no fan to shroud clearance

[Tspringer]

Hello!

I am working on getting the RSR back together....

For a bit of background, the engine in this car I have never seen run. This is a 3.4L twin plug crank fired, with 50mm PMO's that was built by Dave White Racing. It is supposed to be fresh with dyno time only.

I took the fan and fan shroud off to have them powder coated. When I did, I noticed that the fan belt was totally loose.... no idea why. This did raise questions because the engine was supposed to have been run and tuned on the dyno before being shipped to me. If it was run/tuned.... why is the fan belt loose?

Anyhow, I remove the fan and shroud. When removing the alternator from the shroud, I discovered that it had a bunch of little shims on the 6 studs used to attach the alternator to the fan shroud. The number of shims was not the same stud to stud. Apparently, these shims were used to position the fan in the shroud at a slight angle in order to prevent the fan blades from contacting the side of the shroud. Is this normal?

So when I got the parts back from the powder coater, I carefully reassembled the fan, alternator and fan shroud. I spent about 3 hours playing with the little shims, tightening down the alternator and fan, having a clearance problem, adjusting shims again.... repeating over and over until I had the fan spinning nicely in the shroud with the alternator tight.

So I went to install the assembly in the car. It all went in fine... until I went to tighten down the shroud with the retaining strap. If the strap is tightened even slightly, just enough to deform the lock washers, the fan will no longer spin. It binds on the shroud.

The clearance between the ends of the fan blades and the side of the shroud is VERY tight. I cannot imagine that with proper fan belt tension it would cause enough deflection to cause contact.

Any ideas? Im tempted to just sand a bit off the ends of the blades, but the fan is freshly powder coated. Should clearance be this big an issue?

[Ken911]

no it sounds like the shroud needs to be replace it might have been bent before I had a simliar problem on my carrera and when I removed the shroud I found it was cracked around the base for the alternator, found a new shroud on e bay for $50.00 cleaned it up ad painted itlooks great.and doesnt rub.

[NY65912]

Don't forget that powder coating will decrease the clearance between the fan and fan housing.

I had to sand off the powder coating from the tips of the fan to provide more clearance, and it worked.

As far as shimming is concerned, I would suspect that the fan housing is somhow bent or mishapend and has to be shimmed in order to square it up. I would look for a new housing.

Good Luck

[tctnd]

I purchased a "rebuilt" 3.0 a few years ago and discovered that the fan rubbed the shroud. Careful inspection revealed several cracks in the housing around the spokes. Evidently this is a fairly common problem, but shimming is definitely not a proper repair.
regards,
Phil