I have a 7a with an ECI IO-360, duel Pmags and a 4 pipe exhaust now with 61 hours. I have had my CHT's wanting to blow passed 400 deg. on take off and a hard time keeping them below 380 deg. in cruise. Oil temp is 180. My baffling is very good and run the A curve on the Pmags.
What I've found from looking at some local tail wheel 8's, is that I have much less cowling exit area because of the four pipes and the nose gear. And no, I did not measure, but it's obvious. After talking with Allan from Antisplat, I placed nylon spacers on both sides of the exit opening the lower rear cowl and created a wedge like gap on either side. The spacers lowered the cowl next to the exit 3/4". I went for a test flight and I could leave the throttle wide open and the highest CHT was 381 deg. and the oil temp also came down causing me to close the butterfly valve to the oil cooler to almost full closed. To me, it is clear that I need to increase my exit area and I don't believe louvers are the answer.
These are what I see as my options:
1. Open the exit area by lowering the trailing edge (the easiest)
2. Open the exit area by widening
3. A combo of the above
3. Adding a cowl flap in conjunction with one of the above for takeoff
Thanks
What I've found from looking at some local tail wheel 8's, is that I have much less cowling exit area because of the four pipes and the nose gear. And no, I did not measure, but it's obvious. After talking with Allan from Antisplat, I placed nylon spacers on both sides of the exit opening the lower rear cowl and created a wedge like gap on either side. The spacers lowered the cowl next to the exit 3/4". I went for a test flight and I could leave the throttle wide open and the highest CHT was 381 deg. and the oil temp also came down causing me to close the butterfly valve to the oil cooler to almost full closed. To me, it is clear that I need to increase my exit area and I don't believe louvers are the answer.
These are what I see as my options:
1. Open the exit area by lowering the trailing edge (the easiest)
2. Open the exit area by widening
3. A combo of the above
3. Adding a cowl flap in conjunction with one of the above for takeoff
Thanks