Ok I need to upgrade the radiator cap

Can i buy one from Canadian Tire and what psi cap should i get if i want to upgrade it?

I found this post on the "big fat cooling thread"

16psi cap (Stant 11233). Raises boiling point of coolant.
what does stant mean?

 

Why do you *need* to upgrade the cap?

IMHO, higher pressure caps aren't a good idea. I believe it can put more stress on the water seals, and you really shouldn't be running temps so hot that you need a better cap in the first place.

With good fan control and the temps in check, you're just fine.

Dale

 

+1

Quoted from the cooling thread:

117C (243F): dangerous. boiling point of pure water with 13psi pressure cap.
124C (256F): way too hot. Boiling point of pure water with 19psi pressure cap. Boiling point of 50/50 coolant mix with 13psi pressure cap.

Running a 50/50 mix at 13psi gives you a boiling point of 256F. You should only reach that if something goes very wrong (i.e. thermostat sticks closed or WP fails), and then the increased boiling point isn't going to help. Running higher pressure on a working stock cooling system just puts more stress on the rubber components without any useful gain in cooling ability.

 

About a year-and-a-half ago I had one of my fan motors to quit and when it happened coolant boiled out the top of the cap, so when I replaced the fan motor I just went ahead put the GReddy 1.3bar cap on mine. Of course it did cost me $30 plus shipping but I don't think it'll ever have to be replaced again.

 

One thing to consider is how the coolant is getting hot. It's getting hot because the metal parts inside your engine are even hotter, and the coolant warms up as it flows around them.

Let's say your car is sitting and idling. The motor isn't producing much heat, but there is no airflow through the radiator so the cooling system isn't dissipating much heat either. If the fans are not activated, your coolant temps can go as high as 230-250F and continue to rise. To me, this is a pretty good indication that the metal parts inside your engine can get even hotter than 250F.

This example assumes you are sitting at idle. I can guarantee that your rotor housings are getting a lot hotter when you're at full boost at high RPMs. For reference, I attended an engine dyno session yesterday: a 4-cylinder that produced 300HP at 7000 RPM made about 30HP at idle.



To summarize, what I'm trying to say is that even though the AVERAGE coolant temps are below the boiling point of the radiator cap, that doesn't mean that the entire system is below that boiling point. The last thing you want is for your coolant to boil at the hottest spots inside the engine. There is an excellent book called "Tune to Win" by Carroll Smith, among other things it has advice on what works well for cooling systems in race cars. Check it out sometime, it's a great read.




Regarding the meaning of Stant 11233, I'll give you a hint: "11233" is the part number. If you still need help, try www.google.com

 

Unless you're talking about a car used for road racing, is the 7F increase in boiling point with the 16psi cap significant? I could see increasing the boiling point with the intent of running 100% water, but with an antifreeze mix in a street car? I guess it can't hurt, but the trade-off is pressure on the system components (not that much of an increase of course).

 

It was significant enough for Mazda to do a recall and fit the car with better clamps, replace the hoses and lower the pressure to prevent under the hood fires

 

sorry to get off topic, but thats a very interesting...program ^^^ at the bottom of the sig. It knows my ip address, my provider, operating system and even the version of my internet explorer, I wonder what else it knows about my computer..lol

 

That's what I was getting at - is the increase in boiling point worth the extra pressure, going from 13 to 16psi? I think Mazda reduced it from 19 to 13psi, a 30% drop in pressure, which is definitely significant.

 

They dropped it from 1.1bar (16psi) to .9bar or (13 psi). I chose a different route and went with a waterless coolant with a boiling point of 375+ at zero pressure. Figure it eliminates two of the causes of the failures in our cars (most cars) 4+ years on the same coolant no hose failures, and so far no signs of electrolysis. Some feel it's a band-aid I just haven't figured out that is.