Originally Posted by Roelof

It depends the bell material. Aluminium comes in many different alloy's...

Most of them can go soft due the heat and then the surface can be peeled. That is depending the shoe material, a hard shoe will cause more slip so a lot of heat. Do not use an aluminium shoe because aluminium on aluminium will distroy the surface.

Keep in mind that an aluminium bell has a short life, the heat will make the aluminium structure weak and can shater in pieces.

A venting clutch bell is wise to have, heat from the inside wiil be transported out much quicker. But I will sugest to use a steel because the weight difference will not do much with the allready heavy weighted drive train and car and is on a longer use much more reliable..