VWDiesel.net The IDI, TDI, and mTDI source.
General Information => General => Topic started by: Dr. Diesel on July 31, 2004, 07:52:08 pm
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Rummaging around my stuff, I found a forgotten-from-gas-rabbit-days half case of coolant. Not just any coolant. This stuff is made by Evans cooling, and they call it NPG. Non-aqueous Propylene Glycol. They sell it alone or with kits for common detroit iron engines to create reverse flow cooling systems. All pretty fancy. The basic idea is that this coolant doesn't use water, and simply picks up heat way better. For VW engines, they told me don't bother with the reverse flow idea (from the rad outlet to the cylinder head rather then up through the block. Keeps the combustion chambers cooler and allows more detonation resistance) just run it in the factory system as is, or with no pressure.
Seeing as I had everything in pieces, I decided to use it when it was all back together. This time, I made a small hole in the expansion bottle cap. It runs with no pressure in the system. That's right, at full operating temps, you can squish the hoses as if they were cool. No more blow-ups with failed hoses.
End result: the temperature now averages at one line cooler than before. Not bad. And won't kill your cat either.
Check the stuff out here:
http://www.evanscooling.com/main25.htm
I highly recommend it!
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Non-aqueous Propylene Glycol.
They put it in cheese whiz, so its gotta be good! :D
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so that's why this coolant goes so well on toast! :D
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Dr. Diesel
You wouldn't happen to have an extra two gallons of this coolant that you could sell to me, would you? :D
Peter
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Is it just propylene glycol or do they add something to it?
Dropout
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I have one spare gallon, which I'd like to hold onto, and I have no idea if it's straight PG or spiked with something. Maybe try contacting them for your answers.
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I have one spare gallon, which I'd like to hold onto, and I have no idea if it's straight PG or spiked with something. Maybe try contacting them for your answers.
They probably add some corrosion inhibitors and stuff, but otherwise you can obtain the base propylene glycol real cheap at a food producer. Water significantly degrades the boiling and freezing points of the stuff, and probably corrosion resistance as well. It's important to ensure there's no water in the cooling system at all...
I've followed this company (Evans Cooling) since the late 80s when there was a write-up about it in the then VW&Porsche magazine (now European Car). I don't have a cooling problem in my car (in fact, I have a LACK OF HEATING problem in winter :P ) but I believe it does work as advertised.
Note however, that the intent is not for this coolant to run cooler, although it can be a side effect (or benefit, depending on how you see it). In fact, it's in order that it CAN run hotter. P.G. has a boiling point ~100+ *F higher than E.G./water blends, so localized nucleate boiling (i.e. at a hot spot in the cylinder head) can be that much delayed -- in other words, P.G. will stay liquid (which is much more effective for heat capacity in a given volume than vapour) to a higher temperature than E.G. If you are seeing a BIG temp drop from going to the P.G. coolant, you probably have inherent hot-spot problems that this coolant is able to fix or mask. You might have similar results on a water/E.G.-based coolant and adding a bottle of Redline Water Wetter.
It should be noted that P.G. has a lower specific heat capacity than either water or water/E.G. blend, so the real overall capacity of the cooling system, if the coolant capacity is not increased, is actually lower.
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Evans' product has been popular in circle track racing for more than 15 years. The principal byproduct from the reduction in localized nucleate boiling is that an otherwise identical engine can be run approximately 100 *F hotter, which directly translates to higher thermal efficiency...ie, more power.
I don't know that it would really help a small, lightly loaded diesel, though. Most simply aren't loaded heavily enough to need it.
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it seems to me that the greatest asset of this stuff, for highway use, is that you dont have to pressurise the system.
like the doc said, no more blown hoses spewing screaming hot water vapor on your hands and face.
but at 25.00 per gal you wouldnt want to let any leaks get away from you.
oh yea! no pressure, no leaks! :lol:
K
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Well, that's a good point, K, but how many times has that happened to you? I've been driving for 35 years, and last year had my first hose slip off a radiator barb...on a car with 304,000 miles!
FWIW, I've never had one fail. I change them every couple of years.
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That would be cheap for me - so far I have dropped 4 loads of green on the ground - due to hoses and over pressure.
Running with no pressure at hyway speeds and for me full loads would be better.
Remember - I carry 1000 lbs plus most of the time over hill and dale - Turbo is always whining hard.
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as a matter of fact I just blew one the other day on my turbo!
my PM schedule isnt what it should be. Ive been lucky to get my oil changed on a somewhat regular basis. :oops:
the only other drawback I thought of is availability.
