I just got done painting the rad and cooler black on my S4Rt.  I used eastwood's rad paint for the fins, and some satin black duplicolor for the end tanks.  3-4 coats of each and everything is looking good.


I plan on using evans NPR-r coolant for my monster.  I was going to pull the plastic overflow bottle out and paint it black to make it less noticable, but now I'm thinking of ditching it altogether.

In addition, my fans have never kicked on, ever.  Highest the temp ever got was in the mid 90's here, and my temp climbed to 212deg one day while waiting for a wreck to clear.  99.9% of the time it's in the mid 170's....even when stopped waiting on the wreck @212 deg, the fans wern't on.

Loose the fans?

Loose the overflow?

Whatcha think?

I wouldn't ditch the overflow bottle, it's a necessary part to allow the cooling system to purge air out and slurp coolant in to replace it.

You could remove the fans, but then it's all on *you* to watch the temp religiously.

My 996 track bike has no fans...

It runs fine as long as I'm moving...

It also get hot in no time at all if I sit still.

I'll double check, but I don't think the evans coolant expands at all.  In fact, I don't believe there is any pressrizing of the rad system after switching over the evans NPG.

Please post pics when you bolt up the newly painted radiator. 

I will update my "Project S4Rt" thread when I get it all back together.  LOTS of powdercoated goodies I'm waiting on to get here. 

Quote from: TAftonomos on October 03, 2008, 07:48:45 PM
I'll double check, but I don't think the evans coolant expands at all.  In fact, I don't believe there is any pressrizing of the rad system after switching over the evans NPG.

I believe Boyles' Law will disagree with you...

PV=nrT

Evans isn't water based at all, it's 100% Propylene Glycol.  370 degree boiling point at zero pressure.  I'll have to call on monday, but I'm pretty sure I can cap off the overflow and go

I took a quick skim through their website, tech stuff here:
http://www.evanscooling.com/html/tech1.htm

I'm a bit concerned about the increased viscosity, and lower specific heat, of the NPG versus the traditional 50/50 water/EG mix.

Unless I'm missing something, the higher viscosity will make your water pump work harder.
The lower specific heat means it absorbs less heat per pound, but whether that will make the cooling system work better or worse, I'm not sure... heat transfer is a complicated deal.

It'd be good to have Howie in on this, he may be able to shed some light.

Quote from: TAftonomos on October 03, 2008, 09:49:13 PM
Evans isn't water based at all, it's 100% Propylene Glycol.  370 degree boiling point at zero pressure.  I'll have to call on monday, but I'm pretty sure I can cap off the overflow and go

So you're telling me you can put a sealed metal tank of that stuff in a fire and it won't explode?

Quote from: TAftonomos on October 03, 2008, 09:49:13 PM
Evans isn't water based at all, it's 100% Propylene Glycol.  370 degree boiling point at zero pressure.  I'll have to call on monday, but I'm pretty sure I can cap off the overflow and go

Boyles Law isn't based on water..

It's about pressure volume and temp

Quote from: ducpainter on October 04, 2008, 04:56:38 AM
Boyles Law isn't based on water..

It's about pressure volume and temp

+1con boyles law , for 1 thing unless you hook a vacum pump up it will be pressurized to 14.7 psi thats what the air pressure is at sea level , 2 you will have to change radiator cap because of the one way valve, 3 because of expansion of metal how are you going to stop vapor locking just my 2cents

The question that needs to be resolved. Will the system retain the coolant when it is subjected to expansion at its maxium operating temperature?

I agree with both ducpainter and Speeddog.  If you heat any liquid it will expand, including propylene glycol.  If memory serves me well, the expansion rate is higher than ethylene glycol.  Speeddog is also correct about heat transfer and the viscosity of pure propylene glycol.  I don't know if the viscosity or heat transfer would be an issue, but I certainly would worry about heat transfer in city traffic.   Read Evan's table table:
                                    http://www.evanscooling.com/main27.htm
Their web site is telling you you do not need to pressurize the system or only need to pressurize it a little because the boiling point is so high.  I'm not suggesting you add water to the Evans product since I they ereccomend using it straight but do keep in mind you may find you are running higher coolant temperatures.  This will not be a problem for the bike since it will not boil over or cavitate easily, but may not be great for your comfort.

Hmmm...might just be something I need to try.  I've spoken with a few other people who have run it....all say you really don't even need a rad cap except to keep the coolant from splashing out.

Yes yes, I understand normal ATM is 29.92/14.7psi, but I'm talking about the pressure inside the coolant system.  If there is little to no pressure, and no chance of boil over, when why would I need a reservoir for it?