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Re: Overheated, low coolant, advice.

Posted: Thu Nov 06, 2008 12:22 am
by bigdaddycain
A 50% mix may well increase the boiling point of water, but what use is that if the coolant is flowing too quickly to carry what heat is in the cylinder head effectively?

Re: Overheated, low coolant, advice.

Posted: Thu Nov 06, 2008 12:52 am
by dandywarhol
Did you read the bumf iposted in the last post Ste?
http://www.engineeringtoolbox.com/ethyl ... d_146.html

Might be wrong but I reckon Mazda would have allowed than in their design calcs.

Re: Overheated, low coolant, advice.

Posted: Thu Nov 06, 2008 1:29 am
by bigdaddycain
Yep, i read it alan, it indicates that an increase of 16% of coolant velocity would be neccessary to effectively cool at 50% mix.

The bongo was never intended to be used in europe, (well, it was initially, but plans changed nearer production), so the design calcs of mazda engineers only needed to take into account the use of their own type of anti-freeze, which is ethylene glycol based, but with added phosphates used to suit their softer water.

The chemical make up of their anti-freeze needs to be of a 50% ratio to be effective, the european version (with no phosphate) needs to be only of a 30% ratio mix with water.

By all means add a 50% ratio if you need to,but your link says that effectively the coolant will then be 16% too slow to be 100% effective for heat dissipation.

I have run at 30% for years now,granted, it doesn't get as cold here though... :wink:

Re: Overheated, low coolant, advice.

Posted: Thu Nov 06, 2008 11:23 am
by Hippotastic
What can I say? Thank you very much for the grown up conversational solution. It has answered all my questions.

I used the hose pipe method the first time as I wanted to flush the old coolant out and replace it all. So it me this method allowed this, and I added antifreeze once the system was plain water. I agreed with the idea that if you would flush the air out of the system with a steady flow. I aimed the bleed pipe at my bucket, and aimed the hose at the header tank, and stood there for a whie whilst the liquid was replaced.

I did have the bleed pipe downwards roughly level with the passenger footwell, but it was flowing when I bunged it as the cap was off, and then once bunged, I topped up to the flange ignoring the max line and put the cap back on. It seemed to work. I added 5lts of Antifreeze (red) to a 13lt system, so a 38% mix less what I lost changing the pipe. Should still be over 35% mix.

I am going to use the see saw method next as I am not flushing the system, just replacing the bit I lost changing the pipe. The bleed pipe I imagine can indeed fill with air if you hold it high enough, for long enough, but I found that you can look into the pipe and move it up and down, and the water level in the pipe will match the top of the engine. Up no flow, down flows as its lower than the body of water in the engine. With the funnel you have given yourself a wider pipe to allow the raise and fall to be slower and more manageable. And after thinking it through, it can be easily managed to not allow air in as long as it is not lowered too much and the extra coolant in the funnel is there to keep the pipe filled.

I might change to the new pipe at the weekend, and spend some time messing with the bleeding. I think I agree with Dandy that a high pipe will allow the air to escape and fits in with my thinking of hot air rising. My efforts so far have been okay, my Bongo seemed okay all weekend, but I have read of Bongo's going a week before the airlock makes its precence known. I might add some antifreeze here to bring the mix up, have not decided yet.

And thank you all for clearing up the confusion. Top notch stuff and another reason why I am really happy choosing a Bongo.

Hippo

Re: Overheated, low coolant, advice.

Posted: Thu Nov 06, 2008 5:03 pm
by dandywarhol
bigdaddycain wrote:Yep, i read it alan, it indicates that an increase of 16% of coolant velocity would be neccessary to effectively cool at 50% mix.

The bongo was never intended to be used in europe, (well, it was initially, but plans changed nearer production), so the design calcs of mazda engineers only needed to take into account the use of their own type of anti-freeze, which is ethylene glycol based, but with added phosphates used to suit their softer water.

The chemical make up of their anti-freeze needs to be of a 50% ratio to be effective, the european version (with no phosphate) needs to be only of a 30% ratio mix with water.

By all means add a 50% ratio if you need to,but your link says that effectively the coolant will then be 16% too slow to be 100% effective for heat dissipation.

I have run at 30% for years now,granted, it doesn't get as cold here though... :wink:
Ethelye Glycol has been available since the 1920s in Europe - the same stuff as Japanese manufacturers use. Usually blue or green coloured.
Organic Acid Technology has been around for a few years now - thats the longlife stuff, usually red or orange.

The two aren't compatable.

The latest O.A.T. antifreeze which is greeny yellow claims to be compatable with all antifreezes

Re: Overheated, low coolant, advice.

Posted: Thu Nov 06, 2008 5:22 pm
by mikeonb4c
dandywarhol wrote:
bigdaddycain wrote:Yep, i read it alan, it indicates that an increase of 16% of coolant velocity would be neccessary to effectively cool at 50% mix.

