter!!:Brow: :TU: You won't strip those threads if you don't have to go in there.:grin: I put a larger inline filter on....MUCH quicker to inspect and change!!:TU:
Right now Im runnin two edelbrocks, they dont do to bad,but saving for 2 demons,but it all depends on what you want to do.Its been my expieriance a well tuned q-jet is all around a good mileage/performance carb.But performance is limited,for example Ive seen a q-jet simply run out of fuel on the top side of a drag strip, where a holly,or demon would out perform it.
I know i can set up a holley to out perform a Q-jet any day. Sorry but thats the truth. Look at your top drag racers and see what they are running?
from a tuning stand point the holley is the simplest. on all the brand x's Ive worked on Ive seen a massive seat of the pants improvement and reported mileage increase when I took off carter/edelbrock and installed the holley. on buicks my experience so far is qjet,thermoquad and 3barrell holley qjet was best for me but I'm now going to try a n offy2x4 with 2 1850 holleys also Ive had better luck with double pumpers over vacs but thats just me
For me there are two kinds of people, those willing to learn a Q-Jet and those who aren't. Mind you I only cruise, I don't race. If you're willing to learn how to tune a Q-Jet then you'll laugh at anybody who calls it a Quadra-junk, Quadra-Bog or any other name. It's a great carb
I used to run a Q-jet.....they run good when set up correctly......what I don't like about them is that they leak under the secondary metering well, (they make a kit to fix that) mine even leaked under the primary metering well, and the air horns warp easily. Once, on one carb I had, the soft plug on the main fuel inlet (I think '66 and '67 only) popped right out of the carb and it pumped raw fuel all over my hot engine.:shock: My car could have burned!:rant: I ran a holley once on a Furd I had and even though it got better fuel mileage, and more perf than the motorcraft 4 bbl. It was quite undependable.......when new it kept spilling gas into the engine every now and then (usually on the way to work:af: ) and it was the most tempermental carb I ever had. The factory sent me some heavier float springs that fixed the problem and I had to lower the pump pressure to 2 psi. That carb never really ran right. By design, I think Carter and Edelbrock makes the best carbs from a durability and dependability standpoint. That's all I will ever run on my Riv from now on. But then, I don't race it either.
Hey Joe, So far I haven't had any of the problems you talk about my Q-jet is the Original from '71 And after a tear down, clean up two years ago I haven't had any problems, In fact the only problem I've ever had is the choke sometimes won't kick on. Usually on days that aren't really cold, just a little to the cool side.
Mine used to do that too. I will say, however, the qjet I had ran PERFECT......no stumble, cold warmup operation even with the cam was good.....it really ran the best. I think that since '65 was the first year for this carb, ('66 for Buick) GM had the problems ironed out by the time yours was made. I noticed the lead plugs look different in the later carbs. As long as the dual Carters have the "cool factor" and continue to run good, I'll keep them no matter how much better my qjet ran. Jusy my opinion. Besides, 650 CFM x 2 = 1,300 CFM : :Brow:
Back in the mid 90's when I worked for an engine builder we did a test with a customer's (one of the members of this board) engine a stout street/strip 455. He had a set of iron stage 1 heads that we ported, good compression, cam, etc. He was using a special race $1000 quadraflush on it and it made 530hp. We bolted on a 850dp with a few metering tweaks but stock casting and the motor picked up 35hp. If you want gas mileage go with a quadraflush, if you want hp go with a holley.
I've only ever run a Q-Jet and an AFB, and I'd have to say that on their respective applications, both have performed quite well, with the AFB being the only performance application (my Chrysler, listed below). For simplicity of tuning, the Carter wins hands down. I needed a mentor when I was playing with my Q-Jet, and I haven't really learned all that much yet. I still want to learn, though! If I had to choose from the list above, though, I'd have to say either TQ or Q-Jet. Cheap, with a bounty of supply.
I tried to replace my Q-jet with an edelbrock and found out what a piece of crap edelbrock is! The car would not even start. I put my screwed up Q-jet with the secondaries held shut because they fall open at idle back on and it started up, no problem. I have a holley 4160 , 750 cfm on there now and it runs great! The Q-jet responds better but can't compare to the holley at high RPM.
Love my Thermoquad 850, smaller primaries and bigger secondaries than my 800 cfm qjet. Also a breeze to tune.
The only Buick I haven't run a Q-jet on was my drag car back in the 80's. (Okay I lied, my 64 Skylark and 65 GS) Used a massaged 1000 thermoquad on my racer. You can't beat a Q-jet for an all around carb if you ask me.
