Perry Mick wrote:

I finally got to test the shorter intake runners including bellmouths.
Happy to say I recovered the RPM I lost with the long runners. But
overall I can't say there is any noticable difference between the stock
intake manifold with dynamic chamber and the new one with the plenum.
But I did get a lot of weight out and got the stuff off the top of the
engine so the whole thing is a positive change.

I was wondering, since my engine apparently always runs lean all the
time, could that be why my oil temp is higher than everyone elses?  The
excess fuel helps to cool the engine? Now that it's warm again, my oil
temps are once again too high, time to try more mods with the oil
cooler, like mod #10 or so.

--
Perry Mick

You will fool around with it the rest of your life until
you build a water manometer and find out what is really going on. :)
Do I need to fly up there with my water manometer and help out? :)

Forget the drag for a moment and cut out a rectangular hole over
the oil cooler and put some venetian blind flaps over it.
At least if that works you know you are on to something.

Paul Lamar

Been there, done that.  That is what it is now, a big hole over the top
of the oil cooler. You are right, I am going to have to plumb in some
permanent pressure measuring into the oil cooler inlet and exit.  But it
is still going to be trial and error to find out what works and what
doesn't. Dan's analysis awhile back showed that the ducting doesn't work
very well, I don't think any wonderful solution came out of the analysis
to fix it. I have one thing left to try, that is a block at the leading
edge of the exit duct. If that doesn't work I will probably have to add
a second oil cooler.

So what do you think of lean operation causing high oil temps?

--
Perry Mick
Custom Composite Props
mick@bridgingworlds.com
http://www.ductedfan.com

You need a digital camera. Last pictures I saw the outlet looked ineffective.

The heat rejected to the oil does go up a bit when lean but not
to the degree you are seeing. Your big problem is getting the
air to flow through the cooler.

I seriously doubt it has anything to do with your inlet duct.

Have you tried this configuration? It is very very important
that it looks exactly like this.

Paul Lamar
 
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