My carb guy says my Rochester 4GC is the second worst carb ever, second only to the Ford Variable Venturi (that's saying ALOT!) I've had mine rebuilt twice by guys I trust, and they ALMOST got the flat spot to go away. (yeah, the floats are new and set right, the accelerator pump is working just fine, good mixture, etc.) Also, the 283 it's on gets only 15 MPG on the highway with a 3:08 gear in a 3300 LB car. It's got no kick when you stab it. Can the mileage and performance be blamed on this carb alone? Will the Carter WCFB be a noticable improvement in economy and performance? SOMEBODY has been down this before.
WCFB no question. Or better yet get and earlier Carter AFB. I run two 500CFMs on my 2x4 Chevy and they are great. Edelbrocks are a copy of the AFB but later style throat. They are good out of the box. But be ready in two years to jet them down. I don't know why but it seems the three I've had began to run rich about that time and had to be jetted down. Good luck, Tim
Simply put, your carb guy's a retard. There's nothing wrong with a 4GC. Your particular carb could be worn out to the point that rebuild kits won't do it any good, but it's a good design. Maybe Carbking will chime in on this.
Well put Heathen. Yes carbs do wear out I worked in a Chevy dealership and did hundreds of quadrajets. Sometimes they were worn to the point that a kit would help. BUT it wasan't like new. Not a damn thing wrong with 4gc I think the WCFB is one cool looking carb esp. in dual 4 setup. Everyone has an Edelbrock carb me included BUT I think a 4gc , wcfb, afb. avs is better looking
I drove Olds' and Pontiacs with 4 jets in high school. The only problem I encountered was fuel starvation on a hard left turn. Never had to work on ours. I have a pair of WCFB's and a pair of AVS's waiting for my 370 Pontiac...we'll see.
The most worn and most overlooked part of any carb is the throttle plate. Most rebuilds that go bad are for that reason
And the engine is in good condition,ignition timing,cylinder compression and so on? Intake manifold heat riser working?Heated intake is necessary on some engines for nice in town performance,your problem is typical of a cold intake.
Carter received great reviews in the earlier days of 4-barrels from the hot rod fraternity. This for several reasons: (A) they were/are good carburetors, (B) Carter had a Competition Department with a real telephone number and real specialists to answer modification questions, and finally (C) a tremendous selection of tuning parts. Rochester did not cater to the aftermarket; thus those who modified Rochesters were pretty much on their own, both in knowledge and parts. However the Rochester 4-Jet is a really great early 4-barrel. However, the largest version was 625 CFM. If you have an engine that does not require a larger carb than either the WCFB or the 4-Jet; a good carburetor technician should be able to rebuild both, install one on the car, seal the hood, let the customer drive a 1000 miles, bring it back install the second, again seal the hood and let the customer drive another 1000 miles. The customer should see NO difference in driveability, performance, or economy. Second worst 4-barrel ever??? This comment reminds me of the howl that arose from Ford mechanics??? in 1932 when Ford switched to the Detroit Lubricator carburetor. "The carburetor was just no good, couldn't be adjusted, etc., etc., etc." Oh, and Detroit's other major customers in 1932 ..... Cadillac and Packard. The Detroit was one of the finest carbs ever built, but it was different. Back to this subject: would highly suggest you get a second local opinion. As with ALL "carburetor" issues: (A) compression test, (B) ignition check, and then (C) look at the carburetor. Good luck. Jon.
And just for the record, the real reason the Ford variable venturi carb took a reputation beating was simple: ethanol. The carb was designed for gasoline. About the time the carb came out, "gasohol" became popular. Due to the design of the carburetor, a diaphragm was in contact with evaporating fuel. The ethanol messed up the neopreme (sound familiar today with accelerator pumps???). Often problems are not what they seem. Had gasohol not invaded the country for a few years, the Ford variable venturi carb would probably be considered a great carb for the mileage it was able to produce during the manufacturer's struggles to adapt to ever-increasing smog standards. There are many 4-barrels I would rate below the variable venturi. Jon.
This was an issue with both the WCFB and the 4-GC. Both manufacturer's issued a patch that cured the problem when the dealership mechanics read the service bulletins. It involved inserting a brass sleeve in a vacuum passage to stop the effects of inertial fuel surge. Jon.
when I cam home from Nam a bud was running a 56 chev w a 283 and was running a wcfb and he used paper clips for metering rods he got 20 mpg, then we took a alum 3 97 intake and redrilled it and put on a set of carbs from a 348 which worked well after putting on a vacume tank ah to be young and dumb again, i had a 68 imp w a 307 and put the guts of a 1955 2 GC in that and got 20 MPG and a little driveability issue but as a starving student the MPG was fine now I am pulling 16 MPG with a 355 and just keep putting fuel in it!!!and thats on road miles
Jon.. I'd love to hear more about this repair and about the availibility of said sleeves..do you service them?
The WCFB is a superior carb to the rochester 4G for sure. It is doubtful that you will get any better milage out of it. Both are 50 year old carbs at best and a lot of it depends on getting it just right. Lately I have heard that the WCFBs are hard to tune. I never noticed them being any harder than any other carb but that's probably because I didn't know any better. You milage has a lot of variables, hot ignition V stock single point, head choice, cam, compression, even your wheel bearings all play a role in your performance. I don't know what vehicle you are rolling but back in the the '60s 16-18 was considered good mileage and that is the technology that you are playing with. That said the better condition your carb is in the better your chances of getting good mileage and if you can lay your hands on a good WCFB you chances are going to be better than with a poor 4G. Just for information in '70 I had a '54 Roadmaster with a 4G and I got in the 16-18 range. That is one whale of a car with a nailhead. But we milled the heads to bump the compression, and I was running a mallory dual point with a hot mallory coil, a 3/4 race cam. My wheel bearings we good and got greased on a regular basis as well as keeping my tires pretty hard (32-35 psi depending on road conditions.) So it isn't so much the carb but the whole vehicle that determins your fuel mileage.
Rocky - the "fix" is to mill the vacuum passage for the choke in both the airhorn and the bowl to accept a brass sleeve approximately 3/16 in length. The sleeve is then pressed into the bowl and affixed with a drop of locktite. When the two castings are then assembled, the sleeve will extend into the airhorn cavity. This seals the inertial fuel surge when cornering hard. And for the record, the issue is not fuel starvation, rather just the opposite; as the inertial fuel surge would spill raw fuel into the vacuum passage. This created a rich miss, not a lean miss. Jon.
I've owned several 57 Chevy's with the Power Pack and driven several others with both carbs and I couldn't say there was much difference. I wonder why they used 2 different ones?
I've had 56 power packs with both carbs and seem to constantly need to tinker with the wcfb more than the rochester. I still have a 56 rag that I drug out of a potato field in 1974 and am ready to try the rochester again. The alcohol in the gas in a nightmare to the hobby. My 56 died on me and I found actual leaves of algae growing in the fuel filter. If your car sits the alcohol settles to the bottom, absorbs water and leaves a black scale of rust and algae in the bottom of the tank. Buy the way has anyone else noticed the black scum that grows around the gas filler and eventually leaves permanent stains in the paint? Also algae from the alcohol. Recreational fuel seems to be the answer though I've tried algaecide for diesel but haven't had time for real results yet. As for gas mileage, gasohol is less efficient and gets worse mileage than straight gas some report 10 % loss. Aren't Government regulations great?
I rebuilt one of each last winter, and I'll bet the 4GC had half the parts than the WCFB. I'm going to try both on my 255 Merc, so we'll see.
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