1996 Ford P100 start problem

Engine Mechanical problem
1996 Ford P100 4 cyl Two Wheel Drive Manual

just replaced cylinder head and cam after the belt snaped and camshaft broke. But it will not start of the key I do suspect it to be the timming, my problemn is this when you turn the key even from cold it seems to be presurizing the water straight away that it comes straight back out the expansion bottle has any one got any idea as never come accross this befor.