1957 312 carburetors


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By peeeot - 8 Years Ago
I have a stock, original vacuum secondary Carter AFB on my 312 Fairlane. A while back I bought a correct '57 4100 to overhaul and use in place of the AFB, believing it to be a superior carburetor. The shop manual also references the first gen Holley 4150 as an option.

I was wondering, what determined which carburetor ended up on which car? Is one more common than the others? Did the customer choose between the 3, or was it a production order thing, or maybe by location?

By NoShortcuts - 8 Years Ago
Interesting question.  The only information relative to what you're asking is that all D code '57 'Birds with the 312 engine came with the new end bowl 4150 Holley carburetors.  How passenger car 312s ended up with a 4150 Holley, a Carter AFB, or Ford / Autolite 4100 would be enlightening.  Smile
By Oldmics - 8 Years Ago
The 4150s were standard installation on the 1957 312 "D" code engines. 
The Carter AFBs were installed on the 1957 Retractables with the 312 engine
Oldmics
By paul2748 - 8 Years Ago
My understanding is that certain cars did have the 4100 installed.  I bought a 57 312 that had a 4100 on it, it looked like the engine had never been apart.  I made a statement a number of years ago that no 57 came with a 4100 (my belief at the time) , but a number of people told me I was wrong.  Tbirds never got one, but the sedans did.
By peeeot - 8 Years Ago
There is no doubt that all 3 were available in 57 on passenger cars. The 57 4100 is special and unique to that year with a long snout on the accelerator pump that incorporated the overtravel mechanism. Also the nozzle bars have smaller discharge rings than other 4100s and no air gap in the accelerator pump nozzles.

According to this sheet http://www.thecarburetorshop.com/Kford.htm from the carburetor shop, the Holley 4150 was used on thunderbirds and police models, which makes sense if it's the most performance-oriented of the three. There is still no clue about the AFB/4100 applications though.

I bet it's a small percentage of 57 312 passenger cars that retain their original carburetor. I've never seen another y-block using any of these three carburetors but then I have only seen one other 57 312 car in person.

I believe the dual quad cars used the teapot still but the shop manual doesn't cover that or the supercharged version.
By Oldmics - 8 Years Ago
Peeeot
You are 100% correct that all 3 carbs were offered in the 1957 Ford engine lineup.
A quick trip to the Service manual confirms those facts.
I am sure about the Retractables getting the AFBs but now I am stumped as to the Autolite installs.
Learn something new every day.
Thanks for the enlightenment.

Oldmics
By peeeot - 8 Years Ago
Sure thing! It's fun studying up on this stuff.

According to Ted's extensive carb test article, the 4100 is about 440 cfm and the AFB is 400. Maybe the slightly smaller size of the AFB gave better low-end torque and throttle response, thus the use with heavy retractables?

Mine is a fairlane 500 town sedan with a/t and I am confident the AFB was the factory install, so at least some sedans got it too.

Maybe the 4100 was used with m/t or o/d transmissions.
By Ted - 8 Years Ago
In my dealings with the three 4V carbs that were offered on the 1957 312 engines, the only consistency I’ve found is the Holley 4V carb being the only carb offered on the 312 equipped Thunderbirds.  All the 1957 Mercury 312’s I’ve dealt with did have the Carter carbs and all these were automatic transmission equipped but I’ve only dealt with a half a dozen of these cars that were original so I can’t say definitively that the Carter carb was the only one used on that application.  I’ve seen the 1957 Ford 312 equipped cars with both the 4100 and Carter carbs.  Do remember seeing the Holley carb on some of those Ford cars but don't remember if they were original or not.  I don’t have any kind of correlation between the carb style and transmission which may have been a player with which car got which carb.  I have a stack of those 1957 Carter 4V carbs here and not many of the 4100’s so in this part of the country, the Carter carbs came as original equipment on many of the 312’s.
By PF Arcand - 8 Years Ago
Can't comment on which  of the mentioned carbs were used on particular models. However, as noted, the 1957 1st yr Autolite 4100 used on some Fords was altered somewhat for 1958 & later use. It was also original equipment on some early Mustangs. When our modertor, Ted, tested 16 misc carbs on his Mule Y-block, the 1.08 model 4100 was 5th in performance & all but one of the other carbs were bigger in cfm. I'm informed that the one thing to keep in mind on those carbs, is that due to their annular discharge feature, which is unique, they are apparently sensitive to dirt in the fuel. So, if installing one make sure there is a new filter installed with it.  (note, that Summit now sells a modern version of  that annular discharge carb, & apparently John Mummert has had success with it.)   
By slumlord444 - 8 Years Ago
As to the AFB on the Mercury, the AFB carb and intake that I installed on my otherwise stock 292 in a '58 Ford back in '63-64 came off of a '57 Mercury. Worked great on the '58 after shortening the spring on the secondary diaphragm a bit to get the secondary's to open at the same time the tires stopped spinning on takeoff. Had similar 292's later on with the Holly 4100 or 4150 and didn't notice much difference. Easier to convert the Holly to mechanical secondary's with a screw in the linkage. May not have actually preformed better that way but sure felt better and no doubt that they opened.
By peeeot - 8 Years Ago
So it sounds like the AFB was the most prevalent 4 barrel on passenger cars. Curious, since ford developed its own with the 4100. I would think there would be a savings not sourcing carbs from independent companies.

