Cowl Plug

dell30rb

dell30rb

Final Approach
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In my inbox today was an article from AOPA about keeping your cylinders cool when climbing. It appears the diamond in the picture has one cowl inlet plugged by a piece of yellow foam?

Have a look. This link might not work unless you are logged into AOPA

http://www.aopa.org/members/files/pilot/epilot/ft/2012/120601epilot.html?WT.mc_id=120601eflight#one

Here's the pic

120601tip.jpg
 
Diamonds run hot to begin with. Hopefully the pilot noted a couple CHT's shooting through the roof and returned.
 
Supposedly a cylinder cooling restrictor for winter ops. Sure looks like a cowl plug, though.
 
RoscoeT said:
Supposedly a cylinder cooling restrictor for winter ops. Sure looks like a cowl plug, though.
Click to expand...

I'm surprised those are necessary for other than arctic operations. When temperatures got over 100, I could not keep CHT's below 400 degrees on a 65% cruise, in the DA40 I flew.
 
I haven't seen the inside of a diamond cowl or the baffling system but if you covered up one cowl hole (sounds good, cowl hole) on most GA planes would that cause one side of cylinders to run hotter than the other?
 
That is, in fact, one of the two pieces of the winter kit.

Despite what it looks like, it does NOT restrict cooling airflow to the cylinder heads - It partially restricts airflow to the oil cooler which enters through a tube on that side toward the bottom of the air inlet.

The other piece of the winter kit is another plate that blocks outside air flow to the avionics, it gets installed underneath the fuselage near the leading edge of the left wing. Thankfully, it also stops the small amount of air that can flow up through the throttle quadrant which really only gets noticeable when said air is very cold!

dell30rb said:
I haven't seen the inside of a diamond cowl or the baffling system but if you covered up one cowl hole (sounds good, cowl hole) on most GA planes would that cause one side of cylinders to run hotter than the other?
Click to expand...

It does not (see above).

And yes, it is useful in the winter in places other than the arctic. It's marked that it must be removed above an OAT of 50ºF. At OAT's below that, with the winter kit installed, the CHT's run in the neighborhood of about 325-340ºF.

At OAT's over 100ºF, it can be difficult to keep any airplane's cylinders as cool as they should be in the climb...
 
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