The original pulley is steel and has an expansion rate around 1.7 thousandths per 100degree c
aluminium depending on grade is more around 2.2 thou/100 degree
If you heat the pulley to "hot to touch" to fit ,what happens if it gets close to that temperature during running with heat transfer from the charger? aluminium expanding more than steel (the shaft is steel) it seems to me that you are relying on the grub screw.
no other pulley on the engine is using a grub screw,they are bolted,even the idler pulley,which has no load on it at all.
ease of fitting wise it looks fairly hard ,as pressing on the shaft with the charger still fitted to the car would require tapping the pulley on whilst still hot,with a feeler guage behind the pulley to get alignment,
If you pressed it to far on the shaft ,it would need pulling off a bit with puller(oh er missus) |