Its done, got an issue
Its done, got an issue Welp, its to done! got it home and drove it around and have a few issues and i want to ask a few questions.
I have a 95 LT1 383 stroker SCATT forged bottom end, fully balanced, H beam rods.
I have a vibration from idle all the way up. I tried letting it coast and it goes down a little, but I can still feel a vibration.
My question is, could it be the flywheel? (its a stocker) if the engine is fully balanced now, wouldn't a weighted flywheel throw off the balance.
If so, where do I get the correct flywheel?
Also, my newly built trans gets stuck in 4th sometimes.
Thanks in advance for any help...
John
I have a 95 LT1 383 stroker SCATT forged bottom end, fully balanced, H beam rods.
I have a vibration from idle all the way up. I tried letting it coast and it goes down a little, but I can still feel a vibration.
My question is, could it be the flywheel? (its a stocker) if the engine is fully balanced now, wouldn't a weighted flywheel throw off the balance.
If so, where do I get the correct flywheel?
Also, my newly built trans gets stuck in 4th sometimes.
Thanks in advance for any help...
John
Probably the Flywheel. Did your stock unit have a weight on it? Was the motor balanced with the flexplate?
If not, more than likely the stock flexplate is whats causing the vibration. Replace the stock flexplate with a TCI or other sfi approved neutral balanced flexplate. I ordered mine from Summit. I had the same problem, it was night and day when I used the correct flexplate. For a temporary fix, you CAN knock the weight off of the stock flexplate and have it balanced. I would go with a thicker unit like the TCI one though..
I now have a balanced motor and a properly balanced flywheel. Even with poly motor mounts, its smooth as can be.
As far as the trans,,.,, no clue bud. I'm assuming this is an A4?
If not, more than likely the stock flexplate is whats causing the vibration. Replace the stock flexplate with a TCI or other sfi approved neutral balanced flexplate. I ordered mine from Summit. I had the same problem, it was night and day when I used the correct flexplate. For a temporary fix, you CAN knock the weight off of the stock flexplate and have it balanced. I would go with a thicker unit like the TCI one though..
I now have a balanced motor and a properly balanced flywheel. Even with poly motor mounts, its smooth as can be.
As far as the trans,,.,, no clue bud. I'm assuming this is an A4?
Launching!
Joined: Jun 2005
Posts: 277
Likes: 0
From: SC
Do the math. It sounds like you put an internally balanced rotating assembly in and used an external balance stock flywheel. You need a neutral balance LT1 flywheel. The dampener should be OK. I would not even so much as start it again until corrected. It's a lot cheaper to have the stocker balanced then to get a new one. Don't know that I'd run a stock one with a 383 especially if it'll rev out over 6k though....
Last edited by SSellers; Jun 17, 2013 at 01:11 PM.
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Verdad Gallardo Launching!
Joined: Jun 2005
Posts: 277
Likes: 0
From: SC
Just check Summit or Jegs for your year model. There should be ones listed as "external/internal" which means the weight is bolted on instead of cast in like stock so it can be removed to make it a neutral balance.
Just dropped big cash on this rebuild, Wife said no to an extra $400 (im fine with it, 800 credit scores becuase of her budgeting)
Im gonna have to cut it.
Can any engine shop do this!?
Im gonna have to cut it.
Can any engine shop do this!?
Launching!
Joined: Jun 2005
Posts: 277
Likes: 0
From: SC
An engine shop can probably recommend a machine shop that has the equipment to do it if they don't. The place that built my last engine had the capability so I let them check the balance on my new flywheel and clutch kit before even installing anything.
Welp, Just talked to my engine builder and I have to pull the engine so he can balance the whole engine, he said he fucked up and should have balanced the whole thing. His dime, but my time... Arghhhh.
Alight, now whats the best flywheel for my money...
Alight, now whats the best flywheel for my money...
This should be a very big, bright, flashing, Warning sign with a siren going off in your head right now.
Take it from me I have been here before and the battle scars to prove it.
Take it from me I have been here before and the battle scars to prove it.
The engine can be balanced to either the stock flexplate/flywheel counterweight or neutral balance, neutral seems more common on "built" engines but either is fine so long as the flywheel/flexplate is whichever it was setup for.
If he is telling you to pull the engine I wonder if he assumed the assembly was balanced and slapped it together. If he neutral balanced it and neglected to tell you then I would have guessed he would have just told you you needed a neutral flywheel.
If he is telling you to pull the engine I wonder if he assumed the assembly was balanced and slapped it together. If he neutral balanced it and neglected to tell you then I would have guessed he would have just told you you needed a neutral flywheel.
Launching!
Joined: Jun 2005
Posts: 277
Likes: 0
From: SC
He might have done what a lot of shops do....buy a "balanced" kit and didn't check anything. I got the bob weight sheet and everything with mine. The flywheel is still going to be a problem no matter what. At least if something is wrong he's already said "my bad" instead of saying you ran the wrong flywheel. Can't really say if that's just being aloof or honest these days but be grateful for that.
The way to explain it to her is this: You just dumped big cash into the motor build. By not letting you spend the money on the correct part, you might as well have just flushed the whole ammount you put into the motor down the toilet.
Joined: Jul 2007
Posts: 2,861
Likes: 4
From: Ringoes/Flemington, New Jersey
I agree with this statement 100% though. If you're going to do it, make sure you do it right. No cutting corners 
^ Truth. I justified my build by buying her a car LOL
But if she's truly budget minded, that argument will work. She's either all in or all out... and if she's out she should have never allowed the build int he first place.
But if she's truly budget minded, that argument will work. She's either all in or all out... and if she's out she should have never allowed the build int he first place.
