Hi

Thanks for the radiator advice -

Would anyone be kind enough to help me with the following?

1) What year/model Polo radiator is suitable?

2) I'm running a raceline water rail - what pressure cap is needed? I have a 13lbs but not sure that is enough?

Thanks

Rob

Fit the original thermostat housing back on and your overheating issues should disappear. Just make sure you have a by-pass hose plumbed in.

[Edited on 31/7/15 by britishtrident]

Having had two Raceline rails. I can honestly say the best coarse of action, space permitting is to re-plumb as intended with the oem stat housing.

It doesn't look trick, it doesn't look fast. It just works !

Like BT said..

I had a race line rail and it was a nightmare, overheating, overcooling.. Problem with it is the thermostat is too far from the head and doesn't get hot enough to work properly.

Peeps drill a hole in it and that's just a bodge.

I went back to the oem thermo housing and all was well straight away. As said make sure you have a bypass plumbed in.

Just goggle polo rad and they are all the same, both inlet and out are on the left with the thermo switch in the middle. Should be cheap enough although there is some full Ali ones if your rich...

Good luck!

Steve

This is the one I used. 1.3 MkII polo rad VW303

here

Details of my fitting here

[Edited on 31/7/15 by tims31]

is it a silvertop and if so did you fit the correct waterpump a 1.6 escort one is the one that's needed if you have a Mondeo on the impeller is the wrong way round

This is how I plumbed my zetec / raceline, and it worked perfect, and is still fine the new owner has dome several thou UK and Europe.

Raceline cap is a plain type Austin 1300

Header tank is some BMW and incorporates the pressure cap, I think I have another one of these if you want it.

Pipe from just below the raceline cap to the small connector on the pressure side of the tank.

Bottom hose to the bottom of the Expansion tank.

Pressure cap on tank must be the highest point of the cooling system.



Description

If you look at the design of thermostat the lower half of the thermostat contains a bulb that contains wax this is the hot or engine side of the thermostat and is the part that operates the valve and it requires constant flow of coolant over it, if not it will not respond to changes in coolant temperature. This constant flow of coolant through the engine from the cylinder head back to a water pump inlet is the by-pass circulation.

1950's and 1960's engines such as the BMC A series had a very short 1/2" bore hose directly joining the cylinder to the water pump to provide the by-pass flow.
From the early 1970's manufacturers started to increase the by-pass flow by using 5/8" (16mm) hose and put the by-pass flow through the heater plumbing either by using constant coolant flow through the heater or if a water valve controlled heater was used an "H" connector between the flow and return.
More recently manufacturers have moved to even higher by-pass flow rates by using large bore hoses in an effort to even out the temperatures from top to bottom within the engine and reduce the changes in coolant temperature as the thermostat cylcles open and closed during cruising.


As already discussed earlier in the thread the Raceline water rail puts the thermostat in what is effectively what plumbers call a "dead leg" there is no coolant circulation around it when the thermostat is closed. To get it work really well would require drilling and tapping the rail very close to (ie below) the thermostat to fit a spigot too take an ideally 5/8" bore hose connected to the "suction" side of the coolant system.
Even with this by-pass layout drilling a couple of 2 mm holes in the thermostat also helps because it reduces the thermostat response time and makes getting the air out the system easier when filling.

The another effective solution would retain the water rail but use an external thermostat but only one with 3 hose connection, these are available from Car Builders Solutions or you can use the Land-Rover/Rover PRT but this can lead to some very ugly plumbing

[Edited on 1/8/15 by britishtrident]

Thanks for the advice - I was talking to the driver of a Westfield at Mallory Park yesterday - he used to run a raceline water rail (the car ran hot) he now uses a Dunnell (with the thermostat in the original poisition) and the car runs nice and cool.....