4100 1.08 Carb Question

[Scott Amann]

I have come accross a 4100,1.08 Carb - 6A AJ code is on the foot. It is my understanding that this is a California Emissions carb from a 66 Ford Galaxy, 352 FE.

I would like to use this carb on my stock rebuild 289. I am being told that this carb will NOT work on my 289 stock rebuild and I would like to learn why.



What is different about this carb that makes it unusable on a 289? Is the difference something that can be changed during a standard carb rebuild? Any quidance would be appreciated.

 

[BornInAFord]

Other than possible jetting differences, the 66 emissions 4100 carburetor is the same as the 49 state carburetor. I'd check the jets (easy to change), and run it. Emissions were fairly simple in 66, consisting mostly of an air-pump and thermactor system and a PCV. The carburetor wan't altered.

Sounds like a good find (although I am surprised that the 1.08 was used on the 352FE in the Galaxie 500--I thought that those got the 1.12 and the 289 got the 1.08 but have learned to never say "never" with Ford). I get excellent mileage with my A-code 4100.

Daniel

 

[bnickel]

ford even used the 1.08 4100 on 428's in t-birds and gal's. it's not the right application for the carb but it should work ok, don't expect it to work as well as the correct carb though. reason being is that the internal passages of the carb and the boosters is different for every engine, and what works great on one carb won't necessarily work so good on another engine. yes you can change jets and maybe even track down the correct boosters but you still have the problem of the internal passages not being the same as what the original 289 carb would have.

i do not know of any book that details the specifics of the internal passages of the 4100 series carbs either. the 69 ford shop manual has a decent list of what carbs were used on certain engines and gives a breakdown of some of the various parts and part numbers but again doesn't really go into specifics of the sizes of the internal passages or boosters.

there is one ford book on the 4100 but it's almost impossible to find and i don't know if it has any of the info we'd need either. i found it one ebay once but didn't want to pay the outrageous price it went for, now i'm thinking i should have payed it because i haven't been able to find another copy since then.

generally speaking any 4100 carb will work on any engine but how well it will work compared to another 4100 is anyone's guess really. it's generally accepted if you can find one for an engine with similar specs as yours it should work just fine but how well a cali emissions 352 1.08 4100 will work on a 49 state 289 is anyone's guess. my guess is it will work ok, but not near as well as the correct carb for the 289.

me personally i'm on the hunt for a 58-59 1.19 venturi 4100, a 66-69 428 police interceptor 1.12 4100 and any pre 65 352 police interceptor 1.12 4100 for my 351w. i have a pre 65 428 1.12 4100 right now that i plan on using on it but i'd rather have any (or preferably all) of the above.

 

[D.Hearne]

I'd be surprised to find anything internally different in that carb vs the one that the application calls for. I'd bet the only differences were the powervalve, jetting and choke settings, with the rest of the carb the same for all. These are really simple carbs and the factory making completely different carbs for each application (with regards to the basic carb throttle body and passages) would not have been cost effective to do. As with a Holley 4160, simply changing powervalves and jets are really all that's needed in 99% of applications to get the tune right.

 

[bnickel]

I'd be surprised to find anything internally different in that carb vs the one that the application calls for. I'd bet the only differences were the powervalve, jetting and choke settings, with the rest of the carb the same for all. These are really simple carbs and the factory making completely different carbs for each application (with regards to the basic carb throttle body and passages) would not have been cost effective to do. As with a Holley 4160, simply changing powervalves and jets are really all that's needed in 99% of applications to get the tune right.

sorry D but you are absoultely wrong on this one. Ford did set the carb up for each specific application. the internal passages of the carb body and the boosters are basically pressed in brass bushings for the most part and they are present in the power valve area, under the jets, under the idle mixture screws, in the main well and inside the boosters. they are very simple carbs but not quite as simple as one would think. the 2100 carbs are the same way, check it out next time you have one apart. they also have different sized transfer passages and other miscellaneous stuff

 

[D.Hearne]

You may be right, I've never studied these carbs up close. Never had any luck with em either. They work, but never gave me the same results as a Holley. I assumed the passages were cast in as with the ones in Holleys.

 

[69gmachine]

me personally i'm on the hunt for a 58-59 1.19 venturi 4100, a 66-69 428 police interceptor 1.12 4100 and any pre 65 352 police interceptor 1.12 4100 for my 351w. i have a pre 65 428 1.12 4100 right now that i plan on using on it but i'd rather have any (or preferably all) of the above.

I wonder what CFM the 1.19 equates to?? You are probably aware that Pony Carbs has tooled up to reproduce the 4100 castings. Maybe they'll offer one with the rare 1.19 size butterflies. With my big engine I didn't feel the 600 cfm Autolite 4100 would be up to the task. I have to say that with the annular primaries, the Ford spec 735 Holley has great throttle response, starts easily and I'm still tweaking the main jets to improve mileage without losing power. I've never had a Holley that got good gas mileage before, so I'm delighted with it. It's also not prone to leaking like they did in the old days. Still, I loved the way the Autolite worked on the engine before I stroked it.

