Carb Tech Discussion

[powerband]

I have some CarbTech questions for the group:

The Holley 2300 and 4412 series carbs are plentiful and some here - have them installed. What can you tell of there use on the small sixes. I know the're the circle track standard for sanctioned racing with 2.3 bangers.

2300's and 4412's:
> Are they the same carb?.
> How do you ID them, there seems to be lots of different ID or casting numbers for them.
> and what's the differences overall?.
> What's the mounting setup/flange bolt patterns -different or same?
Same as 5200's?

The 2300's :
> are available in 350 and 500CFM versions? What makes them different - just jetting?
> same jets as 4412"s ? Same as 1/2 of a 4bbl - ______ ?.

The 4412's :
> CFM ratings ?
> Jets?
>

Anyone try a small 4bbl with suitable adapters on a 200 or 250?

The discussion of the "mid-bog" Holley 5200's brought up a number of holes in my carb knowledge. The 5200 discussion hopefully will continue although it seems to have bogged down also. 'Still trying to get time to test the 2.8-V6 jetting on the Comet road rod. The plan to use the 250 block will mean more CFM needed and I'm still working out the 170 engine with the "built" D7xx head and 5200 carb.

Powerband

 

[CZLN6]

Howdy back PB;

To bring you up to speed- let me respond to your questions in your post;

"2300's and 4412's:
> Are they the same carb?."
Answer- Yes. 2300 is the generic name for all wide base Holley two barrels. The 2300s came in many sizes and configurations over the years in many factory applications, from IH to AMC. The versions you are talking about comes in two different sizes, a 350 CFM rated referred to as Holley list # 7448, and a 500 CFM, list #4412. They are both 2300s.

"> How do you ID them, there seems to be lots of different ID or casting numbers for them."
Answer- The Holley List # is stamped on the choke air horn. Once you know that you will need to go to a Holley reference book for details of application and specs.

"> and what's the differences overall?."
Answer- The 350, #7448 has 1.187" venturis and 1.375" throttle bores. The 500 has 1.375" venturi and 1.69 throttle bores.

"> What's the mounting setup/flange bolt patterns -different or same?
Same as 5200's?"
Answer- Different from 5200. The 2300s all use the same wide base mounting pattern, regardless of other differences. It is the same mounting pattern as the Autolite 2100 two barrels.

"The 2300's :
> are available in 350 and 500CFM versions? What makes them different - just jetting?"
Answer- The cfm is determined by how much air can be passed through the venturis at 3,0" hg pressure. It is measured in Cubic Feet Per Minute, aka, CFM. Jets and power valve channel restrictions determine tuning and applications and varies considerably.

"same jets as 4412"s ?"
Answer- All 2300s use standard Holley main jets. The #4412 and #7448 use different size jets in stock form, but may be changed to suit an application.

"Same as 1/2 of a 4bbl - ______ ?."
Answer- The #4412 and #7448 are basically the front half, or primary side of a Holley double pumper 4 barrel carbs with a center hung float bowl. All of the tuning accessories and equipement available for the primary side of a 4 barrel can be used on a 2300.

"The #4412's :
> CFM ratings- 500 CFM at 3" hg. according to Holley tech.
> Jets-"
Answer- Standard jet size for a #4412 is a 73.

wsa111 has posted extensively on his experiences with using 2300s on his modified log head 200. Do a search on his name to research.

"Anyone try a small 4bbl with suitable adapters on a 200 or 250?"
Answer- I believe Slade is currently running a Holley 4 barrel on his 200. Search him too for details.

It will be worth your time to do some searches on this forum to survey what has already been written and shared.

Adios, David