Balancing Question
Thread Starter
Teching In
Joined: Jan 2005
Posts: 36
Likes: 0
From: baltimore,md
Balancing Question I'm building a 383 for my 96 Z28 and I was wondering if you guys motors are internally or externally balanced ? I may need a damper on my motor & the ones i'm seeing for LT1's are for interally balanced motors. 
The stock balance for an LT1 is internal in front,external in rear. Most 1 piece seal 383 kits are completely internally balanced (reccomended). Some require the use of the weighted stock flexplate. You just reuse the stock damper,it's neutrally balanced from the factory. Mine is internal and i removed the stock weight as reccomended by Eagle.
TECH Apprentice
Joined: Jan 2004
Posts: 315
Likes: 2
balanced motor. I am curious what you meant about the LT1 beinf balanced from the exterior at the back. If this is the case, how would you get your motor balanced if you broke a flex plate specifically balanced for your set up? When my motor was balanced the hub and flex plate were not used. Mine is stock crank, lighter pistons and rods, stock hub and stock flex plate with the stock weight intact on the flex plate. I have no vibration with this set up.
From the factory,it's internally balanced in the front and externally in the rear based a weighted flexplate that are all weighted (balanced) to the same specs. The only way to "properly" replace a flexplate that was balanced to a specific assembly is to get the balance card from the person that balanced the motor originally so that the new flexplate can be independantly balanced and replace the broken one,if need be. I'm sure most builders don't drill on neutral or weighted flexplates though,they just add or remove metal from the crank.
As far as your motor you should be running a neutral flexplate since your rotating assembly was balanced w/o one. Unless.....and most likely,the machine shop used an in house stock flexplate to balance ur motor knowing it's a one piece seal crank. He just didn't use your parts in particular,and that's why you have no bad vibes.
As far as your motor you should be running a neutral flexplate since your rotating assembly was balanced w/o one. Unless.....and most likely,the machine shop used an in house stock flexplate to balance ur motor knowing it's a one piece seal crank. He just didn't use your parts in particular,and that's why you have no bad vibes.
