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General Car Related Discussion.To discuss anything that is related to cars and automotive technology that doesnt naturally fit into another forum catagory.
Hi i have a cosworth headertank on my XR4i. And want to increase the pressure of the cooling system.
I think the pressure of the header cap is aroun 1.2 bar. But want to increase the pressure to1.4bar are there any caps around? if not what could be an option to do this?
Id agree with Glenn, it seems the problem is elsewhere, Id not advise turning the pressure up anyway as it puts undue stress on everything in the cooling system.
if its not a bad air lock or head gasket issues then Ive heard of people use Evans waterless coolant, I cant recall the results but it should help the situation.
Edit: and with the waterless coolant you reduce the pressure in the coolant system as iirc it behaves differently to water, its not cheap mind.
No it isn't a gasket. The car does fine when normally used.
The block is o ringed to prevent gasket faillure.
The coolant going to the radiator is 96 degrees which is already on the hot side
the waterless coolant boils later and has less pressure. But you also need to have a good cooling system as it will absorp less heat than water
i have a cosworth radiator in it. Which i believe should be plenty enoug for the job.
most people with a tuned 2.8 cologne have heat problems.
big radiator bigger pump etc. all doesnt help.
im goinig methanol injection, bigger cooling surface and a lower stat. But also wanted to increase the pressure in the cooling system a bit
I think a double depth radiator would fit it. Do not forget though that some cossies ran turbo after coolers between the turbo and the expansion tank so you could surely fit one of those anywhere (if not in the place where a cossie had them) and even run a 12v pc fax X2 on it if in remote location.
The turbo after cooler on a Cos simply fits to the water outlet on the Turbo and then feeds in to either a swirl pot or to the header tank. I guess you could fit it anywhere that has flow though.
No it isn't a gasket. The car does fine when normally used.
The block is o ringed to prevent gasket faillure.
The coolant going to the radiator is 96 degrees which is already on the hot side
the waterless coolant boils later and has less pressure. But you also need to have a good cooling system as it will absorp less heat than water
i have a cosworth radiator in it. Which i believe should be plenty enoug for the job.
most people with a tuned 2.8 cologne have heat problems.
big radiator bigger pump etc. all doesnt help.
im goinig methanol injection, bigger cooling surface and a lower stat. But also wanted to increase the pressure in the cooling system a bit
If you are using Evans, then a higher rated cap is utterly pointless, as the system should be making minimal pressure in the first place. Your problem is elsewhere. If you're barfing out of a 1.2 bar cap, a 1.4 bar cap isnt going to make a damn bit of difference.
Either there is a HG issue, or a design flaw with the system, or you've too much coolant in it.
I was taught from a very young age by my father "the coolant and the air are free, make sure both are flowing freely"
As long as your current cap is sealing and holding a few psi of pressure I can't see what your going to gain by changing the cap other than a very small amount of temperature increase before boiling point reached
I would suggest you either have insufficient coolant causing an overheat issue, flow of water, and air through core needs checking, or you have combustion pressureizing the coolant.
I've had this several times on machines and it only takes a few flutes to be blocked in the radiator to cause issues, light load scenarios will be fine but full load flat out temps quickly rise and will boil and blow water out
Obviously check thermostat is fully opening as well
The car went on the dyno and suddenly barfed it out. The tuner also thoughed it was the gasket. We topped the car off and hit it again after 10minutes and it didn't barfed it out. So probably an air bubble.
He said that the car just ran hot when its stepped on. And with 140km/h of driving wind it took long for the car to reach a notmal temp again.
It's pretty hard to blow a gasket in this engine. Not impossible but still pretty hard.
i need some more cooling.
i try to do that with a larger surface area on one of the coolant pipes. Im also going to replace the water pump. And to lower the normal working temp of the engine, its going to have a lower opening temperature of the thermostat.
i can put the turbo aftercooler in line with the mateix heater in the car.
Imo you have some sort of blockage within the cooling system, wether the thermostat is jammed shut or the radiator is blocked as a couple of examples. I had a 2.8i Capri that done this many moons ago now, was getting hot, building pressure in the cooling system and spitting the water out of the heading tank after driving.
I immediately thought head gasket but fortunately it was the radiator that was blocked which was a much easier and quicker fix not to mention cheaper. I would flush your cooling system and check everything is as it should be, stat, pipes etc and go from there.
Fitting the aftercooler behind the intercooler wouldn't make sense in my case. The supercharger belt is in the way. And the coolant needs to go from bottom of the engine to the top and go down again.
