pontiac YA 455, coded for 1970 GTO, loading up - 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 04-06-2007, 08:22 PM
Gladis's Avatar
Registered User
 
Last photo:
Join Date: Dec 2006
Location: OR
Age: 28
Posts: 177
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
pontiac YA 455, coded for 1970 GTO, loading up

Withdrew the money today in cash to buy a 70 firebird with a 70 GTO motor in it. I believe it is a 70 gto motor by the numbers, there is no such thing for any year as a YH 455, correct? I think he misread the serial on the block. Anyway, he says the engine is loading up when it gets warm. Basically he says it feels like it's burning real rich at lower throttle, really groggy, then at higher throttle it comes out it's slump and goes. By anyone's estimation is this a carb issue? I am going to double tap the timing on arrival with the timing gun, he doesn't know what it is adjusted to, or even what it should be. For a Pontiac 455, putting out stock 360 hp, what size and model of carb should be put on it. Also, how do I tell the difference between a 600ish and 700ish holley carburetor( that is the current carb setup, intake is not an edelbrock, but is aftermarket. He also said that the issue may be caused by the intake, I think he is referring to the seal may not be sealing, a vacuum leak maybe? I also have another general question, a pontiac 455 is a 400 with a different crank and stuff, but still the same base block and dimensions right? Thank for your time and expertise.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 04-07-2007, 06:03 AM
Registered User
 
Join Date: Jan 2007
Location: iowa
Posts: 15
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
pont

unless the bird is very well worth the money be carefull where you tread,,make sure you are getting what you think...doc41
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 04-07-2007, 06:08 AM
Registered User
 
Join Date: Apr 2007
Location: ks
Posts: 2
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Pontiac

The numbers that I find to fit a 1970 455 engine block are 231386, and 487638. That would be the number on the drivers side at the back of the block. Sometimes tough to read while still in the car. In the Motor repair manual I have it does list a YH code for a 455 w/auto trans. and a 4 barrel carb though. 1970

It shows timing to be at 9 degrees initial, at 650 in drive. These numbers are totally stock.

On the carb issue, read the numbers that are stamped on the choke tower, then go to a Holley web site to identify.

I would say 750 cfm minimum for the Holley. Some of the Pontiac guru's might have a different opinion though. I've run an 850 for years on an old Edelbrock Torker, and had excellent results. My 65 GTO is race only however.

Sounds like the carb may need a rebuild, or adjusted. Put a vacuum gauge on it and see where you're at on vacuum. Tune for optimum vacuum.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 04-07-2007, 11:52 AM
Gladis's Avatar
Registered User
 
Last photo:
Join Date: Dec 2006
Location: OR
Age: 28
Posts: 177
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
9799140
1970 455
http://www.gtoalley.com/engcodens.html
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
I'm Bored...How About A 1967 Pontiac GTO Project ??? izzymiddleton Hotrodders' Lounge 9 03-07-2009 10:26 PM
Pontiac 455 Head Question BattlestarOne Engine 15 01-29-2009 09:22 PM
gm th400 4 bolt- to- 455 pontiac.... how do i make it fit... 71_gto Transmission - Rearend 11 04-04-2008 06:18 AM
Pontiac GTO commercial street racing fourbyfourblazer Hotrodders' Lounge 28 08-11-2005 04:15 AM
Torque specs for a 75 455 pontiac flywheel 64_catalina Engine 2 06-28-2005 10:50 PM


All times are GMT -6. The time now is 10:58 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.