texas97z

First off, let me say the engine is running good, just not perfect.I feel a VERY slight vibration at idle, but no funny noises and the car is not shaking.

Something has been bothering me about this engine since I bought it but wasn't until after wards I realized what it is. Come to figure out the rotating assembly is an external balance setup. They welded on the dampner to get it to balance. This is ugly and since I do not know the shop personaly(bought used), who knows who well it was done.. I was wondering if anybody could point me in the right direction to correct with this without having to remove engine. and take it apart and buy a new rotating assembly.

Can I just buy a fluid dampner and put it on there and all will be well? I realize that the flywheel is part of the balance as well.

MachinistOne

You are SOL without having the rotating assy spin balanced correctly.

texas97z

Well, it was balanced. And the car runs good. It is more a cosmetic thing than anything. It looks like jeg leg balancing,but it works. I was just wondering if I got a fluid balancer if it would work cause it would look a lot better. And I know it is not easily visible to the rest of the world, but I will know. If it is the case that I would have to tear everything apart again, then I will leave it alone. I don't want to break something for the sake of apperances and just throw it on there and see what happens, So I thought I would ask.

Stl94LT1

If the dampner was used for balancing, the new dampner will need to be match balanced.

gatorhead

If you are experiencing harmonics in your seat it won't be long until you have to put the right assembly in there.

Injuneer

The stock LT1 is externally balanced, using a neutral-balanced damper and a large weight on the flywheel or flex-plate. If they installed an externally balanced rotating assembly, it should have been set up for the stock flywheel or flex-plate, and ideally, balances with it, along with the damper.

At this point, if the had to "weld on the damper", its too late to go changing things "externally". How much weight did they add to the damper? Where did they add it? The damper is set up to counter the harmonic rotational vibrations in the crankshaft. If they "unbalanced" the damper, there's a good chance it is no longer serving its intended purpose, and may be hurting the crank more than it is helping it.

texas97z

I thought the LT1 was internal balance assembly with the weight on the flywheel being a small amount?

If I am wrong, I have a stock balancer, brand new with no weight welded on it, should I try it and see what it does?

Also to answer your question about how much they welded on the front, it is pretty sold mig about 1/2 wide and 3 inches long. Seems like a lot and putting one of my stock dampner's on there probably won't help but thought I would ask.

texas94z

yeah try the stock balancer. that could solve your problem.

sweet user name btw lol. obd I for life.

texas97z

LOL, yeah after I picked that I saw some of your posts. Great minds think alike!!! Do you know if anything is going on at Sanger on Saturday?

cehan

The "balancer" you are referring to is actually a torsional vibration dampner, not a balancer and not intended to correct an out of balance condition

texas97z

Right, so from what I was getting from Injuneer's post was that the way the dampner is now with all the weld on it, might be doing more harm than good. So my thought was to try going back to stock with no weld on it and seeing what that would do.

Brings up a question before I try this though...If I start the car and I am wrong about the stock dampner working, it will be way out of balance based on the amount of weld on there......is the likely hood pretty good that something will break? Or atleast mar something on the rotating assembly? If that is a pretty good chance, I may just drive it as is. The vibration is only for 500 rpm and I sent an email to previous owner and he said he never felt it. Now I know better than to trust everyone you buy things from, but it leads me to believe something else is the cause of my annoyance, I just thought this was a logical blace to start.

Kevin Blown 95 TA

If you take it off then make sure you can get it back on in the same position in case it isn't keyed on the crankshaft like the stock ones. matter of fact, if they didnt key it, then it can possibly spin and cause a problem that way. The flywheel weight would be less than what is on the damper cause the weight is further from the center of rotation. Too bad they set it up this way, sounds like a mess.

WS Sick

If they welded a weight to the stock balancer I'llbet that that is their balancing job. Ask the shop that did it, it helps to communicate a little. If it's there to balance the motor then youre gonna have to use it unless you yank the motor and get it balanced with stock pieces.