Evans waterless coolant

[Bill_H]

There is no thermostat, either in the liquid coolant cycle or the oil cycle. Some add one to the oil cycle (for faster winter warmup), search this RV-12 forum for "thermostasis"

[Rick_A]

As previous posters have mentioned, Rotax now recommends anti-freeze and water.

Specifically, anti-freeze that is labeled "Dexcool", run as a 50/50 mix with distilled water (do NOT use tap water). The mix can be up to 60/40 water/Dexcool.

Water has a higher heat capacity than anti-freeze.

[Harvey rv12]

I drained the Evans waterless coolant, and am filling with Dex-Cool coolant.
I will report back with temperature measurements, hopefully they drop by 20+ degrees.

Tom O.

[DaveWelch]

Hmm...maybe this is addressed somewhere else, I haven't looked, but since it's being discussed here and now, here goes...

If Evan's and water are totally incompatible, how do you drain and flush out the very last bit of Evan's coolant before you refill with Water/Dexcool?

Is it an issue? If not...cool (sorry)
If it is, will someone please describe or refer to the procedure to minimize the possibility of someone else doing damage.

(On behalf of someone who may benefit) Thanks!

Dave (Proudly overthinking problems and solutions since 1951) Welch

[bajapilot]

Dave,

It's not important when going in that direction (back to glycol), just flush it out with a little water and you're good to go. Add the 50/50 glycol.

The reason you can't have any water in with the Evans is because it runs so hot you're likely to boil any water mixed in with and create cooling voids because the water will turn to steam. The directions on Evans is very clear that if you have been running any water you must flush the system with a product that they make just for that purpose. The flushing product absorbs any water in the system and then you dispose of it before adding Evans.

So to sum it up. A little Evans in the glycol coolant - no problem. A little water in the Evans coolant - big problem.

Bill

[BillL]

Originally Posted by DaveWelch

Hmm...maybe this is addressed somewhere else, I haven't looked, but since it's being discussed here and now, here goes...

If Evan's and water are totally incompatible, how do you drain and flush out the very last bit of Evan's coolant before you refill with Water/Dexcool?

Is it an issue? If not...cool (sorry)
If it is, will someone please describe or refer to the procedure to minimize the possibility of someone else doing damage.

(On behalf of someone who may benefit) Thanks!

Dave (Proudly overthinking problems and solutions since 1951) Welch

Like BajaPilot says - flush with water - - but always use distilled water in cooling systems where aluminum is present (basically all).

[DaveWelch]

Thanks Bill, makes perfect sense.

I'd misunderstood the "totally incompatible" statement to mean that the Evan's coolant and water are not mutually soluble.

Whew...another non-issue safely avoided!

[Harvey rv12]

I flew the plane today with the dex-cool ethylene glycol coolant, 50-50 mix with distilled water. the temps were about 30 deg cooler than with evans waterless coolant. And for the first time, the CHT's were cooler than the oil temp. my CHT's in a climb were around 205, and then in level flight around 195. Conditions were 75 deg OAT, 5400 rpm.
I'm happy.

Tom O.

[Harvey rv12]

Originally Posted by DaveWelch View Post

If Evan's and water are totally incompatible, how do you drain and flush out the very last bit of Evan's coolant before you refill with Water/Dexcool?


Dave;
Evans says you can have up to 3.6% water mixed in.