Ian & Irene Beadle wrote:

                         Jerry
                         My 2.85 system will run all day at 6400rpm 180

MPH coolant sitting

               on the

                    thermostat. RV6A standard air inlet and 7" X 2 1/2"

inlet for oil. Extra

                    oulets at the side which need adjustable flaps. I

intend to have max RPM at

                    7200 when I get the inlet to the engine and prop.

pitch sorted. I will let

                    you know when it goes faster than You Know Who.
                    Ian

          Ian,

          Do you have any current pictures showing your oil cooler

installation,

          inlet, and ducting? What sorts of oil temps do you see and at

what ambient

          temps?

          Mike Wills

Ian, I must have missed your original post somehow. It is encouraging to

hear that 6000 plus rpm are working in the real world. Since you are using
conventional RV inlets, I assume that you have cheek rads. What is their
size? Also, do you have any cooling problems during long ground operations?
Lastly, are you using the Mazda oil cooler?

Cheek rads (see pict) only 9"X 10" square on to air flow 2 1/2" thick.
Trumpet duct.

Jerry Hey wrote:

 I think you have proven that 42 sq. in of inlet area (RV 6 cowl) is
sufficient to cool the rotary at sustained 6000 plus rpm. Others have not
had the same result. Why do you think your installation is working so
efficiently?----Jerry

Short answer, 1) Duct shape. 2) air outlet area equal to or greater than
inlet area. All information gleaned from the list, without which I would be
pouring buckets of water over it!
On the ground does not seem to be a problem even after running her up to set
the Michrotech parameters. I don't have a taxi or traffic problem at our
club strip. I guess on a 35 C [95 F] degree day on hot tarmac might be different, but
then the Piper I fly has to be shut down whilst waiting for clearance.

Paul Lamar wrote:

First let me say RPM alone is not the final criteria. One can have high
RPM
with a prop that is not adequately pitched and therefore the engine is
generating less HP than one might assume based on RPM numbers alone.
The intake manifold pressure  determines the actual HP generated at that

RPM. PL

My Michrotec indicates 5"Hg at full throttle 6400rmp 180 MPH. (inlet still
needs work its a NACA)
A few more adjustments and I will see 200. Just for fun.

5" Hg? I think you mean 25 inches of Hg. 29-30" Hg would be full power. 
What altitude?  PL

At 1500fpm you are not in the heat too long!
I have the magic 40 hours now. The engine has used zero oil, and zero
coolant in that time. The oil looks brand new. Coolant is water wetter.
Ian

Liquid cooling is very sensitive to ambient air temperature.
Ambient temperature determines the rate of waste heat dissipated.
77 F is still pretty cool ambient. Cooling is roughly 20% better 
at 77 F than it would be at 100 F. The real acid test will come for 
his cooling system when Ian flies the airplane at 35 C or 95 F and 29" Hg.

Never the less I think we have seen the light at the end of the cooling tunnel.

Here are the coordinates again for the Kuchemann & Weber trumpet shaped duct
Ian mentioned. 

Paul Lamar
 
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