'73-'87 stock compression - 460 Ford Forum
Engine Tech A place to discuss all 385-series engine tech and theory.

User Tag List

 
LinkBack Thread Tools Search this Thread Display Modes
post #1 of 10 (permalink) Old 08-24-2009, 10:59 PM Thread Starter
Junior Member
 
79Bird466's Avatar
 
Join Date: Aug 2009
Location: Ohioville, PA.
Posts: 35
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
 
'73-'87 stock compression

I punched the numbers into the C/R calc and got about 7.85:1. Is that about right? I have always seen the ratio listed as 8:1...is that just a rounded figure? This is for a 10.322 deck with stock D3VE (95cc) heads, 22cc dish piston and a .041 head gasket. Do all these numbers look accurate for a stock smogger?

'79 Thunderbird
466CI/C6/3.25 Traction Lok 9" Rear
D1VE block, D3VE heads, C8SE Intake & Cam, Carter AFB 625cfm carb, Duraspark II, Police oil pump, EFI timing set, 8.3:1 CR, etc...
79Bird466 is offline  
Sponsored Links
Advertisement
 
post #2 of 10 (permalink) Old 08-24-2009, 11:05 PM
Administrator
 
Cale Aronson's Avatar
 
Join Date: Mar 2007
Location: Chillicothe, MO
Posts: 808
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
           
72' was 8.5.1 So I think it was close....

Cale Aronson - Administrator
Black Magic Clutchs - Aronson Motorsports
Shelby Performance Mountain Motor Pro Stock Mustang
Shop - 660-646-4553 - Cell - 816-390-0852 - Email - cale@BlackMagicClutches.com
WWW.BLACKMAGICCLUTCHES.COM - WWW.GOFASTQUICK.COM

Jon Kaase Racing Engines - Ford Racing Parts - RAM Clutches - Browell - Trick Titanium - Bohr Racing - PEM Gears - Orme Brothers - Penske Racing Shocks - Innovators West - DJ Safety
Cale Aronson is offline  
post #3 of 10 (permalink) Old 08-24-2009, 11:28 PM
Senior Member
 
Diggindeeper's Avatar
 
Join Date: Feb 2009
Location: Timmins, ontario
Posts: 2,221
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
 
yeah you're likely on the right track. The compression ratio flat sucked in the smogger era for the 460.

Despite what you've heard, opportunity does not knock
Diggindeeper is offline  
post #4 of 10 (permalink) Old 08-24-2009, 11:47 PM
Administrator
 
Cale Aronson's Avatar
 
Join Date: Mar 2007
Location: Chillicothe, MO
Posts: 808
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
           
Scary part is in 71' they were 10.5.1!!!!!!

Sheesh!

Cale Aronson - Administrator
Black Magic Clutchs - Aronson Motorsports
Shelby Performance Mountain Motor Pro Stock Mustang
Shop - 660-646-4553 - Cell - 816-390-0852 - Email - cale@BlackMagicClutches.com
WWW.BLACKMAGICCLUTCHES.COM - WWW.GOFASTQUICK.COM

Jon Kaase Racing Engines - Ford Racing Parts - RAM Clutches - Browell - Trick Titanium - Bohr Racing - PEM Gears - Orme Brothers - Penske Racing Shocks - Innovators West - DJ Safety
Cale Aronson is offline  
post #5 of 10 (permalink) Old 08-24-2009, 11:51 PM Thread Starter
Junior Member
 
79Bird466's Avatar
 
Join Date: Aug 2009
Location: Ohioville, PA.
Posts: 35
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
 
Quote:
Originally Posted by Cale Aronson View Post
72' was 8.5.1 So I think it was close....
Did the '72s use flat tops or did the D2VE heads have smaller chambers? or neither?

'79 Thunderbird
466CI/C6/3.25 Traction Lok 9" Rear
D1VE block, D3VE heads, C8SE Intake & Cam, Carter AFB 625cfm carb, Duraspark II, Police oil pump, EFI timing set, 8.3:1 CR, etc...
79Bird466 is offline  
post #6 of 10 (permalink) Old 08-24-2009, 11:54 PM
Premium Member
 
Paul Kane's Avatar
 
Join Date: Jan 2006
Location: Bay Area, CA
Posts: 5,390
Mentioned: 0 Post(s)
Tagged: 1 Thread(s)
Quoted: 12 Post(s)
           
Cool

Quote:
Originally Posted by 79Bird466 View Post
I punched the numbers into the C/R calc and got about 7.85:1. Is that about right? I have always seen the ratio listed as 8:1...is that just a rounded figure? This is for a 10.322 deck with stock D3VE (95cc) heads, 22cc dish piston and a .041 head gasket. Do all these numbers look accurate for a stock smogger?
Actual real world comrpession ratio for the 1973-1986 engines is about 7.7:1, and possibly less depending on actual cylinder block deck height (which varies from block to block by several thou) and acutal combustion chamber volume (which also varies).