It would be good to check the coolant system again. Got everything flushed 4 years ago. Didn't had any problems tho. No crap came out of it then. Radiator is 2 years old and so is the stat.
Problems kind of started when the original radiator was replaced with the cossie one. But for the 180hp that wasn't a real problem.
Im going to check to be sure tho. Still the problems begin at low speeds and at high speeds it will happen but it takes longer for the temp to creep up. It will cooldown again but the system just can't take the heat at low speeds
Increasing the pressure isn't the best remedy but still better thanlosing coolant.
So if anybody knows where to get a diffrent cap. I would still like to hear it
Last edited by carbon1993; 25-01-2020 at 02:45 PM.
OEM, cheap copy, chinese alloy ? quality ? other ?
If the problem is at low speed or even cruising etc....then power you think the engine has, has fuck all to do with it. Because at cruise...it isnt making xx bhp.
Airflow is all important...only cool air in the front and through the rad, never around it. And hot air has to be able to escape. The fact you say the problems started when you changed the radiator....well...has to point at something to do with that radiator install.
It has an airtec black big core rad. The things that got changed with that is surface area and top feed location of the coolant to the radiator.
the hot coolant needs to travel down 30cm before it can reach the rad.
driving it normally the temps are good. and the coolant stays in.
The things i did/planning to do is: watermethanol injection, oil cooler, a coolant pipe with cooling ability due to large surface, a colder thermostat, increasing pressure and if it fits an turbo aftercooler in line with the matrix heater.
It also gets an extra coolant temp sensor to see how much the coolant cools through the rad.
all bits should help and these methods will not cost much compared to another rad which i have no room for.
Last edited by carbon1993; 25-01-2020 at 03:04 PM.
as it is an 2.8 v6 the coolant top feed to the rad is at an lower location. Because the xr4i rad doesn't have an intercooler above it, the xr4i one is taller and has more surface.
as it is an 2.8 v6 the coolant top feed to the rad is at an lower location. Because the xr4i rad doesn't have an intercooler above it, the xr4i one is taller and has more surface.
That is a good step up radiator for a 2.0 Cosworth engine but you are using it on a 2.8 supercharged V6? Have you enquired if there is an alloy high capacity radiator to suit your V6? I personally do think it is not man enough to cool your engine properly.
That is a good step up radiator for a 2.0 Cosworth engine but you are using it on a 2.8 supercharged V6? Have you enquired if there is an alloy high capacity radiator to suit your V6? I personally do think it is not man enough to cool your engine properly.
If the rad is of good quality, and it is installed to ensure only cold air through it, and never around it etc etc....then it should be ok. It's not making that much power.
Although would there not be room for an intercooler in front, and a full size radiator ?
Heights etc of inlet pipes is not a concern as long as you are not trapping air.
got a bleed line on the highest point in the engine so that air can come out. I haven't enquired a high capicity one. thought this would do the trick but its all guess work.
There is some room to fit an intercooler in front of the radiator. But thean the chargepipes will be verry long and diffucult to make.
Some one that has the same engine but running 380hp twin turbo has an custom radiator with the normal xr4i length but also experience about the same problems.
got a bleed line on the highest point in the engine so that air can come out. I haven't enquired a high capicity one. thought this would do the trick but its all guess work.
There is some room to fit an intercooler in front of the radiator. But thean the chargepipes will be verry long and diffucult to make.
Some one that has the same engine but running 380hp twin turbo has an custom radiator with the normal xr4i length but also experience about the same problems.
It is a case of checking everything twice that is involved with the cooling system. Water pump, Fans thermostat switch , Are the fans kicking in when they should, Water thermostat, Is the radiator completely clean , are any waterways in the engine partly blocked, etc etc. We are in Winter with cooler temperatures , what will it be like when there is hot Summer weather. Now is the time to sort out the cooling problems so you have no problems later on Best of luck!
I fitted a Modine oil cooler to my 2.9 twin turbo when I built it. Iol temperature was fine but the coolant temperature was too high. I replaced the Modine with a thermostatic sandwich plate and Mocal 13 row cooler. Oil temp is still fine and the coolant temp is now back to normal. The cooling system couldn't cope with the extra heat from the oil as well. Fitting an oil cooler will reduce the heat being dumped into the cooling system so it may be your best bet.
20-01-2020, 09:23 PM
increasing header tank pressure
