Flexplate/Balancer internal or external balance? - 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
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 01-22-2013, 10:03 AM
Registered User
 
Last photo:
Join Date: Aug 2011
Location: Fort Worth, TX
Posts: 502
Wiki Edits: 0

Thanks: 142
Thanked 9 Times in 9 Posts
Flexplate/Balancer internal or external balance?

Hey guys, for any of you that might have read some of my previous thread about the 350///357, I sold that short block. Im having another short block built.
The shop needs me to order my flexplate and harmonic balancer so they can balance the assembly.

I do not know which type to order... these are the ones I have picked out but im trying to make sure.

The balancer is internal balance and the flexplate is external balance so I assume this is wrong.

Brand:Chevrolet Performance

Chevrolet Performance Harmonic Balancers 12551537 - SummitRacing.com

Manufacturer's Part Number:12551537

Part Type:Harmonic Balancers

Product Line:Chevrolet Performance Harmonic Balancers

Summit Racing Part Number:NAL-12551537

Engine Balance:Internal

Safety Rating:Not SFI-approved

Degree Markings:Yes

Outside Diameter (in):6.750 in.

Harmonic Balancer Material:Cast iron

Harmonic Balancer Construction:Steel

Harmonic Balancer Finish:Natural

Mounting Hardware Included:No

Quantity:Sold individually.

Notesesigned for timing pointer in the 2 o'clock position.






Brand:Hays
http://www.summitracing.com/parts/hay-10-025

Manufacturer's Part Number:10-025

Part Type:Flexplates

Product Line:Hays Heavy-Duty Flexplates

Summit Racing Part Number:HAY-10-025



UPC:084041100257

Ring Gear Tooth Quantity:168-tooth

Rear Main Seal Style:1-piece

Engine Balance:External

Flexplate Material:Steel

Safety Rating:SFI 29.1

Quantity:Sold individually.

Notes:With counter weight.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 01-22-2013, 10:15 AM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 60
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Depends on if you have a 1- or 2-piece rear main seal crankshaft. 1-piece uses an external flex (http://www.summitracing.com/parts/hay-10-025 is correct).

Both 1- and 2-piece RMS 350 sbc use an internal damper, the one you linked will work.
Reply With Quote Quick reply to this message
The Following User Says Thank You to cobalt327 For This Useful Post:
0trbo4myCHEVUICK (01-22-2013)
  #3 (permalink)  
Old 01-22-2013, 10:17 AM
Registered User
 
Last photo:
Join Date: Jul 2004
Location: At Speed
Age: 51
Posts: 1,386
Wiki Edits: 0

Thanks: 2
Thanked 39 Times in 37 Posts
What is the description of your crank?
The crank is usually intended to be run either internally or externally balanced, and sometimes can differ from front to rear, but without knowing that you are just guessing on what parts to get. The balance shop should be able to give you an idea, but they may need to spin the assembly to find out.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 01-22-2013, 10:46 AM
Registered User
 
Last photo:
Join Date: Aug 2011
Location: Fort Worth, TX
Posts: 502
Wiki Edits: 0

Thanks: 142
Thanked 9 Times in 9 Posts
Quote:
Originally Posted by lmsport View Post
What is the description of your crank?
The crank is usually intended to be run either internally or externally balanced, and sometimes can differ from front to rear, but without knowing that you are just guessing on what parts to get. The balance shop should be able to give you an idea, but they may need to spin the assembly to find out.

the block is a 1pc rear main seal 4bolt roller provisioned block. The crank is GM STEEL
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 01-22-2013, 10:52 AM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 60
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by 0trbo4myCHEVUICK View Post
the block is a 1pc rear main seal 4bolt roller provisioned block. The crank is GM STEEL
One good thing is the bolt circles/patterns differ between the two: smaller circle for the 1-piece crank and larger for the 2-piece "traditional" crank. Makes inadvertently using the wrong one impossible.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 01-22-2013, 11:14 AM
Registered User
 
Last photo:
Join Date: Aug 2011
Location: Fort Worth, TX
Posts: 502
Wiki Edits: 0

Thanks: 142
Thanked 9 Times in 9 Posts
Quote:
Originally Posted by cobalt327 View Post
One good thing is the bolt circles/patterns differ between the two: smaller circle for the 1-piece crank and larger for the 2-piece "traditional" crank. Makes inadvertently using the wrong one impossible.
Okay well Im going to buy the ones I had listed and ship them directly to the machine shop.
After taking my previous short block to the shop and hearing him tell me the pistons where .043-.047 in the hole I decided to just sell the thing and start over.

Im having this one built with D cup keith black hypers 1.561 comp. height.
Keith Black KB Performance Pistons KB142-030 - SummitRacing.com and a decked block for
.010 piston to deck clearance.
Its a 4bolt instead of 2, steel crank, lt1 or X rods with arp rod bolts. All balanced. So im happy! Should be far better than the previously purchased short block. Ill post pictures as soon as I get it at my door in the crate. Gonna take 4 LONNG weeks though!
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 01-22-2013, 11:55 AM
bondo's Avatar
Member
 
Last photo:
Join Date: Nov 2002
Location: Chaumont Bay N.Y.
Posts: 960
Wiki Edits: 0

Thanks: 7
Thanked 15 Times in 15 Posts
Quote:
Originally Posted by 0trbo4myCHEVUICK View Post
Okay well Im going to buy the ones I had listed and ship them directly to the machine shop.
After taking my previous short block to the shop and hearing him tell me the pistons where .043-.047 in the hole I decided to just sell the thing and start over.

