Board logo

At what temperature will it boil?
2cv - 5/6/10 at 12:57 PM

Following on from my "Radiator Question" thread, I just wondered if anyone can tell me at what temperature my colant will boil. I'm running a sealed system with a pressure cap. If the fan comes on at full speed at 100 degrees C how much leeway is there before it starts boiling?

t16turbotone - 5/6/10 at 01:02 PM

about 120 degrees

norfolkluego - 5/6/10 at 03:23 PM

Depends on the pressure cap, they're not all rated the same, some 'race' pressure caps are rated higher (pressure) than bog standard ones (obviously the rest of the system would need to be up to the job of taking that pressure), probably depends on the mix of your coolant too

[Edited on 5/6/10 by norfolkluego]

rusty nuts - 5/6/10 at 03:47 PM

Antifreeze concentration will also affect the boiling point as well. Water Wetter will drop the temperature by as much as 20degrees which could mean the difference between boiling and not boiling

2cv - 5/6/10 at 04:40 PM

quote: Water Wetter will drop the temperature by as much as 20degrees which could mean the difference between boiling and not boiling

I tried this on a Ford Special and it made absolutely no difference to the running temperature at all.

Anyone else have experience with Water Wetter?

norfolkluego - 5/6/10 at 05:10 PM

quote:
Originally posted by 2cv
quote: Water Wetter will drop the temperature by as much as 20degrees which could mean the difference between boiling and not boiling

I tried this on a Ford Special and it made absolutely no difference to the running temperature at all.

Anyone else have experience with Water Wetter?


I've never used it but I know a lot of people who have and they swear by it, especially for cooling troublesome Crossflows

scutter - 5/6/10 at 06:25 PM

I used it in my X-flow, dropped the temps by 10-15, so did help my marginal engine. I'll be adding it to the ST engine once it's up and running.

ATB Dan.

2cv - 6/6/10 at 07:32 AM

Thank you all for your replies.

Plan of action; Fit new radiator first. If that doesn't cure the problem, arrange more air flow and finally Water Wetter.

2cv - 21/6/10 at 04:43 PM

Here's a picture showing the relative sizes of the two Polo radiators. The larger one is fitted to 1.7 and 1.9 litre diesels so should have all the capacity I need. The inlet and outlet stubs are at the same centres so that should help the fitting.

2cv - 2/7/10 at 05:16 PM

Neither fitting the higher capacity radiator nor the addition of Water Wetter has had the slightest effect on running temperature.

To be honest, I never thought the Water Wetter would work but I am disappointed that the new rad didn't cure the problem.

norfolkluego - 5/7/10 at 07:57 PM

quote:
Originally posted by 2cv
Neither fitting the higher capacity radiator nor the addition of Water Wetter has had the slightest effect on running temperature.

To be honest, I never thought the Water Wetter would work but I am disappointed that the new rad didn't cure the problem.


Something wrong there, are you sure you haven't got a air lock in there somewhere, it's a know Xflow problem, is your water pump on the way out?

2cv - 6/7/10 at 03:14 PM

The problem which was mainly one of air flow or to be exact getting it out from under the bonnet has I'm glad to say been solved. Details in this thread;
http://www.locostbuilders.co.uk/forum/9/viewthread.php?tid=139236&page=2