I really like them too, they work better than holley and q-jets. Anyone else having heat issues with them? I've had problems with them perculating fuel after i've been driving a while, and then park. Next time I go to start it, I have to crank the fuel back up into the carb. It also seems to heat soak the fuel, which causes it to expand and run down the carb. Had this issue with a holley, switch to this AFB, and it started doing it too. I had to put thermal spacers between the carb and intake, but they seem to have a constant vacuum leak. It's really getting annoying. The car seems touchy about fuel, I have to lean or richen the carb just a bit sometimes. I also had a issue on a chevy 350 where the crappy WVa winter blend gas would cause my bowl inlet valves to stick closed. They were upside down, and they would stick closed! I'd have to tap the carb to get fuel to run it in again. Only with winter blend gas too. Other than that crap, it's one of the best carbs i've ever dealt with.
Yep, same body design. Edelbrock changed some of the internal passages, but they are basically the same AFB design.
I like what I am reading here! I am hoping for the same results on my 283! putting a new 500 cfm on mine,it's running terrible hope this will be the cure?
Ran Edelbrocks for years. Never again. If they sit for a couple of days, they drain back and you have to pump the hell out of them. The coupes' got a brand new Holley 650 cfm with an electric choke and dual feed inlets with dual metering blocks. Runs like a champ! My 2 cents.
Lined below is a thread discussing the merits of the Edelbrock AFB 'clone' carbs. A couple of pretty well-known carb experts give their educated opinions on this carb. The discussion is on a Pontiac board but the carb guys have plenty of experience with building and tuning carbs for many different makes of cars. Edelbrock carb thread Just a heads up, you can get a Q-jet rebuilt correctly and calibrated by Cliff Ruggles for your exact application for a price comparable to a new E-carb as long as you don't mind waiting (small shop, long turnaround). Cliff runs a '77 800 cfm Q-jet on his '72 Ventura (500HP 455) that runs in the mid-11s and returns 15 MPG if he can keep his foot out of it.
I've run the Edelbrock, the AFBs, the Thermoquads, the Quadrajets, and Holleys. Each has things they generally are better at the the others. And yes, there are those carbs from every manufacturer that do everything right, if you have one of these, keep it and treat it well, it's rare. There are many more that don't do anything right. If you want a carb that requires the least amount of attension, the Edelbrocks and the AFBs win hands down. If you want the most power available, you need to go with the Holley, or one of the aftermarket wanna bes, come on, you know they just started with Holley design and made minor changes, but you will spend a lot of time adjusting them for max power. A Carter AVS will kick some ass, but you will be messing with it a bunch until you get it set to your motor, probablt rates with a Holley, but with less choices of cfm. Both the Thermoquads and Quadrajets fall some where in between the Edy and Afb and the Holley and its bunch. This comes from years of messing with carbs and is based on what I have seen. I have no carb preferance. If gas milage is your biggest concern, probably the Thrmos and the Quads are your best bet, but you better learn to drive for mileage. Noting is more entertaining then listening to a guy complain about his bad gas milage one second the brag about beating someone in a race the next. All carbs are a set of compramises. Every style gives up something to be better at something else. If you desire perfection, you need to go to computerized fuel injection. Yea, I said it. The computer can annilize what the motor needs, based on several sensors, and can adjust the air fuel mixture many times in a minute for optimal performance, fuel milage, and drivability. But then, thats not very traditional, efi didn't begin until about 73, and the American that designed it couldn't sell it to any American company, so he took it to VW. Bottom line, you need to decide what you want from your carb most of the time, and how much you want to screw with it. Buy what fits the bill. Gene
Personaly i love edelbrock carbs..........i can't do crap with a holley.....if i even touch one you loose 10 hp instantly...even got a few books not good for me....can make a quadra jet.....stock ford 2-v do what i want but not them.....i would go with the edelbrock.........heard good things about demon carbs but haven't tried them yet..........
hell, the only thing ill use a edelbrock for is intial startup and breaking of a fresh motor. ive got a 600 edelbrock just for that and nothing else. hook up on fule line and your ready to run the motor. after the motors broke in, i put either holleys or demons on everything. i ran a 600 edelbrock on a 355 for a while and it worked great for about 6 months and then it started acting shitty. tearin it down and cleanin it would help a bit, but it wouls shit up again in a bout a week. so, i dont like the edelbrocks. they look like shit too. ugly sons-a-bitches.
