OK thanks people I have established that the reason my Zetec with raceline water rail is overheating is the following:

water is drawn from the radiator into the engine water jacket, from here it enters the water rail and if the thermostat is open returns to the radiator. - Problem is I have no current bypass mechanism to allow some water to circulate around the thermostat so it opens.

British Trident offered a solution - drill a few small holes in the thermostat .

Question is how many and how small, looking on the various forums people have used one 1mm hole, six 2mm holes, one 4mm hole..........

No one seems to have a definitive answer to the thermostat I should use (74 degrees, 82 degrees , 88 degrees.)

anyone have anything to add this ?

otherwise it's experiment time

thanks

Haynes Mondeo manual says thermostat starts to open 88 degrees.

Mick

check on the westfield boardroom (www.wscc.co.uk) they have been using this engine for ages. Someone will have asked and had the question answered.

I been on the westfield forum and blatchat already seems people are using all sorts of combinations of thermostats and various size / number of holes. I think I will start wilth a 82 degree stat with one 2mm hole and work from there.

thanks

good luck - let us know how you get on as i'm slightly tempted to make a 2litre zetec my long term upgrade...... similar power to a 1700 cross flow and in standard tune.

I know I keep on about this but...Bin the Raceline unit and run it as Ford intended using the standard thermo housing and stat. I got this from Dunnel ,and after seeing the hassle Westfield had by not going this route I'm glad I followed it.

I run a standard Mondeo thermostat which is 93deg. The engine warms up nice and quick and the fan cuts in at 99deg off at 95deg (ECU controlled). The fan never comes on unless the car stops for 4-5mins in traffic regardless of the outside temp.

The problem with the Raceline unit is that it does not allow proper coolant bypass on warm up and hence you get localised heat spots in the head until the main stat opens.

Remember modern (ish) engines are designed to run hotter.

Poss answer is to sell the Raceline unit and spend the cash on something else.

[Edited on 16/12/04 by zetec]

Don't want to disagree, but add something i've heard a few times. Modern engines are designed to run hotter but to reduce emissions. for max power a lower temperature is better.

Cool air inlet good for power
Cool cylinder walls bad for power & efficency
The latter is dictated by the laws of thermodynamics.

Over cooling is very bad for the engine apart from general wear and tear and condensation of acidic by-products in the sump oil the Zetec engine with its hydraulic tappets needs to get the oil up to working temperature viscosity quickly or the tappets jack up.

[Edited on 16/12/04 by britishtrident]

Anyway I have replaced it with a new 82 degree xflow unit, with a single 3mm hole drilled in it to allow water to circulate around (and hopefully open) the thermostat.

I know there are debates running about how appropriate the water rail is, but for every person who has trouble with their water rail another is OK. The truth is I only paid £30 for the thing and it does look very good on the engine. I will have a go at getting the thing working, if I can't, I'll sell it and find some other way of plumbing the system.

thanks people

I'll let you know the results

trident, completely agree but...... i wasn't talking about overcooling, just a little bit cooler!

quote:

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The truth is I only paid £30 for the thing and it does look very good on the engine

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I know £30, was a lucky find, it was second hand from a guy who was breaking his DAX rush. However I have seen various water rails for sale on ebay / findit and the various car forums for between £50 - £80 in the last 12 months. I guess it is a case of being in the right place at the right time.

Initial results are favourable:

to recap:

2.0L zetec running twin 45's
railine water rail now fitted witha 82 degree stat with a 3mm hole drilled in it.
The stat has been fitted such that the hole is the opposite side of the stat to the water flow (I thought this was logical, the water has to pass round the wax capsule to get to the hole).

Nissan Micra Rad, fan controlled by the switch in the rad (not the one in the water rail.

So.........

Car warms up quickly to 85-90 degrees, fan cuts in at about 95 degrees and the car (sitting stationary) runs at a stable 90 degrees. I'm happy with that, we'll see how things change once we get on the road.

Idea l number of holes for a 4 cyl motor would be 3! 2 @ 2mm opposite each other and then 1 @3mm between the other 1// NOT IN THE MIDDLE!

Thats what WRC cars use