Blown 496 carbon fouling middle cylinders - 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 05-17-2012, 09:50 AM
Registered User
 
Last photo:
Join Date: Jul 2011
Location: Wentzville,MO
Posts: 185
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Blown 496 carbon fouling middle cylinders

What am I missing? I have been tweaking the idle on all eight corners to get the A/F at cruise from 12.2 to 13.5 range. I was using #1 as a guide going from light tan to gray as it leaned. I have an intermittent miss at steady speed and the MSD cap and rotor looked pretty crusty so I replaced them. When I pulled the plugs 3,5,4 and 6 were carbon covered and the others look like #1. Wires are all under 200 ohms and cranking compression is 160 on all 8 holes. After 50 miles last night the outer 4 are off white and the inner 4 are off white on one side and black on the other half of the porcelain.
Idle a/f is 12.3 and leans to 15 on light acceleration then will quickly drop in to 11's as I row through the gears. Same on highway.
My set up is:
8.3-1 496 locked 32 timing
420 megablower 1-1 6lb boost
Edel Perf RPM heads
dual 650 dp man ref Holley's QF blocks 9.5 pv's stock ifr
Lunati 114lca 109icl 240/245 @ .050 .647 lift hyd roller
TKO600
29" tall Mickey's
3.90 gear
cruise at 60 in 4th - 2600 5th 1900

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 05-17-2012, 10:57 AM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Mark the inner plugs so you know the position of the black side of the porcelain to the exhaust valve guide- you may be pulling oil in through the guides.
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
blown 496 timing issue Blown496 Engine 8 10-10-2011 09:19 AM
Blown 496 cam recomendations Blown496 Engine 2 10-02-2011 07:36 AM
In the middle of a road trip! 2 questions! Lean cylinders and noisy rockers? stroker444 Engine 3 09-24-2010 05:25 PM
oval or rectangle port heads for blown 496 mean_1 Engine 9 07-22-2004 08:14 PM
what is a better car, a 32 Ford 5 window blown or a 55 Bel Air blown???? hot_rod_kid Engine 9 07-22-2002 04:07 PM


All times are GMT -6. The time now is 09:55 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.