This is not a personal attack on anyone here, but I found that I have taken the advice from people here too freely.

Here is my experience, with real facts to back it up.

I had a rebuild, and it overheated slightly the day after it was rebuilt. I had no PFC at the time, so I don't know what the temps were, but the stock gauge started to move, so you can bet it was high, or it oculd have just been an air bubble, since it never happened again. That is just background info anyway. After that I started trying to find ways to make my FD run cooler. So I flushed the system and refilled with 100% distilled water, just because everyone I came across on the board says that water cools better that antifreeze/coolant. Well, shortly after that I got a PFC so I can now monitor my temps. On 90+ degree days, driving home from work in bad stop and go traffic with the AC on, I was seeing temps as high as 108C. Now I know that is still safe, but I still don't like to see them that high. But for over a month now, I have been seeing the same, anywhere from 103-108C with the AC on in the 90+ degree weather. Well, 3 days ago, I decided to flush again, and refil with a 60/40 or 50/50 mix, not really sure but I used 1 gallon of antifreeze, and I have a Koyo radiator, so whatever percentage that works out to. For the last 3 days, on my way home from work, my temps have not gone over 97 degrees and average around 92, with everything else being the same. The temps outside are still 90+ degrees, still crank the AC (not to mention how much better the AC works now since the car isn't so hot and the pressure switch doesn't turn the AC off as much).

So just be careful what you read here and don't take it as the bible. Many may come in here and still swear that water cools better than coolant, but I will never beleive it again, because I have seen it with my own eyes now.

 

Man, you got lucky. Glad it worked out in the end.

 

thanx for the rock solid info.

 

Water alone has a higher heat exchange than water and coolant mix. The problem is that it also boils at a lower temperature and there it looses it's cooling ability by not properly cooling hot spots...

This is the magic of Evans because even though its heat exchange is lower, it doesn't boil at normal temperatures...

 

After over 400 posts and you just now found out??

 

neit_jnf

You are correct. In addition, water alone will cavitate easier (for the same reason - it has a lower boiling point) in the water pump and therefore not not flow as fast, causing higher temps.

In a system with enough cap pressure to overcome these localized boiling and cavitation problems, water, alone or with an anti-corrosion additive, does cool better than water with antifreeze.

In the FD, with its hot spots, fragile coolant o-rings, and, thus, a 13-psi radiator cap, plain water does not work well.

 

Did you use any water wetter in that mix?

-b

 

If you mean in the first example, when I was running straight water, no. Well, actually, no in both cases.

 

I lost my engine recently to bad coolant seal..

So, what would you suggest??

Stick with normal green stuff and distill water? or Distill water and water wetter? or distill water and 16lb cap? or NPG+??

I've heard that NPG+ has lower heat exchange.. and sometime temp runs higher

Distill water is good, but cause higher rates of pitting

antifreeze and distill will protect and pretty much OEM.

distill water and water wetter incleases the heat exchange better than water itself??? I was thinking water wetter..

 

Use Evans,


-GOD.

 

I am no expert, and am not here to give any advice, just my personal results. But I was running Distilled water and a 16psi cap. And obviously my results were BAD. And people keep talking about NPG running 125C no problem, but that doesn't make it good. Just because it doesn't boil at that temp, the engine still cant handle that heat.

 

Your A/C works with the PFC? I call BS
Just kidding. In my experience 25% coolant, 75% water, and a bottle of water wetter worked better than a 50/50 mix did. I believe there is a point where too much water is bad, as others said due to cavitation, boiling, etc. Of course I run Evans now, have a Koyo, and rarely see over 100C even when running the A/C in 110 degree weather.

 

Your wrong its not the heat that is the problem. It is the pressure that the steam produces that is the issue.
Evans boiling point is 370degrees F.
Water boiling temp is 212degrees F
Evans doesnt run over more than 7psi.
Try measuring the steam your boiling water is producing.
There are engines that can run off that steam pressure alone.
Evans also does not cativate and creat hot spots. The fluid is in contact with the metal at all time thus cooling more efficently. I am no expert either but i have a better understanding that you.
This is some info you should read., Hope that it helps you understand.

http://www.kneedraggers.com/pages/ht...npgdetail.html

 

I agree with you.. I do know that NPG has extremely high boiling point.. but also if you put straight anti freeze it will also have high boiling point.. I'm looking for higher heat exchange rate.. And more I think of it water and water wetter sounds pretty good to me.. especially living in AL, where my car will never see 0F weather.

