Coolant loss

[skippydiesel]

Thanks for that, l will change over , is it available at most auto shops

Yes if they supply Castrol products - be sure to get the precise Rotax Castrol recommendation before purchase SI-912-016 4) Coolant page 6

 

You will see that there are variose coolant products recommended - most of which are not available in Au. The Castrol named as "Antifreeze All - Climate" & "Anti- Boil" are sold in Au as Radicool

 

 

[skippydiesel]

evans web site info

 

.

 

With Evans waterless coolant, the likelihood of coolant loss and the need for topping up are greatly reduced. In the event that there is significant coolant loss from the system during operation and no Evans waterless coolant is available to fill the system, water or water-based coolant may be used. However, repairs should be made as soon as possible, and the system should be drained, purged and re-filled with Evans waterless coolant.

Check out the Rotax strong recommendations against mixing any H2O with Evans - SI-912-016 4.3.1) Waterless Coolant page 7

 

 

[skippydiesel]

As far as I understand -

 

• There is no operational advantage to using Evans or other water-less coolants.
   
  
• The Evans costs more to purchase than the recommended glycol types.
   
  
• When you are doing your 5 year rubber replacement you will have to very carefully save your Evans, make sure of no contamination before returning it to the cooling system.
   
  
• According to Rotax you must not top up Evans with water - if you do you are required to to halve a detailed inspection performed to check for damage (why risk it?)
   
  

 

Seems to me much easier just to use Castrol Radicool (or similar meeting Rotax specs) at the prescribed 50:50 ratio, using a pure water.

 

• According to Rotax it has a higher thermal efficiency
   
  
• Is cheaper to purchase
   
  
• In a pinch, can be topped up with water without fear of damaging the engine/cooling system but better to use coolant/water mix..
   
  
• Should be replaced periodically - the 5 year rubber is a good time.
   
  

 

Further;- it is my understanding that the use of Castrol (& similar) coolants,

 

• raises the boiling point (of water),
   
  
• prevents freezing
   
  
• inhibits internal corrosion of your cooling system
   
  
• lubricates seals
   
  

 

You will only need approximately (depending on your peculiar system) 1.5 L of concentrate and the same in pure water - its not going to brake the bank - its just the most cost effective/efficient way to go - so why not go with the Rotax recommendation????

 

 

[skippydiesel]

Hi RR Note the max is 50/50. Ratio must be less than 50% radicool to the water mix. Have a good read of the instructions. (don't exceed the 50% ratio of radicool.) Cheers

For most cost effective and efficiency 50:50 is the recommended ratio - however if you should;

 

• Add more coolant concentrate - you are likely to pay more for a less thermally effective mix. Unlikely that there will be any negative effects in the short/long term
   
  
• Add less coolant concentrate - save $$ but reduce many of the claimed benefits. Unlikely that there will be any negative effects in the short term.
   
  

 

Most importantly use a pure water - ordinary tap/creek/dam water is likely to contain "contaminants" that will reduce the efficacy of the coolant concentrate and may, over time, damage your cooling system.

 

 

[M61A1]

As far as I understand -

 

• There is no operational advantage to using Evans or other water-less coolants.
   
  
• The Evans costs more to purchase than the recommended glycol types.
   
  
• When you are doing your 5 year rubber replacement you will have to very carefully save your Evans, make sure of no contamination before returning it to the cooling system.
   
  
• According to Rotax you must not top up Evans with water - if you do you are required to to halve a detailed inspection performed to check for damage (why risk it?)
   
  

 

Seems to me much easier just to use Castrol Radicool (or similar meeting Rotax specs) at the prescribed 50:50 ratio, using a pure water.

 

• According to Rotax it has a higher thermal efficiency
   
  
• Is cheaper to purchase
   
  
• In a pinch, can be topped up with water without fear of damaging the engine/cooling system but better to use coolant/water mix..
   
  
• Should be replaced periodically - the 5 year rubber is a good time.
   
  

 

Further;- it is my understanding that the use of Castrol (& similar) coolants,

 

• raises the boiling point (of water),
   
  
• prevents freezing
   
  
• inhibits internal corrosion of your cooling system
   
  
• lubricates seals
   
  

 

You will only need approximately (depending on your peculiar system) 1.5 L of concentrate and the same in pure water - its not going to brake the bank - its just the most cost effective/efficient way to go - so why not go with the Rotax recommendation????

You seem to be concerned about the expense, on that basis, why would I throw it out when it’s all working perfectly? Also, if you read the SI it says you can mix glycol coolant with the Evans.

 

Realistically, if you’re stuck, you still need coolant, you can’t just add water because it lowers the boiling point excessively. If I can get coolant at a servo, I can change it then and there. Not a big deal.

 

 

[facthunter]

It's not unusual for a thermostat to "hunt" but if your cap isn't maintaining the correct pressure it's possible you will get some steam pockets especially at altitude. That will explain the coolant displacement and the varying temp indication. You must be sure the cap is the correct one. and the part of the radiator where it fits is not damaged. . Pressure test the system. Nev

 

 

[rhtrudder]

It's not unusual for a thermostat to "hunt" but if your cap isn't maintaining the correct pressure it's possible you will get some steam pockets especially at altitude. That will explain the coolant displacement and the varying temp indication. You must be sure the cap is the correct one. and the part of the radiator where it fits is not damaged. . Pressure test the system. Nev

It looks like it’s leaking back out the cap , going to order a new one today

 

 

[skippydiesel]

You seem to be concerned about the expense, on that basis, why would I throw it out when it’s all working perfectly? Also, if you read the SI it says you can mix glycol coolant with the Evans.

