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Show us your cowl exit air pics

It's good BUT you still have to use the 1:3 ratio with yours it's still 1:1.
I know my H9 Sukhoi does not have 3:1. In fact I'm sure my cowl exit is less than intake. However it does create a low pressure zone and pulls air out. I just baffle the engine and that was it. My last flight on wed had a peak temp on a long full power Upline of 287F. 3:1 does not mean the engine will cool properly at all. I have a plane with that and it can get well into the mid 300F range if I didn't baffle it.
 

TazmanianDevil

Xtreme by DeFinition !
The round cowl can really make wonders.
Sometimes you just don't need to do all the cuts and trims with it.
I guess it's does have a connection with the engine and oil ratio your using.
Cans also help the process.
 
The round cowl can really make wonders.
Sometimes you just don't need to do all the cuts and trims with it.
I guess it's does have a connection with the engine and oil ratio your using.
Cans also help the process.
I've always ran tuned pipes with very little openings on both my Sukhoi and extras. I think the extras cool easier because of the smaller path for air. The Sukhoi was harder to get it right. Stihl HP ultra oil at 40 something:1. 1.8 gal for each bottle.
 

Ohio AV8TOR

Just Do It
I ended up using the cover that was supplied from Extreme Flight on my 91" Extra.

FullSizeRender.jpg
 

ghoffman

70cc twin V2
I like how clean the cowl is, with no cutouts for the stock noisy "mufflers". The pipe makes more power and is quieter.
 

Ohio AV8TOR

Just Do It
I did a split cowl so my exhaust openings are just clearence circles, no slots. Actually I kind of like the sound of the Jtec mufflers and actually get compliments so it sounds like we both have the best setup ;) and 4¢ between us
 

rate1

30cc
My first gas engine plane. Hoping that the louvers together with the baffled inlet and the cut out for the tunnel is enough. If not there is still room for one more louver in the cowl and more opening holes for the tunnel.
 

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