Evans Coolant

[hrcollinsjr]

I was wondering what the ideal temperature of an engine would be for mpg and came across this new, to me, coolant.

Evans NPG Benefits in Detail

At first thought it seems a little high priced but when compared to using synthetic oil or just filling one's gas tank it becomes more reasonable especially for some with restored cars. If only a few of the claims are true it might be well worth it for some. Any thoughts?

Harold

[RallyBob]

I'll be using the Evans for my racing Manta due to the high heat generated(turbo). But I spoke to them long term and discussed the upgrades I would need (bigger radiator, different low pressure cap, different pump, coolant line sizes). Not cheap, but neither is a new engine should I cook it.

I'll be using the racing NGP-R, which is less viscous than the 'plus'. It also has a higher 400* F boiling point.

[oppositelock]

I used this stuff about 15 years ago in my Dodge Omni Turbo rally car ahd I'm a real believer. Cooling was a real issue in that car, especially with left foot braking boost was up all the time. I had a big oil cooler and a slightly larger LeBaron radiator but before switching over I would regularly see water temps as high as 280 degrees F and oil temps in the 230-260 range on stage. The trick with the Evans coolant, which is basically just propylene glycol, is that you don't use ANY water and no pressure is needed. Propylene glycol has a boiling point of something like 370 degrees F unpressurized so there is no need to use any pressure. No pressure means there is a lot less stress on all parts of the cooling system and less chance of leaks. When I bought my Mecca/Evans setup I got the coolant, a zero pressure cap, and a condensor thingy for trapping an moisture that got into the system. The condensor went in the hose between the radiator and the overflow tank. The deal with this stuff is that water is an impurity. You have to get all the water out of your cooling system because water boils at a much lower temperature than this stuff. The instructions that came with detailed a method for doing this. Basically I disconnected the radiator hoses and drove the car around the parking lot in figure eights, backed it up a steep slope, etc. until I was satisfied I got all the water out that was going to come out. Then, following the instructions, hooked a clear plastic tube several feet long to the overflow tube of the radiator (where the overflow tank usually connects) and hung the other end about 6 or 7 feet up. I secured it to the garage door or something. Then filled the engine and radiator with the Evans coolant and installed the no pressure cap. You can make one of these out of a regular cap (not the lever kind) by cutting off the spring plunger so it just seals at the top of the radiator neck. Then you shut off or disconnect the electric fan and start the engine and get it warm, no, hot. What you are doing now is boiling any remaining water out of the system. The propylene glycol expands a lot when it heats up, that's why you need a long piece of tubing hung up high. You want it clear so you can see what's going on. The propylene glycol (I'll call it PG coolant from now on) will expand up the tube a ways but you will see the steam coming out the tube as the water boils off. Don't worry about the engine getting too hot, it can handle higher temps with the PG coolant, I'll explain later. Depending on how much water was left in the system this boiling off process could take a while but eventually no more steam will come out. Now you're good to go.
The reason this stuff work is this. In your engine you get hot spots, in the head, around exhaust valves, etc. where when you run the engine hard you get what they call "nucleate boiling." The overall engine temperature might be OK, let's say the gauge on your dash says in the neighborhood of 200 degrees F, but you can have nucleate boiling in these hot spot areas. In other words steam. It's so hot that a water/glycol mix which is in a constant boiling/recondensing cycle is not staying liquid so you have no liquid to metal contact there. Which means cooling efficiency is reduced and heat is not being transferred out of the metal there. Because the PG coolant's boiling point is so high you don't get this nucleate boiling, hence better liquid to metal contact and greater cooling efficiency. Better heat transfer. Which is why you won't necessarily see lower peak temperatures with the PG coolant.
What I noticed on my Omni after I converted was much better cooling efficiency and better heat transfer. I had good Stewart Warner water and oil temp gauges in the car. I also had a switchable electric fan. Before with the normal water/glycol mix typical water temp was about 180 degrees F at idle, driving around town, on the freeway, etc. With the PG coolant temp was about 160 at idle with the fan off. You could let it idle all day long with the fan off and it would never go above 160. Driving on the freeway was some what surprising as the typical temperature wet up a bit. Depending on how fast you were going... At 55-60mph it would be about 170-180. Speed up to 65-70 and temp would climb to 190, 75mph and you might see 195 degrees. Slow back down to 60mph and the temp would drop back to 180 just that fast. You might think that doesn't sound good, but it is. That was a direct correlation of the improved heat transfer. When the temperature climbed it showed me the coolant was getting that extra heat out of the motor, something the standard water/glycol mix wasn't efficient enough to do with it's nucleate boiling. On a rally stage with left foot braking the boost is on almost constant so the engine gets really hot. My peak temperature with the PG coolant was pretty similar to before, maybe a little less but it was a lot more consistant. Probably in the 260 F range but it would never go above that and more importantly on transits after the stage the temp would cool down quickly back to normal temperature, much more quickly than before. Before, sometimes if it was a short transit it would never cool all the way back down to normal before the next stage. That was never a problem with the PG coolant. You cound watch the needle on the gauge move back down just as quickly as I'm typing this, practically. Like I said, the PG coolant expands a lot and sometimes when I got the car real hot I would overflow the overflow bottle! I recommend a large overflow resevoir with this stuff. And don't fill it up. Just fill up the radiator and leave the overflow mostly empty because when the engine gets really hot it will fill up, but when it cools off it will go back down again.
A couple of notes. The Evans coolant is just propylene glycol with some anti corrosion, etc. additives in it. You can buy some of the enviromentally friendly coolant like Sierra for a lot cheaper and it's really the same stuff. Just read the label and make sure that it's propylene glycol and there is no water in it. Water is a contaminant! I have sustituted Sierra (I believe it was) and it worked just as well. Also this stuff is flammable (so is ethylene glycol) so if you spray it on a red hot turbo it can ignite. But since you run this unpressurized that really shoudn't happen. I have had a coolant fire in a rally car using a mixture of Sierra coolant and water in a pressurized system (the fan quit working and the overflow hose blew off. If it had been using the straight PG coolant unpressurized that never would have happened!
Here are a couple of other things they use propylene glycol in:
Beer. They use it as an anti-foaming agent. It's non toxic. You can drink it, and you have.
You know those smoke machines they use in nightclubs and rock concerts? Thats propylene glycol that's misting out.

