: What is the cfm of the carb on a 429?



pyroman
11-23-09, 06:50 PM
Hi all, i am going to change the old knackered carter carb for an
Edelbrock performer, But which one?
the 1406 is a 600 CFM
the 1407 is a 750 CFM
does anybody know what the CFM of an standard 429 is.
Many thanks
Dave

jayoldschool
11-23-09, 07:11 PM
Don't know what the stock carb was, but for that 429, I would suggest the 1407. I use a 1406 on my 350 in my 71 Pontiac.

csbuckn
11-23-09, 07:29 PM
Was it the 1406 that works good on the olds 307? Ive been trying to find that thread about the carbs. I believe it was the edelbrock 1406 that was the easiest to switch to.

Submariner409
11-23-09, 08:01 PM
Unless you intend to race the car and use exclusively high rpm operation, the 600 cfm carb will give you the best overall gas mileage and throttle response.

BUT, it's not just an out-of-the-box drop in. You'll need to do some tuning and maybe jet work to get the best midrange and WOT performance.

A 750 Quadrajet is really too much carb for one of my Olds 455 marine engines.

Google "engine air flow formula" and do some math work, using realistic rpm and displacement figures. Use a Ve (volumetric efficiency) of 80%. You may be very surprised at what CFM your engine really needs. Not as much as you might think..........

Get Doug Roe's paperback manual on Rochester carburetors. (If you're going to a spreadbore, otherwise look up some Carter AFB and later references.)

jayoldschool
11-23-09, 09:06 PM
I don't think a Q Jet and an AFB are a fair comparison. The Q jet in stock form often is rated at 800cfm. However, with the tiny primaries it is fine for mild cars.

On the 307, I would stick to the Q jet. The Edlebrock AFB won't go on the intake without an (inefficient) adapter anyways. If you want to spend money, rebuild the Q jet.

1964CoupeDeville
11-24-09, 12:48 AM
I don't think your Carter Carburetor is fundamentally flawed. Perhaps it needs a good rebuilt. I recently bought myself an original NOS Carburetor off a 1964 Cadillac and I'm considering swapping it off for my old one and getting the original rebuilt. Edelbrock carbs get worse fuel economy and if I were you I wouldn't make the economy of such a boat any worse....

sven914
11-24-09, 04:26 PM
Edelbrock and Jegs carburettors are not stock replacements. Because they are for performance applications, they usually don't have enough vacuum ports to run you accessories, and they give too much gas.

Cadillac only used Carter for the 64 and 65 429's and they used a Rochester for 66 and 67. I believe the Carter and the Rochester are interchangeable, and a stock carburettor will give you the best results. There was 4 or 5 listings for 64-67 Cadillac 429 Carburettors, but they all ended. There was still one left in an eBay store, for a 67 429 Quadra-Jet (http://cgi.ebay.com/ebaymotors/1967-CADILLAC-ELDORADO-CARBURETOR_W0QQcmdZViewItemQQhashZitem19b799a22dQQ itemZ110454481453QQptZMotorsQ5fCarQ5fTruckQ5fParts Q5fAccessories).

Submariner409
11-24-09, 06:06 PM
You might make a call to the guys at www.jetchip.com. (JET Performance Products.) They have built Quadrajets for me, marine applications, and I'm pleased with the results and pricing. They also do Carter, I believe.

You can pretty much make a QJ into any CFM carb you want by fooling with the secondary air valve opening spring wrap (too loose and you get a midrange stumble, big-time) and the secondary metering rods and hangers. If you frequent swap meets, pick up old QJ's for $5 -$10 and tear them down and save the metering rods, rod hangers, needle valves and other odd parts. A box of metering rods is necessary for fine tuning, and there's no cheaper way to pick up a few sets.

cadillac_al
11-25-09, 09:54 AM
I have never seen a Edelbrock 600 cause a performance increase in any engine. They will run ok for just riding around but performance will not increase. If the original carb is really worn out and you can't find a replacement, then I would at least go with the 750 Edelbrock. Actually, I have a nice running Edelbrock 600 that is set up for the old style throttle rod accelerator. If you want to try one cheap just PM me and I will sell it to ya for $40 delivered since it is going to a good cause.

pyroman
11-25-09, 07:53 PM
Hi Al,
i am not after any upgrade in performance, i just want to car to run. it is a stock 429 and it will stay a stock. i believe the carb is original, so its 44 years old and it has sat in storage since 2001. we have had the car running and it runs nice, i have to turn up the idle to stop it stalling. it is easier to change the carb than get the original fixed. If i can find someone in the UK that can repair it then when its off i will do this and then swap them back and sell the edelbrock. Are they easy to do, if so does any one know a web site that sells repair kits for it, I dont think i said i am in the UK and the stock carter carbs just dont exist here. i like your offer but what is the shipping to the UK
Thanks
Dave