The Ford Barn

s55mercury66 · 04-12-2018, 02:00 AM

I have a 66 Mercury S55, with a 1.08 C6AF F tagged 4100. The carb is stamped 6AF. The boosters I found in it are D3 primary, and T2 on the secondary side. Does anyone know if these are correct? I am honestly more concerned with driveability than originality, but in searching for hard answers I have come up empty. My next question concerns the stamping on the carb tag. It has C 6DB stamped under the C6AF F. Is that a date code? I have been tinkering with this car and carb since 2008, but a few days ago I decided to check the float level again, and see just what I had for jets. Surprise, surprise, surprise. Someone had installed 67s in the primary side, and 46s in the secondaries. Now I have a few spares, and live at 6600' above sea level, so I put the 46s in the primaries, and 55s in the secondaries. After readjusting everything, driveability improved quite a bit. I haven't been into the secondary side much af this time, I will see how it goes.
Now, while doing some booster research, I came across a post that stated the idle speed could be adjusted to a degree with the secondary throttle plates, and recommended installing a bolt instead of the adjustment screw. That post created a little uproar from some, but after checking into it, yes, the secondaries do have an idle circuit. One thing it helps provide, is moving fuel from the secondary bowl. My carb had a bad secondary diaphragm when I got the car, and the secondary bowl had sat idle long enough to allow the wells to plug completely. It took a lot of soaking to clean it up. If your carb is installed and don't want to remove it to check your secondary throttle plate adjustment, you can do it with screwdriver bit, and a 1/4" wrench. I used a piece of paper to check for clearance between the screw and the tang, and applied 7/8 of a turn beyond that. Playing with this stuff is fun, any thoughts out there?

s55mercury66 · 04-12-2018, 02:10 AM

Another question, I have a baffle plate that came from a 2100. It attaches over the primary booster with the hollow screw that holds the booster in place. I have seen them on 4100s, and will be trying it on mine soon, with results posted. Has anyone tried one? Does anyone know what they were for?

rotorwrench · 04-12-2018, 11:11 AM

I would search for a Ford parts catalog that covers your model if you don't already have that information. It should have internal part information for those carburetors and some type information. Ford made carbs for the higher altitudes. They were subtle changes but they did ID them on the tag or stamping as a general rule (at least in the 50s anyway). That info should be in the parts catalog. The S55 was an up-rated version on its own as were the Marauders but the info should be in there for them.

I finally swapped out the 4100 on my old 64 T-bird for a Holley due to problems with the vacuum diaphragm on the secondary throttle control. They would work OK for a while and then it would be back to a two barrel only. I just got tired of that. Maybe the 66 was better than the 64 but I don't know.

KULTULZ · 04-13-2018, 03:53 AM

Correct, a period MASTER PARTS CATALOG will give you the correct assembly parts per the I.D. TAG and a period correct SHOP MANUAL will give you the calibration/proper adjustments information (as well as a OVERHAUL KIT INSTRUCTION SHEET)

C 6DB is the ASSEMBLY DATE CODE and should equate to the 2nd week of MAY 1966.

Go Here- http://www.carburetor-parts.com/Free...ls_ep_274.html

...and scroll down to FORD-AUTOLITE-MOTORCRAFT 4100 and it will give you several free manuals to view (be aware of publishing dates).

Actual assembly jetting (Basic PN 9533) will be found in the CARB PARTS LIST per the I.D.

s55mercury66 · 04-13-2018, 12:55 PM

Thanks for the replies, gents. I will do some searching for the paper books.I am finally getting an understanding of the date codes stuck in my head. Kultulz, I was born and raised in Athens, Oh. 40 miles west of Parkersburg, and 30 miles north of Mason.

s55mercury66 · 04-13-2018, 02:02 PM

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One small correctiion, 6DB would be the second week of April, 1966. That jives with the April date on the engine tag, and the May 5th production date on the warranty tag.

KULTULZ · 04-13-2018, 02:11 PM

Quote:

Originally Posted by s55mercury66

One small correctiion, 6DB would be the second week of April, 1966. That jives with the April date on the engine tag, and the May 5th production date on the warranty tag.

CORRECT...

I can't seem to be able to count...

s55mercury66 · 04-13-2018, 02:54 PM

Youre doing fine, thanks for the info.

KULTULZ · 04-13-2018, 05:01 PM

Quote:

Originally Posted by s55mercury66

You're doing fine, thanks for the info.

It is best to check behind me as CRS is a terrible thing...

Did you come across the FORD 4100 THEORY TEXT on the site I gave you?

s55mercury66 · 04-13-2018, 06:31 PM

No sir, I havent found that yet. I just took a look through the site again, and it didnt stand out. I have dowloaded 3 files from there, but havent completely read them all yet.

KULTULZ · 04-13-2018, 07:08 PM

Quote:

Originally Posted by s55mercury66

No sir, I havent found that yet. I just took a look through the site again, and it didnt stand out. I have dowloaded 3 files from there, but havent completely read them all yet.

SIR?!? ...

...who came in?

