[John Rogers]

I would check spark, ignition timming and injector firing since the engine was just rebuilt and something could be miss-set. The valves could have no clearance when cold and the engine should still start but run progressivly worse and worse as it get hot. If the valves were not shutting and there was a very small valve to piston clearance they could hit, but you'd hear that when cranking the engine or turning it by hand. Starting a new and rebuilt engine is nearly the most stressful thing a 914 owner can experience, except for the oil pressure light coming on in turn nine flat out at Willows! Good luck.