Rebuilt Motor Vibrating Bad - LS1LT1 Forum : LT1, LS1, Camaro, Firebird, Trans Am, Engine Tech Forums

Welcome to LS1LT1.com/LS3forums.com - please click here to register...

LS1LT1 Forum : LT1, LS1, Camaro, Firebird, Trans Am, Engine Tech Forums
Presented by:

New User? Register
LS1 Forums Register Photo Gallery Tech/FAQ Members List Calendar Auto Loans Search Today's Posts Mark Forums Read Auto EscrowInsurance
Premium Membership Videos Perf Tools Mobile/iPhone Link to Us! Social Groups Follow LS1LT1 on Twitter


Go Back   LS1LT1 Forum : LT1, LS1, Camaro, Firebird, Trans Am, Engine Tech Forums > Engine Tech > LT1 | LT4 | L99 Engine Tech

LS1LT1.com is the premier Pontiac Forum on the internet. Registered Users do not see the above ads.
Reply
 
Share LinkBack Thread Tools
Old 05-30-2011, 09:49 PM   #1
Regular Member
 
E-money81's Avatar
 
Join Date: Jun 2008
Location: Greensboro, NC
Posts: 101
E-money81 user's tech expertise is unknown at this point
Default Rebuilt Motor Vibrating Bad

Hey guys. My engine builder finally got done with the 383 install on my camaro. Unfortunately, the motor seems to be vibrating badly. The block and internals have been balanced at a local machine shop. They flywheel wasn't since it is stock and internally balance. I've also got poly motor mounts on the car. My builder says it could possibly be the mounts, but the vibration is so bad that he kind of doubts it. We plan to start with replacing the mounts back with the stock ones and if that's not it we plan on checking the flywheel. Worst case scenario it could possibly be the crank. BTW, the crank is a forged Eagle piece. Another interesting thing is that it seems the pulleys chewed up the serpentine belt and my said that might be due to the fact the balancer didn't seem to fit quite right. Any insight as to what the issue maybe would be greatly appreciated.
__________________
'96 Camaro Z28, 383 stroker, Crane Gold 1.6 rr's, M6 swap, 3.73 gears, Moroso CAI, BBK 58mm TB, Ported/Polished intake manifold, Ported/Polished stock heads, LE custom cam, LPP LT Headers, 32lb Accel injectors, Detroit Locker posi trac, Eibach lowering springs, torque arm bar.
E-money81 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Sponsored Links
Advertisement
 
Old 05-30-2011, 10:34 PM   #2
Regular Member
 
Join Date: May 2011
Posts: 89
lakeratiam user's tech expertise is unknown at this point
Default stroker vibe

Check that balancer. If it didn't fit right it may have been damaged installing it. Next question why didn't the balancer fit right? Is it the old stock unit? Is it an aftermarket unit and is it compatible with the Eagle crank? If it is an older stock unit, they can get "spun" and really make an engine vibrate!
Good luck!
lakeratiam is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 05-30-2011, 10:39 PM   #3
Regular Member
 
E-money81's Avatar
 
Join Date: Jun 2008
Location: Greensboro, NC
Posts: 101
E-money81 user's tech expertise is unknown at this point
Default

As far as I know, it is the old stock unit. Why it didn't fit right I'm unsure about. I'd have to ask my builder more on that.
__________________
'96 Camaro Z28, 383 stroker, Crane Gold 1.6 rr's, M6 swap, 3.73 gears, Moroso CAI, BBK 58mm TB, Ported/Polished intake manifold, Ported/Polished stock heads, LE custom cam, LPP LT Headers, 32lb Accel injectors, Detroit Locker posi trac, Eibach lowering springs, torque arm bar.
E-money81 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 05-30-2011, 10:45 PM   #4
Regular Member
 
Join Date: Sep 2010
Location: Indiana
Posts: 336
My Facebook
Psycho Apprentice Level Tech I
Default

See this thread.
lt1 balacing - LS1TECH
Psycho is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 05-30-2011, 10:46 PM   #5
Regular Member
 
Join Date: May 2011
Posts: 89
lakeratiam user's tech expertise is unknown at this point
Default

While you are at it ask him to check and make sure that old stock balancer hasn't "spun".
lakeratiam is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 05-31-2011, 12:59 AM   #6
95Z
Admin
 
Join Date: Mar 2008
Location: MD
Posts: 8,045
95Z Apprentice Level Tech III
Default

I'd be worried the flywheel is not correct.

