Whilst there aren't many production road engines of 1.3l producting 140hp - for the simple reason that people who buy 1.3 litre engines want economy and a bit of torque rather than power - it isn't hard nor especially expensive to get one up to over 100bhp per litre. If you are lucky there is a good chance you'd be able to do it without actually having to buy new parts - just alter the cam timing, skim the cylinder head a bit, and remap the ECU (although I concede that a better intake and exhaust system, along with a decent aftermarket ECU would yeild better results - and you'd do this anyway on a kitcar.