radiator cap

[Charl]

im sure there is a post some where but browsing is a problem. just a quick one: what is the preasure rating on the radiator cap? i can't find anything in the manual and mine needs replacing. is it ok if i buy a temp from a shell garrage or something?

[Draco]

You got me there mate.....I sent him your detailes thanks....

[Toby]

Get one from Nissan - I did. Don't know what the pressure rating is tho, but it's an acceptable purchase, about R65.

[Charl]

he just called, will return his call later, can only take calls between 12 and 1 today

thanks

[tanaka]

1.1
aftermarket 1.3

[Charl]

after market radiator? why is there a difference>

[tanaka]

A 1.3 bar radiator cap will reduce operating temperatures in your engine and is a great performance add on. If you're running a higher pressure on your cooling system it helps keep the temperature down on the entire system, by raising the boiling point of the coolant. This will help during hot operating conditions like running the air conditioning while climbing hills, long road trips, bumper to bumper traffic, and high performance track or strip driving. It's especially helpful if you live in a warm climate. got it from the box of a NISMO CAP

[Charl]

Oooo ok, it makes sense, in a way, well if the box says it you can trust it.

maybe i make this more technical. does higher preassure not cause more friction between molicules and a higher temp? or does this only apply to a gas and not a fluid. im thinking that the higher preasure cause as a higher flow rate so there will be more circulation through the radiator and a higher cooling rate.

[johansx]

If you burst a waterpipe at 1.3 bar, the results will be much more spectacular, specially the much warmer coolant
I would rather get a more effective / bigger capacity radiator than run higher pressure system. My 0.02Zim$

[Charl]

Ok so now all of a sudden my water is emptying itself through the expansion tank. i recently replaced the radiator cap and the highest i could get is 15 psi which is almost 1.1 bar. (the big cap, not the small ones like on the stock radioator) i cant find the previous one to compare my question is when it heats up it goes in to the expansion tank, but when it cools down, it doesn't 'vacume' the water back in to the system from the expansion tank like its suposed to

[johansx]

Leak in your system, either the pipe outside is sucking air, or the inside system sucks air. Since the water goes to the bottle outside, my guess is that the pipe sucking back from the reservoir is leaking. Probably where it fits on to the radiator side.

[Charl]

aaah... the outside pipe