Pontiac 400 Idles to fast - 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
lost password?   |   register now

LinkBack Thread Tools
  #16 (permalink)  
Old 09-08-2010, 10:48 PM
quadrajunk a name earned
Last photo:
Join Date: Nov 2009
Location: Parts Unknown
Posts: 360
Wiki Edits: 0

Thanks: 3
Thanked 13 Times in 13 Posts
Correct Timing Info

What are the proper timing parameters as far as initial and centrifugal? I will clean up the weights and re-measure.


Reply With Quote Quick reply to this message
Sponsored Links
  #17 (permalink)  
Old 09-08-2010, 11:22 PM
cobalt327's Avatar
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
The 18 initial is a starting point, the exact number will depend on the cam specs mainly, to a lesser degree the CR (if higher than stock).

The amount of mechanical advance available depends on the configuration of the advance weights and the "cam" that bears on the weights. The RATE of mechanical advance is controlled by the springs. You want all the mech. timing in by at the most 3000 RPM and less if the engine will allow it w/o detonation. That will depend on the weight, use, rear gears, etc. of the vehicle.

I would use about 34 degrees of total timing. With 18 degrees coming from initial, that leaves 16 degrees that has to come from the mech. advance.

What you will need to do, is clean it up, get the mechanical advance operational and recheck how many degrees it is allowing, and tune it from there.

There are different ways to go about adding or limiting advance from the mechanical advance, but see what you have first. You may not need to actually modify the mech. advance- there's leeway in what the initial timing can be, and that may be all you need to work with to get it dialed in.

Also you will want the vacuum advance to add about an additional 10 degrees when at idle and/or light throttle cruise conditions. You can cross that bridge after determining where you are w/the mechanical advance.
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:


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
400 sbc vs 400 pontiac Artemis Entreri Engine 52 09-08-2010 06:17 PM
How to make more power in a pontiac 400 psmvchaser Engine 15 05-17-2010 09:10 PM
pontiac 400 camaro guy Engine 4 04-04-2007 05:28 AM
Pontiac 400 wider than Chevy 350 Goatman01 Engine 3 01-31-2007 12:11 PM
pontiac 350 vs 400 bb jjweb74 Engine 15 11-12-2004 02:30 PM

All times are GMT -6. The time now is 06:48 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.