I've seen in the past where there have been a few of you roaming the woods around here. I'd be most interested in how you setup your Q-Jet and how it performs. Such as primary rods, jets and secondary rods and hanger combo's. Any mods, etc.. Thanks!!!
Thanks Sam!! Hehe, Actually, I Built the carb on his car right now, he brought it to me 100% apart. Looks good but its not setup good for his combo, 350 100% stock with the exception of a 4bbl vs 2bbl and a Pertronix... TH350 stock and a 2.56 open rear (yelcH!) Has 69 jets with 44b rods and I think AS or something like that secondary rods... He needs to get the right jet rod combo... his car was knocking something fierce... Dan
:TU: I have the 800 on my 350 now and I love it to death! Unfortunatly I cant help you with the numbers, my carb guy tuened it with the engine mods, so its really guess work when it comes to combination. All I know is that when I stomp on it you REALLY hear the moter swallow the air :laugh: . Catch ya later! Larry
John Osborne set up my 800. It has 76 jets, 46B primary rods, and BG secondary rods. It runs flawlessly, with clean transition from primary to secondary, and no bog.
I'd like to add, if I had the money, I would send my carb to Osborne... Being poor, I got pretty good at playing with Q-jets... But I am far from a pro.
Dan is correct.. I did have that q-jet in every piece possible when the unfortunate happened. Ya put 44b pri rods, 69jets, K hanger with AS rods. When I got home.... :grin: I tore it down again and put new (yea, new edelbrock) pri jets 71, kept 44b rods and K hanger and have since yesterday been playin round with secondary rods.. Don't use BS rods with this carb! lol.. Pings like a pinball machine. I have in there now, all edelbrocks : high volume needle & seat, accellerator pump, power piston spring kit (currently have 8Hg installed), phelonic float, jets 70-72 (now have 69-73) and a few other items, that aren't internal. I have B G H K P U hangers with DU (i think, real rich), CL CP BS AS DD and AY secondary items to choose from.. So gents, lay on yer combos... If I have to buy new stuff, PAW is your friend.. :grin: Thanks Guys!
Quadrajet links and pieces. Scott, I have just been through the same process that you are going through. For what it's worth here is the combo that I run in my 401 powered electra. It's a heavy car with an even heavier foot operating the throttle so take that into account. My carb is a replacement 'Carter' Quadrajet for a 76 Pontiac 400 or 455 motor. It's an 800cfm unit. I found that my needle/seat was the .130" type and is big enough for my needs. I use CP rods (waiting on a set of 'AX' rods. You can use CC or CK) and a 'B' hanger (don't look for a hanger leaner than K they are too lean for even mild performance applications). Make sure that you adjust the air valve so that it doesn't flop open but also make sure that it's not too tight either (the links below have the procedure for adjusting the air valve). You should feel a medium amount of resistance (about 1/2 turn past zero tension). You'll have to play with it until the bog dissappears but the results are worth it. Take an allen key and a thin screwdriver and go test driving (the best part... :Brow: ). My tip would be to try the different hanger and rods first as they are the easiest mod to perform and show the greatest difference. This should be a good setting for you too or at least a good starting point. Just a note for those who haven't played around with different hangers and primary metering rods; I suggest that you go and get some richer rods and an earlier hangers (medium and long rods are better for performance and the hangers are rated alphabetical A=rich Z=Lean) and start playing. The difference is measurable and noticeable not to mention that it's one of the easiest mods to do and if your settings are lean at the moment you will notice a big difference. There are only a small handfull of articles worth reading on the net about quadrajets (I know because I spent weeks looking and all roads pointed to these articles aver and over again. Here are nearly all of them and you will find what you need within these articles - I can guarantee it (well, actually I can't, but you know what I mean) They are (in no particular order) listed below and if you start at the top by the time you work your way down to the last link you will know how to tune a quadrajet. Read on...then go out and floor it! My Quadrajet Tips (Corvette FAQs) is an excellent article (even though the pictures are missing) (The best) Dorians Qadrajet page (one of the best) Tuning your your Computer-Controlled Quadrajet for better performance Quadrajet Tech by Randy Frazier. (definately one of the best) And, even though this one is aimed towards Holleys it's an excellent article and a must read for anyone interested in the science of mixing fuel with air. Carburettor tuning the scientific way (interesting). Then there's this article (I'm not sure from which magazine) called Rochester Quadrajet - Supertuning . Of course, the Olds guys have always got good info about Quad's and SP400 trans' etc) check out this page called Quality Quadrajets . I also just found this one while I was looking for you. It has scans of magazine articles related to re-building a quadrajet. It's called simply Quadrajet I hope they help. They certainly did for me. Bill
