waterless coolants
 

Hi all ..Just thought I might start a massive arguement regarding propylene glycol..If you have used it and had probs ? As for me [and I may be wrong] Anything that stops massive pressure build up when hot has gotta be better than running anything with water in it !! I know PG doesnt conduct heat quite as well as water ,which may mean your temp gauge runs a bit higher...But that would be as high as it ever gets...and at the end of the day your thermostat controls the internal temp of your engine regardless of using water,glycol or donkey piss...Its just that Ive got it in 2 cars now and would NEVER add water at all ever again...But I see some negative veiws on it all on the net..Any how any thoughts out there..?

I'm not sure about the properlyne glycol. But from my experience in racing bikes straight coolant can cause massive issues with overheating. Now given that we push our bikes to the limit on the track and are basically in the redline from the moment you get past the 50m mark, it probably may not be such an issue in a passenger vehicle. Although an XJ sits on that edge regardless so IMO I would want the stock system working 100%. Straight coolant could not achieve that. In an XJ jeep engine I see no point in using such a product because the benefit is not required in an engine that has hardly any cast alloy components. Like I said in another thread pressure is required for the cooling system to work properly regardless. If I wanted low pressure I would replace my $15 rad cap with a lower pressure $15 rad cap rather than go to the expense of exi coolant.

Regards A

Im just thinking ..if your stuck in melb traffic on a 45C day..Its a kind of insurance sort of thing...When people start having issues with cars overheating and losing coolant they top it up with water..this lowers the boiling point and compounds the issue...If there was no water in there in the first place..??..I dunno Im no expert..

Mine has been stuck in peak hour South Road Adelaide which can equal to 40mins to travel 2km on the worst days and at 45deg mine didn't over heat. I did have a very well functioning stock system at the time though. The under bonnet temps would have been horrendous but the internal temps were what matters and it never boiled. Trick to keeping an XJ from over heating is making sure the stock system is working as well as it did when it left the factory.

Regards A

Theres not much to argue about.

The stuff is much the same as eth-gly ... just a degree or two variation in boil and freeze points.

That Evans waterless coolant is just eth-gly and propylene with a sprinkling of rust inhibitor agents ...

They claim that mixing the eth-gly and propylene anti-freezes - reduces the toxicity too.


What you need to to be aware of ... is the heat capacity of,

Water & gly mixes,
eth -gly, and
propylene.

Basically ... A radiator that satisfactorily cools a water & gly mix ... will probably be struggling to cool straight eth-gly or propylene as effectively.


The XJs radiator dimensions are barely adequate for the 50/50 mix down here ... let alone a 100% fill with anti-freeze.


Straight anti-freeze might not boil until 190ish degrees.

... but what temp are you going to be happy with as a running temp ... or the max temp before you shut the engine off,

... factoring in the little things like fuel vapourisation, engine gasket survival, melting plastics, and peeling bonnet paint .. ;);)


Personally ... I wouldnt run the stuff in an XJ without increasing the height/width of the radiator.

... of course you could speed up the flow ... instead of a bigger radiator,

.... but then you need to consider whether the increased flow ... is evenly collecting heat/cooling in the engine, or has the increased flow - created flows and eddies in the cooling jacket with unsatisfactory variations in temps of surfaces.

Rumour also has it that .... the higher viscosity of straight anti-freeze, will rob you of horsepower coz the waterpump is working harder .. :rolleyes:

... but thats probably just another internet furphy,
... like the need to use 50/50 coolant mixes in australia .. :rolleyes: .. :mrgreen:

I'd been running the 50/50 mix ethy glyc since I owned it, because that's what was 'recommended'. Almost 6 yrs now.

However: since I had to add coolant regularly due to a radiator leak (still not fixed) and at some point ran out of 50/50 mix, I added just distilled water. And what do you know...as time went by, my running temps slowly but surely came down on the gauge...

Carves's 'bottom line' statement I (now) support, at least regarding here in QLD ;)

The other, allwheeldrive, 4.0l, auto, station wagon, sitting in the driveway,

... specs 30/70 as the coolant mix ratio ... in the owners manual,

... probably in case the thing does a run to Jindabyne ....... in July .. :rolleyes:


Mind you ... Ford and Holden specs will probably all state 50/50 mixes ... as a nescessity :rolleyes::rolleyes: ... once they become imports from the northern hemisphere ... in 2016/whenever.