Jim M wrote:

Paul

July 31 I filled the gap behind my spinner as you suggested to improve cooling. I installed a 3/8" plywood split ring on the front of cowl behind spinner leaving 1/16 clearance. Test as follows.

Aug 1-   OAT 91 F, coolant temp. 215 F , engine oil temp 208 F , gear box temp 220 F. I did not get above circuit height ( 1700 ft. ) as the red lights were flashing. curtailled flight went downwind temps dropped 3-4 degrees, landed, duration 9 min.

Aug 4-   OAT 84 F., coolant temp 204 F, engine oil temp 203 F max. 195 F min., gear box temp 212 F max. 212 F min. OAT 4000 ft. 76 F , RPM 5450, duration 40 min.

Aug 6-   Plywood filler removed, OAT 92F, coolant temp 197 F max. 192 F min., engine oil temp 197 F max., 192 min., gear box temp 194 F, max., 192 min., OAT 4000 ft. 82 F , RPM 5450, duration 40 min.

As you can see filling the gap did nothing to improve my cooling, I must be getting considerable cooling to the gear box from this gap.
I have not done any pressure test inside the cowl, but I have monitored the inside cowl temps in the past, they were running around 100-115 degrees so I just don't bother anymore.
I have not had any cooling issues for the last 1 1/2 years, so if it's not broke don't mess with it.


Jim Mosur
RV6
C-GAPF

Thanks for the great data Jim. Too bad about no pressure data. Hard to tell what
is going on with out that. Course cooling is the bottom line.
Perhaps air is coming out there as Ray suggest.
Here is a pictures of your air outlet area under the cowl at OSH.
Do you have the sheet metal firewall stream liners like Chuck
and Tracy? If not you might try that for us. I love the way you
take data.

Paul Lamar
 
The AirCraft Rotary Engine NewsLetter.              Powered by Linux.
ACRE NL web site.
http://home.earthlink.net/~rotaryeng/            http://www.linux.org