Topic: Autolite 4100 difference

[Tiny]

Can anyone advise re the difference between an Autolite 4100 1.08 Venturi coded for a 65/66 289 engine and an Autolite 4100 1.08 coded for a 65/66 390-428 engine.  Is there a difference because both carby's look identical to me.  Currently I have a 1.12 Venturi on my 289 which is just drinking fuel and does not perform at its best.  I have a chance at picking up a 1.08 Venturi but it is coded for a 390-428 engine.  Does this matter.

cheers

[midlife]

Most likely there are differences in jet sizing, and associated settings for choke, secondary openings, etc.  Almost every Ford model/engine had its own version of the 4100, and even within a model/engine combination, there were variations (e.g. due to thermactor, transmission, and AC). 

[Tiny]

Sounds logical.  thanks for the advice, much appreciated

[Tiny]

Thanks for the info.  See the attached images re the Identification of the Carby in question.  Can it be as simple as changing the main jets to suit the correct engine size or are there other aspects of the Carby that cannot be altered.

On a side note, its not very often that an Autolite 4100 is offered for sale in Australia.  They appear to be quite rare especially trying to find the correct date codes etc.  Obviously the USA have heaps but with the exchange rate and postage it doesn't seem too viable.

[outlawincorporated]

"On a side note, its not very often that an Autolite 4100 is offered for sale in Australia."

sometimes its as simple as asking on either the Australian forum or this one.

Just my 2 cents.....................

regards.

PHILL BERESFORD.
MELBOURNE.
AUSTRALIA.

[midlife]

That's not for a small-block Ford, according to Mannel's book.  I do not have information on its application, but I do have choke and fuel bowl settings for it.  No jet information...sorry.

[Hipo giddyup]

I believe that fits for a 66' 390 full size Ford with automatic. Perhaps a Galaxie, etc. It shows this carb is indeed the 1.08 venturi which is what was used on small block Fords (except Hipos). Of course it isn't correct for your application like Midlife says but should be a better fit than the 1.12. If the price is right you could purchase and rebuild that one, then resell the 1.12. At least the 1.08 is closer to what you need. Or just save up to get the correct app. for your car. What exactly are you looking for?? You have a 66' 289 automatic?? Or do you know the exact carb model you are looking for  such as C6ZF-b , etc...  Maybe some folks reading this can give you some good leads. I'm sure most everyone on here is willing to help out, and we have all been in a similar "part-hunting" situation with this hobby.

[krelboyne]

I believe that there is a difference on the throttle linkage between the car lines. Hence the specific part numbers indicating different applications.

[Hipo giddyup]

 +1 , it should have the big block kick down linkage as part of the throttle linkage.

 Easiest solution is again, to find the right carb for your specific application.

[Dino1]

I believe that fits for a 66' 390 full size Ford with automatic. Perhaps a Galaxie, etc. It shows this carb is indeed the 1.08 venturi which is what was used on small block Fords (except Hipos). Of course it isn't correct for your application like Midlife says but should be a better fit than the 1.12. If the price is right you could purchase and rebuild that one, then resell the 1.12. At least the 1.08 is closer to what you need. Or just save up to get the correct app. for your car. What exactly are you looking for?? You have a 66' 289 automatic?? Or do you know the exact carb model you are looking for  such as C6ZF-b , etc...  Maybe some folks reading this can give you some good leads. I'm sure most everyone on here is willing to help out, and we have all been in a similar "part-hunting" situation with this hobby.

The jetting is different, but the big obstacle to over come is having the correct boosters. the carb will never run quite right without them. the 1.08 would be the better choice, better low end throttle response. But the air fuel ratio throughout the RPM curve will never be quite right. He needs one for a 289, or at least the correct boosters to swap to the one he can get his hands on.

[Hipo giddyup]

Yes, all correct. And I have also opened 4100s that had the wrong boosters, likely from a rebuilder's warehouse. Mannel's book contains priceless info for the correct boosters,etc.