Autolite 1100 Carburetor

[68 Six]

Hi, have been searching on forums and can not find answer so will ask.
Is there a difference between a double pumper and a single pumper Autolite 1100 carb for use on an automatic or manual transmission or will both work? I am trying to get the correct carburetor match for my loatomatic distributor and have read that if you have an Autolite 1100 and a loadomatic distributor you have to have a Spark Control Valve on your Autolite 1100.

Thanks in advance
Raul

 

[CZLN6]

Howdy Raul:

The basic answer to your question is Yes, they will both work. FYI- the double pumper feature on the typical 1100 for use with on an automatic trans engine is really a throttle return damper, like a dash pot in later years. It is not a pumper, like an accelerator pump. For the same year they are interchangeable through '67 (for all but Calif/Emission engines). We typically found that carbs from an engine with an auto trans were in better shape for rebuilding than ones on an engine with a standard trans. The big difference was the condition of the butterfly valve shaft and the holes in which the shaft rotated. Auto trans carb shafts were generally tighter.

FYI- Main jet size varied too, but we could find no consistent reasons for the variances. We looked at locale, for elevation and climate, trans type, vehicle type with no predictable results.

You are wise to match the carb to the distributor. Carb with Spark Control Valve to a Load-O-Matic distributor.

In application, the only significant difference between an engine with an auto trans and an engine with a manual trans was the initial ignition advance setting- 6 degrees BTC with a manual, 12 degrees BTC with an auto trans.

Hope that helps you.

Adios, David

 

[68 Six]

Thanks again,
The more I get into restoring my Mustang the more I learn.
Tanks

Raul