I also am running a 600CFM Edelbrock Performer w/ electric choke on 283/PG in my '67 Nova 4-door. (Edelbrock Performer Intake too!) It works beautifully and improved gas milage over the original 2-bbl! I am going to try to tweak it with different jets and metering rods to bump the milage up a little next summer... They are pretty much identical to Carter AFB and, yes, air-horn diameter is 5 1/8. I got a nice 9-inch air cleaner from K&N made from 300-series Stainless, it is snap to polish and leaves the carb body visible.
Send me those bitches. I can rebuild them if they are not already been ruin'ed. They are a PITA to rebuild because of how the fuel well seals to the uppwer casting, and because the phenolic bodys like to break. It took me three thermoquads to make one good one last time fir my 73' 340. If anyone doesn't want their thermoquads - I will take them. On my daily drivers I will run nothing but the edelbrocks. I have one that has not been rebuilt ever. I have had it for 8 years on a half dozen different cars and it always has run well. I also have a 750 holley dbl pumper, and a "750" Race Demon that actually flows closer to 850cfm.
The common understanding in my area is if they work out of the box ,your good but if you have to tune em, your most likely not going to be happy. thats been my personnel experience also. The guys that are loving these carbs probaly never tried bolting on a good holley or demon. Go to a big swap meet and you will see a lot of edelbrock carbs for sale, must be something up. Yes you see holleys too but remember they've been around a long time so there are more used ones.
i like the idea of calling demon and getting what you need. is the cost to quality really an issues. do they last for awhile w/o having to re-tune? i guess its like anything else. some guys like them some guys dont but it sounds like for the money (i have bought every carb i have at the swap meet) buying a NEW edlebrock is a good investment
I need to select a carb for my 403 (currently at the Machine Shop and will be putting back together shortly), I am in the same boat with Altitude. I live at 6,700' and will be driving up to 10,000' regularly and down to 5000 often as well. I'm also having a difficult time selecting the CFM rating, running the numbers I come out to a CFM requiremt of 409 CI * 6500 RPM /3,456 * .85 (Volumetric Efficiency for hot street engine) = 653 CFM, but that's not taking into account altitude. My 403 should be anywhere from 9.0-10.0:1 CR (haven't CC'd the heads yet) and the Cam will be have a duration at .050 inch Lift of 219 int. - 228 exh and around .500" of lift (give or take a little on any of those numbers), being at altitude I can get away with higher CR on pump gas than at sea level. The smaller 600-650 CFM carbs should provide more velocity and better throttle response, but a lot of articles I'm reading and using the Holley online tool are recommending 750-800 CFM for my setup. I know I can jet down a 750, but I'd rather no have my engine over carbed. I want the car to have power, but maintain good street manners as this car won't be on the track. I realize EFI is the best bet, but that's an extra $1,000+ that I don't really have at the moment. Reusing the 307 Qjet is out of the question as I'll be running an Edelbrock RPM intake and there's also no way the old school computer that runs my E4ME could compensate for such a radical change from stock.
do it right the first time man. If you feel EFI is the best then wait a bit and save up. Going to be winter your way soon anyway. no point spending cash and regretting it down the track just to save a few months.
The two issues guys can have with the Edelbrock is a stumble or bog in many cases this is caused from excess fuel pressure a lot of the off shore made stock fuel pumps can put out pressures as high as 9-10 psi the Edelbrocks run best at 4.5-5 psi so using a regulator is not uncommon. The other thing is always use a heat insulator with them minimum of 1/2".
