421 SBC not making power - Page 2 - 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
  #16 (permalink)  
Old 02-14-2013, 07:07 AM
gearheadslife's Avatar
MentalMuffinMan
 
Last photo:
Join Date: Nov 2012
Posts: 2,050
Wiki Edits: 0

Thanks: 84
Thanked 227 Times in 214 Posts
Quote:
Originally Posted by yorkcounty View Post
Yes it is electric and I have a 10 gauge wire ran to it. I have it ran through a relay off the switch. It's approx. 4 feet from the fuel cell under the truck.

Now the return line issue is very interesting. I am running a deadhead style regulator to the carb. I have 3/8 lines from each side of the regulator to each bowl but no return. I do have a pressure gauge inline and I'm on 7-8 psi.

I wasn't aware that the electric pumps stop after reaching pressure so to speak.
electric pumps DON'T STOP but the dead head regulator shuts off the fuel flow, and then the pump just sit's and spins, the fuel is what cools the pump, and is what lubes it.. what psi you have after you top out 1st gear, the fuel being stopped at the deadhead regulator, and your using it at WOT is your issue, the pump can't get the fuel to move in the 1/ line fast enough.. and the fuel volume in the line works against you..
looss the dead head and add a return line,, problem solved

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #17 (permalink)  
Old 02-14-2013, 12:31 PM
Registered User
 
Join Date: Feb 2013
Posts: 6
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Do I even need the 1/2 line? Can I just leave the 1/2 to the pump and then go back to 3/8
Reply With Quote Quick reply to this message
  #18 (permalink)  
Old 02-14-2013, 02:10 PM
gearheadslife's Avatar
MentalMuffinMan
 
Last photo:
Join Date: Nov 2012
Posts: 2,050
Wiki Edits: 0

Thanks: 84
Thanked 227 Times in 214 Posts
Quote:
Originally Posted by yorkcounty View Post
Do I even need the 1/2 line? Can I just leave the 1/2 to the pump and then go back to 3/8
yes you can use 3/8's for the return, the fuel moving in the line at all times will help tons, as the psi drops in the line (regulator to carb,) there will be no delay when the regulator opens flow to the carb..
as the column of fuel will be moving, remember as you run through the gears the fuel in the line wants to go backwards, adding to the load to the pump.. with it always moving forward (an item in motion stays in motion) when you need the fuel it'll be there..
make sure you didn't kill the pump with the deadhead regulator and no flow through the pump to cool it..
even after the return line, make sure you have 5-6 psi at carb at the top of every gear..
Reply With Quote Quick reply to this message
  #19 (permalink)  
Old 02-15-2013, 12:29 PM
Registered User
 
Join Date: Jan 2011
Location: West Virginia
Posts: 8
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
have you had the carb updated! same thing happened to me one time, it drove me crazy, over the winter the carb builder had changed something in the carb metering plates from tubes to jets, it ran great on the dyno but would fall down on the track. he fixed all three carbs.
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
How to Build a 421 SBC ??? Chevy406power Engine 10 11-06-2010 05:45 PM
421 sbc Hick_101 Engine 61 04-07-2010 10:30 PM
sbc 421 monster mouse Engine 0 11-27-2009 12:59 PM
421 vs 434 sbc 69Caprice Engine 14 03-05-2009 03:42 PM
Stroke on 421 sbc? Need4Speed Engine 0 09-01-2002 08:56 AM


All times are GMT -6. The time now is 01:29 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.