Paul

We're On The Web; Click Below:
High Flow Dynamics
Performance Components for the 429/460 Engine Family
Paul Kane is offline  
post #7 of 10 (permalink) Old 08-25-2009, 12:10 AM
Administrator
 
Cale Aronson's Avatar
 
Join Date: Mar 2007
Location: Chillicothe, MO
Posts: 808
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
           
Paul is right.... looking at my books that is true. The 73's were about 7.5.1 in all actuallity.

Here.... this might help a little...


Cale Aronson - Administrator
Black Magic Clutchs - Aronson Motorsports
Shelby Performance Mountain Motor Pro Stock Mustang
Shop - 660-646-4553 - Cell - 816-390-0852 - Email - cale@BlackMagicClutches.com
WWW.BLACKMAGICCLUTCHES.COM - WWW.GOFASTQUICK.COM

Jon Kaase Racing Engines - Ford Racing Parts - RAM Clutches - Browell - Trick Titanium - Bohr Racing - PEM Gears - Orme Brothers - Penske Racing Shocks - Innovators West - DJ Safety
Cale Aronson is offline  
post #8 of 10 (permalink) Old 08-25-2009, 12:23 AM Thread Starter
Junior Member
 
79Bird466's Avatar
 
Join Date: Aug 2009
Location: Ohioville, PA.
Posts: 35
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
 
I think the calculator is a bit off. I just entered the specs given from that book for a '72 460 and came up with 8.06:1. I even used the high end of the chamber size range (92.9cc) ...I'm assuming they used the same pistons as '73-'87 (-22cc)

'79 Thunderbird
466CI/C6/3.25 Traction Lok 9" Rear
D1VE block, D3VE heads, C8SE Intake & Cam, Carter AFB 625cfm carb, Duraspark II, Police oil pump, EFI timing set, 8.3:1 CR, etc...

Last edited by 79Bird466; 08-25-2009 at 12:26 AM.
79Bird466 is offline  
post #9 of 10 (permalink) Old 08-25-2009, 12:35 AM
Premium Member
 
Paul Kane's Avatar
 
Join Date: Jan 2006
Location: Bay Area, CA
Posts: 5,390
Mentioned: 0 Post(s)
Tagged: 1 Thread(s)
Quoted: 12 Post(s)
           
Cool

Quote:
Originally Posted by 79Bird466 View Post
I think the calculator is a bit off. I just entered the specs given from that book for a '72 460 and came up with 8.06:1. I even used the high end of the chamber size range (92.9cc) ...I'm assuming they used the same pistons as '73-'87 (-22cc)
1973-1986 heads have a chamber volume of closer to 97ccs typical, and the OEM 1973-1987 dished pistons are closer to 24cc total dish volume. Plug those numbers in and see what happens.

Paul

We're On The Web; Click Below:
High Flow Dynamics
Performance Components for the 429/460 Engine Family
Paul Kane is offline  
post #10 of 10 (permalink) Old 08-25-2009, 12:49 AM Thread Starter
Junior Member
 
79Bird466's Avatar
 
Join Date: Aug 2009
Location: Ohioville, PA.
Posts: 35
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
 
Quote:
Originally Posted by Paul Kane View Post
1973-1986 heads have a chamber volume of closer to 97ccs typical, and the OEM 1973-1987 dished pistons are closer to 24cc total dish volume. Plug those numbers in and see what happens.

Paul
I came up with 7.75:1 with a piston-to-deck clearance of .032 (listed in the book)

7.66:1 using .040 as a PTD clearance, which is what I have been told it is closer to.

'79 Thunderbird
466CI/C6/3.25 Traction Lok 9" Rear
D1VE block, D3VE heads, C8SE Intake & Cam, Carter AFB 625cfm carb, Duraspark II, Police oil pump, EFI timing set, 8.3:1 CR, etc...
79Bird466 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the 460 Ford Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
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:
OR

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.



Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes
Linear Mode Linear Mode



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

 
For the best viewing experience please update your browser to Google Chrome