SBC Tri Power Help - Hot Rod Forum : Hotrodders Bulletin Board -- 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
lost password?   |   register now

LinkBack Thread Tools
  #1 (permalink)  
Old 01-13-2008, 03:49 PM
Registered User
Join Date: Oct 2007
Location: streetsboro. Ohio
Posts: 15
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
SBC Tri Power Help

I am in the process of putting tri power on a 350 chevy. i have 3 rochester 2GC small base carbs. The center carb has had no changes from its orginal runnig state other that a rebuild and the addition of a side mounted choke. The 2 end carbs have had the idle mixture screws plugged as well as the holes on top of the base. (belived to have whole idle circuit plugged). The rear vacumn ports on the base have been plugged as well as the venturi vacumn that it tradtionally used for the distrubter. They have been rebuilt as well with no chenges to the jets or acclerater pump. i have a new elebrock intake.
The center carb was put on the motor and driven on for a few miles to ensure there was no problems with it before it went on the tri power manifold. When i put the carbs on the new manifold the front and rear carbs were blocked off with gasket paper. the car strated and ran great. no problems. i only have fuel runing to the center carb. i pulled off the front carb and removed the gasket paper and put it back on. i started it up and it ran a little rougher than before but the car still idled. When i went to give it gas it was very hesitant and slow. then i removed the gasket paper from the rear carb and put it back on. when i started the car it ran really rough, barley even running.
then i taped up the top of the front annd rear carb to try to prevent vacum leak. when i closed the choke on the center carb the car runns a little better but still not great and it is still hesitant when i give it gas. i turned the idle screws out all the way on the center carb to give it more gas and that also smothed the car out some but not great.

What is wrong or were could the vacum leak come from? Are there more idle circuit holes that i need to plug? do i need those new thicker buterflies to seal the base of the carb better? does there need to be fuel run to the front and rear carbs? i have been as descriptive as i can if there is any more info you need to help please ask. i am lost and dont know how to stop the vacumn leak. If you would like to call collect or email me your phone number so i can call you that would be fine as well. 330 653-3563 usalley after 3PM ask for Jeff. alternate e mail is


Reply With Quote Quick reply to this message
Sponsored Links
  #2 (permalink)  
Old 01-13-2008, 04:59 PM

Last journal entry: Choo-choo town
Last photo:
Join Date: Feb 2002
Location: adairsville ga.
Age: 74
Posts: 413
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
tri power

Are the front an back carb. Idle screws backed all way off, if not its loosing vacuum through them.
I ran 3 x 2's way back when, it was a home made set up. I backed all way off the front and rear idles, set the mixture screws on these carbs. 1 1/2 turns out. set the middle carb. mixture screws with a vacuum gage to the highest reading I could get. ran a progressive linkage. lol
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 01-14-2008, 06:06 AM
Registered User
Join Date: Oct 2007
Location: streetsboro. Ohio
Posts: 15
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
The idle mixture screws are plugged with JB weld. They are no longer in use,
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 01-14-2008, 08:06 AM
MI2600's Avatar
Member# 3287

Last journal entry: Vortec Heads
Last photo:
Join Date: Jul 2002
Location: N. Muskegon, MI
Posts: 2,632
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Try this:

what Rochester carbs for tri-power

There's also a link in that thread for a Club Hotrod thread.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 01-14-2008, 09:27 AM
Registered User
Join Date: Oct 2007
Location: streetsboro. Ohio
Posts: 15
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Will centering those plates make that much of a differnece? it seems like its a pretty big vacumn leak.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 01-14-2008, 09:50 AM
Henry Highrise's Avatar
Lost in the 60's
Last wiki edit: Removing stuck fasteners Last photo:
Join Date: Dec 2001
Location: Dixieland
Age: 72
Posts: 15,195
Wiki Edits: 4

Thanks: 0
Thanked 18 Times in 16 Posts
Yes you need to get a fuel log and run fuel lines to all three carbs, Also you need to get the linkage kit for tri-power from It is a progressive linkage that is adjustable and allows you to run on the center carb until a certain speed or untill you kick the other two in...much like a 4 barrel. Your butterflys in your front and rear carbs must seal off perfectly...take your carbs off and with the butterflys closed shie a flashlight under should not be able to see any light coming from around them...they must be centered and the edges & roundness must be perfect. I had to work on mine quite awhile before I got them to seal off good.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply

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:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


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
How much power will a stock SBC rod take........ Trans Am Tony Engine 87 10-30-2007 08:52 PM
rochester tri power ollie horton Engine 3 12-19-2005 05:16 PM
SBC Tri Power setup help Not A T 25 Engine 7 09-23-2003 01:50 PM
Proper Jetting for Tri Power 305 SBC Not A T 25 Engine 0 09-21-2003 09:25 PM
Tri power spam on e bay DragLinkscc Hotrodders' Lounge 0 05-10-2002 07:56 AM

All times are GMT -6. The time now is 09:16 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999 - 2012. All Rights Reserved.