Tracy,

 

I flew again today.  I'm still staying very close to the airport and was forced to limit my altitude to 2500' due to clouds.  OAT was about 90* and oil got to 215, but came right down after leveling off and settled in at 190*.  The strange thing is the water temps in economy cruise (5200 engine rpm, 1800 prop rpm) were in the 157* range.  I'm measuring water temp in and out.  Water out was about 161*, so I'm getting very little temp drop through the radiator.  We're figuring that this is probably due to too much air to the water radiator or too rapid coolant flow through the radiator (I'm running the 20B pump).  My main pulley has been downsized, but I may also need to enlarge the wp pulley a little to slow the flow.  I'm considering doing a quick mod to check this theory.  If that's true, then my oil temps should drop because I suspect airflow through the two radiators are fighting for the exit space and the water radiator is winning. 

 

Mark

 

On 9/29/07, Tracy Crook <tracy@rotaryaviation.com> wrote:

Haven't had any 100+ days since installing the Renesis but cooling is similar to the 2nd gen I had a few years ago when we had 10 consecutive days of 100+ temps.  Didn't have to wait it out but simply limited power after initial climbout.  Still had more ROC than most certified planes at the reduced power setting.  I start with around 2500 FPM on a standard day and never had to settle for less than ~1000 fpm due to heat issues.

 

Hope my 20B RV-8 does as well or better but I will install spray bar for initial tests.

 

Tracy (delayed 20B test schedule due to motorcycle distraction)

 

On 9/27/07, Mark Steitle <msteitle@gmail.com > wrote:

Tracy,

 

So, what do you call a "hot" day?  In Austin, it is normal during the summer for temps to be in the upper 90's and even above 100 on occasion.  I don't want to be grounded waiting for the Texas heat to subside.  I guess I could install a spray bar for summer flying.  Right now I can keep temps in the green up into the low 90's.  Living in Texas, I would like a little more margin than that.  Not everyone can swing a summer home in Colorado.   ;-)

 

Mark S.

(Just happy to be flying again.)

 

 

 

On 9/26/07, Tracy Crook <tracy@rotaryaviation.com > wrote:

Engine will cool at any throttle setting that enables the plane to fly.  The coolant & oil temp curve looks about like the power required curve of the airframe, minumum at around 95 mph and rises on either side of that speed.  Only exception is WOT at Vx on hot day.  Engine will exceed redline temps if this is maintained more than a minute or so.   Fortunately there is never any real need to do that. 

 

Tracy

 

On 9/26/07, Mark Steitle <msteitle@gmail.com > wrote:

Tracy,

 

Is there a particular speed that you must reach before your system cools? 

 

Mark

 

On 9/26/07, Tracy Crook <tracy@rotaryaviation.com > wrote:

For another data point, the delta T on oil cooler depends on power setting on my installation (no big surprise).  It is around 40 degrees F at higher power settings.

 

Tracy

 

On 9/18/07, Mark Steitle <msteitle@gmail.com > wrote:

For those that are flying (rotaries), I'm curious as to what delta-T you're seeing across the oil cooler.  And at what speed you attain adequate cooling.

 

Mark S.