I dont think you can find this stuff at any podunk mini-mart in a pinch.
Im still thinking about it though.
Ken
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I have one spare gallon, which I'd like to hold onto, and I have no idea if it's straight PG or spiked with something. Maybe try contacting them for your answers.
They probably add some corrosion inhibitors and stuff, but otherwise you can obtain the base propylene glycol real cheap at a food producer. Water significantly degrades the boiling and freezing points of the stuff, and probably corrosion resistance as well. It's important to ensure there's no water in the cooling system at all...
I've followed this company (Evans Cooling) since the late 80s when there was a write-up about it in the then VW&Porsche magazine (now European Car). I don't have a cooling problem in my car (in fact, I have a LACK OF HEATING problem in winter :P ) but I believe it does work as advertised.
Note however, that the intent is not for this coolant to run cooler, although it can be a side effect (or benefit, depending on how you see it). In fact, it's in order that it CAN run hotter. P.G. has a boiling point ~100+ *F higher than E.G./water blends, so localized nucleate boiling (i.e. at a hot spot in the cylinder head) can be that much delayed -- in other words, P.G. will stay liquid (which is much more effective for heat capacity in a given volume than vapour) to a higher temperature than E.G. If you are seeing a BIG temp drop from going to the P.G. coolant, you probably have inherent hot-spot problems that this coolant is able to fix or mask. You might have similar results on a water/E.G.-based coolant and adding a bottle of Redline Water Wetter.
It should be noted that P.G. has a lower specific heat capacity than either water or water/E.G. blend, so the real overall capacity of the cooling system, if the coolant capacity is not increased, is actually lower.
has anyone here tried getting some base prop-gly and running it?
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anyone?
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Since I've been running Evans NPG+, I've been asked to update this thread. I bought it locally at a racing shop, although I've seen it for sale on the internet. It was up to $32/gallon when I got it. I also bought a gallon of prep fluid for about the same price. You need to drain all antifreeze from the engine, radiator and heater, then fill the system with prep fluid, run it and drain it. Then add straight Evans. I only bought one gallon as my engine had been sitting at all angles for months, so I knew it was completely empty, and I had a new radiator. So I just flushed out my heater cores. The Evans has a higher viscosity than EG/H2O, and less heat capacity, so it may run hotter. But since it boils at a much higher temperature, hot spots in the head are very unlikely. With a more even temp, warping is also unlikely. I first tried it as my IDI ran way too hot, getting up to 250 degrees going up mountain passes, causing me to have to pull over to allow it to cool down, and drive at reduced speed. Eventually the engine died. After adding the NPG+, it still ran hot, but I could keep driving, although I would still slow down if it was approaching 240*. This engine also died after a while, but it was due to unknown holes in the hose between the turbo and air filter, causing the ingestion of lots of dirt and dust which wore the bores and rings way down. This engine ran just as hot as the previous one, but when I took it apart, I saw no signs of head gasket leakage. I'm sure the Evans helped. I now have it in my AAZ that I turned into a TDI. It doesn't have the heat problems the AAZ had, but I will keep running it as since it has no water, it can't corrode anything. Although you can run it with a low pressure cap, I run my system open as I have an old heater which is no longer available that has a very small leak. With no pressure, it isn't a problem.
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heres (http://forums.neons.org/viewtopic.php?t=290325&postdays=0&postorder=asc&start=0&sid=7233fbf0b3c21d583086a06d1b2bcdf6) a good read
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That's funny. I like all the criticism from people who have never run it, trying to say it will ruin the car, its crap, and whatever else. If I thought it was crap, I'd be the first to admit it. The main things I like about it are that you can run 0 pressure and that it doesn't boil or cause corrosion. The things I like least are the price and that it is slightly more flammable, yes antifreeze burns if you get it hot enough.
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Not a comment on the cooling abilities of propylene glycol, but I find it interesting that according to http://en.wikipedia.org/wiki/Propylene_glycol it has been judged safe for human consumption by the FDA, but it is illegal to put it in cat food.
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Well, don't forget that often animals can eat stuff that we can't, so the opposite must be true. Also, mixing EG and PG makes the EG generally non-toxic, not that I'll try it and find out. Same thing with alcohol, like vodka, and EG. They block it from changing into the poisonous stuff in your body which is what actually hurts you. So if you accidentally ingest EG, get drunk ASAP. :P :lol: :lol: :P
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editable cooling fluid, editable is not just for underwear any longer!
Nice find Dr.diesel