Regarding vacuum secondaries, I wasn't sure whether mine were opening until I stuck a loop of duct tape on the diaphragm housing so that it rubbed against the actuator arm, then smeared a film of heavy grease on the arm. The duct tape leaves a track in the grease as the arm is pulled into the diaphragm housing. I can't know if they're always working, but they definitely do at least sometimes!
By Lord Gaga - 8 Years Ago
I also bought a complete stock 1957 Mercury engine that was equipped with an AFB.
Could it be that AFBs were only used on automatic transmission cars because of their integral dashpots and possibly only in Mercs?
By Ted - 8 Years Ago
While I’ve only seen the AFB carbs on the 1957 Mercury 312’s, I’ve come across both AFB’s and Autolite 4100 carbs on the 1957 Ford 312’s.  All the Mercs I've dealt with had automatic transmissions which could help to explain the AFB only scenario.  My recent 1957 Ford acquisition that had an unmolested 312 was AFB equipped along with the automatic transmission.  This was a Dallas built car.
By pegleg - 8 Years Ago
Had an AFB or Has?

By Ted - 8 Years Ago
pegleg (3/14/2016)
Had an AFB or Has?

Frank.  ‘Had’ as the engine and tranny was removed and the 2 dr. post body sold to a local guy.  The engine and its related parts are stored in the core building.
By yalincoln - 8 Years Ago
hey guys, mercury was using carter carbs since 54, lincoln from 56, ford was using holley forever. supply and demand. autolite was just starting to make 4100's and they may not have been ready untill late in the year. everyone was trying to keep up with nascar performance in 56-57 untill the horspower ban. they all made a lot of carbs for the new engines made for 58.with big cu. in. since they were all new in 57, supply might have been a factor. just a thought.
By 2721955meteor - 8 Years Ago
i had a low milage 57 merc it had a holley from new,it also had the 4 headlights,canada may have had diferent carbs.
By 57 Victoria - 8 Years Ago
My 312 Victoria Town Sedan currently has the Carter, from new by the look of it. Never been happy with it so it's going to be replaced with a 4100. I've found that the Carter is a very complicated carb, that's hard to set up, whereas the 4100 is much simpler and more reliable. I'll let you know what differences I notice after doing the swap.
By PF Arcand - 8 Years Ago
References to the Ford/Autolite 4100s should keep in mind that there were two versions of that carb. A 1.08 model & a 1.12 model. Apparently the 1.12 s were used on larger engines. Some later ones were also designed for anti smog setups.. When Ted tested both models on his mildly modified 312 test mule, the 1.08 tested well, but the 1.12 was near the bottom.    
By lowrider - 8 Years Ago
Bought a 4v intake manifold a couple years ago. Seller said he'd include the carb too. It showed up with an ancient looking Carter carb on it. Wasn't worth using as there were many pieces missing/broke on it. I had 2 other carbs I was going to use. A 4100 that starts, runs and drives just great and a Holley that the engine absolutely loves. Runs really strong. The Carter didn't go unused though, I use it for a doorstop in the garage.
By 57 Victoria - 8 Years Ago
Yes, 1.08 is about 480cfm and 1.12 is 600cfm. The measurement relates to venturi size. The 1.08 is suitable for small blocks and the 1.12 was used on big blocks and some hi-po small blocks. I will be using a 1.08.
By PF Arcand - 8 Years Ago
According to the Carburetor Doctor site, the Autolite 4100s in 1957 came on some Mercurys. Fords aren't mentioned that year, so ?? Altered somewhat for 1958 they were used on other engines. The experts on that carb were Pony carburetors in N.Y. state, but I believe they are out of business following the death of the owner manager.. 
By MoonShadow - 8 Years Ago
There is a fellow here in Manchester, NH that has been rebuilding carbs, generators and alternators forever. He has done a few of mine and all has been great. The local restorers use him for their projects. I can post his information to the links are if you like. His prices are pretty fair and he is an honest business owner. He retired to the garage behind his house and shows no sign of quitting soon.

By PF Arcand - 8 Years Ago
57 VictoriaSad I'm interupting the posts subject momentarily)  In your post u confused me, describing your car as a 57 Victoria town sedan. Looking at your avitar (?) photo, it appears your car is a 4 Dr. Hardtop, correct?  Your car's description should be a "Town Victoria," not a Town Sedan, which is a 4 Dr post car..