I can't think of any cooler engine to put in the locost.

http://cgi.ebay.co.uk/Gas-Turbine-Rover_W0QQitemZ4609436719QQcategoryZ18308QQrdZ1QQcmdZViewItem

The noise would be fantastic.

Seriously down on power though...
Now if you'd put TWO of 'm in a locost...

rover gas turbine .... they had horrendous petrol consumption hence why the turbine cars were canned.

I used them as fire pumps in the Navy, used about a gallon of avcat just to start them, plumes of white smoke, aching burning muscles...Happy days