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Bryan,
Check the exits on the baffeling on the bottom of each cylinder. If memory serves, there was a paper released by NASA with some cooling info on these small engines. I thought it was 1.6" times the depth of the cooling fins for the opening at the bottom of the cylinder. I remember going a little wider, say 2" or so.. If they are a little too tight at the bottom, that can cause cooling issues. I opened up mine a little and also rounded them off instead of 90 deg bends. Also for the air inlets on the engine, you are better off to have that be smooth with no steps.
It may be several issues not just one. There is also a test you can do with the vernatherm. I took mine out, put it in oil and ran the temp up to 180 to see if it would open..
Mine did so I solved the issue with "other " items that others are suggesting..
One other item on the plennum,
If it is too tight on the top of the engine, you will never get effective cooling on the engine or oil cooler. I have seen plennums built very close to the top of the engine and they dont work like that. Mine is so close to the inside of the upper cowl, I marvel that it has not rubbed off the paint. It is close which gives a better expansion of the cooing air where you can build pressure to go down the cooling fins. I would also put a shop light under the engine with the plennum off and caulk with high temp RTV every crack and hole you can find with the light. By sealing all that up tight, your cooling air has nowhere to go but through the cooling fins to the bottom of the cowling.. I would do all of these before I start cutting up the cowl.. I have also seen small curls on the opening of the lower cowl lower temps. Believe it or not, outside air is rushing in that opening at the bottom of the cowl. Look at every certifited model with an opening in the
cowl, they all have a louver of deflector to create a wake so the outside flow air does not go in the opening...
Can you elaborate on how the plennum is set up and or provide some pictures?
Sorry for blabbering...
Randy Snarr
"Flight by machines heavier than air is unpractical and insignificant, if not utterly impossible"
-Simon Newcomb, 1902
--- On Mon, 1/31/11, bucky <bwhittier@ltol.com> wrote:
From: bucky <bwhittier@ltol.com>
Subject: [LML] 360 Cooling
To: lml@lancaironline.net
Date: Monday, January 31, 2011, 6:17 AM
Bryan,
This is from the Lancair Mail Newsletter from years
ago. I was having the same problem with cooling. I have fuel injection and
standard baffling. I installed the additional exit air ducting, blocked off oil
cooler intake at #3 cyl. I Installed a 3" naca duct on bottom of cowling,
routed a 3" scat tube to the oil cooler which exits out the side with louvers.
There may be other fixes, but this worked for
me.
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