Fd3BOOST

iTrader: (7)

Ok before this thread gets filled with arguements.
I understand your point and concern. But you guys are assuming that Evans will MAKE your car run hotter. It does not. It only has higher tolerences. It will cool the engine. Your running temps will not increase just because your running evans. Mine have not been over 103C. The bonus is that lets say if for some reason your water pump fails and the water is not being pumped through the rad properly. Your temps can get higher and the engine will stay safe. Thats the theory.
Str8down I was not saying you were stupid I just dont think you grasp the whole concept of what I am getting at.
I went through a coolant seal failure two years ago so I have some experience with WTF i am saying.

DamonB

You're assuming that the engine is also 230 and that's incorrect. The purpose of the cooling system is to keep the engine itself within a safe operating temperature. It doesn't matter if the coolant is 400 degrees; it's the engine that counts. When you see 230 degrees realize that is the temp of the coolant and does not necessarily represent the temperature of the engine itself.

Evans may run at higher coolant temps in some applications because it does a better job at pulling heat out of the engine. Ask yourself how the coolant gets hot in the first place: It absorbs heat energy from the motor. Evans is able to extract more heat from the motor and carry it away, so it's temp readings actually are higher in some cases. This does NOT mean that the engine itself is not seeing more efficient cooling. It seems wrong I know, but Evans is not water. It's different. You can't compare it to water.

Grassroots Motorsports had an excellent article on the use of Evans a few months ago.

Herblenny

iTrader: (13)

I'm going to change the topic a little..

How often does FD water pump fail?? It looks like its just a spindle thats attatched to a pulley?? likely hood seems to be at very small. just wondering.. and what kind of symptoms would I see??

Fd3BOOST

iTrader: (7)

I had a write up on my old site for failing water pump. Basically there is a small hole on the bottom side of the water pump. It will start leaking fluid once the pump has failed. Mine failed at 65k .

93BlackFD

straight water + 10% antifreeze (to lubricate pump), i sit at about 170-175F in traffic/city, and 190-195 on highway

i'm happy

Str8Down

That is a good point Damon. However, if Evans is more Thermally conductive (which I don't beleive) then it will release heat to the enigine faster as well. See, when you see the temp at 230, you are saying that is the water temp, not the engine, but that is not too far off. Since if the water/evans were 400, then the engine could not be 230. They are directly relational. If the water/evans were hotter than the engine, then it would effectively HEAT the engine, giving heat back to it. The coolant cannot be hotter than the engine itself. Which is the whole premise of the Throttle body coolant line. It heats the throttle body at warm up, since the water/evans is hotter that that part at that time.

Str8Down

I think your temp guage is inaccurate then, or you have a drilled out thermostat. The thermostat doesn't even start to open until ~80C which is 176F. So it's impossible to have those temps unless you have a failed open thermostat or a drilled thermostat.

DamonB

Coolant temperature is indicative of the properties of the coolant, not the heat of the engine parts. Coolant in the engine is a heat exchange system. If you use a more efficient heat exchanger media you will see higher temps where the heat is absorbed (engine block) and lower temps where the heat is released (radiator exit). The reason Evans runs hotter is because it has the ability to extract more heat from the motor and transport it to the radiator than water/coolant does. If you were to fill your coolant passages up with a silicone fluid your coolant temps would go down. This would not indicate a cooler running engine though, only cooler fluid. The fuid doesn't get hotter in this case because it is not capable of pulling the heat from the motor. Your temp gauge may show a low reading but rest assured your motor is hotter. All of the heat produced comes from combustion and friction. If less of that heat goes into the coolant then that insists more of it is staying inside the engine.

We're accustomed to judging safe operating coolant temperatures for water. Evans is fundamentally different from water and thus its operating temps are completely different. Just because the the temp gauge reads higher does NOT mean the Evans is not doing a better job at removing heat from the engine. In fact it PROVES the Evans is doing a better job. If there were no other changes made other than coolant type the Evans can only be hotter due to the fact it pulls more heat from the motor and transports it to the radiator.

SleepR1

Phil, I think this is a mistake. You'll quickly overtax water's cooling capacity with FMIC, hot weather, and boost pressure. Once water starts boiling in your rotor housings, localized hot spots will develop, making conditions right for ping--ultimately leading to a failed apex seal. That's how I lost my motor @ Mid Ohio with 12 psi boost, 87 F ambient temps, 239 F engine temps, and only 122 F peak air temps.

With Evans NPG+ the liquid stays liquid, bathing all the internal parts, and eliminating localized hot spots.

A hot running motor isn't a big deal, so long as your motor oil temps are maintained within a workable range (250 to 275 F), water pump is flowing efficiently, and you have no leaks in your cooling system.

Many FD enthusiasts don't understand the advantages of Evans. They see high motor temps, and freak out. What they don't understand is that the higher engine temp is absolutely fine.

BTW if you have an underdrive main pulley, and ARE switching to Evans NPG+, make sure you re-install the stock main pulley. Evans recommends higher water pump flow rates.

The underdrive pulley helped minimize water cavitation (b/c water has higher surface tension) by turning more slowly...

KevinK2

This is not true. Evans has a lower heat tranfer rate, but also a low specific heat. For an equal state of flow/load/temp, when it rises 10F it pulls less heat from the metal than when 50/50 rises 10F, and even less heat/btus than when water rises 10F. Hotter coolant does not mean a better heat transfer fluid.

Evans doesn't boil, and doesn't need pressure, and doesn't need to be changed. These are the 3 big advantages.

str8down:

I've never heard of the 245F engine temp limit, what is the technical basis?

