Blower pulleys - 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 06-20-2009, 01:00 PM
Registered User
 
Last photo:
Join Date: Sep 2005
Location: Texas
Posts: 27
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Blower pulleys

How do you tell or how can you make a blower under-driven or over-driven ? And amount of pounds ? Do you count the number teeth on the crankshaft pulley and the blower . Our if the crank pulley is smaller make it under-driven ? Like mine has 32 on the crank and 35 on the blower. I am figuring like a 10-12lb boost. On a small block with a 8-71 BDS. I like to look for some pulleys. They have lots on ebay. But have no idea what numbers or sizes to look for. Also I have only one vacuum port and that is for my trans. modulator. I have it hookup to the intake near the dist. But was told it needs to hookup to the bottom of one of my carbs. Which is correct ? THANKS !

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 06-20-2009, 01:29 PM
Member
 
Last wiki edit: Wiring diagram 1953 Chevrolet
Last journal entry: Spare Tire Dent Removal
Last photo:
Join Date: Aug 2003
Location: a little S/E of Nome
Posts: 793
Wiki Edits: 647

Thanks: 7
Thanked 5 Times in 5 Posts
Take a look at the chart contained here: http://www.blowerdriveservice.com/techcharts.php
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 06-22-2009, 09:39 PM
camaroman7d's Avatar
Member
 
Last photo:
Join Date: Dec 2003
Location: Vacaville, California
Age: 47
Posts: 2,245
Wiki Edits: 0

Thanks: 3
Thanked 9 Times in 9 Posts
At the base of the carbs you will always have vacuum, if you tap into the manifold which is below the blower you will have vacuum at times and boost at other times, this is not a good place to connect anything that is looking for strictly vacuum.

If the blower pulley is smaller than the crank pulley the blower is overdriven. If the blower pulley is larger than the crank pulley the blower is underdriven.

The size of your engine will come into play and be a large factor in how much boost will be made. I would guess you will need to be ~6-8% underdriven to be in the ~10Lbs range assuming it's a 350ci engine. You will have to adjust that according to your compression ratio, fuel type, and what your parts will support.

There are other factors that will come into play as well, boost is the measure of back pressure in your manifold, cam timing can and will effect your boost, head flow will effect boost as well.
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:
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
blower idle rpm problem Ratoflic Engine 7 12-01-2008 04:31 AM
671 Blower Pulleys...Help pls!!!!!!!!!!! binder47 General Rodding Tech 4 07-07-2008 01:22 AM
6-71 Blower Question Ratoflic Engine 11 11-16-2007 05:28 PM
Thinking about a small supercharger... Blazin72 Engine 11 12-21-2005 11:37 PM
Toyota Camry Blower Motor Problems donemore2003 Electrical 12 11-11-2004 11:45 PM


All times are GMT -6. The time now is 08:42 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.