I recently got my motor built for turbo.The build up was necessary due to blown bearings and balance shaft that happened becouse of an oil line that broke cousing oil starvation.Anyway I got the motor back ,I put it in ,currently Im running a Jackson Racing Supercharger set at 6 lb.While braking it in I noticed a strong vibration between 3 and 4 thousand rpm.After the breaking it in I brought it back to the shop and they were able to adjust the balance shaft timing which removed some of the vibration but not all.They told me that they set the timing dead on and they not sure where the vibration is coming from.I know that the mashine shop put in a new balance shaft so I m thinking maybe it was balanced incorrectly.
My question is ,where do you guys think the vibration is comming from and do you thin its doing any damage?The car is otherwise running good with no problems and no smoke.Thanx for your feedback.

 

do you have an underdrive crank pulley?

 

yes I do,but I checked that and everything on the outside of the motor.

 

wat type of header are u using?
~boom