Sick SBC - 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 03-27-2006, 08:20 PM
Registered User
 
Last photo:
Join Date: Nov 2004
Location: Dallas, TX
Age: 56
Posts: 6
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Sick SBC

Ok guys since I have found great help here in the past here we go again. Just another issue with my sons SBC. Here are the details

SBC stock bottom end
Dart Iron Eage S/S heads with a 2.02/1.60 valve job
Erson cam (mild) .429/.449, erson timing set, lifters
Erson Roller rockers
Z 28 springs
Performer intake
600 CFM Edlebrock performer series carb
MSD HEI distributor
Headers

Issue is this....has been running great until about last week.
It has developed a rough idle and while driving below 1500 RPM feels like engine is missing and stumbling...above 2000 runs pretty well....wants to stall at low RPM...holding throttle open in driveway at about 1200-1500 you can hear popping in the exhaust sounds like it is dropping a cylinder and if you blip the throttle you can get it to backfire through the carb...

Have checked the following.

1. Checked timing...all in at about 3200 RPM total 30 degrees
2. New plug wires....Taylor Vertex
3. New plugs....
4. New cap and rotor
5. Complete rebuild on carb
6. Checked vacum and is pulling about 16 in at idle....slight needle movement....less than 1/2 in just wobbles a little.
7. Checked for vacum leaks....found no issues there

Any guesses???.....have not pulled the valve covers....this is next on the list.

Thanks for your help!!
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 03-27-2006, 08:51 PM
67 Deuce 4 Me's Avatar
Bowtie or Die!
 
Last photo:
Join Date: Dec 2004
Location: TN
Age: 42
Posts: 637
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Could have a wiped cam lobe. Need to pull the covers and take a look at the valve movement. Fuel PSI ok??. Ignition module and or pick up coil could be failing! Spark strong enough?
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 03-27-2006, 09:07 PM
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
I also would have to go with a cam lobe/lifter/rocker problem.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 03-27-2006, 10:31 PM
eight90's Avatar
Member
 
Join Date: Dec 2002
Location: Mentor,Ohio USA
Age: 66
Posts: 73
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
I also agree with a cam or valve spring problem,,,,,, first of all 30 degs of total timing sounds a bit low to me. Give it more total timing,, 36-38 degs and see what happens.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 03-27-2006, 10:38 PM
sbchevfreak's Avatar
Licenced Automotive Technician
 
Last photo:
Join Date: Feb 2004
Location: Land of big Easter eggs, Alberta
Age: 34
Posts: 1,604
Wiki Edits: 0

Thanks: 8
Thanked 9 Times in 9 Posts
If they're not screw in studs, could have pulled a rocker stud. 67 Duece could also have hit it with the P/U coil.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 03-28-2006, 03:22 AM
57 Chevy's Avatar
Registered User
 
Join Date: Dec 2005
Location: Montana
Posts: 156
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
just my 2 cents, but I'm thinking like the others above on the cam issue. When he first fired it up, did he take it up to 2000/2200 RPM for about 20 minutes to break in the cam? Engine speeds below that don't spray enough oil to lube the cam and seat the lifters to the cam.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 03-28-2006, 07:08 AM
Registered User
 
Last photo:
Join Date: Nov 2004
Location: Dallas, TX
Age: 56
Posts: 6
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Thanks!

Thanks guys for all of the response.

I did a little more checking last night after I posted and noticed that while I had the timing light out that when I pulled the vacum line to the vacum advance canister on and off the unported side of the carb that I saw no difference in the timing???...I would have assumed that I would have seen some?....correct or not???....

The "old man" ran out of gas last night before I could start on the valve train so that is on tap this afternoon.

The cam was broken in properly when installed and has performed flawlessly over the past 5000 or so miles.

I do have a brand new module laying in the garage that I thought I would swap in this evening to see if that helped.
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
Why I have grown to hate the Small Block Chevy..... an essay Centerline Hotrodders' Lounge 316 02-08-2012 10:46 PM
SBC 350 superiority rebuttle...was:POWERED BY CHEVY, WRITTEN ON A FORD, (from 'Engine Oldsmolac911 Hotrodders' Lounge 50 01-12-2011 10:00 PM
Why not a 350 sbc? bowtieorbust Engine 29 09-05-2008 09:43 AM
Sick to death of SBC kc_ksom Engine 9 01-11-2006 06:11 AM
Late model 350 SBC Question Smoker113 Engine 3 02-19-2005 10:12 PM


All times are GMT -6. The time now is 07:44 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.