Autolite 2100 Carb + 2V 250 Question

[Anonymous]

Hello, all.

I posted this to the Oz list, but I thought I would inquire here, as well.

I noticed that the Autolite 2100 carb used to drive a Ford 266 V8 engine. Given that, would the 2100 or 2150 be a good choice for an Oz 250 with a 2V head on it? Would I have to find a carb adaptor to mount it? Anything else I should consider?

Any and all comments would be apprecaited.

 

[65coupei6]

As long as you have the Holley carb adapter found here :

http://fordsixparts.com/Related%20Parts.htm

You will not have a problem. But, the 2100's do come in different CFM's. I do not have my list on me but you have to check part numbers because not all 2100's are the same.

 

[Anonymous]

That's good to know... Do you know where I might find one of these lists? I'm wondering if whatever was on the 266 V8 would be a good fit since the displacement values are so close together?

 

[CobraSix]

SHould be as follows, so long as my memory serves:

Look on the side for a 3 digit stamp.

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

If interested, I have a 1.08 and a 1.21 2100, both rebuilt, one missing choke mechanism, both for sale.

Slade

 

[Anonymous]

Which cfm would be the best shot for the 250 2V? ... I mean, I would at _least_ need one that ran 350 cfm, wouldn't I?

 

[CobraSix]

Depends on other mods and who you ask.

I'd say, with a stock cam and valves...300-350CFm would be good. Wilder cam and bigger vavles...350-500Cfm.

Slade

 

[CZLN6]

Howdy Back Max and All:

I replied to your post on the Aussie forum.

The small Ford V8 was a 260 c.i. It ran 1.01 and 1.02 Autolites. They are rated at 245 and 240 respectively. I think the discripency is that the later .02 got the annular discharge veturi boosters while the earlier 1.01 had regular, smaller boosters.

To compare the carb size of a V8 engine to a 4 or 6 cylinder engine divide the number of cubes by the number of cylinders to get a single cylinder volume. For example your 250 has cylinder sizes 41.66 c.i. To find a V8 carb with similiar single cylinder displacement, multiply that number by 8, or 333.33 c.i. It is the volume of each cylinder that creates the suction or vacuum signal for the carb. That leaves you to chose from a 2 barrel from a 302, which will be small, or a two barrel from a 351, which will be a little large.

289s and 302s uses the 1.14, 300 cfm, early (through '67) and the 1.08, 287 cfm ('68 to FI).

I'd recommend the 1.21 in your situation. Setting the float level is critical with these carbs to get a smooth transition. To high and it will flood, too low and it will chug on transition from idle circuit to transition to cruise.

Adios, David

 

[Anonymous]

David,

Thanks for that explanation--it helps a lot to understand this stuff. Since you recommended the 1.21, would the 1.23 be ok if I can find that? The cfm ratings seem to be really similar.

 

[CZLN6]

Howdy Back Max:

Yup, the 1.23 would work too. They were only used in '67 - '70 on 351s, 390s and 429s. They may have a slightly richer idle and larger jets even though the total CFM is not all tht different.

Adios, David

 

[CobraSix]

They are hard to come by. the 1.08's are by far the most common. You'll have to find one either on the ebay or classified markets, or pony carbs. Otherwise, if you get a generic rebuilt one, you'll probably end up with a 1.08. my 1.14 and 1.21 have the same part numbers in most catalogs.

Slade

 

[Anonymous]

To everyone who's written about this--thank you.

Is the Autolite 2100 a good choice compared to, say the Weber 380 cfm 2bbl or the Holley 350 cfm carb? Are there any others that I don't know of that I should be considering? I like the Autolite because I learned on one in class, so I feel pretty confident about it, but I'd be willing to try another if it is a good/better option.

 

[CZLN6]

Howdy back Max:

Carbs are alot like people. They all work pretty good if they are well maintained and happy and work in a suitable environment. You will find lots of opinions, but it comes down to what you are happy with and what works for you in your situation. Which ever way you go, learn to tune what you have. To bolt on a different carb and have it perfect is a very rare occurance.

The pluses of the 2100 are, annular discharge venturi booster for a stronger vacuum response and better distribution of the gas spray, no gasket line blow the fuel level, more CFM choices, efficient bowl venting, and super simple to work on. The down side is that they are no longer manufactured and parts are not easily accessible, compared say to a Holley 2300.

I have had no personal experience with the Holley/Webers, but there are many satisfied user on this forum.

Adios, David