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Discussion Starter · #1 ·
I'm going to attempt to switch to the Evan's NPG+ non-aqueous coolantand I need to completely flush as much of the standard coolant as possible.

I'm just curious how I should go about accomplishing this. Any water in the system is considered an impurity and will degrade performance slightly so I need to get as much out as possible.

Aside from a standard flush, any ideas on getting the remainder of the water out of the cooling system?

More on how it works: http://www.evanscooling.com/html/tech1.htm

Dubbya~
 

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Aside from a standard flush, any ideas on getting the remainder of the water out of the cooling system?[/b]
i too would start with a flush, and probably even flush the system out several times with just water so as to be sure all of the old coolant is out of the system (do not forget to run the heater and flush that loop out as well). i believe that by simply removing the drain plug at the base of the radiator, one would be able to remove only about half of the fluid in the entire system, possibly a bit less than that even. the engine block drain plug out to be removed, i would also pop off the lower radiator hose, as this may sit lower than either drain plug. disconnecting heater hoses and making sure those drain would also be something i'd check.

and then, the fun of filling the system back up, minus the inevitable air bubbles. keep us updated on how well this new coolant works for you.
 

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If you have access to a high vacuum pump you could use this. Flush & drain as much as poss and then connect the vac pump to a hose and let it suck (blank off the fitting the hose went on to with a flat plate and tape, you don't want to suck anything in. The pressure will drop rapidly until you reach the boiling pressure for the ambient temp. The vac level will stabilise until all the water has boiled off and then suddenly start to drop again. This is when you know you've shifted all the water.
Kev.
 

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Discussion Starter · #4 ·
I don't have access to a strong enough vacuum pump (vapor pressure of 50/50 glycol is only 270 mmHg and would thus require more than 490 mmHg of vacuum), and flushing with water may not be an option as water is the primary contaminent to avoid!

I do have access to a compressor ... but I doubt it will be terribly useful. It may help a little though.

In emergency situations they reccomend topping off the cooling system with certain other coolants. (Assuming more NPG+ isn't available) ... so I may be able to use these to flush the cooling system.

I did buy 3 gallons of the NPG+ coolant, which is .7 gallons more than required by the 9-3's. I may be able to use about half of one of the containers to attempt to flush, but I want to have some in case I need to top off so I probably won't do that.

Also I'm considering the 82 degree 9000 thermostat instead of the stock 89 degree 9-3 one. Any oppinions on if this would be helpful? It rarely gets below freezing here (if ever) and often goes well past 100F. I'm just curious whether the ECU will put up with a different coolant temp.

Dubbya~
 

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Methylated spirits (wood alcohol or denatured alcohol in the 'States???) will "dilute" water.
Do a thorough clean with ordinary water and then get as much as possible out by normal means.
Now flush through a couple of times with meths and the residual water in the system will be insignificant.
Now evaporate the remaining meths by blowing through with compressed air until the smell has gone.
Job done.
Since meths is used in huge quantities to remove polish from paintwork before respraying, it must be dirt cheap by the drum.
 

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I would flush several times, then manually drain at the various drain points as mentioned, then remove thermostat , and connect a blower onto the system, leave running for a while, moving dry air (hopefully of low humidity)in california should easily pick up and blow through all moisture in the system fairly quickly.
 

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Originally posted by Adrian W:
[qb]Also I'm considering the 82 degree 9000 thermostat instead of the stock 89 degree 9-3 one.  Any oppinions on if this would be helpful?  [/qb][/b]
The 82 stat is better for performance, the 89 for economy.

I did some tests on the stats a while back and found that at 100 deg C the 82 is significantly further open than the 89, so will flow more coolant through the head.
 

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Discussion Starter · #8 ·
In regards to the thermostat I'll think I'll keep the 89C one for now. If it runs hotter I'll install the 82C to keep temps to where they should be. I'd like to maintain the economy of the 89C t-stat if possible.

I've been reading up on places that have tested this stuff. Several said that they were unable to get hot-spots in the head. That sounds somewhat un-important, but if you've ever noticed a significant difference in power related to coolant temp this stuff will behave like your current coolant does when cool. (In regards to detonation sensitivity anyhow.)

Even on very hot days my car runs quite a bit more power when the coolant is first warming up at around 80C than it does when it reaches 100C operating temps. If this stuff has the same effect for me I may have solved my hot weather woes.

Also I thought I'd note ... while it's been pointed out that this stuff has a lower specific heat than water or 50/50 gycol/water ... it has a considerably higher heat of vaporization and is denser. Since most of the heat is transfered out of the head via boiling (Just like when you boil water on the stove) a liquid with a higher heat of vaporization and high density should cool far better.

We'll see though. I'm kind of getting excited about it. Hopefully it's not a let-down. I e-mailed the folks at Evans and they said a 5% impurity of remaining coolant in the engine was not a problem and that it would find it's way out on its own for the most part. But I'm still going to shoot for as much as I can get out.

Dubbya~
 

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Hi Adrian,

I looked at the Evans site some time ago, but was put off by the suggestions that it may require the use of a different waterpump and/or radiator. Do you know if Saab type waterpumps (are 900/9k/93 and 95 all of same type?) will function OK with this fluid?

Look forward to hearing the results of your pioneering.

Kevin
 

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Discussion Starter · #10 ·
Their standard NPG is very viscous and requires a stronger pump, but the NPG+ is brand new and less viscous. It's supposed to be a "pour in" solution. But I will report back when it's done!

Dubbya~
 
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