If they balanced it w/o the flywheel did they assume it was a neutral balance one? If so and its a stock one they assumed wrong and you do in fact have a weight on it.

The stock LT1's have a weight (same size) on all flywheels and flexplates to help balance the assembly due to the removed material when the switched to the 1 piece rms.
__________________


Yep its slow.

Making the world a warmer place one gallon at a time.
95Z is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 05-31-2011, 06:03 AM   #7
Regular Member
 
Join Date: Sep 2010
Location: South Jersey
Posts: 806
Racy Roadmaster Apprentice Level Tech II
Smile

Quote:
Originally Posted by Psycho View Post
See this thread.
lt1 balacing - LS1TECH
For anyone thats going to rebuild their LT1 now or in the future ,you should read this thread. I am pretty sure one of these guys are going to
balance my LT1, I DONT WANT TO HAVE TO DO THE JOB TWICE. ed
Racy Roadmaster is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 05-31-2011, 06:07 AM   #8
Regular Member
 
Join Date: Sep 2010
Location: South Jersey
Posts: 806
Racy Roadmaster Apprentice Level Tech II
Default

Quote:
Originally Posted by lakeratiam View Post
While you are at it ask him to check and make sure that old stock balancer hasn't "spun".
Laketrain, Can you define stock balancer hasn't spun,do you mean the outer ring may have moved in reference to the inner ring? thanks ed
Racy Roadmaster is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 05-31-2011, 06:54 AM   #9
Regular Member
 
Join Date: Sep 2010
Location: South Jersey
Posts: 806
Racy Roadmaster Apprentice Level Tech II
Default

Quote:
Originally Posted by 95Z View Post
I'd be worried the flywheel is not correct.

If they balanced it w/o the flywheel did they assume it was a neutral balance one? If so and its a stock one they assumed wrong and you do in fact have a weight on it.

The stock LT1's have a weight (same size) on all flywheels and flexplates to help balance the assembly due to the removed material when the switched to the 1 piece rms.
I went down to my toy box where I keep all the parts that I plan on using in my build and checked my flyhweel GM pn 14088765 and it has a big
honkin weight welded to it-externally balanced-. I was also wondering ,looks like there are only
3 holes in the flywheel to attach the torque converter to ,is that correct?
I believe the older ones had 6 holes. ed
Racy Roadmaster is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 05-31-2011, 07:22 AM   #10
Regular Member
 
E-money81's Avatar
 
Join Date: Jun 2008
Location: Greensboro, NC
Posts: 101
E-money81 user's tech expertise is unknown at this point
Default

Quote:
Originally Posted by 95Z View Post
I'd be worried the flywheel is not correct.

If they balanced it w/o the flywheel did they assume it was a neutral balance one? If so and its a stock one they assumed wrong and you do in fact have a weight on it.

The stock LT1's have a weight (same size) on all flywheels and flexplates to help balance the assembly due to the removed material when the switched to the 1 piece rms.
Well assuming it is the flywheel, what do I do at this point? Do I need to pull the flywheel and motor again and have the internals and flywheel balanced? Also, do I need to find a neutral balanced flexplate?
__________________
'96 Camaro Z28, 383 stroker, Crane Gold 1.6 rr's, M6 swap, 3.73 gears, Moroso CAI, BBK 58mm TB, Ported/Polished intake manifold, Ported/Polished stock heads, LE custom cam, LPP LT Headers, 32lb Accel injectors, Detroit Locker posi trac, Eibach lowering springs, torque arm bar.
E-money81 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 05-31-2011, 07:25 AM   #11
Regular Member
 
E-money81's Avatar
 
Join Date: Jun 2008
Location: Greensboro, NC
Posts: 101
E-money81 user's tech expertise is unknown at this point
Default

