Any sponsor vendors sell a neutral balanced LT1 M6 Flywheel?
07-22-2007, 06:58 PM
#1
Any sponsor vendors sell a neutral balanced LT1 M6 Flywheel? Reading some threads, I've seen some very informative references regarding the importance of going to a neutral balanced flywheel when the LTx are rebuilt and balanced. S.A.M./Erik Koenig rebuilt mine and I didn't realize you couldn't just bolt on a stock GM LT1 flywheel and drive away, vibration free. The motor shakes BAD when I've rev'd it above 4k so I just don't do that. Kinda pointless having a solid roller cam that can't be rev'd.... 
THanks!
Dave
THanks!
Dave
07-24-2007, 12:32 PM
#3
Teching In
Join Date: Nov 2006
Posts: 28
Likes: 0
Received 0 Likes
on
0 Posts
Cant you just get a fidanza flywheel and remove the bolt on weight? I believe it is neutal balanced without the weight.
Originally Posted by mightyquickz28
Reading some threads, I've seen some very informative references regarding the importance of going to a neutral balanced flywheel when the LTx are rebuilt and balanced. S.A.M./Erik Koenig rebuilt mine and I didn't realize you couldn't just bolt on a stock GM LT1 flywheel and drive away, vibration free. The motor shakes BAD when I've rev'd it above 4k so I just don't do that. Kinda pointless having a solid roller cam that can't be rev'd....
THanks!
Dave
THanks!
Dave
07-24-2007, 12:46 PM
#5
Thanks, I did find one on my own. The SPEC Steel (part# SC85S) is neutral balanced and has a removeable counterweight on it. Apparently with the counterweight, it matches stock balancing requirements. Removal of the weight renders it neutral balanced. A new stock flywheel from gmpartsdirect is over $200. Having it machined is $100 while the Spec delivered to my door is only $280 and it's SFI approved.
07-24-2007, 01:04 PM
#7
The downtime is important. If I pull the stocker out, find a machine shop, wait for them to get to it, drive over, pick it up, drive back, find another day to devote to putting it in, well... too much time/driving/waiting. This new SPEC will be here, clean and shiny, by Friday so I can install it in one 4 hour effort. Then I can take the stocker and have it neutral balanced for a backup/future replacement.
Trending Topics
07-27-2007, 01:59 PM
#9
Got the SPEC Steel Flywheel for my LT1 from UPS today..
In the box..
www.taekwondoplus.org/z28/SPEC01.JPG
Opening the box (sealed in plastic wrap)
www.taekwondoplus.org/z28/SPEC02.JPG
Out of the box, backside
www.taekwondoplus.org/z28/SPEC03.JPG
As presented, it's counterbalanced like a stock LT1 flywheel.
Remove this weight, and it's then 'Neutral' balanced.
www.taekwondoplus.org/z28/SPEC04.JPG
Thanks everyone for their insight.
In the box..
www.taekwondoplus.org/z28/SPEC01.JPG
Opening the box (sealed in plastic wrap)
www.taekwondoplus.org/z28/SPEC02.JPG
Out of the box, backside
www.taekwondoplus.org/z28/SPEC03.JPG
As presented, it's counterbalanced like a stock LT1 flywheel.
Remove this weight, and it's then 'Neutral' balanced.
www.taekwondoplus.org/z28/SPEC04.JPG
Thanks everyone for their insight.
But, it is SFI approved.
07-27-2007, 07:16 PM
#12
TECH Fanatic
Would like to know if there's any noticable difference. I have a rebuilt motor that is supposedly "balanced"... Never heard anything about not using the stock flywheel before.
07-27-2007, 07:21 PM
#13
On The Tree
Join Date: May 2007
Location: N.E. PA
Posts: 143
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by hyperzone
Would like to know if there's any noticable difference. I have a rebuilt motor that is supposedly "balanced"... Never heard anything about not using the stock flywheel before.
07-27-2007, 07:33 PM
#14
TECH Fanatic
The motor I have came as a long block. I swapped all my parts onto it including the stock flywheel. I had it turned since I was putting in a new clutch at the time as well. So, this particular engine wasn't balanced with the particular flywheel that is on it.
Are you just saying that the builders will typically balance them to work with stock flywheels unless you ask for something else?
Are you just saying that the builders will typically balance them to work with stock flywheels unless you ask for something else?
07-27-2007, 08:23 PM
#16
When I had my LT1 balanced, they did not ask for the stock flex plate, mine being an Auto. I have the stock one on the car as well as the stock harmonic balancer. Should these parts have been balanced with the pistons, rods, and cranK?
07-27-2007, 09:27 PM
#17
TECH Resident
Join Date: Jul 2005
Location: Midland
Posts: 861
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by dangalla
lt1 from the factory is externally balanced(with the counter weight on the flywheel), so yes they will build it that way unless you ask otherwise, normally
07-27-2007, 09:36 PM
#18
On The Tree
Join Date: May 2007
Location: N.E. PA
Posts: 143
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by 91Z28
Once again, this is misinformation. The LT1 is INTERNALLY balanced, that little counterweight on the flywheel does not mean that it is externally balanced. Every SBC (LT1 included) produced since 1987 is internally balanced and has a 1 piece rear main seal and that is the real reason for the counterweight on the flywheel. The only externally balanced factory small block ever produced was the 400.
your outa your ****** mind, do your reseach before you post useless bullshit
if it was balanced internally why would there be a weight on the flywheel, there wouldnt be, you have a weight on there to BALANCE the rotating assembly
lt1 is neutral balance on the front and external balance (by the flywheel or flexplate) on the back
07-27-2007, 10:04 PM
#20
TECH Resident
Join Date: Jul 2005
Location: Midland
Posts: 861
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by dangalla
your outa your ****** mind, do your reseach before you post useless bullshit
if it was balanced internally why would there be a weight on the flywheel, there wouldnt be, you have a weight on there to BALANCE the rotating assembly
lt1 is neutral balance on the front and external balance (by the flywheel or flexplate) on the back
if it was balanced internally why would there be a weight on the flywheel, there wouldnt be, you have a weight on there to BALANCE the rotating assembly
lt1 is neutral balance on the front and external balance (by the flywheel or flexplate) on the back
"Internal" and "external" balance DOES NOT refer to which side of the rear main seal the balance weight is on, although it's tempting to think that.
In fact, the LT1 has exactly the same balance as the Gen 1 SBCs, such as 283, 305, 350, etc. The ONLY SBC that's truly "externally" balanced, is the 400.
The deal is, with the Gen 1 SBCs such as the 305 and 350, part of the balance weight was made onto the flywheel flange of the crank. However, the 1-pc rear main seal system won't go on over that weight; the cranks flange needs to be round (or at least smaller than the seal... duh...). So the weight that used to be part of the crank, had to be moved to the flywheel. The motor technically is still "internal" balance, even though some of the weight LOOKS to the untrained and oversimplifying eye, as if it's "external" to the motor.
In fact, the LT1 has exactly the same balance as the Gen 1 SBCs, such as 283, 305, 350, etc. The ONLY SBC that's truly "externally" balanced, is the 400.
The deal is, with the Gen 1 SBCs such as the 305 and 350, part of the balance weight was made onto the flywheel flange of the crank. However, the 1-pc rear main seal system won't go on over that weight; the cranks flange needs to be round (or at least smaller than the seal... duh...). So the weight that used to be part of the crank, had to be moved to the flywheel. The motor technically is still "internal" balance, even though some of the weight LOOKS to the untrained and oversimplifying eye, as if it's "external" to the motor.
Last edited by 91Z28; 07-27-2007 at 10:11 PM.