 

My thoughts on reasonable things to look at for better cooling.

1) give it a good complete flush. lather/rinse/repeat.
2) run 60/40 or 70/30 with good coolant. water wetter optional.
3) install a real temp gauge.
4) seal up the areas on the sides of the radiator.
5) think about an aftermarket (all aluminum) radiator.

Just sme thoughts. Any other recommendations?

-bill

 

you could have simply fixed your lack of coolant when you did the antifreeze install

 

NPG+ sounds good on that site: http://www.kneedraggers.com/pages/h.../npgdetail.html

And I'm not a specialist either.. but wouldn't lower heat exchange rate mean hotter engine?? And hotter engine means at certain point out of effiecency level and increase in chance of detonation?? I could be wrong about that.. but if I am, I would like an explaination so I could learn.

Their comparison didn't mention anything about NPG+ having better heat exchange rate than 50/50.. just pointed out about increase in boiling temp..

 

Ok, I'm not going to get into a pissing match with you, but please don't tell people they are wrong when you have no idea what you are talking about. It's not the pressure and steam, it's the heat. The engine is layers of steel and aluminum and they expand and contract at different rates due to heat, and that causes warping of the components. This causes the o rings to become exposed to the pressure of the combustion chamber, when they were not before. That causes them to fail. So saying stpid crap like evans doesn't boil until 10 million degrees means jack ****. The engine can't handle over 245F degrees anyway, so it doesn't matter where it boils, as long as it's higher than 245F. If it were only steam and pressure that were the issue, and not the heat, then whay even have a cooling system? Then you wouldn't have to worry about pressure and steam, only heat, and you say that doesn't matter right? SO get rid of the radiator and coolant all together, and let your car run as hot as it wants, you will be fine

 

there are a lot of people hopping on bandwagons around here, Fd3BOOST just happens to be on the NPG+ bandwagon

you just have to sort through the information and make up your own mind Str8Down, my best advice is to try it and see

 

I have to agree with Str8down.. And only reason is because I know also increase in oil temp is also bad..

hey 93blackfd, are you using NPG+??? I didn't know that?? so, what is your take on it?? did you see any difference??

 

You are wrong. I'll find the links to explain detonation if you need them.
Let me again point out that less pressure in your cooling system is a large benifit.
You should be paying less attention on the running temps and more attention on the cooling system effiency. When water boils is becomes uneffiecent. It creates steam and this added pressure is bad. It is what is hepling to cook your coolant seals.

www.google.com
Its a great resource.

 

Your an idiot., The evans will keep it cool. Did I say that you can run at a million degrees and be ok??I am telling you that evans is better to run than water but hey you changed to distilled and then to 50/50 so now your an expert yourself.

 

fd3Boost, I do know that boiling water is very ineffiecent.. and cause over heating and hot spots.. also I think running temp is just as or more important than pressure.

 

Yep; people always forget the pressure part. Any fluid under pressure will have a higher boiling temp than when not under pressure.

It is 100% fact that water exchanges heat energy better than coolant. Coolant is only meant to protect the system from corrosion and freezing along with adding some lubrication properties, so it makes sense to run the least amount of coolant that will give you the freeze protection you need.


Mazda themselves recommend a 90% water to 10% coolant mix:

"Fluid
We recommend using a 90% water to 10% glycol mix. Water has superior heat transfer properties (2-1/2 times better) than glycol-based coolant products. Using distilled or purified water will reduce scale build-up.
It's important to remember to change back to a 50/50 water/glycol mix when storing the car, especially if you live in severe winter climates."

I run about 80% water to 20% coolant here in Texas and for the few months it's actually cold I flush the system and go to 50%/50%.

 

Evans clearly states on their own site that you will see HIGHER running temps!!!! And you call me an idiot? It just doesn't boil until a higher temp, which just allows you to run high performance additions, that cannot be kept cool under any circumstance!! That is all that CRAP is good for. So what it does is, if you cannot keep your parts to a reasonable temp in the first place, then at least stop the coolant from boiling, because once it starts boiling it's not doing it's job. You even stated that. But a 50/50 mix will not boil at 13 psi and 230F, therefore boiling is not an issue. So if boiling is not an issue with either product, then use the one that dissipates heat better, which is the 50/50 mix, which is why it runs cooler that Evans!! Jesus, it's just a little physics, not that complicated.