moomin Posted February 17, 2003 Posted February 17, 2003 DMS, I would concur trying Water Wetter. I have not run mine without, but temperature control seems to be just fine (it's the opposite end of the scale to your engine though ). Worth noting that assuming you have a sensible mix of coolant in there (i.e. water and anti-freeze), you won't see steam until around 120c, since the boiling point is raised. Moom. Quote
Blatman Posted February 17, 2003 Posted February 17, 2003 Er, raised boiling point has nothing to do with the ethylene glycol content (that's the anti freeze bit) of the coolant, and everything to do with the system being under pressure, which does raise the boiling point of water.......... Quote
stu999 Posted February 17, 2003 Posted February 17, 2003 Antifreeze does raise the boiling point of water, but not by much... Quote
Blatman Posted February 17, 2003 Posted February 17, 2003 I'm fairly sure it doesn't..............whatever..........it's the pressure of the system, not the ethylene glycol that keeps the sytem from boiling over at temps above 100 degrees C........ Quote
Stueyboy Posted February 18, 2003 Posted February 18, 2003 Actually, it is both the pressure of the system and the solvation effect of addition of ethylene glycol and water which raises the effective boiling point of the coolant. Boiling point elevation article Think of it like the distillation of my favourite alcoholic beverage, malt whiskey; The distiller knows that at a very particular temperature range above the boiling point of ethanol but below the boiling point of water, the ratio of alcohol to water will be around the 60% mark, which is when all the goodness comes out. Too low and you get watery p***, too high and you get a nasty hangover from all the higher alcohols created in the fermentation process. This is around the 90 deg C mark I think Now, Ethylene glycol boils at well over 100 deg C on it's own (197 deg C in fact), so if the ethylene glycol is the water in the whiskey analogy and the water is the alcohol bit (you know what I mean), the boiling point of the mixture is elevated before it gets under pressure. In Chemical synthesis and purification, we do the oppisite (apply vacuum) to drop the boiling point of liquids making them safer to purify by distillation at lower temperatures. The addition of pressure to the system adds to the increase in boiling point quite a lot too. The suppression of the freezing point is really the most important thing about ethylene glycol and has something to do with the phase diagram mixing of both liquids, but I'm not too sure, that's why I was never any good at thermodynamics. Anyway, just thought I would chip in as I know more about this subject than I do about the mechanical workings of my Westy. Stu Quote
Blatman Posted February 18, 2003 Posted February 18, 2003 Genuine expert opinion is always welcome.......... Quote
Stueyboy Posted February 18, 2003 Posted February 18, 2003 ...and it's the only time i've been able to give you one (ooh err) on this message board Quote
Blatman Posted February 18, 2003 Posted February 18, 2003 I'd be interested in your opinions of Ethylene Glycol based coolants, versus Propylene Glycol based coolants, and also HOATS (of which PG based coolants are a member, or a cousin of, AIUI). Quote
Stueyboy Posted February 18, 2003 Posted February 18, 2003 Can't help much, but I did find this rather informative, if worryingly detailed description of all things cooling and also gives facts and figures for the boiling points of 50:50 EG/W at atmospheric and under pressure Cooling facts Incedentally, ethylene glycol is a really nasty metabolic toxin and would lead to a very painful death should you mix it with your Austrian wine for instance. Right, I really am out of my depth now and should stop before someone slaps me Stu Quote
Blatman Posted February 18, 2003 Posted February 18, 2003 Fair enough. It was a bit of a loaded question from me though. I wasn't trying to catch you out ('cos I'm not qualified to), but was hoping to get either confirmation, or counter viewpoint to those raised in this thread. After reading the article, and because I believe most of what Peter Carmichael takes the time to write, I'll be using Comma Xstreme Red in my Westfields when the time comes to change the coolant. Being as EG based coolants seem to be less desireable than PG based coolants for a number of reasons (cavitation and cooling properties being the most important, IMO), I may well be changing the coolants in my vehicles sooner rather than later. It may save me a head casting or two in the long run.............. Quote
hilux Posted February 18, 2003 Posted February 18, 2003 it's the pressure of the system, not the ethylene glycol that keeps the sytem from boiling over at temps above 100 degrees C........ I agree. Additives will help but primarily the pressure is the main reason. IMHO too much pressure is not resolved with "additives" Quote
conco Posted February 20, 2003 Posted February 20, 2003 Hi! What if you cover the exhaust manifold and pipes in the engineroom with that heat reducing material. Just wire around and it should reduce heat up to 70 %. have only read about it, but if it works it should help keep the heat down. Cheers Quote
Blatman Posted February 20, 2003 Posted February 20, 2003 The exhaust wrap *may* help, but don't expect it to be "the" answer.......... I use it on my N/A Cosworth powered sprint car, and it'll still overheat if the fan doesn't cut in when I'm sitting in the paddock (or traffic)..........My Cossie car uses a Seight rad too, so coolant capacity/size of rad isn't an issue........... Quote
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