I have more or less committed to giving it a try.  At this point I am trying to decide upon a safe redline...  Pineapple racing (rotary) uses 250-260. After hearing your story I might start at 240 and see how things go...

Heck, don't some of you guys see temps in the 230-240 range on occasion with water/glycol mix?  I think the main drawback here is that Lynn has mentioned that you lose power above a certain temp.  I'd have to check the archives again, but I thought it was something like 180 degrees for water, and 160 for oil. 

 

The most interesting usage of NPG was on the Rotax 912S that I recently sold.  As you know, cylinder head temps generally run higher on air cooled engines than water cooled, so they have to be made to run at those higher temps (metals, clearances, etc).  It would appear that Rotax kept the air cooled cylinder head temps, but used NPG to cool them.  I was told there is no spec for coolant temp, only cylinder head temp.  Interesting, but useless to us :-)

 

You've actually got me thinking about NPG now.  I've never seen water temps over 200, even in a climb to 8500 feet at 120 mph.  My temp in cruise is usually way too low, like 140.  It would be nice not to worry about boiling, or pressure.  Hmmmm... More to think about.  

 

Rusty (still no quote for engine parts)