As I am performing numerous mods this winter, one result is the complete draining of the engine coolant. In the past I have used the usual combination of ethylene glycol/water. There is a product made by Evans that is non-aqueous propylene glycol. No water is used at all and they claim almost no system pressure, no corrosion and less detonation problems.

Has anyone ever used this product and what did you think of it? At $25.00 a gallon this conversion will be costly.

90Indy

 

I haven't heard anything about it, but I'll have to check into it. Yet until I hear a lot of people who like it, why switch when the old ethylene glycol/water mix hasn't failed us in so many years.

 

If you look around the Evans website you will find that he is suing GM because he alleges that they used his reverse cooling design on the LT1 and did not pay him. If at some point I am running a high compression liquid cooled engine I would be very temtped to try the Evans coolant. The theory seems very sound.

 

I would only recommend using the Evans Coolant if you have a reverse cooled engine (LT1 or LT4).

It appears that the Evans coolant has 2 disadvantages: The coolant has a much lower specific heat than water, and it is more viscous.

The effect of the low specific heat is: The coolant will increase significantly more in temperature on it's path through the engine. This extra fluid temp will come back down in the radiator, but there is a problem. In a conventional non-reverse cooled engine, you will have cool fluid entering the block, and but it will be hotter than normal by the time it gets to the cylinder head ... Cool bores, and hot heads are the exact opposite of what you want. Now in a reverse cooled LT1 or LT4, you would have cooler than normal heads and hotter than normal bores, which would be incredibly good for detonation resistance and power production.

The effect of the fluid being more viscous is that it takes more horsepower away from the crank to drive the water pump.

Bottom line: If I had a LT1 or LT4 I would definitely try it. L98: my guess is a net power reduction.

 

how much is the temp difference ???

 

The reason that the coolant is hotter coming out of the engine is because there is more heat trasfered to the coolant.

Think of it like this: when you boil a pot of water the hottest temp you can get the water is 212' at sea level and no pressure. (with pressure the temp goes up thats why a 15 pound system doesent boil at 275')

no matter how much flame you put to the water it will read 212' as it boils off. (beleve me, the coolant in your engine is flashing off (fancyword for boil) around the exhaust valve) that means that the water is completly saturated with heat and wont remove any more. with a cap in place (like on a radator) pressure from water "flashing off" builds.

Ok stay with me. Evans boils at a much higher temp (375'+) there for it can remove a greater amount of heat from the engine. I would EXPECT the coolant to be hotter because it has pulled more heat out because it doesent "flash off" as quick as conventional coolant.

There was quite a disscussion on Z28.com about this

http://web.camaross.com/forums/showt...ighlight=evans

The problem is that most people dont understand heat transfer.

As an aircraft mechanic and a heating and cooling tech. It makes perfect sense to me. A engine coolant system is just another type of airconditioner (remove heat from the engine and transfer it to the outside air) the engine is the evaporator and the radator is the condenser.

Everyone knows that R-12 was a much better refridgerant (read coolant) than R-134a is. Why? because R-12 can remove more heat. R-134a systems use more pressure and still doesent cool as effectively as R-12 But, R-134a doesent "kill" ozone particals like R-12 does.

I hope this clears up some of the confusion.

 

i was wondering if he had direct #'s

 

One of the reasons I love this forum is that everyday I realize just how much stuff I don't know!

Thanks for the very interesting/informative discussion.

 

Yes I have it in my Blown C4. I love it, but if you spill any it stinks like you just poured oil on the header. They recommend that you do not use a thermostat, but we could not get my car over 140 degrees without one, and this was during the summer. I installed a thermostat and now the car runs at 177 in traffic all day and around 170 on the 172-177 on the interstate. Not only that there is no pressure in the system, you can remove the rad cap right after you park the car from driving. I will never go back to the water/coolant combination unless it is in my truck. By the way my motor is L-98 style normal cooling.

 

I have an L98 ('88) but it is stock. The no pressure thing is very interesting to me. Now again, I'm basically a mechanical nincompoop, but am I right that a no pressure system would put less stress on gaskets and connections, and therefore be less prone to coolant leaks/loss? Whats the downside? I run a 180 degree t-stat in my car.

 

You are correct,It is much eayser and safer than a pressure system. I think the evans system does require a pressure cap but It is only 3 pounds.

They do say to use their waterpump but they said that my mezinere was sufficiant I plan to run this coolant this year.

 

In the Camaro thread the guys say they run 10 to 20 degrees hotter. Car craft or Hotrod had an artical (I cant rember which) where they tested this on a turbocharged 4.0L v-6 Ford ranger they measured temp around the combustion chamber and found it to be cooler.

I have the artical somewhere If I can find It I'll give you more specifics than trying to remember what the artical said off of the top of my head.

 

yep its in my turbo car, my customers' wrx's, a c3 I built with a tpi 383, and my dad's s10. the only thing is you need faster flow since it doesn't have the specific heat (amount calories needed to heat a gram of water one degree) other then that it can solve alotta headaches for you. Or allow more timing on the pump pee.

 

That is incorrect. That logic only applies if the two coolants in question have the same specific heat. Specific heat is one of the biggest factors there is in analyzing a liquid cooling system's performance.

In this case, the specific heat of water x it's density is 38% higher than Evans NPG+. This means that for a case in which both coolants are transfering the identical amount of heat from the engine, the NPG will have a temperature rise 38% higher than the water coolant system on it's path through the engine block and heads.

 

All of you are way too damn smart for me.

 

 

The old Spitfire WWII fighter planes used a 100% Ethylene Glycol mixture; on that basis I have always tended towards a high ratio of glycol (Higher than recommended) in all my watercooled vehicles.

Never heard of this product - Interesting...I agree with someone elses hypothesis that if its more viscous it would require more effort to pump; therefore use more HP.

 

Here's what I use. Extremely lightweight stuff.

 

Excellent explanation! I knew you had some HVAC background!! I've heard also that you must remove as much of the old coolant as possible, like removing freeze out plugs and such, really better off using the Evans after an engine rebuild, start off fresh. I have a '92 LT1, but for some reason I'm a little hesitant to use the Evans. I don't race or auto-x, so I guess I'm ok with the original coolant!