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  #21  
Old 06-25-2019, 09:16 AM
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DanH DanH is online now
 
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Quote:
Originally Posted by NovaBandit View Post
I think I was one of the first to put the AntiSplat cowl flaps in a 10 in lieu of the traditional louvers.

I battle a little with high CHTs, especially if I'm heat soaked... even in moderate temperatures. I absolutely have room for improvement on my baffling, and I'm hoping that will help a lot when I redo the baffling material, but the cowl flaps are not a magic bullet.
You got it. If the air is bypassing the hot parts, it contributes only drag. Exit area as big as a garbage can won't solve an underlying problem with poor heat transfer. Cold air in, only lukewarm out, and the engine stays hot.

It's why I ask folks to measure exit temperature.
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  #22  
Old 06-26-2019, 04:53 PM
rvdave rvdave is offline
 
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I have stock 8.5:1 io540 and feel I have tight baffling and rtvíd gaps . I struggled with whether to put in louvers based on others that have gone before and decided not to. Iím in Michigan but have flown in Florida with 90+ temps and am comfortable with my cylinder temps in cruise and simply donít climb as quick if temps get around 400 but usually thatís not a problem. Oil temps not an issue with butterfly valve which works well and can keep oil temps where I want them. I have dual ei and not sure if that makes a difference or not. Just more info to ponder.
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  #23  
Old 06-26-2019, 06:00 PM
Kyle Boatright Kyle Boatright is offline
 
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Quote:
Originally Posted by falcon900guy View Post
i spent a day at jet guys out of covington, tn and owner shared a tip with me how to make a lip on aft exit of cowl, and also we put a half piece of pipe on bottom of firewall each side of cowl at the exhaust to create a low pressure sucking the hot air out.
I don't exactly follow you on this. Did you fair the lip on the firewall with that piece of pipe to get a smoother transition (and better exit velocity)?

Thanks,
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  #24  
Old 06-26-2019, 09:37 PM
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DanH DanH is online now
 
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Quote:
Originally Posted by falcon900guy View Post
i have some pictures to show what we did. don't know if this helps but there you have it
Kenny, you have my email. Send the pictures?
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  #25  
Old 06-26-2019, 10:03 PM
jpowell13 jpowell13 is offline
 
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Location: Baton Rouge, LA
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Default Anti-splat Cowl Flap

I put one anti-splat cowl flap on the right side of my cowl because the #3 cylinder of my 6A's O320 runs hottest. One nice thing about Anti-splat is that it is very easy to install. I see a CHT reduction of about 5 degrees F when I open it in straight and level cruise.

I need to work on baffling to get more balanced CHTs but I'm glad I have the cowl flap for those real hot days. John
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  #26  
Old 06-26-2019, 10:52 PM
lr172 lr172 is offline
 
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Location: Schaumburg, IL
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Quote:
Originally Posted by rvdave View Post
I have stock 8.5:1 io540 and feel I have tight baffling and rtvíd gaps . I struggled with whether to put in louvers based on others that have gone before and decided not to. Iím in Michigan but have flown in Florida with 90+ temps and am comfortable with my cylinder temps in cruise and simply donít climb as quick if temps get around 400 but usually thatís not a problem. Oil temps not an issue with butterfly valve which works well and can keep oil temps where I want them. I have dual ei and not sure if that makes a difference or not. Just more info to ponder.
Thanks for sharing.

Larry
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  #27  
Old 06-27-2019, 09:18 AM
greghale greghale is offline
 
Join Date: Jan 2006
Location: TULSA, OK
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I had the same problem in climb with CHT's (400) when I was in phase one. I used Nick Nafsinger's cowl flap design and added cowl flaps outboard of the cowling exit on the bottom. My temps dropped to 380 during climb and I was able to climb out at 110kts and 800-1000 fpm.
These cowl flaps were added after the -10 was painted. Very little touch up was needed.
I have drawings and pictures on my web site http://www.nwacaptain.com/cowl_flap.html if you are interested.
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