P.S.: I guess a lot of what I said is already at the link in the original post above, sorry. But I got some of my real world experiences in my long diatribe at least.

[hrcollinsjr]

Originally Posted by oppositelock The Evans coolant is just propylene glycol with some anti corrosion, etc. additives in it. You can buy some of the enviromentally friendly coolant like Sierra for a lot cheaper and it's really the same stuff. Just read the label and make sure that it's propylene glycol and there is no water in it. Water is a contaminant! I have sustituted Sierra (I believe it was) and it worked just as well. Also this stuff is flammable...

From the Pineapple Racing (rotary guys) site:We typically recommend that you run Sierra brand ("environmentally friendly", "pet safe") coolant as an intermediate step, since it is an aqueous propylene glycol. After draining your cooling system as much as possible (engine warm with the heat on, so the heater core can open), blow compressed air through the system if possible, and then install the Sierra coolant straight so that it can absorb remaining water. Run for several heat cycles with the heat on, then drain completely and replace with NPG. This should minimize water contamination and any remaining Sierra coolant is compatible with the evans, since they are both propylene glycol based.

From the Sierra site: Because of it's PG formulation, SIERRA Antifreeze is less toxic than conventional EG based antifreeze and, therefore, is safer to pets, people and wildlife in cases of spills, leaks, boil-overs or careless disposal.


I believe Sierra's less toxic statement means don't pour it in the pet water dish.

Harold