Go Back   The Ford Barn > General Discussion > Early V8 (1932-53)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 11-27-2020, 08:15 PM   #1
chain drive
Member
 
Join Date: Oct 2020
Posts: 73
Default 4100 carb

anyone ever run a 4100 carb on a flathead?
chain drive is offline   Reply With Quote
Old 11-27-2020, 08:43 PM   #2
scicala
Senior Member
 
scicala's Avatar
 
Join Date: Jun 2010
Location: Detroit suburb, MI
Posts: 3,697
Default Re: 4100 carb

I'm sure it would work well, but would need an adaptor to fit on the small 4 barrel pattern on flathead intakes. They were made in a few different sizes from about 400 to 600 CFM.

Sal
scicala is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 11-27-2020, 10:25 PM   #3
1948F-1Pickup
Senior Member
 
1948F-1Pickup's Avatar
 
Join Date: Oct 2015
Location: Socal
Posts: 794
Default Re: 4100 carb

Haven't run a 4100 on a flathead but you'd use a Navarro or Offy or other purpose built 4-bbl manifold.
From Autolite the 4100's range from around a 1" venturi to a 1.19....
a bit over 300 cfm to about 600 cfm at the other extreme. The SAE standard would be to flow automotive stuff at inches of mercury, Autolite may have done it at inches of water because the 4100 numbers aren't quite as impressive as Holley's.
Here's an experimental "blower" 4100 with 1.23 venturis-
Attached Images
File Type: jpg IMG_2077.jpg (55.3 KB, 22 views)
File Type: jpg IMG_2079.jpg (42.6 KB, 22 views)
File Type: jpg IMG_2080.jpg (84.2 KB, 21 views)
1948F-1Pickup is offline   Reply With Quote
Old 11-28-2020, 11:55 AM   #4
rotorwrench
Senior Member
 
rotorwrench's Avatar
 
Join Date: Jun 2010
Location: San Antonio, Texas
Posts: 16,371
Default Re: 4100 carb

When I had an old 64 T-bird, I had problems with the vacuum diaphragm that operated the secondary throttle plates. I ran the car mostly on the primaries due to that. I replaced that diaphragm multiple times and they just didn't want to last. Maybe I was too heavy on the throttle or the parts were just crap I don't know.
rotorwrench is offline   Reply With Quote
Old 11-28-2020, 05:57 PM   #5
1948F-1Pickup
Senior Member
 
1948F-1Pickup's Avatar
 
Join Date: Oct 2015
Location: Socal
Posts: 794
Default Re: 4100 carb

You just needed one of these nifty vacuum secondary override kits.....
Attached Images
File Type: jpg IMG_1485_.jpg (64.8 KB, 32 views)
File Type: jpg IMG_1486_.jpg (43.1 KB, 30 views)
1948F-1Pickup is offline   Reply With Quote
Old 11-29-2020, 11:34 AM   #6
rotorwrench
Senior Member
 
rotorwrench's Avatar
 
Join Date: Jun 2010
Location: San Antonio, Texas
Posts: 16,371
Default Re: 4100 carb

Sponsored Links (Register now to hide all advertisements)
Making it mechanical would certainly solve that problem.
rotorwrench is offline   Reply With Quote
Old 11-29-2020, 11:53 AM   #7
scicala
Senior Member
 
scicala's Avatar
 
Join Date: Jun 2010
Location: Detroit suburb, MI
Posts: 3,697
Default Re: 4100 carb

Quote:
Originally Posted by 1948F-1Pickup View Post
You just needed one of these nifty vacuum secondary override kits.....
Or fix the carburetor so it works as designed. Should be simple. The manual over ride secondaries is also a guaranteed hesitation/lag/backfire if you nail the throttle without a secondary squirter. That's a teenager trick.

Sal
scicala is offline   Reply With Quote
Old 11-29-2020, 12:06 PM   #8
1948F-1Pickup
Senior Member
 
1948F-1Pickup's Avatar
 
Join Date: Oct 2015
Location: Socal
Posts: 794
Default Re: 4100 carb

Has been working just fine since 1981, but then again I don't try to
open all 4 bores at 15 mph....
1948F-1Pickup is offline   Reply With Quote
Old 11-30-2020, 01:28 PM   #9
rotorwrench
Senior Member
 
rotorwrench's Avatar
 
Join Date: Jun 2010
Location: San Antonio, Texas
Posts: 16,371
Default Re: 4100 carb

It would take some venturi vacuum to open the secondaries. It always takes a bit to get enough flow from the primaries to get the secondaries to open up. My problem wasn't that the diaphragm would be damaged by a back fire. It's that the way the diaphragm is made, it just has slots to clear the retainer screws that hold it in place. It eventually just pulls the diaphragm into the chamber. Holley's design for vacuum secondaries is better. I'd get on the old bird to pass someone but it was no drag racer off the line. I think a person would be better served by two 2100s with a progressive linkage or simply use a Holley 4V instead. Ford used the Holley for performance applications for a reason.

I don't think those Eelco kits are available anymore.

Last edited by rotorwrench; 11-30-2020 at 02:02 PM.
rotorwrench is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 05:29 AM.