Poncho 400 from 71 gto - 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> Hotrodding Basics
User Name
lost password?   |   register now

LinkBack Thread Tools
  #1 (permalink)  
Old 12-04-2004, 11:22 PM
Join Date: Nov 2004
Location: Maryland
Age: 65
Posts: 71
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Poncho 400 from 71 gto

Recently got the car, a 68 Firebird with a 71 400 GTO engine "YS" transplanted. Compression on the engine measured as follows, the first number is dry and the second number is with a half a teaspoon of oil added. All plugs were out and throttle wide open during testing.

cyl dry wet

1 146 160
2 152 153
3 150 151
4 145 146
5 154 170
6 159 164
7 150 151
8 154 160

Cyl 1, 5 bumped up quite a bit higher with some oil added while the others didn't show much difference. The readings seem to be close to the shop manual range 0f 150-170.

I'm wondering if this engine is in need of rebuilding before gettomg other work done to the car. It's not running well. The ignitions wires look old and questionable. The carb need to be sorted out too. It has a vibration peak at around 2500 rpms and odor of raw fuel

I have no idea how many miles the engine had on it when swapped into the car or how many miles afterwards. There is plenty of varnish and deposits under the valve covers.

Reply With Quote Quick reply to this message
Sponsored Links
  #2 (permalink)  
Old 12-04-2004, 11:58 PM
lluciano77's Avatar
Last photo:
Join Date: Jun 2003
Location: california
Age: 40
Posts: 3,548
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Usually cylinders should be within 10% of each other. You are right at that point. It is up to you. Do you feel like rebuilding it? Is a fresh new engine worth the trouble? If so start making arrangements. There are a lot of nice engine kits on Ebay for cheap.
Reply With Quote Quick reply to this message

Recent Hotrodding Basics 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 08:45 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.