Power Valve Selection - 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 11-24-2007, 05:50 PM
fbodyfreak's Avatar
Who loves burnt rubber
 
Join Date: Dec 2005
Location: TN
Posts: 30
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Power Valve Selection

I am trying to choose the correct power valve for my engine, and I have a small idea of how to do it, and I know it has something to do with the vacuum that the engine produces at idle. I am getting 6" of vacuum at idle, because of the camshaft that I have, and I know the power valve that I installed when I built the carb is probably for an engine producing 15" of vacuum or more. Does anybody have any ideas or know the correct way to figure after you measure engine vacuum
thanks

sbc 400
RPM Range: 3,500-7,000
Intake Duration at 050 inch Lift: 244
Exhaust Duration at 050 inch Lift: 254
Duration at 050 inch Lift: 244 int./254 exh.
Advertised Intake Duration: 302
Advertised Exhaust Duration: 312
Advertised Duration: 302 int./312 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.510 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.533 in.

Lobe Separation (degrees): 114

Sportsman II heads 2.1 intake 1.8 exaust (I think)
trw 2477 pistons .145 dome
Approximate 11.65 static comp.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 11-24-2007, 06:09 PM
Registered User
 
Join Date: Jul 2007
Location: New Hampshire
Posts: 725
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Does your car have an automatic or a standard trans? If it's an automatic check the idle vacuum in gear. What brand of carb is it? Holley recommends taking the idle vacuum and dividing it by 2. That will give you your power valve number. I know they make a number 35 which means it opens at 3.5 inches Hg. I don't know if they make smaller ones or not.

Last edited by ernkazern; 11-24-2007 at 06:15 PM.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 11-24-2007, 06:36 PM
fbodyfreak's Avatar
Who loves burnt rubber
 
Join Date: Dec 2005
Location: TN
Posts: 30
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
It is an automatic trans, and thank you for the information
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 11-25-2007, 12:50 AM
Registered User
 
Last photo:
Join Date: Mar 2006
Location: Justin, Tx
Posts: 194
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Get a buddy.... Put the car/truck in 1st gear and check the vac. divide by 2 and you have the powervalve you need..They make a 2.5" thats what I have...Suposedly they make a 1" but I havent ever seen one..
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
Valve Lash adjustment hiball Engine 36 05-11-2009 10:12 AM
Modifying Holley baseplate so power valve references manifold on s/c motor blownS10blazer Engine 5 09-05-2008 10:21 PM
power valve removal zephyrc Engine 1 06-16-2007 05:35 PM
Hotrodders Knowledge Cluster: Power Steering Conversions Jon Suspension - Brakes - Steering 0 09-03-2003 11:20 PM
Looking for a deal on power Brake booster,with pedal&combo valve for willys Harry Hut Interior 0 04-02-2002 01:36 PM


All times are GMT -6. The time now is 09:08 AM.


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.