Quote:
Originally Posted by Racy Roadmaster View Post
Laketrain, Can you define stock balancer hasn't spun,do you mean the outer ring may have moved in reference to the inner ring? thanks ed
I'm also not sure what a spun balancer means? What would a spun balancer look like?
__________________
'96 Camaro Z28, 383 stroker, Crane Gold 1.6 rr's, M6 swap, 3.73 gears, Moroso CAI, BBK 58mm TB, Ported/Polished intake manifold, Ported/Polished stock heads, LE custom cam, LPP LT Headers, 32lb Accel injectors, Detroit Locker posi trac, Eibach lowering springs, torque arm bar.
E-money81 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 05-31-2011, 07:40 AM   #12
Regular Member
 
Join Date: Sep 2010
Location: South Jersey
Posts: 806
Racy Roadmaster Apprentice Level Tech II
Default

Quote:
Originally Posted by E-money81 View Post
I'm also not sure what a spun balancer means? What would a spun balancer look like?
Lets wait until we get an official answer,my guess would be that the outer ring moved, where its attached by a rubber insulator, in relationship to the
inner part of the balancer. I think and remember its a guess,that the only way to tell if it moved would be if you had it marked by some type of paint line,but this would have to been done before it moved in the first place. ed
Racy Roadmaster is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 05-31-2011, 11:33 AM   #13
95Z
Admin
 
Join Date: Mar 2008
Location: MD
Posts: 8,045
95Z Apprentice Level Tech III
Default

I'd call up the shop that balanced it and ask exactly how they balanced it/what flywheel they want you to use. If they say stock (with weight), turn your attention to the damper on the front of the engine. If they say it needs a neutral balance flywheel you just need to get a new fly wheel with no weight on it and it should be fine.

Ed, yes the LT1 uses 3 bolts on the flexplate. It also has a different tooth count than the older ones.
__________________


Yep its slow.

Making the world a warmer place one gallon at a time.
95Z is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 05-31-2011, 12:45 PM   #14
Regular Member
 
Join Date: May 2011
Posts: 89
lakeratiam user's tech expertise is unknown at this point
Default

The outer ring of the damper would have moved in relationship to the inner hub. It is virtually impossible to tell by looking at it. Sometimes you can actually see were the rubber and steel have separated or pulled. More than likely the flex plate/flywheel is incorrect. Just wanted to look at what I felt was an obvious point due to the mention of the damper not fitting right and the belt being damaged by the pulleys. But that could also be a alignment issue.

Last edited by lakeratiam; 05-31-2011 at 12:48 PM.
lakeratiam is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 05-31-2011, 08:53 PM   #15
Regular Member
 
E-money81's Avatar
 
Join Date: Jun 2008
Location: Greensboro, NC
Posts: 101
E-money81 user's tech expertise is unknown at this point
Default

Ok, today my builder spoke to the machinist that balanced the internals. He said the machinist balanced the crank using a stock flywheel and balancer. If that was the case then the crank should be balanced when it was put in my motor using the stock flywheel and balancer. I don't think the crank was balanced the way some people say that it should be, but in the end balanced is balanced.

Also, my builder explained to me some more about the balancer not being on the crank properly. He said there's a key way (or a notch in layman's terms) underneath the snout of the crank. He said for some reason, the balancer isn't fitting against the notch the way it should. He thinks thats probably the reason why my serpentine belt got shredded somewhat. He also seems to think I may not have an LT1 crank at all because he's never had an issue with the balancer not lining up the way it should.
__________________
'96 Camaro Z28, 383 stroker, Crane Gold 1.6 rr's, M6 swap, 3.73 gears, Moroso CAI, BBK 58mm TB, Ported/Polished intake manifold, Ported/Polished stock heads, LE custom cam, LPP LT Headers, 32lb Accel injectors, Detroit Locker posi trac, Eibach lowering springs, torque arm bar.
E-money81 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Sponsored Links
Advertisement
 
Reply

Bookmarks

Thread Tools

Posting Rules
You may not post new threads
You may not 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


» Recommended
Find technical articles on a Chevy Corvette, including tips and tricks on a Chevy Camaro and expert advice for Pontiac Firebird, along with reviews on the Cadillac CTS.
» Auto Insurance
» Sponsors
Powered by vBadvanced CMPS v3.2.2

All times are GMT -5. The time now is 07:30 PM.



Powered by vBulletin® Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.5.2
Copyright © 2005 - 2011 by LS1LT1.com

Our Friends:


Illegal Street Racing | Super Cars | LT1 Tech Articles