the oil in an NA motor doesnt get much over 300*F as far as i can tell... The oil is used to cool the motor just like coolant is. and if the coolant doesnt get over 220*F, i doubt the oil is going to get higher than double that... so its not gonna get near the point where it cokes up... itll start to create vapors and "steam" but not break down into basic carbon granules. at least it shouldnt.

if you are pussy footing an NA motor, you cant cool it down anymore than it was while you were driving it... now if you are BEATING on one at high RPM's and high load, it would benefit from a short cooldown cycle, not more than a minute. sometimes, itll get HOTTER sitting still than it will if its moving, w/ air flowing around it and the radiator/coolers.

Most of the Vortechs ive seen have sealed oil resivours and give you a special lube to use in it... i havent seen a centrifugal supercharger that makes you run external oil feed and drain lines. and a centrifugal blower will get hot, but not to the point of coking oil... the gear drive will build heat from friction, and the compressor will heat up the intake charge.

you are allowed to run up to 1600*F on most applications, or 900*C. anything above those temps and you are melting SHIT. (not "ish", but SHIT... its SHIT, got it?)

4cyl=turbo, 8cyl=blower?? are you sure? What about Tony christian's Twin turbo Pro-Street Bel-Air... what about the Grand National/Regal T-types? what about all the jackson racing blowers for the hondas and the neuspeed blowers for the VW's?