Know Your Ford Carburetor!

Autolite 2100 ID 1960-1974

All information is listed in the description below.

1. What sizes? There were 8 different venture sizes for the 2 barrel 2100.
.98 @190 cfm
1.01 @245 cfm
1.02 @ 240 cfm
1.08 @287 cfm
1.14 @ 300 cfm
1.21 @ 351 cfm
1.23 @ 356 cfm
1.33 @ 424 cfm

Autolite 4100
1.08 @ 480 cfm
1.12 @ 600 cfm
1.19 @ 669 cfm

2. In order to know what size venturi you have look on the drivers side of the float bowl. There will be a set of numbers that corispond to the venturi size we just talked abut. Thus yu can know what the cfm of the carburetor is.

Tech tip: CFM stands for cubic feet per minute and lets you now how muchg air and fuel will pass the veturis when the car is running.

3. The carb tag ia and was the most detailed part of the carburetor info. If it has the carburetor tag it will list the Decade, year, model of car, and group (Carburetors are Group F) the leter after that denotes what the use was, typically it was for manual or automatic. Below that on the tag is the change level then the date year is first, followed by month (There is no I in the date coding system as it could be confussed with a 1 then day.

IF the tag is missing the carburetor info is on the drivers side front foot of the carb. But it will lack the date code.

4. In stock configureation, at 4,000 rpm at 90 percent volmetric efficency, the Autolite 1.14 venturi carburetor will perform very well. But it won’t get the kind of miulage that a 4100 autolite can. Simply put, a 4V carburetor will get better gas mileage if you don’t dploy the secondaries because the primaries are smaller. The chart I am showing is available on our website at the url below.

289-302 go with 1.08 primary. (this in the 4100 is 480 cfm) and will net you better milage.

Our 260 has a 240 primary.

5. The Autolite 4100 has some sticky points.
• No PCV port on the carb. The only port is on the spacer.
• Many aftermarket intakes will not support the 4100 spacer due to the base plate confifureaton.
• Thre manual shift 1.08 carbs are expensive since they are for the HiPo 289 typically.
• The 1.19 venturi is ultra rare and was only used on the 383 “high torque Mercury engine in 1958.

Issues on both the 4100 and 2100
• Jets on both carburetors are usually specific Ford jets but can be obtained from places like Mikes Carburetor. Early carburetors up intol 1966 ish used a jet the same size as Holley.
• Power valves are common to Holley but some caps can interfier with the power valve.
• The throttle shafts can be worn and might exibit issues will weird idle charicteristics.

Carburetor Spacer Kit: C3OZ-9A589C
https://www.autokrafters.com/p-233-carburetor-spacer-kit-1963-65-and-1969-ford-fairlane-1965-69-mustang-1965-68-falcon-1969-montego-others-4bbl-c3oz-9a589c.aspx

https://www.fordification.com/tech/partnumbers_overview.htm