Adrian, I won't know the answer to that until summer! After running to normal temp, only the centre section was hot to the touch. I considered painting the underside matt black, and may do that eventually. The peak heat under there is the 'top hose' stainless pipe and that's further away from the cam covers. There's plenty of room between the cover and bonnets, and while moving I don't think it will be a problem at all. The Plus 4 is well cooled and others have made engine covers - in fact there may be photos on here. I may just do a search..........