I shimmed my SN2000 today in preparation of the VR4 impeller installation. I have a couple questions, or at least some confirmations.
I inspected all the internals balls measure 1.063+/- all with even wear, races where clean, output shaft smooth.
The internals of the SN2000 are different than SN89 I have.
The shim pack measured 0.022; I added shims to the pack which netted 0.043. This was way too much, after torquing the race retainer to 150”lbs (12.5’lbs) the rotational torque was 85”lbs. Stock with the 0.022 shim pack it was 27.5”lbs. Long story short, after four tear downs and tests, I ended up with 0.029 shim pack and 120”lbs (10’lbs) on the retainer bolts. This setup resulted in 55-57.7”lbs of rotational torque. (With all seals in place and balls lubed)
Is 55”lbs okay for a street/strip blower? I have a larger fluid cooler.
Does the shim pack size sound correct? I would have thought a lot more shim would be needed. I ask because the SN89 unit I was given had a 0.058 shim pack.
Is adjusting the torque of the race retainer bolts okay for adjusting the final rotational torque?
Any thoughts from the VR4 owners out there?
I took step-by-step pictures which I will post in a new thread once I sit down and edit it.
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