Cortina radiator pressure

[milliemarlin]

I have what I believe is a Cortina radiator in my car (Millie). Since fitting the new engine (new somehow becoming 13 years old) I’ve had a niggling problem in that when running hot, water occasionally comes out of the rad overflow. The set up has an expansion tank fitted with a Ford Sierra, Focus, etc expansion cap but retains the expansion cap on the radiator. It’s not been a big problem so I’ve not dedicated any time to it. Now I come to look at it the problem is obvious the Cortina cap is set to 13lbs while the later Fords use 18lbs so of course the water is pushed out of the rad cap before venting the expansion tank cap. An easy fix for this was to fit a racing style cap rated at 21 to 25lbs.

The worry is; can the rad take the increase from 13 to 18lbs pressure? Does anybody have any experience of running Cortina radiators at higher pressure?

I’ve had a couple of outings in this hot weather, parking up to get the rad fan running, and so far so good.
Paul

[b_caswell]

Re: Cortina radiator pressure

I don't think you need two pressure caps most systems work either pressure cap on rad and then open expansion bottle or have a blank cap on the rad and
a pressure cap on the expansion tank.
For every pound of pressure exerted on the coolant in the system, the static boiling point
of the coolant is raised by approximately 3° F

[Dane_Rescueman]

Re: Cortina radiator pressure

Hi. On my Pinto powered Berli I have moved the radiator further forward to greatly reduce the gap between it and the front cowl. This means that it is difficult to gain easy access to the rad filler cap.
I have installed a Ford Ka header tank elsewhere in the engine bay which has a pressure valve type cap. I’ve fitted a plain (from Burton) cap to seal the radiator filler.
The Ka tank has a large outlet: to feed the connection at the water pump and a small outlet, that takes an 8mm hose. This connects to the rad overflow spigot to seal the rad to the system. A tee piece also connects this small hose to the bleed spigot on these later Pinto (Sierra) water pumps.
The system has worked faultlessly since installation with no leaks. The rad takes the 1.2 Bar of the Ka pressure cap with no problems. Cooling is great. I drive very long non-stop journeys in UK and the temperature is rock steady. In France last year it stayed at the correct temperature despite sultry temperatures in excess of 32°C.
This system has been in the car for at least six years.
So, if you fit a pressurised expansion tank, the rad only needs a plain cap. Either blank off the radiator vent tube or, as in my case, connect it to the small outlet on the new expansion tank (if it has one.) Good luck with it

[kahawi]

Re: Cortina radiator pressure

No idea what/which/who’s radiator ‘Ula’ has, but this is our arrangement. Copper Rad fitted on it’s side (and flow is reversed)! With blanking cap in the ‘top’ hose, the overflow goes to the bottom of the bulkhead-mounted expansion tank, which has a 13lb cap fitted.

IMG_0149.JPGIMG_0151.JPGIMG_0150.JPG

Only problem I’ve had with high-pressure rad caps (Citroën) was with an elderly aluminium radiator that I stupidly pressure washed, thereafter it leaked like a sieve!

[milliemarlin]

Re: Cortina radiator pressure

My thanks to all who have responded to this thread.

As you may have read elsewhere my trip to Portugal has given me the chance to really put Millie’s cooling system through its paces.

First a while before leaving I changed the rad cap to one rated at 21-25 psi. Ben is right to say a blank cap would have been better and cheaper. I also extended the overflow hose as coolant was getting blown onto various places in the engine compartment. It was while I was fitting this I noticed that the jubilee clip on the bottom radiator hose had not been seated properly and some coolant was leaking from there. That was quickly remedied.

I also changed the Omex Engine Control Unit (ECU) to switch on the rad fan at 85 degrees. According to the ECU In normal running the engine runs at 83°. The dashboard thermometer displays 90-100° when up to normal temperature. The fan kicks in when the dial shows slightly over 100° and switches off at about 95°. I’m not sure why the two measuring devices differ so much. They are both located in the same housing at the rear of the engine.

So far normal running which included some fairly long motorway climbs in ambient temperatures of over 70° the engine maintains a steady 95° on the gauge. In traffic including steep uphill on a hot Portuguese summer day in stop start traffic the fan keeps the temperature between 95 and 100°. No leaks.

So, touch wood, all is going well.

Except, one little anomaly; when bombing along the motorway, in blighty, the heater is not very warm. That is at 70mph or 2,500 rpm. When I slow down for a junction or something the heater wakes up. Over here when I blip the throttle or use higher revs for engine braking or to accelerate in a lower gear the coolant temperature goes up a few degrees for half a minute.

It’s as though the impeller is not quite circulating the fluid quickly enough unless the revs are quite high.

Has anybody else noticed anything similar?
Paul

[Dane_Rescueman]

Re: Cortina radiator pressure

It may be that you have a lazy thermostat. I have the 88° one which has worked well with the rest of the gubbins.
90° to 100° is OK for a Pinto. I have never found Temp gauges and senders to agree on exactly the sae temperature. I set the dial for my fan to cut in a about 102°. It shuts off at around 90°. It only comes on when stopped in traffic anyway. When moving the temp stays rock solid at 90° (on my present sender and gauge from VDO).
Hope this helps.