Altitude calibrations for GENUINE CARTER AFB carburetors: Standard calibration - sea level ~ 4000 feet One size lean rods - 4001 ~ 6000 feet Two size lean rods - 6001 ~ 7000 feet Three size lean rods - 7001 feet and higher Since most street driving is done on the primary side only, Carter did not specify a different secondary calibration. For those trying to race at altitude, or with a truck pulling a trailer, some secondary changes would be useful/mandatory. Note that Carter did NOT suggest changing primary jets. Since the effective metering area on the primary side is the area of the primary jet less the dynamic area of the step-up rod. The word "dynamic" is used to show that the step-up rod has different diameters, and the rod area in the jet at any given time is the rod area used. Trying to adjust with primary jets only will allow for correct metering at one vacuum only. The percent deviation area from the standard area requirement varies with the altitude, the step in question, and other carburetor calibration (air bleeds, bypasses, restrictors, etc.). Reiterating: the above are for genuine CARTER carburetors. Trying to use this information on any of the clones is at the users risk. Custom rods are available. Jon.
The reason Carter did not have the flooding issue is that Carter had at least five different floats for use in the genuine Carter AFB. These vary in physical size (the larger floats have more buoyancy). The smallest floats (useful for RACING ONLY - greater bowl volume, lowest buoyancy) were used only in the Carter Competition Series carburetors. Racing engines utilize higher idles, thus more fuel is used at idle, and flooding issues are reduced. Floats used in carburetors used for street application were larger, and thus would withstand higher pressure. I personally run the Carter electric (forgot the number) on the genuine Carters on my shop truck. Pressure is above 7 PSI. No flooding issues. Bog using Carter AFB's generally was caused by starting with the incorrect AFB. Carter made 505 different AFB carbs. If one compares the auxiliary air valves from an AFB for a "screamer" engine versus one for a "torque" engine, one will find the attack angle on the "screamer" valve is much greater than the one on the "torque" valve. Have seen lots of AFB's where someone mistakenly ground off anywhere from a little to most of the weights, when it was the angle that needed changing. Jon.
I have 600 CFM E-brock carbs on 3 of my street rods / hot rods. All elect choke versions - 1939 Ford with 351-w build to 1969 4v specks with 290/300 cam and 10 to 1 compression. the Second is 1939 Ford with 302 crate 345 hp engine with the E cam. Last one is mild roller cam 302 with Mustang GT cam, and home ported 351-w heads (C9OE) with 9.5 compression. All these car sit for months and not driven. The Edelbrock carbs perform good - only metering rods to tune them. Years ago - ran 600 Holleys - get it running nice - them fuel leaks or power valve issues. No problems like this with the E-brock carbs.
All kinds of questions related to fuel pressure in Edelbrocks "FAQ" in the Carburetor section they don't seem to agree with you https://www.edelbrock.com/faq
Edelbrocks newest Carb maybe a better coice over the 1406 and a nice rebate in effect https://www.summitracing.com/parts/edl-1906
I run Edelbrock's on 2 SBC's 350's. Ran them on 327's years ago. First got to know the old AFB's while working on the SR-71's. Our start cart's were powered by a pair of Nailheads with AFB's. Simple, easy to work on, rebuild them when recquired and don't have to remove them.
Most of the badmouthing that I have directly encountered about Edelbrock carburetors is due to improper fuel pressure, choosing the wrong size, failing to tune properly (or at all), or modifications based on ignorance. I have installed over 100, often in pairs, and even boost-referenced on top of blowers. The number I have been asked to remove, and replace with another brand: 0.
Jeff - my comments were about Carters, not the clones. However, always a good idea to pay attention to the factory documentation. Fuel pressure CAN be an issue, especially when the offshore fuel pumps put out the pressure they often do. My point was for STREET carbs, the larger floats DO have more buoyancy. Jon.
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