Regarding initial observation of 50/50 being better than water, this is only for your 1 data point. The reason is most likely the 15F higher 50/50 boiling point, and likely small internal leaks in the pressure cap. Of 2 oem and 2 stant used ones I tested, one of each had a slow internal leak thru the middle poppet valve. Pure water is thinner, and more likely to leak this way, and reduce system pressure.

with egw or water, it's important to be sure the bulk coolant temp, as ead on a gauge, is well below the boiling point ... say 20-30F, so any normal localized boiling induced vapor is wuickly condensed.

DamonB

Even if you are comparing two disimilar fluids? If you're measuring your temps inside the engine block and all else is the same except for differing fluids and one fluid runs hotter at the point where heat is absorbed (inside the engine) then isn't one fluid hotter due to its ability to extract more heat from the motor?

How could it be otherwise?

DaveW

Damon B

It could be otherwise (cooler) if the coolant is also more efficient in transferring heat to the radiator (which it would be if it has a better heat capacity and heat-transfer rate), resulting in cooler coolant entering the engine.

SleepR1

Personally, I think water's heat transfer and specific heat capacity is over-rated.

Again, if you're running SMIC, or VMIC, don't worry about switching to Evans NPG+.

FMIC owners should strongly consider the switch!

DamonB

..but it could also be cooler because it doesn't have the ability to carry more heat away in the first place. On the other hand the heat comes from the engine and so if the coolant has the ability to be nearly as hot as the engine then isn't the coolant doing a better job of transporting the heat away? Coolant temp can't rise unless the coolant absorbs energy from the engine in the first place right? And if the coolant can absorb more heat from the engine than isn't it carrying more heat energy away from the engine? Of course a more efficient heat exchanger will have higher deltas at both ends: it will be hotter in the engine and cooler after the radiator than a less efficient fluid.

I'm confused?

DamonB

If it's overrated why don't you fill your motor with Jello gelatin and call it a day. The smell of warm tapioca at the track would be a nice bonus

We're talking about cooling ability of a motor; the heat transfer IS what matters. If you can't transfer heat from the motor you can't do your job of cooling the motor.

Herblenny

iTrader: (13)

This thread is become educational.. I like it!

First, thanks FD3Boost!!. now I know what that little hole was for..

Far as NGP+, how DamonB describes the stuff, it sounds like its has higher transfer rate.. but I read somewhere it didn't.. If it did, I would definitely use it.. No problem..

Also, wouldn't pressurizing help in general?? I'm little rusty on my phyics... but another reason why using pressurized cap is to increase number of molecules with in given space?? hence increase in.. say maybe heat transfer?? I think thats also what water wetter claim to do..

I just feel that NPG+ is nothing but straight anti freeze.. But I guess I'm wrong about that.. I guess I could give it a try..

Tom93R1

iTrader: (2)

Fluids dont compress, you will not get more molecules per volume by applying pressure to the system. A pressurized system serves 2 purposes. One is to raise the boiling point of the fluid and the other is to prevent the lower radiator hose from collapsing at high engine rpm when the water pump is sucking water from it faster than it can supply and creating a vaccuum.

I run evans. You know the boiling, gurgling noises you get when you shut down the car? That is due to localized boiling, hot spots within the engine. Evans is doing its job quite well and that damaging boiling process does not happen in my car, not at all. That alone is enough to make Evans worth it to me.

SleepR1

Over-rated in the sense that people shouldn't JUST consider heat transfer as the ONLY property of a good liquid coolant.

SleepR1

Again read the Evans threads. Evans coolant base is polyethylene glycol, but what makes plain old polyethylene glycol, Evans NPG+ are the additional additives that allow NPG+ to be a lifetime coolant.

There's also an Evans NPG-R, but you have to change that every two years. The upshot is higher boiling point 400 F at 7 psi, and much less viscous than Evans NPG+.

DaveW

Quote from DamonB: [..but it could also be cooler because it doesn't have the ability to carry more heat away in the first place. ]

If the coolant can't carry heat fast enough from the engine, then the engine components get hotter, and, as a result, so does the coolant. The coolant temperature is a pretty good indicator of the "average" engine temperature - that's why we pay attention to it.

scotty305

iTrader: (2)

So instead of argue about if Evans *might* have better heat transfer properties, why not measure them? All you would need to do would be measure the temperature of the coolant going into the radiator T(hot) and the temp coming out of the radiator T(cool), do this for both Evans and different mixtures of water/coolant. Whichever fluid has a greater difference in temps (delta T), will prove to be better at exchanging heat from the engine. All these measurements should be performed on the same car. It would be nice to measure the oil or metal temperatures inside the motor also, if possible.

So who's got an extra $100-200 and a day's free time to perform the test?

-scott-

paw140

Propylene glycol, not polyethylene glycol. HUGE difference.

IIRC, Evans has much worse specific heat and heat transfer capabilities (from reading their website a long time ago).

Damon: I don't think you are considering the whole picture here. To truely test to see if NPG is better than water, one could measure the input and output temperature of the radiator coolant. Knowing the capacity of the radiator and the specific heat of the fluids, one could calculate how much heat energy is actually being lost, and thus determine the more efficient fluid. I tend to think that water would be better, based on it's superior heat capacity and transfer capabilities, but I don't have any data to back that up. Organic compounds are generally very poor conductors.

paw140

You beat me to it! However, you would have to consider more than just the difference in temps. You would have to calculate the total heat lost based on the radiator capacity and the respective specific heats of each fluid.

DamonB

I'm gonna dig up the GRM article tonight and reread it. I either misunderstand or don't recall something correctly.

scotty305

iTrader: (2)

please scan it if you can, I really should have renewed my GRM subscription...