04-12-2018, 02:00 AM	#1
s55mercury66 Senior Member Join Date: Feb 2013 Location: SW Wyoming Posts: 155	Autolite 4100 C6AF F questions and discussion I have a 66 Mercury S55, with a 1.08 C6AF F tagged 4100. The carb is stamped 6AF. The boosters I found in it are D3 primary, and T2 on the secondary side. Does anyone know if these are correct? I am honestly more concerned with driveability than originality, but in searching for hard answers I have come up empty. My next question concerns the stamping on the carb tag. It has C 6DB stamped under the C6AF F. Is that a date code? I have been tinkering with this car and carb since 2008, but a few days ago I decided to check the float level again, and see just what I had for jets. Surprise, surprise, surprise. Someone had installed 67s in the primary side, and 46s in the secondaries. Now I have a few spares, and live at 6600' above sea level, so I put the 46s in the primaries, and 55s in the secondaries. After readjusting everything, driveability improved quite a bit. I haven't been into the secondary side much af this time, I will see how it goes. Now, while doing some booster research, I came across a post that stated the idle speed could be adjusted to a degree with the secondary throttle plates, and recommended installing a bolt instead of the adjustment screw. That post created a little uproar from some, but after checking into it, yes, the secondaries do have an idle circuit. One thing it helps provide, is moving fuel from the secondary bowl. My carb had a bad secondary diaphragm when I got the car, and the secondary bowl had sat idle long enough to allow the wells to plug completely. It took a lot of soaking to clean it up. If your carb is installed and don't want to remove it to check your secondary throttle plate adjustment, you can do it with screwdriver bit, and a 1/4" wrench. I used a piece of paper to check for clearance between the screw and the tang, and applied 7/8 of a turn beyond that. Playing with this stuff is fun, any thoughts out there? __________________ Looking for bucket seats and rocker mouldings for full-size 1966 Mercury.

04-12-2018, 02:10 AM	#2
s55mercury66 Senior Member Join Date: Feb 2013 Location: SW Wyoming Posts: 155	Re: Autolite 4100 C6AF F questions and discussion Another question, I have a baffle plate that came from a 2100. It attaches over the primary booster with the hollow screw that holds the booster in place. I have seen them on 4100s, and will be trying it on mine soon, with results posted. Has anyone tried one? Does anyone know what they were for? __________________ Looking for bucket seats and rocker mouldings for full-size 1966 Mercury.

04-12-2018, 11:11 AM	#3
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,436	Re: Autolite 4100 C6AF F questions and discussion I would search for a Ford parts catalog that covers your model if you don't already have that information. It should have internal part information for those carburetors and some type information. Ford made carbs for the higher altitudes. They were subtle changes but they did ID them on the tag or stamping as a general rule (at least in the 50s anyway). That info should be in the parts catalog. The S55 was an up-rated version on its own as were the Marauders but the info should be in there for them. I finally swapped out the 4100 on my old 64 T-bird for a Holley due to problems with the vacuum diaphragm on the secondary throttle control. They would work OK for a while and then it would be back to a two barrel only. I just got tired of that. Maybe the 66 was better than the 64 but I don't know.

04-13-2018, 03:53 AM	#4
KULTULZ Senior Member Join Date: Aug 2012 Location: IN A 'GALAXIE' FAR FAR AWAY Posts: 6,479	Re: Autolite 4100 C6AF F questions and discussion Correct, a period MASTER PARTS CATALOG will give you the correct assembly parts per the I.D. TAG and a period correct SHOP MANUAL will give you the calibration/proper adjustments information (as well as a OVERHAUL KIT INSTRUCTION SHEET) C 6DB is the ASSEMBLY DATE CODE and should equate to the 2nd week of MAY 1966. Go Here- http://www.carburetor-parts.com/Free...ls_ep_274.html ...and scroll down to FORD-AUTOLITE-MOTORCRAFT 4100 and it will give you several free manuals to view (be aware of publishing dates). Actual assembly jetting (Basic PN 9533) will be found in the CARB PARTS LIST per the I.D. __________________ *** - MULTI-VEHICLE SYNTHETIC TRANSMISSION FLUID - Multi-vehicle transmission fluids are becoming more and more popular in the marketplace. Oil marketers design these fluids for a wide range of automatic transmission types. While they are not licensed by any specific auto manufacturer ... ??? ... enough said ... DIAGNOSED CDO** - (OCD In Correct Alphabetical Order)

04-13-2018, 12:55 PM	#5
s55mercury66 Senior Member Join Date: Feb 2013 Location: SW Wyoming Posts: 155	Re: Autolite 4100 C6AF F questions and discussion Thanks for the replies, gents. I will do some searching for the paper books.I am finally getting an understanding of the date codes stuck in my head. Kultulz, I was born and raised in Athens, Oh. 40 miles west of Parkersburg, and 30 miles north of Mason. __________________ Looking for bucket seats and rocker mouldings for full-size 1966 Mercury.

04-13-2018, 02:02 PM	#6
s55mercury66 Senior Member Join Date: Feb 2013 Location: SW Wyoming Posts: 155	Re: Autolite 4100 C6AF F questions and discussion Sponsored Links (Register now to hide all advertisements) One small correctiion, 6DB would be the second week of April, 1966. That jives with the April date on the engine tag, and the May 5th production date on the warranty tag. __________________ Looking for bucket seats and rocker mouldings for full-size 1966 Mercury.

04-13-2018, 02:54 PM	#8
s55mercury66 Senior Member Join Date: Feb 2013 Location: SW Wyoming Posts: 155	Re: Autolite 4100 C6AF F questions and discussion Youre doing fine, thanks for the info. __________________ Looking for bucket seats and rocker mouldings for full-size 1966 Mercury.

04-13-2018, 06:31 PM	#10
s55mercury66 Senior Member Join Date: Feb 2013 Location: SW Wyoming Posts: 155	Re: Autolite 4100 C6AF F questions and discussion No sir, I havent found that yet. I just took a look through the site again, and it didnt stand out. I have dowloaded 3 files from there, but havent completely read them all yet. __________________ Looking for bucket seats and rocker mouldings for full-size 1966 Mercury.