The bongo was never intended to be used in europe, (well, it was initially, but plans changed nearer production), so the design calcs of mazda engineers only needed to take into account the use of their own type of anti-freeze, which is ethylene glycol based, but with added phosphates used to suit their softer water.

The chemical make up of their anti-freeze needs to be of a 50% ratio to be effective, the european version (with no phosphate) needs to be only of a 30% ratio mix with water.

By all means add a 50% ratio if you need to,but your link says that effectively the coolant will then be 16% too slow to be 100% effective for heat dissipation.

I have run at 30% for years now,granted, it doesn't get as cold here though... :wink:
Ethelye Glycol has been available since the 1920s in Europe - the same stuff as Japanese manufacturers use. Usually blue or green coloured.
Organic Acid Technology has been around for a few years now - thats the longlife stuff, usually red or orange.

The two aren't compatable.

The latest O.A.T. antifreeze which is greeny yellow claims to be compatable with all antifreezes
Ethylene Glycol - aaah! the mention of it brought back old memories of reading about Spitfire Aces having their kites all shot up, with the stuff spilling over the windscreen. So I wnet Googling, to see if my memories had any sound basis. I found this extract in piece about the development of the RR Merlin engine:
Then Rolls-Royce adopted Ethylene Glycol as a coolant, which is more efficient than water, a radiator for the new coolant could be much smaller than those used with water-cooled engines, the wing condensers were then done-away with. The cooling system was vulnerable to damage by gunfire, particularly as the header tank was situated at the very front of the aircraft. A hit here by the rear gunner of a German bomber would cause a Spitfire pilot to have to break off his attack and land before the engine overheated. Even worse, pure Ethelene Glycol is flammable and added to the risk of the engine catching fire.



Ethylene glycol was first prepared in 1859 by the French chemist Charles Wurtz. It was produced on a small scale during World War I as a coolant and as an ingredient in explosives. Widespread industrial production began in 1937, when its precursor ethylene oxide became cheaply available, the engine was switched to this system instead. Ethylene glycol (IUPAC name:ethane-1,2-diol) is a chemical compound widely used as an automotive coolant and antifreeze. In its pure form, it is a odorless, colorless, syrupy liquid with a sweet taste. Ethylene glycol is toxic, and its accidental ingestion should be considered a medical emergency.

..so there you have it. Not sure which is more remarkable - E/G or Google :lol: :lol: :lol:

PS - it also implies that a 50/50 mix will be more efficient at cooling yer motor than a lower E/G concentration. I guess it's due to a combination of higher thermal capacity and better conductivity. The same argument MAY be true of the more modern anti-freezes - worth checking just in case?

Re: Overheated, low coolant, advice.

Posted: Thu Nov 06, 2008 7:53 pm
by haydn callow
How refreshing to have a topic such as this...nice and long...informative....able to give a point of view which may not always be in total agreement with others.....and not get slapped down

Re: Overheated, low coolant, advice.

Posted: Thu Nov 06, 2008 7:56 pm
by francophile1947
Now, Now Haydn [-X - green ink :shock: :lol: :lol: :lol:

Re: Overheated, low coolant, advice.

Posted: Thu Nov 06, 2008 8:34 pm
by bongomaan
just to add this i noted on the link given by mr warho l" Note! Distilled or deionized water should be used for ethylene glycol solutions. City water is often treated with chlorine, which is corrosive, and should be avoided." this to me is common sense not only because of the chlorine but in our area the water is harder than nails,i as i have said before used the deionized water from our tumble dryer...

Re: Overheated, low coolant, advice.

Posted: Thu Nov 06, 2008 8:37 pm
by haydn callow
makes sense to me !!

Re: Overheated, low coolant, advice.

Posted: Thu Nov 06, 2008 8:59 pm
by dandywarhol
If ah can pit ma tap water intae ma whisky ah'll sure pit it in ma Bongo!

Re: Overheated, low coolant, advice.

Posted: Thu Nov 06, 2008 9:15 pm
by bongomaan
ya"ll milt ya hoooses....

Re: Overheated, low coolant, advice.

Posted: Fri Nov 07, 2008 12:18 am
by cheffy34
Can it be guys :?: surely not :!: this must be the longest coolant thread since i joined :roll:


and it still hasn't been locked :lol: I wan't to do my coolant in the near future but i am reluctant to because it all looks cool if you excuse the punn :D :D

Re: Overheated, low coolant, advice.

Posted: Fri Nov 07, 2008 12:20 am
by daveblueozzie
I think this must be the longest because everybody has kept their COOL. #-o :shock: =D> =D> =D>

Re: Overheated, low coolant, advice.

Posted: Fri Nov 07, 2008 12:44 am
by cheffy34
It nearly got overheated :D at one point tho mr ozzie

:roll: :roll: