74 Vette 350 engine troubles - 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
  #1 (permalink)  
Old 03-22-2003, 09:03 AM
Registered User
Join Date: Mar 2003
Location: Michigan
Posts: 2
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post 74 Vette 350 engine troubles

I bought this car from a guy who said he had an engine fire, and had replaced the block. My troubles began a few days after i got it, when i noticed the engine 'loaping', i guess is the best description... at any speed, it goes thru a small spot where theres less power, the rpm's drop slightly, and theres a noticeable change in the exhaust (dual, no crossover) sound... heres what he said he's done to it:

1. put a 400 cam in it
2. new engine block
3. wiring harness

heres what ive checked:

1. timing
2. dwell
3. checked spark on an oscilloscope (all even spikes, no jumping around either)
4. new plugs, cap, rotor, wires, coil
5. vacuum at 15-17 inches
6. used premium fuel for awhile, no difference
7. tuned carb (holley 650), even put a like for like on and same issue, i have 2
8. compression test (all cylinders around 145 lbs)
9. new vacuum hoses and pcv valve

im sure im overlooking something... talked to some gear heads and they all swear i have a bad valve or lifter... but wouldnt that show up in the compression test? someone also said the 400 cam just 'does that, live with it'...

any help would be appreciated...

also, is there a chat room associated with this site? i havent seen a link...

Reply With Quote Quick reply to this message
Sponsored Links
  #2 (permalink)  
Old 03-22-2003, 12:18 PM
LoudMalibu's Avatar
Join Date: Jan 2003
Location: Vancouver, Canada
Posts: 130
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts

well a 400 cam is not a 350 cam so thats your probellem. replace the cam , usally 350 and 400 parts can't interchange as theres always something different
Chevy G-Body Malibu For Life!
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 03-22-2003, 03:31 PM
1BAD80's Avatar
The Smell of Nitro in the morn
Last wiki edit: How to adjust valves Last photo:
Join Date: Jun 2001
Location: Mich
Posts: 2,423
Wiki Edits: 2

Thanks: 0
Thanked 3 Times in 2 Posts

The cam's are the same in all sbc's from 1957 thru 1987 , could be your power valve is coming in ,secondaries are opening a little, distributor advancment not working.

[ March 22, 2003: Message edited by: 1BAD80 ]</p>
Luv the smell of NITRO in the morning.
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:
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

All times are GMT -6. The time now is 10:03 AM.

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.