Steam power would be worse than diesel! Anyone who ran that at Le Mans would be crazy!
Its far to dangerous for a start.
Sorry, I have to majorly disagree - and declare my reasons. I carry out statutory Pressure Systems Safety Regulations inspections on steam boilers, power stations and other pressure vessels.
If the steam raising plant is properly designed and constructed in accordance with the relevant design codes and the Pressure Equipment Directive, the system would NOT be dangerous.
This type of steam raising system would use a flash steam generator which, unlike a normal water filled steam boiler, has very little steam volume. The water passes through a coil over a heat source and 'flashes off' to steam. It can be further heated to provide a degree of superheating to produce more available energy.
This steam would then pass to the motive power unit, a turbine or reciprocating engine to drive the wheels. I suspect the exhaust steam would then not exhaust to atmosphere (wasteful) but be recycled via an air cooled condenser back to the feed water storage tank to be reheated.
The only concern with this type of system is the need to have storage tanks on the car for both fuel and water. The fuel can be diesel or kerosene (no different to the dangers associated with other racing fuels) and I've yet to see water burn.
The boiler unit itself (which is perceived as being the only source of 'stored energy') in reality - as stated above - has a very low steam volume and hence low stored energy.
An alternative would be to produce the steam via a hydrogen fuel cell - a number of manufacturers are presently working on this idea.
Get real - steam is no longer a 19th century romantic vision of Puffing Billy and Ivor the Engine - it's here and now.