I installed an edge 9.5 3500 stall converter and Im now getting a serious vibration.... I kept the stock flexplate on it,, but why is there a weight on an internally ballanced motor? thanks guys

 

The presence or absence of a weight has nothing to do with whether the engine is internally or externally balanced.

 

To balance the flexplate idk... But if the vibration started after you put the converter on then chances are it's the converter.

 

I drove the car the trans n converter came out of.
No vibration but it had an aftermarket flexplate with no weights on it. Now its vibrating once its in stall range. Not at idle or above 3k

 

did alot of research last night and this morning.... if anybody is running an aftermarket internally balanced crank you have to cut the flexplate weight off,, if your reusing your stock flexplate..... i was getting a slight vibration with the old setup( stock converter/stock flexplate and rubber tranny mount.... now with having a neurtal balanced converter and a weighted stock flexplate with a poly trans mount its very very noticable so Im going to try and get the weight off with the tranny still in car but if not its time for an sfi neutral balanced one.

 

The car ran fine.
A part was changed.
It now has a vibration problem.
You're going to modify a different part that worked fine before the install of said part.



Here's what you just indicated:
The stroker crank with a flywheel that has a weight was fine.
You're now going to remove a weight and have a bigger balance and vibration problem.

You haven't verified that the engine the converter was previously behind is the same generation rear seal (85-down or 86-up) or flywheel balance type.

You have a "383" which was running fine with a weight so you either have a 400 SBC balance situation or a 86-up internally balanced w/ external weight setup.
Not the neutral balance setup you wish it had.

There's about zero chance that your engine is balanced for a neutral weight flywheel so removing that weight is at your own risk.

 

thank god we have a genius like you that knows more than the guys at Car Craft, and the techs at Eagle Specialty products.... The crank is internally balanced and requires a neutral balanced flexplate according to Eagle. Also as previously stated it was vibrating before, just not as noticeably with the stock converter,,, now that there is a 3400 stall edge converter that measures 9.5" and is also neutrally balanced it is,,,was,,, more prevalent..... im not asking you,,,, Im telling you!!!! thanks anyway for your completely incorrect information..

http://www.carcraft.com/techarticles.../photo_07.html

 

On your particular crankshaft as it was balanced in your engine. Not every aftermarket crank requires this.

 

yep, I miss spoke,,,, aftermarket crank kits that are internally balanced need to have the weight cut off,,,,, at least for eagle and scat who both verified this. If I would have known I would have ordered an sfi flexplate z/b for the install... laying under there and removing the weight was a bit messy....... safety glasses definitely required

 

Lol, I thought I was getting a bit of a missfire ever since I built the motor(only has about 500 miles on it). It was the flexplate weight. Just fired it up and it feels silky smooth,,, no vibration at all even with the poly trans mount..