|
By peeeot - 3 Years Ago
|
I have a stock-calibrated Edelbrock 1405 (600cfm) on my stock 1956 312. It runs great, seems responsive, pulls pretty hard without drama when I floor it. So, as a baseline, it’s good.
I also have at my disposal an unmodified Edelbrock 1406 (also 600cfm). This carb is supposedly the “economy” version of the 1405, which is for “performance.” It has different calibration internally including various fixed metering orifices being changed relative to the 1405. I haven’t tried it on the car.
I also have a stock 1957-specific Autolite 4100. It is considerably smaller than the edelbrocks—supposedly around 450 cfm, with vacuum secondary.
I will probably try all three of these carbs at some point, just for curiosity’s sake. The Edelbrocks have more calibration options than the Autolite to dial them in, but the Autolite was designed for the 312.
As for objectives, this is a cruiser/driver that I occasionally mash the pedal on just to feel it push me back in the seat. I do like the idea of dialing in whiscruber carb I go with for best performance/economy.
All that being said, which would you choose and why?
|
|
By 55blacktie - 3 Years Ago
|
|
If any of those carburetors will be used on your 56 312, and you are happy with the carb that's on it, why do you want to install one of the others?
|
|
By Florida_Phil - 3 Years Ago
|
I suspect you are going to get many different answers to your question. Maybe it would be some help if I told you about the carb I have and why I chose it. My Tbird has a Holley 1848-1 465 cfm carburetor on a .060" over 292 with 312 heads and "B" intake. This carb scored high in the test Ted ran a number of years ago. If you haven't read his article, it's at https://www.eatonbalancing.com/2012/09/25/four-barrel-carburetor-testing-on-the-y/. The 465 carb is a modern Holley version of the stock 1957 312 Tbird carb. Nostalgia and memories are important to me. When I remember my early Y-Blocks, that's the carb I remember. I don't remember a shiny AFB with an Edelbrock sticker or a Ford 4100. Both are fine carbs, but they just don't look right to me. My 465 has instant throttle response and pulls hard through the gears. It's perfectly sized for my Y-Block. I am sure a 600 or larger carb would be slightly better at higher RPM, but I never twist my YBlock over 5,500 so it's not going to be much help. The biggest reason I like my 465 is that it's still available new. I have had more than my share of problems with old carbs and I don't want any more.
|
|
By DryLakesRacer - 3 Years Ago
|
|
I always like reading Teds test results. Too bad the 2 smaller Summits were not included. For top rpm Ted has found a bigger carb is normally best numbers but looking at Phil’s 465 and the Ford 1.08 or 440 I see drivability. Unless kicking mine in the butt it rarely sees 3000 driving light to light in weekend driving. My preference is what gives you the best of “what you want” and for me that’s snappy off the line at the crack of the throttle pedal without flooring it and no hesitation during heavy acceleration like passing on a 2 lane road. My 375? cfm Carter WCFB defiantly gives me that. Good luck
|
|
By paul2748 - 3 Years Ago
|
Put the other one on and try it. Not that big a deal to change from one Edelbrock to another. Then decide which one is better.
|
|
By Ted - 3 Years Ago
|
In the end, carburetor choice boils down to drivability more than full throttle performance.
Even when the carburetors are the same part number, they may not be equal in performance. This has to do with manufacturing variances within the carburetors themselves. An example of this are four new Holley 750 cfm HP carbs that were purchased and were back to back tested on one of the EMC engines. Not surprisingly there was a 10 horsepower difference between the best and worst of these carbs. All these carburetors started and idled just fine. Slight variations in drilled hole sizes, discharge nozzle alignments, microscopic casting variations or flaws, and a multitude of other items can contribute to carburetors of the same part number not being identical in performance.
|
|
By peeeot - 3 Years Ago
|
Phil’s comment about originality and reviewing Ted’s test reminded me that I also have an original 1957 Carter AFB with vacuum secondary, like the last-place performer in Ted’s test. If I had the Holley I’d have the full set!
