Waterless coolant & bore scoring

[eddtheduck]

My local specialist scoped my bores (2005 997.1 C2S, 46k miles) as part of an inspection. Cylinders 4,5,6 have what he describes as a VERY mild scoring in comparison to cyls 1,2,3. There is no oil consumption between services and no other symptoms at all. He is happy to keep an eye on things. One thing that he has recommended is the Evans waterless coolant. I understand the science behind why it might help and don't begrudge the £500 to do it but if the club have data/knowledge to reassure me I'm not about to throw good money after bad I'd be very grateful.

 

[Geoff_Fields]

A low temperature thermostat would be a priority over the coolant for me. But both would do no harm.

 

[Murv]

Hi I would agree with Geoff low temperature thermostat is a must, perhaps coupled with Millers Nano Technology Oil. Waterless sounds great but costly if you spring a leak, lets face it 997's like to weep from the cross-over pipes, water pumps, radiators and filler caps and other places, IMHO stick to a good antifreeze and distilled water mix and spend your money on the thermostat and oil. Regards, Jas

 

[eddtheduck]

Thanks guys - off to research some more!

 

[Gazza3501]

I have recently made the move from air cooled to a liquid cooled car in the form of a 997 C2s. I am considering Evans Coolant also. One point to remember is that there is no pressure with this liquid so the cars are less likely to leak than with conventional pressurised coolant.

Gaz

 

[rogerandoutman]

I was considering evans, but read a long critique on the norosion web site. Evans is pure gycol and operates at a higher temperature and also is more viscos, so needs the water pump to work harder to circulate the coolant. Also as it runs at a higher temperature, you need to re set the cooling fan operating temperature, otherwise it will be operating constantly. This info came from the norosion, an american operation web site , so I suppose as they are in competition with evans, you have to be circumspect, but they have some interesting points. the main advantage with evans that as it is gycol, it does not expand and has a higher boiling point.

 

[SterlingMess]

Sorry to hijack your thread Edd, but I was interested by what you said Murv. My 997.2 3.8 requires regular expansion tank top-ups with no obvious signs of leaking or unusual temperature gauge movements. Would you say this is normal? (It also requires regular Mobil 1 top-ups too!)
Thanks
Windy

 

[Gazza3501]

Interesting points.

RPM Technic converted a Porsche in 911 & Porsche World a while back and they have I believe converted a number since. No mention has been made regarding the fans running. From what I have found out so far, the engines run a little hotter but this can be helped by fitting a lower temperature thermostat. I think one benefit is that when the engine is suddenly used hard the cooling is more constant with less of a temperature spike due partly to lack of cavitation which can occur with water based coolant. It is this cavitation that is believed to be a major cause in bore scoring.

I'm still evaluating this as it is a large outlay although it may save money in the long run.

 

[Murv]

Hi guys, when I stated that Porsche can spring leaks, what I meant was that these elements, water pump, cross over pipes, front rads, coolant expansion tank can fail, but once rectified the car shouldn't require regular top up. To go waterless, IMHO you should change the water pimp, which fails at the bearing not because of water pressure, the cross over pipes because they weep due to external corrosion / their location on the car. So it can be very expensive if done properly to protect the investment in waterless! And the engine runs hotter, is that not the very reason cylinder scoring occurs when the oil is thinnest? No car car should need a regular coolant top up, early stages of water pump can cause this but equally the two small coolant pipes (rubber) located at the lowest part of the engine and thus exposed to road dirt can perish. The spring chips used to secure them can also corrode and weaken their ability to remain tight enough to prevent high pressure leaks.

 

[Murv]

Windy, I believe the water temperature gauge is buffered and therefore digitally controlled and cannot be truly relied upon to indicate temp changes until the temp exceeds preset levels. The oil temp gauge is much more reliable in telling what's happening. You should get the leak investigated. I had a rubber hose clip fail, it just lost its spring tension due to rust and allowed coolant to leak when the engine was at normal ruining temperature. Murv

 

[Murv]

Windy, I believe the water temperature gauge is buffered and therefore digitally controlled and cannot be truly relied upon to indicate temp changes until the temp exceeds preset levels. The oil temp gauge is much more reliable in telling what's happening. You should get the leak investigated. I had a rubber hose clip fail, it just lost its spring tension due to rust and allowed coolant to leak when the engine was at normal ruining temperature. Murv

 

[SterlingMess]

Murv - thanks, I'll get it checked. I have OPC extended warranty so worth a try...
I think you're right about the water temp gauge. After track work the oil temp is clearly higher than I ever see it on the road, but the water temp never seems to go a degree above 80C!

 

[Chris_in_the_UK]

I think it's fair to say that the Evans stuff is still largely unproven. One of the members of another (Porsche) forum had this to say in relation to using it in a Porsche turbo:-

I wouldn't, it's about the worst thing you can do to a high output engine. It's fine for old 1930's plodders and older yank stuff with low specific outputs but absolutely not suitable for anything modern making high outputs. It has as specific heat capacity of around 0.68 vs pure water at 1, it is also far more viscous than water so you end up with a perfect storm of lower bulk flow rates (and a water pump operating outside of spec with regards viscousity of the pumped medium) coupled with less specific heat capacity which in turn raises the operating temperature of the block and heads. You'll find the engine far more likely to det in this situation so at best you're running the castings with a mating surface way hotter whilst the engine control is reducing boost and spark advance to avoid det.

In addition it's also flammable, something which water is very good at not being. So on a car with multiple known failure points that lead to large scale coolant loss in areas around the exhaust and turbos it's probably not the best thing to fill the cooling circuit with for this reason alone!

Water is actually very hard to beat as a cooling medium, it's still what we use in the F1s which should tell you something Smile

 

[Murv]

Hi, Please let us know what OPC find it may help others! Regards, Murv

 

[Murv]

Hi, Please let us know what OPC find it may help others! Regards, Murv