 

[bnickel]

I wonder what CFM the 1.19 equates to?? You are probably aware that Pony Carbs has tooled up to reproduce the 4100 castings. Maybe they'll offer one with the rare 1.19 size butterflies. With my big engine I didn't feel the 600 cfm Autolite 4100 would be up to the task. I have to say that with the annular primaries, the Ford spec 735 Holley has great throttle response, starts easily and I'm still tweaking the main jets to improve mileage without losing power. I've never had a Holley that got good gas mileage before, so I'm delighted with it. It's also not prone to leaking like they did in the old days. Still, I loved the way the Autolite worked on the engine before I stroked it.

it's supposed to be somewhere around 650cfm, which would be just right for my long rod, roller cam'd, aluminum headed 351w and would look perfect sitting on top of that C90X intake, if i can't find one of the 1.19 4100's i'll probably have QFT build me a custom 650 holley with the annular boosters and ford style bowls so i can get the better atomozation and stock looks of a ford branded holley carb. why did have to be born as such a picky bastard?

of course i also still have this thing for the holley commmander 950 pro-jection system too and if the budget can handle it i'll probably go that route but more than likely i'll end up with a carb, at least for a while anyway.

D, probably the reason you haven't had such good luck with the 4100 carb is because of the differences in the carbs original applications and of course that they don't flow more than 600cfm, even though the 1.12 version is supposed to flow 600cfm i think it's actually more like 550-570 or so.


i have heard that Pony carbs is supposed to be making new 4100's but i have yet to see any real info about them yet.

 

[D.Hearne]

Never played with the 4100's. All my experiences were with the 2100's. LAst one I rebuilt ran OK, but had a problem with hot starts. Swapped it with a Holley 500 2 bbl and the troubles went away.

 

[bnickel]

I wonder what CFM the 1.19 equates to?? You are probably aware that Pony Carbs has tooled up to reproduce the 4100 castings. Maybe they'll offer one with the rare 1.19 size butterflies. With my big engine I didn't feel the 600 cfm Autolite 4100 would be up to the task. I have to say that with the annular primaries, the Ford spec 735 Holley has great throttle response, starts easily and I'm still tweaking the main jets to improve mileage without losing power. I've never had a Holley that got good gas mileage before, so I'm delighted with it. It's also not prone to leaking like they did in the old days. Still, I loved the way the Autolite worked on the engine before I stroked it.

gmachine, have i ever shown you some info i found on how to modify your air cleaner to work with a taller intake? i know you were having issues with using a stealth, or RPM intake and being able to keep your shaker. anyway if i haven't here they are

Blue Thunder Aluminum Intake


Stealth Aluminum Intake

 

[ultrastang]

I've had several Autolite 4100s and still have one 4100 out in the barn, but I haven't run a carb in a long time.

Best I can remember, the 1.08 4100 was a 470 CFM unit. The Hi Po 289s got a 480 CFM 4100, and the 1.12 version was a 600 CFM carburetor.

You might check with Pony Carburetors to see if you can get any information from them. At minimum, they might have a manual for sale with the information you are looking for.

Carburetor, Carburetors, Carbs, Carb Parts. Pony Carburetors - Your Ford Carburetor Restoration and Part Sales Specialist

 

[bnickel]

I've had several Autolite 4100s and still have one 4100 out in the barn, but I haven't run a carb in a long time.

Best I can remember, the 1.08 4100 was a 470 CFM unit. The Hi Po 289s got a 480 CFM 4100, and the 1.12 version was a 600 CFM carburetor.

You might check with Pony Carburetors to see if you can get any information from them. At minimum, they might have a manual for sale with the information you are looking for.

Carburetor, Carburetors, Carbs, Carb Parts. Pony Carburetors - Your Ford Carburetor Restoration and Part Sales Specialist

they won't give any info of the kind, i've tried and so have several others. i think they're afraid to give out too much info lest people not have a reason to send them their carbs anymore

 

[69gmachine]

gmachine, have i ever shown you some info i found on how to modify your air cleaner to work with a taller intake? i know you were having issues with using a stealth, or RPM intake and being able to keep your shaker. anyway if i haven't here they are

Blue Thunder Aluminum Intake


Stealth Aluminum Intake

Great article bnickel, but I don't think I would be willing to cut on an original 351W shaker base. They didn't make very many and it took me years of Carlisile shopping to find one that wasn't a rusted piece of junk. The Torker II works just fine.

 

[bnickel]

Great article bnickel, but I don't think I would be willing to cut on an original 351W shaker base. They didn't make very many and it took me years of Carlisile shopping to find one that wasn't a rusted piece of junk. The Torker II works just fine.

true, but in the spirit of modification you could always mod a regular base for both the intake and the shaker top and mid plate