Greetings All
BCSC Rev 2 flying in VERY high ambient temps - our average day is around 80ºF-100ºF OAT while flying. On the ground we regularly see 105ºF and a couple of days a year we see 120ºF
we bought the plane with a very poorly designed lower cowl scoop (builder had done his own thing, NOT followed BCSC), which we fixed temporarily by adding an aluminum lip which we riveted on to create more "suction", this seemed to work well. now we want to re-mould the lower scoop and I have some conflicting advice from tech's around me.
side view cross section, prop would be on the left of the picture, back of plane on the right.
- Option 2 - some say "extend past the firewall, "cause thats how cessna does it" - I see this option constricting the outflow of air because it narrows the cross section. might work for a Cessna that usually see 70-90kts IAS but not for a BCSC that is slow.
- Option 1 - this seems to be the most common cowl design out there from what I have observed.
- Option 3 - my gut feel tells me this one will create the most "suction", it increases the cross sectional area the most.
I know and understand that the more cooling drag I create the more it affects my speed, but since I operate most of the time at 40-60kts IAS, and when I am slow then down to 20-40Kts IAS, I dont care much for top end speed, I need cooling, cooling, cooling.
advantage of Option 1 is that if we end up not needing the lip then we can cut it back and we have the cowl ending neatly at firewall edge.
please let me know your thoughts/opinions.
BCSC Rev 2 flying in VERY high ambient temps - our average day is around 80ºF-100ºF OAT while flying. On the ground we regularly see 105ºF and a couple of days a year we see 120ºF
we bought the plane with a very poorly designed lower cowl scoop (builder had done his own thing, NOT followed BCSC), which we fixed temporarily by adding an aluminum lip which we riveted on to create more "suction", this seemed to work well. now we want to re-mould the lower scoop and I have some conflicting advice from tech's around me.
side view cross section, prop would be on the left of the picture, back of plane on the right.
- Option 2 - some say "extend past the firewall, "cause thats how cessna does it" - I see this option constricting the outflow of air because it narrows the cross section. might work for a Cessna that usually see 70-90kts IAS but not for a BCSC that is slow.
- Option 1 - this seems to be the most common cowl design out there from what I have observed.
- Option 3 - my gut feel tells me this one will create the most "suction", it increases the cross sectional area the most.
I know and understand that the more cooling drag I create the more it affects my speed, but since I operate most of the time at 40-60kts IAS, and when I am slow then down to 20-40Kts IAS, I dont care much for top end speed, I need cooling, cooling, cooling.
advantage of Option 1 is that if we end up not needing the lip then we can cut it back and we have the cowl ending neatly at firewall edge.
please let me know your thoughts/opinions.
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