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  #21  
Old 03-05-2013, 07:57 PM
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Don Jones Don Jones is offline
 
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Quote:
Originally Posted by LifeofReiley View Post
This change happened after the install? Seem like you're in slow cruise mode?
No, cooling has always been marginal. It's a Sam James cowl and plenum.
I left too much spinner gap and think it's pressurizing the lower cowl. I have the baffles tight and sealed up. It was actually worse before the mod was installed. Wheel pants will fix the speed
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Last edited by Don Jones : 03-06-2013 at 01:09 AM.
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  #22  
Old 03-05-2013, 08:48 PM
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petehowell petehowell is offline
 
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Default Carb heat?

Hi Don,

This is very interesting - I had similar issues until I started playing with Carb heat - I know your airbox set up is different, but it might be worth exploring. I "think" my carb heat sets up turbulence in the the airflow that helps balance the mixture - the heat might help atomize the fuel, too.

I run LOP almost all the time with carb heat fully or partially on. 150+KTAS on 6GPH at 7500. I love it!

My only concern would be if the grid breaks up and gets sucked up. That said, I love the innovation! Good luck!
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  #23  
Old 03-05-2013, 09:18 PM
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N941WR N941WR is offline
 
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Quote:
Originally Posted by billnaz View Post
You may have a game changer here if your results are repeatable. I'd given up on anything close to lean of peak with my carb'd 0360. I'd understood that the problem with fuel distribution in carbs was uneven fuel mixing down stream from the venturi. How does this straightener effect that? Any expert opinions?
Install dual electronic ignition and you can run LOP with a stock LOP w/o carb heat.

I typically run my O-360 this way with no issues and get between 100 and 50* LOP.

Now to try this mod and see how that improves things.
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  #24  
Old 03-05-2013, 09:45 PM
SHIPCHIEF SHIPCHIEF is offline
 
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If the grid breaks up and gets sucked it, then the material and thickness would be significant.
Thin aluminum hex would probably break up, get sucked into the cylinder, smoosh around and fly out the exhaust without much damage...
If made of steel, it still might break up, but once inside the cylinder, could do more damage.
On the other hand, the material used in mass airflow sensors is proven to NOT break up, so there is value in that approach.
One thing for sure; on a single engine plane, the big fan must not stop until you say so!!
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  #25  
Old 03-06-2013, 05:11 AM
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Don,

Have a micrometer handy? Can you measure the thickness of the aluminum cell wall?
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  #26  
Old 03-06-2013, 07:44 AM
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Originally Posted by DanH View Post
Don,

Have a micrometer handy? Can you measure the thickness of the aluminum cell wall?
I will have to find some of the scrap or measure next time I have the thing in my hand. Just a guess, but it's around .005 or so.
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Last edited by Don Jones : 03-06-2013 at 07:47 AM.
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  #27  
Old 03-13-2013, 08:54 PM
BD4Guy BD4Guy is offline
 
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Default Bump

Don-
Great work! Got any pics of your airbox, and the installed straightener?

Thanks,

Craig
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  #28  
Old 03-13-2013, 09:53 PM
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Default how about polyimide honeycomb?

http://www.hexcel.com/Resources/Data.../HRH327_us.pdf

high temp, fatigue resistant

if it does get sucked up, minor damage
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  #29  
Old 03-13-2013, 11:17 PM
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Don Jones Don Jones is offline
 
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Quote:
Originally Posted by Steve Melton View Post
http://www.hexcel.com/Resources/Data.../HRH327_us.pdf

high temp, fatigue resistant

if it does get sucked up, minor damage
Looks like a good choice. Wonder how expensive and what quantities it can be bought?
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  #30  
Old 03-13-2013, 11:24 PM
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Don Jones Don Jones is offline
 
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Quote:
Originally Posted by BD4Guy View Post
Don-
Great work! Got any pics of your airbox, and the installed straightener?

Thanks,

Craig
I don't have pics right now. I am actually working on a replacement for the airbox. I am replacing it with a piece of 3" mandrel bent aluminum tubing. It should clean up the air entering the carb even more. I will post more info and pictures as my experiments progress. I just finished painting the wheel pants so I can get them on this weekend. I will also post some before and after engine monitor graphs when I get a chance. I have been working on cooling. It's still running warmer than I would like in cruise and climb. It's been like that since before the carb air straightener. The straightener evened the temps out, but hasn't lowered them, well not much anyway.
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