is a BBC 396 crank same as 427? - 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 03-12-2006, 03:29 PM
bigwildgrin's Avatar
Rooster
 
Join Date: Mar 2003
Location: montana
Posts: 176
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
is a BBC 396 crank same as 427?

yes, I know they have the same stroke but are they the same? GM listed some with the same casting numbers, but others have different casting numbers within the same year, for example a 3882841 is a 396 crank from '65-71, and 3882842 is a 427 crank from '65-'69. If they're the same why the different #? I read an old thread where a guy said they are balanced differently. He said you can put a 427 together with a 396 crank but the balance would be way off. Anyone know?
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 03-12-2006, 04:24 PM
Deuce's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Choosing a trailer
Last journal entry: Jan 13 2013
Last photo:
Join Date: Aug 2002
Location: Deuceland USA
Age: 65
Posts: 5,657
Wiki Edits: 6

Thanks: 0
Thanked 9 Times in 9 Posts
Some of the 396 crankshafts do balance differently.......

When I worked at the shop where we balanced engines......w changed extra for SOME 396 crankshafts.....in a 427. If I remember correctly....they were considerably lighter........maybe the 65,66,67 Models....but this was over 25 years ago........so I could be wrong on the years or models....

Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 03-12-2006, 05:49 PM
BOBCRMAN@aol.com's Avatar
Member
 
Last photo:
Join Date: May 2002
Location: Holly, michigan
Posts: 7,951
Wiki Edits: 0

Thanks: 13
Thanked 218 Times in 207 Posts
Duece, you are correct.. 366-396-427 all fit in the same space but are balanced differently. Especially when you get into the tall deck/truck motors with the HEAVY pistons..
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 03-12-2006, 06:19 PM
Sandflea427SS's Avatar
Anything with a throttle
 
Last photo:
Join Date: Apr 2003
Location: South Central Pa
Posts: 440
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
4.094 for the 396
4.250 for the 427
the 396 piston would weigh less hence the lighter counterweights on the 396 crank
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 03-13-2006, 08:38 AM
Member
 
Last photo:
Join Date: Aug 2005
Location: Virginia
Posts: 875
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
So then material should have to be removed from the 427 crank to stuff it in a 396?
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 03-14-2006, 09:57 AM
Registered User
 
Join Date: Mar 2006
Location: texas
Age: 27
Posts: 35
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
the only thing i can think of is that the counterweights are different in weight and placement.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 03-14-2006, 10:14 AM
Member
 
Last photo:
Join Date: Aug 2005
Location: Virginia
Posts: 875
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I am just guessing here, but I can't think of any reason the weights would be in a different location. I have a 6223 steel 427 crank at the engine builders now to go into a 396....he hasn't said anything.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 03-14-2006, 11:15 AM
Old does not mean dumb
 
Last photo:
Join Date: Dec 2003
Location: Central Tennessee
Age: 72
Posts: 98
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
The weight (counterweight) is in the same location. There is just less of it because of the lighter 396 piston. Some are shaved down and some have holes drilled in the counterweight.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 03-14-2006, 12:15 PM
bigwildgrin's Avatar
Rooster
 
Join Date: Mar 2003
Location: montana
Posts: 176
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by Rich1691
The weight (counterweight) is in the same location. There is just less of it because of the lighter 396 piston. Some are shaved down and some have holes drilled in the counterweight.
so it would seem that this would ba a good thing.... lighter crank= less rotating mass. or am I just being dumb?
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 03-14-2006, 05:37 PM
Bumpstick's Avatar
Hammer and a torch
 
Last photo:
Join Date: May 2003
Location: Southeast TX
Age: 53
Posts: 1,258
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Yes lighter is better but you would have to be sure and have the assembly balanced to make a 427 from a known 396 crank... Not just a throw it together combo...
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
the history of chevy v8's savman1 Hotrodders' Lounge 43 03-02-2012 06:57 PM
Bbc 427 z3pr Engine 7 01-07-2006 03:30 PM
A 454 is a 427 with a crank or rods or what? esears Engine 10 07-01-2005 05:50 PM
500 crank in a 427 tall deck? brian12c Engine 3 04-25-2005 06:52 PM
396 0r 427 in 78 camaro myrl Engine 6 02-03-2005 05:43 PM


All times are GMT -6. The time now is 08:58 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.