I have decided to put together a comparison test of my own for all 4 of these carbs. I’m planning to measure performance as Edelbrock suggests: timing WOT acceleration through a specific RPM range, probably 2500-4500 rpm. For economy, I’ll install a tank selector and run a separate, very small tank of fuel over a planned route and see how far I get before running out. Throttle response and drivability will be evaluated as well, but probably just subjectively. Should be fun to see how they stack up!
|
|
By Florida_Phil - 3 Years Ago
|
The one carb that I have always wanted to try on my TBird engine is a Holley 650 double pumper. I wonder if my car is light enough and my gears tall enough to make this work? Would it bog, be hard to drive and could I feel any real performance gain? So far I haven't wanted to know bad enough to invest $600. 
|
|
By 55blacktie - 3 Years Ago
|
|
Phil, I think the majority will tell you to stick with a vacuum secondary carburetor for the street. But for kicks, maybe you can beg, borrow, or steal a double pumper. It might be more effective on a ported B manifold/Mummert. If you have money to burn, keep an eye on Holley's factory-refurbished carbs on their website. It's not likely they have one in stock, but you can request to be notified by email when/if one becomes available. You'll save a considerable amount of money, free shipping, and it comes with everything a new carburetor includes, including the warranty.
|
|
By Deyomatic - 3 Years Ago
|
|
Good point on the Holley refurbished carbs but if you DO get the email you need to jump quick. I recently checked my email in the afternoon, found that they were back in stock, and clicked on the website to find that they were sold out again!
|
|
By 2721955meteor - 3 Years Ago
|
|
I WENT FOR THE HOLLEY REFURBISHED 600CFM ON MY 292 WITH 574V DEVIDED PLENUMS.ECZ HEADS CONVERTED TO 57312 INTAK VAVES. 3.71REAR AXEL 4SPEED 4TH OD. RUNS GREAT. IN MY 1949 MERC 1/2TON. THE GUY FROM HOLLEY SEAD MOST OF THE RETURNS HAD NO ISUES,INSTALLER LEARNED AFTER THEY GOT #2 ON WARANTEE
|
|
By ian57tbird - 3 Years Ago
|
|
I bought a new Holley 465 for the Tbird a while back. I think they are not available new anymore.
|
|
By 55blacktie - 3 Years Ago
|
|
Meteor, what camshaft did you install?
|
|
By 312YBlock - 3 Years Ago
|
|
The best carburetor under the sun is only half of the equation, in my experience ignition is the bellwether ingredient. I have Taylor wires, Mallory E-Spark pointless conversion, new Mallory tach drive distributor, MSD 6A ignition box with recommended coil and a Summit 600 CFM carburetor sitting on a stock B intake. It runs like a cat in a thunderstorm.
|
|
By DANIEL TINDER - 3 Years Ago
|
ian57tbird (3/5/2022)
I bought a new Holley 465 for the Tbird a while back. I think they are not available new anymore.
I guess we’ll find out. I just ordered one from CASCO. Their current site listing had no ‘out of stock’ notation, but until I get a shipping confirmation, who knows?
|
|
By PF Arcand - 3 Years Ago
|
Peeeot: As already mentioned, I'm not sure why you want to make a change? However, while that Ford Autolite you have was not as common in '57 as the Holley carbs, it was available. From what I've garnered from info in Y-Blk magazine & elsewhere, it's likely to give you the best fuel mileage, partly due to having "annular" discharge nozzles above the venturies. While not more powerful, in a back to back dyno test printed in the the magazine, it was "30 percent" better than one of the other carbs in fuel consumption..
|
|
By peeeot - 3 Years Ago
|
The “why” is because I like to tinker and I enjoy carburetors.
I have found that most articles addressing how performance is affected by changes made to any particular aspect of an engine do so exclusively at wide open throttle and typically on a dynamometer. I have never seen a carefully planned and executed “apples to apples” fuel economy comparison between different carburetors, ignition systems, transmissions, etc. and think it would be fun to try to do such a comparison myself. Perhaps I’ll end up right where I started, but I’ll have learned something along the way!
|
|
By 55blacktie - 3 Years Ago
|
|
If your objective is to test every carb, ignition, transmission, etc. combo/w goal of determining which combo will provide the best fuel economy, it will be a full-time job, requiring lots of parts. Conducting such tests in a controlled setting (on a dyno), probably won't be conclusive. In the real world, you have to consider traffic conditions, weather conditions (wind/temperature), road conditions, elevation, and so on. My guess would be that a 272/w stock heads, a bit more compression (zero-decking/milling), metric rings (reduced friction), Holley 390 cfm 4-bbl. carb, 1 1/2" headers, stock cam, no power steering or A/C, manual transmission/w OD, and rear axle ratio around 3.00 will be hard to beat as far as MPG is concerned.
|
|
By DANIEL TINDER - 3 Years Ago
|
ian57tbird (3/5/2022)
I bought a new Holley 465 for the Tbird a while back. I think they are not available new anymore.
CASCO delivered one today.
|