What would happen if i took off my 2bbl set up and put on a 4bbl in take and carb, but not change the competion?? any help is welcome pat p.s. bush 4 more years
If by the word "competion" you meant compression, it really shouldn't matter. It's better because you can still use cheap gas. The difference a 4 barrel makes you will definitely feel.:bglasses:
Go for it! A quadrajet gets better gas mileage than a 2bbl all day. ...if you can keep your foot out of the carpet.:Brow:
When I read your first post, I missed "bush 4 more years". I'll leave that one alone.....politics ruins freindships.
Bush is a Tush! Bush is a Tush! Bush is a Tush.....:Brow: TO reply to your thread, I swapped out my 2 Barrel for a 4 on my 71 350. My gas mileage went from around 10 mpg, all the way to 16. I was very pleased. The car had much more top-end power, at the expense of the lower end. IT wasn't a crazy loss, but I certainly could feel a difference. Of course the 2.73s didn't help ou: It was a completly different car though. It pulled all the way to 65 in first, which was about 5500 rpm, while before it pooped out around 4000. IT is worth it :TU:
I used to have an old Fird station wagon that I put a souped up 351W in. It had 2:26 gears. Yup, that's right, 2:26.:shock: That thing was slow off the line, would barely do a burnout, but man.......nail it at 30 and she really went. Top end was good too. The four barrel did nothing for the off the line, but that thing really came alive at higher speeds. I broke something in the trans one day nailing it from 30 and had to drive home in second gear (one nice thing about firds:grin: ) I don't remember what it was, but I fixed the c4 trans myself. The part was split wide open.:laugh:
Lesabre, Just a suggestion- use a better title for the topic. Titles like "Help!" or "I wonder..." or things like that will get you much worse answers than "4-bbl manifold on 300 engine?" which explains your topic. I usually skip right over any articles that don't have a relevant subject line. You never know what expert you might be able to snag by using the right keywords in the subject line. -Bob Cunningham
Smartin is right, your mileage should improve. But, while you will feel the impact of the back barrels, you won't have a much faster car. Car Life Magazine (May, 1967) tested a 1967 GS340, which has the 260 hp 340. They tracked tested it at 16.7 in the quarter at 81 mph. I think I've seen other 340-4/ST300 tests with 0-60 in about 10 seconds in A-body cars. So, even if you dropped my 340 into your heavier car, you will still be left behind by modern compact cars. Not trying to be overly negative, and certainly encourage you to improve your ride, but don't expect too much from it with that drivetrain.
Years ago, I did exactly what you're thinking about, and loved it! Just don't do what I did, which was use one of those silly adapters to match up a Holley carb to a Q-jet manifold. Some people may like Holleys, but I firmly believe that unless you're going for that LAST .01%, a proper Q-jet is WAY better all around. Holley = fire hazards while setting float bowl level, blown power valves, gaskets below the fuel level to leak, and a dozen other things. Poor design is why there are SO MANY Holley performance parts out there, because there are so many things to correct! :Smarty: And then there's the "adapter" that places the secondaries an inch away from the manifold openings! :af: Get a Q-jet!!!
Several ways to get a quadrajet carb, listed in order from low cost / high effort to high cost / low effort. 1. Pick up a decent one from a local junkyard, and put a rebuild kit in it yourself. 2 key things to look for and avoid: a warped airhorn (the top 'lid' of the carb itself, when the bolts are tightened too much it pulls the front corners down), and sloppy throttle shafts (you want very little to no up-and-down or front-to-back wiggle). Get one from the same year as yours, or as early a donor as possible. This should run you around maybe $50 total. 2. Go to Autozone/Pep Boys/O'Reilleys etc, and buy a remanufactured one. Again, watch out for sloppy throttle shafts and a warped airhorn. I've got one that was reman'd, and the airhorn and carb body are warped about 1/16-inch! :af: Autosone lists one for a '71 350 right at $159.00. 3. Look around, there's likely a carb shop nearby, they can sell you one if they're any good. Probably a little more $ than Autozone... 4. Get a decent carb from somewhere, and send it to John Osborne (JOP455@aol.com) or one of the other Q-jet gurus, and have them rebuild and set it up for your exact engine/car setup. Cost estimates I;ve seen range around $250, depending on what all is needed. Now, over the years (once I grew up and trashed the Holley), I've done #1, #2, and #3, and now that I've gotten tired of tinkering with it (and grown up some more), I'm finally sending mine off to John O. You might want to send John an email and see if he has one on hand he could do for you, it may be the cheapest/easiest way in the long run.
Several ways to get a quadrajet carb, listed in order from low cost / high effort to high cost / low effort. 1. Pick up a decent one from a local junkyard, and put a rebuild kit in it yourself. 2 key things to look for and avoid: a warped airhorn (the top 'lid' of the carb itself, when the bolts are tightened too much it pulls the front corners down), and sloppy throttle shafts (you want very little to no up-and-down or front-to-back wiggle). Get one from the same year as yours, or as early a donor as possible. This should run you around maybe $50 total. 2. Go to Autozone/Pep Boys/O'Reilleys etc, and buy a remanufactured one. Again, watch out for sloppy throttle shafts and a warped airhorn. I've got one that was reman'd, and the airhorn and carb body are warped about 1/16-inch! :af: Autosone lists one for a '71 350 right at $159.00. 3. Look around, there's likely a carb shop nearby, they can sell you one if they're any good. Probably a little more $ than Autozone... 4. Get a decent carb from somewhere, and send it to John Osborne (JOP455@aol.com) or one of the other Q-jet gurus, and have them rebuild and set it up for your exact engine/car setup. Cost estimates I;ve seen range around $250, depending on what all is needed. Now, over the years (once I grew up and trashed the Holley), I've done #1, #2, and #3, and now that I've gotten tired of tinkering with it (and grown up some more), I'm finally sending mine off to John O. You might want to send John an email and see if he has one on hand he could do for you, it may be the cheapest/easiest way in the long run.
Change it to a 4bbl.You will love it. Better mileage, better performance. Not much of a downside here. I know that many of you love Q-jets and Hollys, but I swear by Edlebrock. I am running them on both of my Buicks and also my 56 and my 46. They perform very well and are available at most of the discount parts stores such as Pep Boys and Kragens
I dont think people here have any problems with the Edelbrock AVS carbs... they are pretty close to q-jets arent they? Im thinking I will get an Edelbrock once I get my engine built...
Yea and Eddy carb is just a "better" built Qjet. I have seen lot of them goin cheap though on ebay. $35-$40 needing a rebuild.
