Overcooling with Raceline water rail

[dave_t]

I picked up my first ever Westie a couple of weeks ago. I've only been out for a couple of drives since then, but have noticed that my engine (Zetec 2.0l; no heater) runs very cold (~70deg when moving).

Searching here on shows that this has been quite a common problem in the past, and was solved by putting in a bypass pipe to take the radiator out of circuit whilst the engine warmed up. However most posts seem to address 'normal' set-ups (i.e. no Raceline rail).

Is this standard practice with Raceline water rails, as well?

If so, where is the bypass pipe taken to/ from? (I have the necessary T in the metal pipe from the radiator - which is blanked off at the moment - but can't see/ find out where this needs to go at the engine end? Is the take-off for the heater on the Raceline rail used?)

Sorry for the newbie question    I've searched but can't find any info answering this point (i.e. with a Raceline rail)

[CedricTheBrave]

Firstly check it has a thermostat fitted as some are removed from the rail to prevent heat surge when it opens, if it is there then check the size of the whole drilled in the stat as it may be too large. thirdly you can add the bypass using the heater take offs as you mention.

also do another search there is quite a lot on this subject

[markcoopers]

Idearly the ford thermostat housing has a main outlet direct to the radiator top, a smaller warm up circuit under this that should tee into the radiator return house and needs to be 16mm ID. A heater outlet facing the inlet side that can be used and returned back into the bottom rad return and a small breather tube from the top that goes to the expansion tank.

Running without the warm up circuit depending on set up will mean the rad is in constant use and thus will never warm up.

As the water heats up and the thermostat opens, it blanks off the warm up circuit.

The raceline kit i am not familiar with but if it removes this circuit and just uses a thermostat to open to the rad, then it should reach the temp for the thermostat to open, but you are running the risk of the water in the block being very hot while that water in the rad and the rail very cold.....

I am sure there are plenty that like the kit and swear by it, but personally.....use the Ford designed kit, it work.

[Tim Ellershaw]

Firstly check it has a thermostat fitted as some are removed from the rail to prevent heat surge when it opens, if it is there then check the size of the whole drilled in the stat as it may be too large. thirdly you can add the bypass using the heater take offs as you mention.

also do another search there is quite a lot on this subject

I agree with ^^^^

I have the same setup (2L zetec, no heater, Raceline water rail)

Didn't have a thermostat in when I bought it, and did exacly what yours does.

Fitted a standard Ford thermostat. Was advised to remove the small ball-bearing pressure relief valve bit and make the hole a little bigger to allow a small flow around the system while the engine is warming up. Working perfectly now.

cheers

Tim.

[dave_t]

Thanks for the replies  

From these, plus some further searches (I've managed to find a couple of posts that are relevant), it seems that a rad bypass shouldn't be needed with a Raceline water rail.  So I don't plan to put one in (to cure my overcooling).

I 've now checked my thermostat, and there are 3 holes (each a couple of mm) drilled equidistantly around the edge.  So it looks like these are letting too much water through, and hence the engine never reaches temperature.  I'll replace it, and put in just a single smaller hole, and see how I get on

[ljsanders]

I had a waterrail fitted by Raceline themselves to my 1800 zetec, a few years ago.

The system he fitted was as they recommended, with heater, no expansion tank and didn't do the bypass mod that is suggested elsewhere on this forum. He also didn't put any drill holes in the thermostat and used a 72C thermostat (which I thought at the time was too cold).

Straight away from cold, I had heat surge. Upto 110C from cold, then the thermostat open and the temperature dropped like a stone.

I took the car back, he put a single hole in the thermostat and it fixed the heat surge problem.

In the summer the car (and on track) runs perfectly ok at around 88 to 90C.  In the winter its a bit cooler at around 75C, so I put a 6inchx8inch piece of card in front of the radiator and that solves the problem. I know I shouldn't have to use the card, but it solves the problem and otherwise its fine.

Lee

[dave_t]

Thanks Lee

I guess you are still running the 72C thermostat then?

[ljsanders]

Yep I'm on the 72C thermostat.

Before the water rail, I was on the original WF setup (mine its a factory car anyway) and it overcooled like a fridge freezer! I also have a V8 bonnet and ducted nose, so that probably doesn't help matters much.

Fitting the water rail solved most of the 90% of the overcooling but not completely. Since its ok for 8 months of the year, then I'm not too bothered by having to put a piece of cardboard to block the radiator.

Although my primary reason for the water rail was to reposition the thermostat housing after whacking the sump on a speed hump.

[dave_t]

Thanks Lee  

[markcoopers]

These engines are designed to run hot. All the drilling etc is doing is trying to get around the overcooling. Ford solved this for you, just plumb it in as the Ford man designed.....works perfectly.

OK you chaps in risk of whacking a thermostat housing on the baulk head i can see whay you would want to move it, but aluminium ones that don't crack are available.......from scrappies as well. If you do not have the bellhousing down the tunnel and are not about to whack a thermostat housing on the baulkhead/shelf, don't bother with the extra cost of a waterrail and the complications around overcooling. You are adding these problems.