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Offline Djairouks

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Re: Heat to the crotch ...fixed
« Reply #20 on: March 05, 2020, 10:30:33 AM »
Still no one seem to have picked my point earlier :164:, about the fluid mix inside the actual cooling system, that might be a big part of the issue before patching things that might not be necessary.

More glycol in the mix will decrease collant system temp, at the expense of less fan work.
More water and the fan will be always on, to reduce the higher coolant temp.
A good mix is paramount to the best operation of the system !
« Last Edit: March 05, 2020, 10:32:18 AM by Djairouks »

Offline Brettus

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Re: Heat to the crotch ...fixed
« Reply #21 on: March 05, 2020, 11:35:11 AM »
*Originally Posted by Djairouks [+]
Still no one seem to have picked my point earlier :164:, about the fluid mix inside the actual cooling system, that might be a big part of the issue before patching things that might not be necessary.

More glycol in the mix will decrease collant system temp, at the expense of less fan work.
More water and the fan will be always on, to reduce the higher coolant temp.
A good mix is paramount to the best operation of the system !

My understanding is that plain water cools better than water plus glycol. The reason you add glycol isn't to improve cooling ...it's to increase the boiling point decrease the freezing point,lubricate the water pump and prevent corrosion. The best coolant mix for actual cooling is the one that allows you to achieve all that with the lowest % of glycol.
« Last Edit: March 05, 2020, 11:50:52 AM by Brettus »

Offline Djairouks

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Re: Heat to the crotch ...fixed
« Reply #22 on: March 05, 2020, 12:18:52 PM »
*Originally Posted by Brettus [+]
My understanding is that plain water cools better than water plus glycol. The reason you add coolant/glycol isn't to improve cooling ...it's to increase the boiling point decrease the freezing point,lubricate the water pump and prevent corrosion. The best coolant mix for actual cooling is the one that allows you to achieve all that with the lowest % of coolant.

Not at all, water will not be the best coolant for the simple reason, that it's thermal conductivity drops massively at 100C, because of vaporisation and as you surely know for every 150m of altitude boiling point decreases by 0.5C.
If my memory is good last time I saw a collant temp information, normal operation is around 80C for most modern bikes, that would only be a 12C margin at 2400m high, when on a nice mountain pass. So we add glycol which helps in this case, but it does because the thermal conductivity of glycol is vastly better than that of water.
But if the liquid carries more heat energy per liter, the radiator, cannot dissipate more heat, because it's fixed size, again not something desired.

Glycol will also avoid the liquid freezing that's right, but since now 15 years at least all engine bodies are cast aluminium, minus some additives so they will not rust, the heatsink itself could slightly but not really in reality, the main issue would be mineralized water, that would make deposits and react with the metals, slowly clogging everything, that's why you use demineralized water there.

That's where it become a bit counter intuitive for some people, but you actually do not want to only put glycol in the circuit, for 2 main reasons.

1 The system is designed to use the fans for a better dissipation of heat spikes, so if you'd have too much glycol then your engine will be cooler to begin with, but spikes wont be dealt as well by the fan action, as they wont come on as much and after a while since the radiator size is fixed, the heat exchange will be worse because you can "overload" the radiator this way, so the bike can look cooler (depending where sensor is located, heatsink vs engine case), but in reality not be because the radiator is struggling to dissipate the heat, the bike with long use will slowly ramp up the heat, too much for the fans and the safety cap might suddenly burst.
2 Since the dawn of cooling systems, there were spring loaded valves in the heatsink cap, because that's how you knew the bike was badly overheating, when vapour starts leaking through that valve.
If I remember correctly it corresponds to something like 160-170C, when it will leak vapour (in reality it's related to system pressure), sure we have analog sensors now giving us the engine temp, but the cooling systems still need to operate in the same temperatures with the safety discharge cap valve, because this sensor has no clue about the liquid composition, so the safety is there to avoid the conduits explode, but that only works with the correct mix.

That's why to opperate the system as intended and avoid problems, you should make sure the mix is correct, of course it's not extremely precise, I do add glycol if the level is low, but you always want to be around 50/50.
Going away from that and the bike might feels toasty, so it's a good practice with an old used bike to purge the system and start anew.

