Monday, September 17, 2018

Still working on the 9

I'm getting a little antsy to get started on the fuselage of the 10 but I promised myself that I would finish up a few projects on the 9 before I dug in to the 10.  So, what are these projects?  First I formed a new induction shroud for my intake.  The one I had in place was a 3D printed shroud with some fiberglass haphazardly slapped on to protect it from the exhaust heat.  It looked horrid but it did the job.  Now I have a nice new (painted) shroud with a slightly different flow profile.  I flew it this weekend and it worked perfectly.

Second I have been wanting to install some sort of automatic alternate air induction system that would keep the engine turning if I had some blockage in the filter or inlet port.  The blockage could come from flying into a heavy snow fall, ice, or even a simple plastic bag on takeoff/landing. 

Both of the first two projects are complete and the only remaining project is getting close.  The final project was to fabricate some sort of oil cooler exit shroud that would allow me to regulate oil temperature in the winter.  With the new oil cooler in place I expect I will have a hard time getting the oil temperature up to 180 degrees in the winter without some sort of ability to control the air flow.  Some people just block off the inlet air flow but since I pull my cabin heat from the oil cooler outlet I need the inlet air to flow normally.

Wow, this one looks weird.  This is looking down the snorkel of the new induction cone.  That black circle in the middle is the top of my K&N air filter.

The new snorkel from the outside.  Much better looking than the old one...and a bit lighter too.

Here is the new alternate air induction ports.  Actually you only see one of them here but there are 4 of these little openings on the circumference of the induction base.  My finger is pointing at the spring loaded door that is kept shut by both spring pressure and induction air pressure.  If the inlet gets blocked for any reason the engine will quickly go to manifold pressure (which is a vacuum) and the air from inside the cowl will force these little doors open thereby providing air for combustion.  The little fan up front will keep turning which means the pilot stays cool.

Here I am pushing the spring loaded door open.