What is the best carb???

[Michael A. Glenn]

I know that people have personal preferences on their fav carbs and I like Holleys personally but Im confronted with the following dilemma. My Rochester E4ME isnt opening the secondaries, the motor is supposed to be a rebuild and I have no Idea what was done and what wasnt. That being said I dont know if the carb has ever been worked on and find it at this point not worth the hit and miss of a rebuild and hoping its got the right size jets and  dialed in correctly. My question (s) are as follows. The motor is supposed to have 240 hp stock and 400 tf lbs of torque, is a 800 cfm needed??? Next.... would a Holley or Edelbrock be better?? I know Edelbrock is a out of the box drop in done type set up and a Holley needs some fine tuning but which would be worth it in the long run.Thanks in advance... Ohhh should I get a manual electric or non choke version, currently there is an electric on it.

[Frank Grasha]

The factory Quadrajet is one of the best ever designed When working properly I got 12 MPG @ 55MPH in Texas  on my 350 GVW 12000  using the primary barrels only, Average MPG was 9 MPG @ average 65 MPH using 4 BBLs as necc !  Frank  P,S I have updated to a 5.7 TBI W 4L80E W OD  and my best avg is 9 MPG @ 65 MPH in PA !

[Jim Stoltz]

In good working order, stock is the way to go. I had the Q-Jet on my 454 rebuilt and it's fine. I still have some fine tuning to do with the choke and idle air but the factory matched the intake and carb just right to lug my big Dead Metal around. 

Rick is right - if the secondaries are not opening it's probably because of the choke adjustment. I have mine propped the whole way open because I haven't been able to get it right. In the summer it doesn't matter much. In the winter it's a problem. I converted mine to electric which is great until the fuse blows and the choke closes and you can't figure out why it's running so rich. Even so, I'd highly recommend keeping it electric.

[Rick Faunce]

And if you do get a new one get the electric choke by all means.

[Rick Faunce]

Ok, You have done the proper diagnosis of the secondaries, now we need to find out why they are locked out. That is usually because the choke linkage is not in the open position. And as far as a new manifold the very last manifold you would want is a Torker! That is a high RPM manifold that does not even start turning on until around 4500 rpm. It would never match up with the stock cam and heads. You want the performer plus manifold which has it's power band from idle to 5500. It is also a much lower profile manifold than the Torker. As far as changing the air cleaner you really want to try to stay with the stock one since it is plumbed to the fresh air out front. An open element, aftermarket air cleaner will be getting noting but the very hot air off of the engine. Not good for performance or mileage. If you look on the passenger side of the Quadrajet at the base of the carb you will see where the linkage has a pin through it for the secondary and a blocking plate attached to the choke linkage. As you move the throttle linkage that blocking plate should be out of the way of the pin for the secondaries. If not the there is some issue with the choke or the choke linkage. Make sure the choke is coming off first off. Hold the choke wide open with you finger and try the throttle again and see if they open. If not you will have to look over the linkage and see where it is binding up. May just need some lubrication. If you decide to buy a Edelbrock what I always tell people is to call edelbrock and tell them what you are putting the carb on and they will tell you exactly what carb to get and also tell you if you will need to change any of the settings. The only time you generally have to change the settings is if you are at high altitude all the time. The nice thing with the Edelbrock is that it is so easily changed for different conditions.

[Lakota Wolf]

If your running a 400C.I to a 454 C.I. 700 cfm is the very lowest I would go,,,, because then you would be dropping it down to a fuel starve and lean run,,, resulting in an over heating engine, spark knock and the inability to do the quarter mile under the 45 minute mark. But in my Honest opinion, a 750 cfm  is the safe way to go.. As with your high rise, so to speak, air cleaner,, thats a good thing that you can get a filter element not as tall. and as previously mentioned   a square bore adapter is required if your changing from a spread bore quadrajet to an Edelbrock..

p/s/,, Dont feel bad about breaking any land speed records,,, when Im towing my 5th with other pick up behind it,,, I have had more then one lil ole lady pass me,,,,,,,,,, and they was on foot with a walker., and not even getting the tennis balls warm.

[Michael A. Glenn]

Lakota... how did you know??? I just did the quarter mile in  30 minutes flat !!! gonna go for a best time of 25 if I can get a good stiff tail wind....lol.... I was also thinking that a lower cfm would also work, just not sure how far I can go before Im being stupid and starving the motor and really mess things up. 650?? 700??

[Michael A. Glenn]

Rick I  make this comment because the whole way back home from picking the Rv up there was nothing when I floored it, the coach was at 55 mph and nothing was happening, when I got home I pulled the Air cleaner lid off and did exactly as you described, by holding the top butterflies open and dumping the gas pedal, nothing happened with the secondaries. The air cleaner is like 10 inches tall so I doubt there would be an issue with throwing something else on as far as clearance as Id just go with a lower profile Air cleaner and housing.  Would anything lower than a 750 starve the Motor??? 

[Lakota Wolf]

Rick hit it on the nose,,, You don't need an 800 cfm,,, a 750 is plenty unless your doing RV drag racing. The secondary is not going to expell fuel just by depressing the accelerator pedal. The secondaries work off vacumm and by available air flow down the carb throat when throttle plate to the rear are open. Quads are actually excellent carbs,, but in the case of replacing them to a newer carb. Edelbrock has a nice unit as Rick pointed out. And as he mentioned,, you will need an adapter plate and from experience,, you will lose available clearance. Its worth the extra few bucks to go with the matching intake manifold as the carb and manifold will work in unison. Usually with a 750 cfm edelbrock carb, the standard choice would be the Torker 2 intake. Thats just my 4 1/2 cents of input.

[Rick Faunce]

What makes you think the secondaries are not opening? They will not just snap open by hitting the gas since they are vacuum controlled. Let me rephrase that, the butterflies are manual control but the air vale on top is vacuum control and will not let any more air in than the engine can handle. That way the engine does not bog down due to an extremely lean condition. The first thing you need to do is to look at the carb when it is warmed up and not running and push the gas pedal all the way to the floor, do the secondary butterflies open? These are the plates on the bottom of the carb, not the ones on top that you see look at it. You can hold them open by hand and look down to see if the secondaries are opening. If they are not is the choke all the way open? If not then that is why. Is 800 cfm needed? Probably not untill you hit 5500 rpm, BUT! On a quadrajet you are working mainly on those little primaries and that is where you get your gas mileage from if you keep your foot out of it and take your time accelerating. You will only ever see that 800 cfm rating at WOT and top RPM. If you were to replace the carb then the best replacement would be a 750 CFM Edelbrock in my opinion. The Edelbrock is infinitely adjustable  for idle, mid range and top end. But it is a square bore and not a spread bore so you will need an adapter. This may not leave you with enough clearance for the stock air cleaner. I usually tell people that if they are going to change to an Edelbrock then get the manifold too since they will b a matched set and you will gain a substantial amount of bottom end grunt. Be sure there is a major problem with the Quadrajet first though since they are fantastic carburetors when running right. You can get a rebuilt stage two Quadrajet from Sean Murphy for around 300.00 the last time I checked. You tell him what it is going into and he will set it up for that application.

[Rich Thomas]

That is one of them the grass is always greener questions that has it's roots (sorry) buried in the sixties. The palace, a 1978 Travelcraft has a q-jet, works good on the SBC 350 of the same era. If it ever takes a dump it will be replaced with a modern fuel injection system following Russ's thinking on the matter. So many advantages to it and there are a couple of members here that have done it to there great satisfaction. Do a search on the site and at least read up on it before you shell out the bucks for sixties engineering. good luck on what ever you choose to do.