400 small block idling problems - 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 04-16-2006, 02:53 PM
19nova72's Avatar
Join Date: Sep 2004
Location: Mass
Age: 30
Posts: 36
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
i never got a chance to play around with the vacuum advance much. i had an adjustable crane can on it and i had it setup for the 305 in the car prior to the 400.

Unfortunately, i lost the cam in the 400 after about 5 miles. it was comp xe268. about half the lifters went concave. i was pretty pissed since i put basically all the money i earned with my summer job last summer into buying the complete 30k mile motor and doing heads for it, cam, intake, carb, noisy gear drive, high pressure melling oil pump, aluminum water pump, etc. altogether i had about 2000 into the drivetrain.

now im about to take it out (as soon as im home from college for the summer) and drop in a 71 350 for the time being.

ive been reading a lot of articles on excessive flat tappet cam failures as of recently. theres been lots of things contributing to this. i think i had problems with the break in because i used stiff springs that came on the heads, comp cams red lube that came with the cam didnt stick well at all and kind of just ran off the cam (next time im using moly lube or comp cams special lube) i did have the valve adjustment right but i also used cheap oil and now that ive read some articles i realize that flat tappet cams need high zinc content which almost no motor oils have anymore because all new cars have roller cams. ive also heard about comp cams having quality control problems and having a high amount of soft cores. also some lifters are from overseas and are not well made.

either way i now have to disassemble the 400 and see the extent of the damage. i also managed to break a pushrod which was probably due to a backfire from the failing cam and the unforgivingness of the gear drive on pushrods (read that gear drives add up to 70% more stress on pushrods). i will keep posted my progress after i get home from school and start work on the car again.

thanks for the help, i have spent a lot of time playing with carb adjustment and vacuum and mechanical advance and managed to get a very strong running 305. i will now see what i can do with a puny vavle (1.72 intake) 350.


Reply With Quote Quick reply to this message
Sponsored Links

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:
Please select your insurance company (Optional)


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
350 or 400 Small block Larry Day Hotrodding Basics 9 04-09-2009 09:12 PM
400 small block compression 19nova72 Engine 2 07-20-2005 02:29 PM
400 Small Block Questions Dark Jester Engine 3 07-08-2005 11:02 PM
396 Big block v.s. 400 small block Adrenaline_Fiend Engine 13 04-12-2003 04:14 PM
400 small block chevy bo 1972 Engine 1 12-24-2002 07:03 AM

All times are GMT -6. The time now is 05:51 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.