Carb questions

[ka_jd7and1]

So I have lots of questions.....

I aquired a 68 F100 w/ a 360/3spd. The engine has been rebuilt 10 years ago. My carb does not have an ID tag, I'm pretty sure it is a Motorcraft 2100 though. It does say 1.08 on the side.

My questions are:

Should a carb kit for any Motorcraft 2100 work? I'm not sure if the carb has been replaced or not. I've not delved into the world of carburetor repair before, but I am somewhat mechanically inclined.

Do I need to run the spacer w/ the coolant line? Is it just a deicing feature or what?

I was doing a little research on the carb CFM and I don't remember this carb being over 350 CFM. Doesn't a 360 (hopefully future 390) need more? I was thinking of replacing it with a Holley 4412, 500 CFM and I have some background with those (I race circle track).

Thanks!

[cep62]

The spacer with the coolant line helps to keep the carb from icing on cold / damp days. So depending on your weather it might matter. As for carb kits they usually have extra parts for the different models available.

The 500 Holly works well, but when stock sometimes under carbed is better.

[FORDification]

First of all you'll need to positively identify what you've got. Look for a list number on the air horn. Check out this link:

http://www.carburetion.com/CarbID/FordID.htm

[FORDification]

Here's a couple PDF's that might help you (and others)out. Right-click on the links and select "Save Link As...".

http://www.bobcat.ca/stuff/DOCS/2150RE~1.PDF
http://d.scribd.com/docs/1eit0ebi9dbmy7s3xfub.pdf

[ka_jd7and1]

Thanks for the info.

I am more confused than when I started. The carb has 1.08 in a circle (which should be the venturi size?), has an "OU B" on the mounting flange under the circle, and has an H stamped sideways on the air horn.

The part I'm confused about is that my carb doesn't have any of this stuff



but otherwise looks like my carb.

Do I need any of that?

[FORDification]

A vast majority of the Autolite/Motorcraft carbs look very similar, especially to the untrained eye. Since you circled the accelerator pump (in the middle of the pic) saying your carb doesn't have that, then this picture isn't what you have. You're going to have to tell us the list number on the air horn and the engineering number (located on the side of the carb base) so that we can tell you what you have, and then we can go from there.

However, to answer your question: the thing you have circled on the left is the choke. Unless you live in a tropical climate, you're probably going to want that. The black plastic cover holds the thermostatic choke (there's a bimetallic spring inside). What you've got circled on the right is the dashpot, which basically keeps the throttle linkage from bottoming out, which will kill the engine, and yes, you'll need that too. You can get both of these from the local auto parts store, but the choke's mounting bracket is something you'll have to get from a parts carb.

...and yes, the 1.08 is the venturi size, showing it as having a 480 CFM rating.

[fordman]

those features in that pic are of a newer carb than what you have. since you say it doesn't have those circled items. if you go to the parts store they can get you the right kit. if its the orginal carb then it should be pretty close to a 2100. i think most of the kits are pretty close to the same anyway. just stay in the 68 year area and you should be close to the right kit.

[ka_jd7and1]

Thanks for the help guys.

FORDification, I thought the accelerator pump was on the front of the carb?

I didn't realize that this was a 480cfm, I thought the list I had looked at wasn't over 400 for any of the venturi sizes listed. Maybe I was thinking of something else, I dunno.

The choke on the truck was just a manual choke cable from the inside of the truck that runs through the firewall and is hooked up to the carb. Do I need all the other fancy stuff?

[fordman]

yes acc pump is on the front of the carb. the back thing is the power valve. probably a typo it happens all the time. especially with me.

[ka_jd7and1]

So the spacer...... I live in SoCal and our weather doesn't get really cold, I assume I could get a regular spacer and be OK....?

[FORDification]

Yep, I mis-typed....sorry about that! I knew what I meant to say.

Anyway, the carb pictured above is actually a Motorcraft 2100D, which was the successor to the Autolite 2100.

Here's a link to some '74 Ford car shop manual pages about the 2100D.

http://oldcarmanualproject.com/manuals/ ... /index.htm

Regarding the spacer: you don't need to necessarily remove it, you can just bypass it completely with the heater hoses. That's actually what I'd recommend doing at first, until you can determine whether you'll have cold start-up problems. It would be a simple task to reroute the heater hoses again if the need should arise. You can't completely remove the spacer and bolt the carb to the intake manifold (the carb linkage will hit the intake), but you can replace it with a phenolic spacer, which many folks use to solve heat-soak problems.

[FORDification]

yes acc pump is on the front of the carb. the back thing is the power valve. probably a typo it happens all the time. especially with me.

Actually, the power valve is on the bottom of the carb. That thing he has circled on top is the vacuum break.

[fordman]

well know i know a little more about carbs. i had thought thats what that was. or is that just part of the valve. isnt under that or connected to that the power valve with that large nut on it? i wish my truck was here.

[ka_jd7and1]

Thanks for the help guys!

I thought the accel pump was on the front and the power valve on the bottom, then you guys got me spun around 3 times, haha. It's all good now.

So my carb doesn't have the throttle solenoid (or another diagram I had said dashpot?), choke diaphragm assembly, or choke thermostatic spring assembly.

I do realize I need to run a carb spacer, the phenolic kind was what i had in mind. I think I will run with rerouted hoses for now and see what comes of it.

I disassembled my carb tonight, so hopefully it will all go back together tomorrow and function OK. After some cleaning, I did notice it has 7 - 69 on it. Using that and the other 2 numbers I know (the 1.08 venturi size and the OUB on the mounting flange), it should be a 2100, right?

I did have 1 more question..... the rod that pumps the accelerator pump has some movement up and down..... is this normal? I saw it looks like it has a roll pin holding it onto the accel pump cover, should I take it apart and put a washer in or something?

Thanks.

[Alvin in AZ]

I did have 1 more question..... the rod that pumps the accelerator pump has some
movement up and down..... is this normal? I saw it looks like it has a roll pin holding
it onto the accel pump cover, should I take it apart and put a washer in or something?

That 1.08" carburetor is for a 302 or something little like that. :/
A 360FE should have 1.23" on it. :)

Someone's picked up a used carburetor somewhere and it looked the same and didn't know
(or didn't care) that it was a little sucker and too small for the 360FE. :/

You need another carburetor. :/

Number = CFM
.98 = 190
1.01 = 240
1.02 = 245
1.08 = 287
1.14 = 300
1.21 = 351
1.23 = 356
1.33 = 424

------------------------------

The accelerator rod should be bent or straightened and fiddled with ;) until you get it to have a little
bit of tension on it from the accelerator pump's internal spring, when everything else is at rest.
See it? :)
-Any- opening motion of the throttle shaft will immediately be transferred to the pump's lever on the
front of the carburetor. No play in that direction. It doesn't take much, just enough is right, too much
will lessen the volume which effects the duration too.

I'm running mine without all that choke crap on it...
http://www.panix.com/~alvinj/file12/choke1.jpg

The accelerator pump rod is in it's lowest position too...
http://www.panix.com/~alvinj/file12/throttle.jpg
http://www.panix.com/~alvinj/file12/throttle1.jpg

Seen lots of pictures of springs being in weird places.
The spring on the brass machine screw was in a hole where the brass screw is now.
I didn't like it. :) It was clunky and hard on the spring to get it in and out etc.

The "ball" stud doesn't need to be a ball shape.
The hole in the rod is simply drilled into it, a cylinder shape.
I used an Allen head screw since they are grade 8 material. :)

All those holes are threaded with jam nuts added to keep every thing in place.
It's seems to have worked, it's been like that for ten years or so. :)

Alvin in AZ