Im having this one built with D cup keith black hypers 1.561 comp. height.
Keith Black KB Performance Pistons KB142-030 - SummitRacing.com and a decked block for
.010 piston to deck clearance.
Its a 4bolt instead of 2, steel crank, lt1 or X rods with arp rod bolts. All balanced. So im happy! Should be far better than the previously purchased short block. Ill post pictures as soon as I get it at my door in the crate. Gonna take 4 LONNG weeks though!
Ayuh,.... Does this new block have the staggered starter bolt pattern,..??

Ya Need it to use the 168 tooth flywheel/ flexplate...
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 01-22-2013, 12:02 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 60
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by 0trbo4myCHEVUICK View Post
Okay well Im going to buy the ones I had listed and ship them directly to the machine shop.
After taking my previous short block to the shop and hearing him tell me the pistons where .043-.047 in the hole I decided to just sell the thing and start over.

Im having this one built with D cup keith black hypers 1.561 comp. height.
Keith Black KB Performance Pistons KB142-030 - SummitRacing.com and a decked block for
.010 piston to deck clearance.
Its a 4bolt instead of 2, steel crank, lt1 or X rods with arp rod bolts. All balanced. So im happy! Should be far better than the previously purchased short block. Ill post pictures as soon as I get it at my door in the crate. Gonna take 4 LONNG weeks though!
Sounds good!

You likely are aware of this already, but your KB hypers require a wider-than-normal top ring gap. More: KB Pistons for Automotive Applications
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 01-22-2013, 12:09 PM
Registered User
 
Last photo:
Join Date: Aug 2011
Location: Fort Worth, TX
Posts: 502
Wiki Edits: 0

Thanks: 142
Thanked 9 Times in 9 Posts
Quote:
Originally Posted by cobalt327 View Post
Sounds good!

You likely are aware of this already, but your KB hypers require a wider-than-normal top ring gap. More: KB Pistons for Automotive Applications
Yeah I saw the "special instructions" for the pistons. I will mention this to the shop but hopefully they are aware.

I do not know about a "staggered starter bolt pattern"
I will call and ask.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 01-22-2013, 12:37 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 60
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by 0trbo4myCHEVUICK View Post
Yeah I saw the "special instructions" for the pistons. I will mention this to the shop but hopefully they are aware.

I do not know about a "staggered starter bolt pattern"
I will call and ask.
You will need to match the flexplate/flywheel ring gear tooth count to the type of starter you want to use.

The larger flywheel has 168 teeth (about 14" OD) , and uses a starter w/offset mounting holes.

The smaller flywheel has 153 teeth (about 12-3/4" OD) and uses the starter w/the mounting holes straight across from each other.

Most all blocks are provisioned w/holes to mount either starter, but check to be sure that you have the holes and that they aren't stripped or broken.

Here is are some photos.

Last edited by cobalt327; 01-22-2013 at 12:49 PM.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 01-22-2013, 12:43 PM
Registered User
 
Join Date: Jun 2010
Location: TX
Posts: 1,226
Wiki Edits: 0

Thanks: 0
Thanked 108 Times in 99 Posts
All SB Chevy engines with a 1-piece rear seal are internally balanced. They are equipped with a counter-weighted flex plate. The counter weight on the flex plate is to compensate for a rear main that does not have a counter weight. The counter weight on the flex ,plate does not mean the engine is "externally balanced".

Always use a neutrally balanced harmonic damper on a engine that is internally balanced. I used a pioneer 872021 damper. It is 6.100" O.D. and is SFI 18.1 approved.

Why would anyone use hyper-eutectic cast pistons in a high performance engine when eutectic forged pistons are available?
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 01-22-2013, 01:06 PM
Registered User
 
Last photo:
Join Date: Aug 2011
Location: Fort Worth, TX
Posts: 502
Wiki Edits: 0

Thanks: 142
Thanked 9 Times in 9 Posts
[QUOTE=MouseFink;1637637]
Always use a neutrally balanced harmonic damper on a engine that is internally balanced. I used a pioneer 872021 damper. It is 6.100" O.D. and is SFI 18.1 approved.





I dont see any neutrally balanced dampers made by GM? How come I cant use a internally balanced damper on an internally balanced engine?
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 01-22-2013, 01:09 PM
Registered User
 
Last photo:
Join Date: Aug 2011
Location: Fort Worth, TX
Posts: 502
Wiki Edits: 0

Thanks: 142
Thanked 9 Times in 9 Posts
Or are internal and nuetral balance one in the same?
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 01-22-2013, 01:39 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 60
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by 0trbo4myCHEVUICK View Post
Or are internal and nuetral balance one in the same?
They're the same thing.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 01-22-2013, 04:23 PM
Registered User
 
Last photo:
Join Date: Aug 2011
Location: Fort Worth, TX
Posts: 502
Wiki Edits: 0

Thanks: 142
Thanked 9 Times in 9 Posts
Thanks alot fellas
Reply With Quote Quick reply to this message

Recent Hotrodding Basics 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:
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
Internal vs. External Balance 68NovaSS Engine 17 06-12-2010 07:57 PM
Converting SBC External Balance to Internal Balance zildjian4life218 Engine 3 02-18-2010 02:02 PM
Internal External Balance MHenricks Engine 10 08-22-2009 09:37 AM
balance-internal or external 6speedwagon Engine 5 03-27-2005 08:36 AM
Internal vs External Balance 614streets Engine 3 05-28-2003 02:25 PM


All times are GMT -6. The time now is 03:09 PM.


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.