The cooling fan motor roars in high speed

If you installed a new motor but use the old fan blades check to see if the are hitting the shroud.

If that's ok, run to engine until it's at normal temp. With the car in park turn on the a/c (this will get the fans running at high speed), then look under the hood to locate the source of the noise.

Soome fans run loud when they are on high (depending on the noise this might be normal).