Push Rod Length Pontiac 400? - 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 06-18-2010, 10:33 AM
quadrajunk a name earned
 
Last photo:
Join Date: Nov 2009
Location: Parts Unknown
Posts: 338
Wiki Edits: 0

Thanks: 3
Thanked 10 Times in 10 Posts
Push Rod Length Pontiac 400?

I am getting ready to swap heads and cam on my 75 Pontiac 400.

Old Parts:

head 6x-8, stock Pontiac cam, stock hydraulic tappet Pontiac lifters, stock Pontiac head gasket thickness.

New

head 6x-4 milled .040", Summit 2802 cam , Summit hydraulic tappet lifters, head gasket thickness .039

Can I use the stock push rods or do I need shorter ones?

I am using the stock rocker arms. Are these considered adjustable? Is there any thing I should be aware of using stock rocker arms?

Thanks
BT

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 06-18-2010, 07:11 PM
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
Quote:
Originally Posted by beertracker
I am getting ready to swap heads and cam on my 75 Pontiac 400.

Old Parts:

head 6x-8, stock Pontiac cam, stock hydraulic tappet Pontiac lifters, stock Pontiac head gasket thickness.

New

head 6x-4 milled .040", Summit 2802 cam , Summit hydraulic tappet lifters, head gasket thickness .039

Can I use the stock push rods or do I need shorter ones?
The heads have a "net lash" adjustment- they are not adjustable, per se. The nut is tightened to 20 ft/lbs (IIRC) against the shoulder of the "bottle neck" stud. The stud has a larger shank than the threaded portion on the top, so the nut won't allow for adjustment, as it comes stock- the nuts are not lock nuts.

As to whether or not you need different length p-rods, you'll have to mock up the engine and valvetrain, install the standard p-rods and see how much (if any) lifter preload you get w/the nut torqued down. If too much, shorter p-rods, if too little, longer.

That said, there are studs that replace the stockers that will allow adjustment using lock nuts or polylocks. Polylocks sometimes interfere w/the valve cover, so you'll have to check to see.
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
need help for push rod length for big block chevy bryant740 Engine 3 04-12-2010 04:47 PM
Measuring for push rod length is driving me crazy TNshadetree Engine 13 03-05-2010 01:34 PM
fuel pump installation wiser626 Engine 8 05-18-2009 09:44 PM
Push rod length sgo70 Engine 3 09-13-2008 07:43 PM
Push Rod Wall Thickness - BBC leejoy Engine 1 03-18-2008 10:18 AM


All times are GMT -6. The time now is 10:08 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.