edelbrock/carter/webber 4bbl carb - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 12-15-2007, 05:07 PM
Registered User
 
Join Date: Nov 2007
Location: cherry hill NJ
Posts: 10
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
edelbrock/carter/webber 4bbl carb

ok how do i word this so it doesnt sound stupid... looking into an elderbrock 4 bbl carb the secondary throttle valves have a extra set of valves over top of these what do these do? would it do any harm to have them held open or remove them totaly. holley carbs dont have these. just thought it would give it more air flow. also would it be possible to shave off the choke horn up to the needle valves for more air flow? have to rebuild them anyway
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 12-15-2007, 05:24 PM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,182
Wiki Edits: 0

Thanks: 2
Thanked 292 Times in 289 Posts
The secondary air valves (air velocity valves) control the air speed of the air going into the secondary barrels when you floor the gas petal. This prevents the motor from getting a sudden big gulp of air without any fuel flow. The fuel is heavier than air and resists getting moving (inertia). The air moves easily. the fuel wants to lag. That momentary lag in fuel flow as the secondaries open, is what feels like a bog when you rug it. The velocity valves increase the velocity of the air so to increase the initial pull (pressure differential) on the secondary fuel flow for a smoother transition from closed secondary throttles to open throttles. If you remove the velocity valves, the motor will bog momentarily as you get into the throttle. it may even stall or backfire. When they are open at WOT they are not much of a restriction to airflow. No need to remove them.
The velocity valves are mounted on a shaft with special shaped and offset and weighted counter weights on each end that regulate how the velocity valves react to secondary airflow when the throttles are opened. Modifying the counterweights will change how much,how fast and how soon the valves open.
If you get carried away by lightening the counter weights you will get a throttle bog. If you want to experiment with the secondary air valve counterweights, best to get another one to play with.
Carter used to have different ones for specific OEM applications but I believe the aftermarket Carter and Edelbrock ones are all the same.
Yes you can improve the total carb airflow by removing the choke horn and adding a K&N stub stack (AFB) to the top of the carb. jetting may need be adjusted.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 12-15-2007, 05:33 PM
Registered User
 
Join Date: Nov 2007
Location: cherry hill NJ
Posts: 10
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
phew. ok i guess i wont mess with those valves then. i have a B&M style scoop for the dual setup thanks for the info
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
600 v. 750 carb on my 350. Help me out! Porschev Engine 11 11-22-2007 02:58 PM
Carb selection help SLR_65 Engine 2 09-03-2007 05:44 PM
Holley carb has me at wit's end cool rockin daddy Engine 23 06-02-2005 02:38 PM
Need help with Edelbrock carb Crazy-J Engine 1 06-01-2005 02:24 PM
4BBL Carb Questions impalamotion Engine 9 09-01-2001 07:17 AM


All times are GMT -6. The time now is 07:08 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.