PDA

View Full Version : help fast please!!



'A20A3'
05-22-2003, 11:04 AM
i really need to change my coolant, and i was wondering if it's ok for me to put all water until i change it again this weekend. it's warm outside, so i don't see why i would need to put anti-freeze in. i'm just checking to see if my radiator is rusted out, and i'll be putting new shit in this weekend too. but need to know if in the meantime, would it be ok just to put water in??

Mike's89AccordLX
05-22-2003, 11:11 AM
Well I'm sure the water won't last long. I wouldn't reccommend putting just water in it. And you do need coolant in the system on hot days to cool the engine. It's not just for when it's cold.

AccordEpicenter
05-22-2003, 01:34 PM
you need to put coolant in because it has anti corrosion properties, and thats important, because you have an Iron block and an aluminum head and an aluminum radiator... The interactions between the 2 metals can corrode stuff in the engine so its best to use a 50/50 mix of antifreeze and water.

95AccordEXR
05-22-2003, 04:11 PM
it won;t hurt to put water in temporarily.

SiR
05-22-2003, 09:19 PM
Water has better cooling properties and its safe to use use for a short time like what 95AccordEXR said. Coolant is just added so its not as corrosive then pure water. Like pure coolant is not going to cool down your car any better.

ACCORD EX
05-23-2003, 12:36 AM
coolant is not only for cooling issues ! it's for conserving the radiator !

MIKE

cruznz
05-23-2003, 12:49 AM
Originally posted by SiR
Water has better cooling properties and its safe to use use for a short time like what 95AccordEXR said. Coolant is just added so its not as corrosive then pure water. Like pure coolant is not going to cool down your car any better.

Antifreeze conducts heat better than plain water , so it cools the engine better...which is why it's recommended for hot weather...as an example....the a/c increase's the temp of the air flowing thru the radiator,...antifreeze can help prevent overheating in hot weather

It also prevent's rust and corrosion by providing a protective film over parts surface, lubricate's the waterpump for prolonged life,and as it's name suggest's,prevents coolant freezing

2twisty
05-23-2003, 06:27 AM
Antifreeze does *NOT* conduct heat better than plain water.

The reason that its recommended in hot weather is because a proper mix of antifreeze and water will RAISE the boiling point above 212*F, therefore allowing the car to run in hotter ambient conditions.

Talk to race teams. If they use water at all as a coolant, chances are it's pure, distilled water.

To answer the poster's question, you're not gonna hurt anything by running pure water for a couple days. If you did it for months, then yeah, I'd be worried about rust and other corrosive actions.

Antifreeze does not revent corrosion because it "coats surfaces." It prevents corrosion because it keeps the water from acting on the metal surfaces.

It does have lubes for the water pump, though.


Chad

mindlos
05-23-2003, 08:37 AM
Water has one of the highest specific heat capacities of liquids, especially compared to organic compounds. So water will take up a lot of heat and dump it too without as much variation in operating temp as other liquids, including pure ethylene glycol (contained in antifreeze). Water has more intermolecular hydrogen bonds and less steric hindrance found in larger molecules. Mixing the two leaves you with a less capable cooling mixture but there are other advantages.

Here is the specific heat capacity of popular liquids (this is the amount of heat in KJ or BTUs that a known mass in kg or lbs will absorb for its temperature to rise by a degree, Kelvins or F).

Liquid - kJ/kg Kelvin | Btu/lb Fahrenheit
Acetic acid - 2.13 | 0.51
Alcohol - 2.93 | 0.70
Ammonia - 0.47 | 0.11
Ethylene glycol - 2.38 | 0.57
Oil, mineral - 1.67 | 0.40
Water, fresh - 4.19 | 1.00
Water, sea - 3.94 | 0.94


Colligative properties of liquids state there will be a boiling point elevation/depression + melting point depression when you mix with other substances. Close to pure water you will have a lower b.p. than water because water has ideal bonding and everything else breaks ideality. However, ethylene glycol boils at 387 *F so at bout 50/50 your b.p. will be alevated to somewhere close to the midway of 212 *F and 387 *F.

Melting/freezing point will always be depressed and it is determined by how much you add. However once you get less % water it start going back up again coz that of pure ethylene glycol is 9 *F.

Galvanic corrossion is when you have dissimilar metals that are brought into contact with water and causes one or both metals to corrode. The metal that prefers to be in ionic state more than the other will always corrode faster that it normally would by itself. Furthermore it is hard to keep water none conductive because it reacts with the metals and carbon dioxide makes it acidic. Antifreeze has agents to combat that. You always have to provide a substance that prefers to be in ionic state more than the metals you are preserving or you can prevent the dissimilar metals from being connected conductively by coating them so that the water does not interface directly with them.

lubes...etc...etc....

2twisty
05-23-2003, 09:56 AM
He had the science to back up what I said, so...

"Yeah, what he said."

Chad

POS carb
05-23-2003, 02:41 PM
lol
nah it's true, water does conduct better but if you're using straight water for extended periods then get a corrosion inhibitor like Prestone Super Anti-Rust

cruznz
05-23-2003, 09:14 PM
hmmm,....seems i've opened up a can of worms here.

Do you really think its worth putting anti-freeze in to a race engine that gets stripped down after every race? There is no need for it.
You cant compare race cars to passenger cars
I'd suggest you do more research , or i can copy out all my documentation for you from R & D at Caltex which i have in my workshop

Mike's89AccordLX
05-25-2003, 03:27 AM
Well since we're getting into the chemistry discussion I will call up a friend and ask her what she thinks. (She's the person I copied off of :) )