 

Realistically, if you’re stuck, you still need coolant, you can’t just add water because it lowers the boiling point excessively. If I can get coolant at a servo, I can change it then and there. Not a big deal.

The cost is just one of several factors, as explained.

 

Where did you get the idea that I was suggesting throwing out a functioning system ?? - if it were me I would not have started with Evans by choice and if I purchased an aircraft with Evans in place would replace it at the next appropriate service.

 

Adding water to a glycol blend, to get you home, is an extremely low risk (to your cooling system/engine) action - cant be clearer than that,.

 

Your reading of the Rotax advice on mixing waterless coolant with glycol blend or water, is diametrically opposite of mine - good luck!

 

 

[M61A1]

Your reading of the Rotax advice on mixing waterless coolant with glycol blend or water, is diametrically opposite of mine - good luck!

Have a read a bit further down past the first line of the SI you quoted.....

 

Adding water to a glycol blend, to get you home, is an extremely low risk (to your cooling system/engine) action - cant be clearer than that,.

 

Also the events of the OP could easily be explained by excessive water in the coolant mix, lowering the BP and boiling off at localised hot spots and especially so if the cap is not holding pressure. A high risk.

 

 

[alf jessup]

I have been using Evans for the past 15 odd years when Rotax recommended it as the Coolant to use.

 

I find all this crap with engine makers painful.

 

One minute glycol mix one minute Evans.

 

Way I see it the manufacturer goes with whoever will pay them the most.

 

Evans does have one advantage I have found.

 

It raised the temp of my coolant about 25 deg.

 

My Sierra never got above 65 deg most times which in turn kept the oil cooler which in Rotax’s case didn’t run at the recommended 90 deg oil temp.

 

Using the Evans I sit in winter between 85-90 on the coolant temp and Oil temp depending on power setting between 80-90.

 

If it ain’t broke I aint fixing it, they recommended it years back and I changed to it, I liked the benefits I gained the some years later oh no you must use this because this company is paying us more than Evans. ( well that’s what it feels like)

 

 

[skippydiesel]

I have been using Evans for the past 15 odd years when Rotax recommended it as the Coolant to use.

 

I find all this crap with engine makers painful.

 

One minute glycol mix one minute Evans.

 

Way I see it the manufacturer goes with whoever will pay them the most.

 

Evans does have one advantage I have found.

 

It raised the temp of my coolant about 25 deg.

 

My Sierra never got above 65 deg most times which in turn kept the oil cooler which in Rotax’s case didn’t run at the recommended 90 deg oil temp.

 

Using the Evans I sit in winter between 85-90 on the coolant temp and Oil temp depending on power setting between 80-90.

 

If it ain’t broke I aint fixing it, they recommended it years back and I changed to it, I liked the benefits I gained the some years later oh no you must use this because this company is paying us more than Evans. ( well that’s what it feels like)

Rotax recommend BOTH waterless and glycol types. It is up to the maintainer/user to decide which one they opt for.

 

All I have done is ask the question why use waterless, when glycol types, seems to me, to be a better option, in the ways I have listed.

 

 

[alf jessup]

Rotax recommend BOTH waterless and glycol types. It is up to the maintainer/user to decide which one they opt for.

 

All I have done is ask the question why use waterless, when glycol types, seems to me, to be a better option, in the ways I have listed.

Skip,

 

I wasn’t in any way having a crack at you, I was just giving my opinion on the subject.

 

 

[cscotthendry]

I believe the heads are sealed and can’t leak and there are no head gaskets , but l will look into it,

Have a look through the Rotax SBs. I seem to recall a SB that came out shortly after the new style heads were introduced that had something to do with where the temp sensor went in. I think some heads were over drilled or something like that.

 

 

[facthunter]

I think the previous statement refers to the ( 912 etc series engines.. The two strokes are more conventional with coolant going from one to the other( Head to barrels.) Nev

 

 

[Downunder]

Have a look through the Rotax SBs. I seem to recall a SB that came out shortly after the new style heads were introduced that had something to do with where the temp sensor went in. I think some heads were over drilled or something like that.

In the old heads, the temp sender was dry and it is called "cylinder head temperature" (CHT)

 

In the new heads the temp sender is wet (in the coolant) and is called "coolant temperature".

 

So I guess it could leak past the sender seal and leak.

 

Rotax recommend BOTH waterless and glycol types

I thought at some point Rotax removed the recommendation for waterless coolant?

 

Perhaps when the new heads were introduced.

 

 

[Blueadventures]

In the old heads, the temp sender was dry and it is called "cylinder head temperature" (CHT)

 

In the new heads the temp sender is wet (in the coolant) and is called "coolant temperature".

 

So I guess it could leak past the sender seal and leak.

 

I thought at some point Rotax removed the recommendation for waterless coolant?

 

Perhaps when the new heads were introduced.

They did remove support for Evans waterless. Maybe around 2012 to 2013 era. Also there was talk of no more than 3.6% (maybe be 3.8%) allowable water in the Evans. There is a test kit to measure the % of water in Evans. I had Evans with my engine kit and chose to go the castrol radicool way. When Greg the Skyranger agent came up to do the final tweets for first flights; I gave him the Evans so it could be given to anyone who had need of it. The Aviasport guages are color coded for the respective engine fit up. Cheers and good flights Mike. .