66 heads on 74 454? - 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 02-14-2006, 10:51 PM
smac's Avatar
Registered User
 
Join Date: Sep 2004
Location: Warren MI
Posts: 6
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
66 heads on 74 454?

I'm considering buying a '74 SS 454. The current owner tells me he has '66 heads on the stock '74 lower end. Says he has to run a mix of racing fuel and premium to keep detonation down due to the 10.5:1 compression...

Does this sound right to any of you BBC guys out here?
Maybe its a common mod, I dont know much about BBC's (yet)

I was really hoping for a stock '74 454 that I could wake up with intake, cam and exhaust and still run cheap pump gas.

Thanks,
Sean

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 02-14-2006, 11:18 PM
1939beast's Avatar
Wherever you go, there you are
 
Last photo:
Join Date: Feb 2006
Location: western NC
Age: 60
Posts: 47
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
They are probably closed chamber heads. Pull the valve cover and check the #s. They make high compression at the cost of poor flow.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-14-2006, 11:58 PM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 12,799
Wiki Edits: 326

Thanks: 744
Thanked 959 Times in 808 Posts
The problem that you'll encounter with any of the motors from '72 up until EFI is that the compression ratios were dismal and squish was non-existant due to the excessive deck height. If you are going to add a little soup to one of these motors, you really should tear it down and correct the deck height / squish. You'll find if you do, that you'll have no trouble running pump gas at up to 11:1 with iron heads and a cam that matches the c.r. (squish at 0.035" to 0.040").
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 02-15-2006, 04:06 AM
curtis73's Avatar
Hates: Liver. Loves: Diesel
 
Last wiki edit: How to find cheap parts
Last journal entry: 1999-2001: Getting it on the road
Last photo:
Join Date: Dec 2005
Location: Pittsburgh, PA
Age: 40
Posts: 5,128
Wiki Edits: 16

Thanks: 0
Thanked 2 Times in 2 Posts
I'm a BBC fan and I don't mind telling you that BBC head's chambers are pathetic at best. The chamber shapes don't do a darn thing for swirl or quench compared to modern heads. 10.5 on 66 heads sounds like 100+ octane to me.

I'm running 8.6:1 on my 454 and I had to carefully tune my ignition curve to prevent detonation on cheap fuel. Modern aftermarket BBC heads have solved that issue, but old-school iron BBC heads don't cut it. Swap those old heads for some newer castings... even 049s and you'll get much better performance and octane tolerance.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 02-15-2006, 04:55 AM
Bumpstick's Avatar
Hammer and a torch
 
Last photo:
Join Date: May 2003
Location: Southeast TX
Age: 54
Posts: 1,258
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Nothing can be figured till you know what heads and what pistons are being used... While all the mentioned info is good things have to be considered... What are you going to use this engine for...? If you want fuel economy forget it... If you want performace then use the higher compression and its advantages... But first find out exactly what you have...
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
Why spend money on heads? F-1Rodder Engine 8 03-07-2008 12:09 AM
Chevy Big Block 454 Marine heads 71 nova Engine 4 09-03-2004 06:08 PM
Heads novatech Engine 10 01-17-2004 01:27 PM
AFR Heads DTL504 Engine 9 12-09-2003 02:55 PM
L98 IROC/TA/Formula heads? dirtlmfan Engine 2 02-17-2003 12:02 PM


All times are GMT -6. The time now is 08:35 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.