You're welcome Scott, I came to this group looking for help on this exact same topic and the group helped me so I'm helping you. :beer :TU: I would even go so far as to say that just visiting www.v8buick.com should be worth 10 horsepower alone! Bill
Scott, you stole my line! :laugh: Thanks alot Bill! I remember tryin to help ya, but find myself in the same situation only lazier.. :spank: I'll head out and change the hanger before I do my midnight testing, I believe earlier I put CP rods back in so that should be good.. Ode, for the day I can lite my tires up again... :ball:
Just a note: When you finally get those secondaries opening at the right time (and fully - don't forget to check to see if the air valve door is opening to at least 85 degrees, but not over 90 degrees) and delivering the correct fuel, there will be an almighty roar when you plant your foot which is almost as loud as the exhaust and it will put a smile on your face a mile wide :grin: . I never expected to hear a different sound coming from the engine but that's what I got. A whole and entirely different engine but then again I was running a Holley of questionable tune and probably realised more of a power increase than most. Mind you, mine was brand new as well... (check out the pics) http://www.buickstreet.com/buickstreettech-carterqjet.html What I like about the Quadrajet is that with only a little bit of knowledge you can start tuning them and achieve good results and the test drives are great fun because how else are you going to feel a 'bog' without flooring it - hard. Just by the way, I perform 3 tests when road testing... 1) Floor it from a stop and carefully 'listen' for the difference. You'll be listening out for a loud squealing noise which seems to eminate from the rear of the car. More noise is good. Bonus points for smoke. Triple bonus for having to let off because "that's enough". 2)Drive at a constant speed of 30-40 mph in second gear and floor it. You'll be looking to eliminate hesitation (tune the air valve) as the secondaries open. Bonus points are awarded for breaking traction at road speed. Triple bonus for having to correct your steering. 3) Take off as fast as possible without breaking traction to feel the smooth delivery of power and to listen for any pinging (windows up). I find that repeated attempts are often required for thorough testing. Once you've finished testing and are satisfied, pick up a fresh tank of gas and a fresh set of tyres and then go and find an 'ordinary' V8 (non Buick) with a holley. Make sure you're wearing clean taillights. Bill P.S. You're welcome Scott (s).
Bill, what is the stock application for that particular Q-jet?? Had one on my 72 SportWagon... Got rid of it in a hurry (put on a 70 350 carb)... It was nasty, ugly, had totally incorrect linkage (you shoulda seen how they figured a way to put the throttle return springs, going to the back of the engine, not hte front!)I also was unable to run an air filter cause of the tower on the front.... Just curious about what that carb came from... (ran much better with the real Buick carb I must add)... Love the website btw...
It took me a while to identify it but I have it on good authority that it's a replacement carb for a 76-79 Pontiac 400 and/or 455. 800cfm and the linkage needed a quick head scratch but it works fine. I had to bore a hole into my air cleaner base to get around that air horn (or whatever it is). It's a good carb though. Really opens up now I've done the mods and I'm sure there's more in it yet.
Makes sense with the Pontiac.. Just worked on a 73 GTO w/ 400 and it has an edelbrock carb, but the linkage looked too familiar... Also, i sent you an email (bill@buickstreet.com) did ya get it?? Dan
Yes Dan, I did get it. I sent you a reply. Thanks for asking re: articles as well (most wouldn't). Bill
Well guys, after taking many nights to test-n-tune with zero results. I drove home yesterday and checked my idle and timing. Idle was low and timing was 4deg retarded! ou: I fixed the timing (now at 12deg initial) and idle, then later that night tookoff to have dinner. Rounded the first corner, laid on the pedal and smoked it up for about 20ft.. woohoo!! Bill, that big grin you spoke of, I had it then.. :grin: After dinner, I tried some straight takeoffs and no tirespinning, and a bit of a bog. Plan on tuning a bit today. As to your rod and hanger suggestion Bill, I went to PAW and got new B hanger and CC rods. Thing was drinkin gas like it was going outta style.. :spank: I put the stock AS rods back with the B hanger and that's what I had last night, no pinging either so I'll stick with that for awhile. Now if I could only get that air-valve spring right! argh! :af: Plus, here's a question for ya'll... Signs of float misadjustment are: (fill in the blank) Gas leaks out the airhorn gasket and down the front and even sides, I see gas around the front vent tube as well.. Thoughts? Thanks Again Bill & Friends!
Hey fellas whats up??! I've been on here for a few days now....reading over all of the useful tips (majority over my head though) to see if I could get this question anwered without having to ask it....but....I have a '70 lark 350 4bbl and my primaries stay open all the time....why? and how much does it affect my performance?
