6.9L vs. 7.3L IDI piston weight ? - Diesel Truck Forum - TheDieselGarage.com
Thread Details Posted by TBolt, this thread has received 1 replies and been viewed 1466 times.

 
LinkBack Thread Tools Display Modes
post #1 of 2 (permalink) Old 06-17-2011, 03:36 PM Thread Starter
Junior Member
 
Join Date: Jun 2011
Posts: 1
Points: 15,204
Thanks: 0
Thanked 0 Times in 0 Posts
6.9L vs. 7.3L IDI piston weight ?

I am new here so Hello to everyone ! I am in the process of changing over an early 6.9L with 4 speed manual trans. to early 7.3 L. I would like to use the flywheel from the 6.9L to make things easy and cost effective.
The 7.3 L was removed from a running vehicle so the engine is assembled.
I am told that there is a balance issue if I do this ? I will rebalance the flywheel but in order to do this I need the difference in the weight of the pistons from the 6.9 L to the 7.3 L.
Any help would be greatly appreaciated. Thank you in advance, TBolt
TBolt is offline  
Sponsored Links
Advertisement
 
post #2 of 2 (permalink) Old 06-17-2011, 04:52 PM
Stuck in Commiefornia...
 
IdahoF350's Avatar
 
Join Date: Dec 2008
Location: Clearfield, Utah
Posts: 1,296
Points: 81,518
Thanks: 102
Thanked 447 Times in 315 Posts
Garage
A little advice from an engine builder's perspective:

See if there is an aftermarket flywheel from South Bend or another reputable source like Centerforce that offers the correct balance, has the same ring gear spec, and offers the clutch pattern you need. Any time you change the balance on a flywheel without it being balanced with the crankshaft, you create a potential problem with vibration. That vibration may not be super evident in your application, but if it's there and goes unnoticed, you could wipe out the bearings or even break the crankshaft in that 7.3. An aftermarket flywheel will have the right balance (offset weight) to be within the oem range and let your project proceed without worry.

I've seen this kind of situation with gas engines literally hundreds of times, where the original engine is a different balance than the later engine and the guy gets the wrong flywheel or flexplate. Happens with small and big Chevrolet and Ford regularly these days. All it takes is a little research to know what the have and the issue is an easy fix, yours is potentially no different.

The Current Truck (Oct-2013 to Present):
1999 (Early) F-350 Lariat, CCLB, SRW, Black/Tan

7.3L Powerstroke, 4R100, 4x4, 3.73, 37x13.50-18s, '05 Axle Swap, 6" Fabtech lift, GTP38 "D66" turbo upgrade, SCT 4-position chip with custom tuning by me, Straight Piped 4" down pipe through 5" dual stacks, N-Fab full length triple steps, Pro-Tech cab guard and tool box, louvered 5th wheel gate, Hella 500 Fog and Driving lamps, much more to come...
The one I'll miss, (Mar-2009 to Jan-2014):
2000 Excursion XLT 4x4

6.8L V-10, 4R100, 4.30, 285/75-18, 271whp / 388wtq
The one I won't, (Jul-2005 to Sep-2012):
2005 F-350 XLT, CCLB, SRW, 4x4 FX4

6.0L PSD, ZF-6S650, 3.73, 35x12.5-18, 4.5" Lift
IdahoF350 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Diesel Truck Forum - TheDieselGarage.com 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










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
uh oh need a piston sidssm 5.9L Cummins 12 Valve (1994-1998.5) 15 04-19-2010 10:10 PM
piston SmokeN 12 ValvE Dodge Parts 3 04-01-2010 05:00 AM
96 yz 250 need jug and piston smokeone ATV, UTV, Dirtbike Forum 1 03-19-2010 04:06 AM
466 Piston cooling nevrenufhp Medium and Heavy Duty 2 03-17-2007 04:48 PM

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