Sorry for the long professor talk  :004: but there's no way to explain this quickly !
« Last Edit: March 05, 2020, 12:48:35 PM by Djairouks »

Offline Brettus

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Re: Heat to the crotch ...fixed
« Reply #23 on: March 05, 2020, 06:47:59 PM »
https://www.hotrod.com/articles/glycol-or-water-coolant/
Bottom line: A large-tube aluminum radiator filled with pure water and using at least a 20-psi cap is by far the best heat-transfer setup, provided the vehicle is not subject to freezing conditions. Be sure to add a corrosion inhibitor when running pure water.
« Last Edit: March 05, 2020, 06:58:42 PM by Brettus »

Online Rtwo

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Re: Heat to the crotch ...fixed
« Reply #24 on: March 05, 2020, 07:21:14 PM »
From a hazy memory

A typical 'off the shelf' coolant mixed at 1:1 with water will be around 18% less efficient at transferring heat than would straight water
The party told you to reject the evidence of your eyes and ears. It was their final, most essential command.
....George Orwell

Check the Facts !!

Offline Djairouks

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Re: Heat to the crotch ...fixed
« Reply #25 on: March 05, 2020, 07:33:44 PM »
Dude this is a Hot rod site, car engines operate at lower temperatures and hot rods have overpowered engines often with pressurized cooling systems, far above the type motorcycles have, so it is to say the least pretty misguided to take your reference from that, apples to oranges...

So in theory yes water is great, but it still boils at a 100C more or less (worse in mountains), which in those cars can work, but it can't in our motorcycles, I see where my explanation wasn't precise enough, I meant the thermal efficiency of glycol is superior, because if you'd put 100% water in your tiger tomorrow, it would boil fast and the engine would seize pretty fast, you need glycol period as it boils at 198C, mixed with water you reach a safer spot without compromising too much on the heat transfer.
As I said 100% glycol wouldn't be preferable either, as the was the system works takes a temperature reading, assuming a 50/50 mix is used so anything really different will either always put the fans on, or never, which are both not desirable.

It's your bike you'll do as you please, but it doesn't cost you much to purge the coolant, clean the conduits and be sure the heat transfer is at it's best, at least that's what i'd do.
For your information this video shows metal parts from bikes, in different "coolant" solutions, be my guest if you want to as they advise on this site use pure water, they don't even say demineralized, how serious
« Last Edit: March 05, 2020, 07:51:24 PM by Djairouks »

Online Rtwo

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The party told you to reject the evidence of your eyes and ears. It was their final, most essential command.
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Check the Facts !!

Offline Djairouks

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Re: Heat to the crotch ...fixed
« Reply #27 on: March 05, 2020, 08:03:26 PM »

Jesus that's freaking me out slightly, my Yami has the cooling temperature and in summer days when it's warm, the bike goes to around 104C so if their Numbers are correct with boiling point at 109C for 50/50, my bike is a bomb wating to explode because the coolant on bikes aren't much pressurized !
At least it's not 100% water, as I would have been blown off the bike  :492:
« Last Edit: March 05, 2020, 08:08:16 PM by Djairouks »

Offline Paulhere

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Re: Heat to the crotch ...fixed
« Reply #28 on: March 06, 2020, 10:47:31 AM »

Yes, "check the facts" like Rtwo says. Beats forum blether every time.


The pressure for motorcycle rad caps is similar to that of cars. No reason for it to be any different.

https://motocrossactionmag.com/10-things-about-radiators-radiator-caps-coolant-overheating/

Current bikes Tiger800 XRx, Tiger Sport 1050, Ariel FH 650, Yam Serow 225.

Offline Djairouks

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Re: Heat to the crotch ...fixed
« Reply #29 on: March 06, 2020, 12:01:33 PM »
Yes fact checking is all good and important in this day of anyone can write anything on internet, but hot rods are still not regular modern cars, and the supercharged engines in those are nothing like motorcycle engines either, conditions are different, so maybe get one's facts from motorcycle sources, simply !

Because if you'd follow their advice on using water only and installing a 20PSI cap, to compensate the higher boiling point, you should also compensate the size of all hoses and seals, to be certain nothing blows, because the system was designed to work within a specific pressure and temperature range.

From my manual :

A year round, Hybrid Organic Acid Technology (known as Hybrid OAT or HOAT) coolant is installed in the cooling system when the motorcycle leaves the factory. It is coloured green, contains a 50% solution of ethylene glycol based antifreeze, and has a freezing point of -35C (-31F)  :190:.

In an emergency, distilled water can be added to the cooling system. However, the coolant must then be drained and replenished with HD4X Hybrid OAT coolant as soon as possible.

Some might argue  they just want you to buy their coolant, true, but this system is designed for 50/50.

Anyway it's a free world in the end of the day, I know I'll stick with 50/50 mix  :062:!
« Last Edit: March 06, 2020, 12:05:16 PM by Djairouks »

 


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