---------------------------------------------------------- TeamGrumman-List Digest Archive --- Total Messages Posted Thu 08/14/03: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:14 PM - Cowling Update 6.1 (Aucountry@aol.com) ________________________________ Message 1 _____________________________________ Time: 07:14:45 PM PST US From: Aucountry@aol.com Subject: TeamGrumman-List: Cowling Update 6.1 --> TeamGrumman-List message posted by: Aucountry@aol.com I made the mod to the rear baffle and dropped the CHT about 20 degrees. I say 'about' because the temps were still rising past 450 when I pulled the power back to let it cool. I don't know how high it would have gone. Today, it was 107 and I was able to climb out at near gross weight and lean it and it never went over 440. That's #3. The other cylinders never went over 409. EGTs were about 1320 plus or minus 10. EGTs are very uniform. I leveled off at 4500 and ran flat out at 2700 rpm and computed a TAS of 144 knots. CHTs actually leveled off to around 390 for 1,2,&4 and 420 for #3. Outside air temp was 84 at 4500 feet. I climbed to 7500 feet under full power and leaned and the CHTs stayed about the same, maybe plus 5 degrees. I climbed to 8500 feet and ran flat out. Level at 8500 feet I recorded 122 knts indicated, 70 degree outside air temp for a TAS of 147 knots. That's at 2700 rpm. Under these conditions, the CHTs settled aroun 380 for all but #3 which was 410. Still 30 degrees warmer. The next cowling will use a different carb air inlet so the 280 cubic feet per minute being used by the engine will be available for cooling. On a stock Tiger/Cheetah with 90 sq inches in inlet area, stealing 12 square inches for the carb isn't a big deal. On my cowling, 12 square inches is 26% of my inlet area. Even at that, I'm happy that my cowling is working/cooling so well. I've already got the scoop built for the next cowling exit. One scoop. 72 square inches of exit area. Gary www.AuCountry.com Home of "Team Grumman" TeamGrumman-List@matronics.com http://www.matronics.com/subscribe