Must have been done 1000 times before but my zetec boils over. I fitted a 1994 escort water pump and im sure the cooling system is right. I have some pics if it. I will add a diagram of it if I can got on my pc

Only thing I can advise is get rid of that water rail. I'm saying that because I had all sorts of problems with one and going back to the OEM thermo fixed it.

A diagram will help as well.

I'll make a diagram asap but the water rail is my only option, theres about a rizzla paper between the bulkhead and the head

The heater feed/bypass hose is the wrong side of the thermostat as designed, so the engine boils before the thermostat has a chance to open, i dont think there is the possibility to relocate the bypass hose closer to the thermostat to allow normal operation.
As a fix, remove your thermostat, check it works okay, then drill 2 3mm holes in the body of the thermostat to allow a degree of coolant bypass.
It's a bodge, but will allow suffcient bypass flow for the thermostat to work correctly.

Dave

Drilling the thermostat will probably be enough start with a couple of 2.5 mm holes.

The old thermostat had a 3mm hole in it and I had the issues, the new one has one 5mm hole in but I'm yet to install it. Here's the diagram, not the best but it'll do I guess.

Is the heater working fine, and able to stop the engine boiling if set on full blast hot?
If not, you might have cavitation/airlocking issues compounding your problems.
I can't see any major issues with your cooling circuit layout, the only thing which may yield an improvement would be feeding the header tank directly into the bottom hose instead of the radiator side feed.
To further improve the bypass flow at the thermostat, you could make a sandwich plate to go under the thermostat, and move the heater tee into this plate.
I cant find an escort one, but something like this

Dave

I can put the expansion tank into the bottom hose, that's no bother, the sandwich plate sounds like a good idea to me. Surley someone must make them for crossflows housings.
The heater don't get as hot as it used to, just warmish and it won't stop it boiling over

[Edited on 19/12/15 by Millworm]

I moved the expansion tank hose to the bottom hose and it's perfect now!!!

Cheers guys I was about to buy a pack of matches instead lol

[Edited on 19/12/15 by Millworm]

Yes the hose for the header tank should as close to the rad on the bottom hose. I would plumb the return from the heater into the bottom hose as close to the water pump inlet as possible. That's how the OEM is plumbed.