Oil Cooler and Radiator Dampers

Yesterday and today I have been working on the design and fabrication of a shutter type device for the oil cooler and radiator.  With the cold weather it takes a much longer time to heat the engine.  The engine oil temperature has to be 122^o before I can run the engine above 2400 RPMs.  During the warmer months I could start the engine and taxi out to the runway while it was warming up.  It would be warm enough to operate by the time I got to the run-up area.  Now if I taxi out to the run-up area I have to sit and wait for 10-15 minutes before I can run-up the engine to check the ignition.  In the form several builders have done these mods and they say it makes a whole lot of difference in cold weather.  

I started yesterday by removing the upper and lower cowlings.  I then began fabricating a shutter for the oil cooler.  It consists of an aluminum plate with guides riveted to the top and bottom edges.  I have drilled holes for the cooler attachment bolts and holes for the oil cooler bolts that remain in place on the lower cowling. 

I cut a door to fit in the guides and then laid out lines for cutting the openings.  When the shutter is pushed to one side there are 7-slots that allow air to pass through the oil cooler.  When it is pulled the other way it closes the openings.  It is not airtight so there will always be some air going through the oil cooler, but very little so the oil will warm more quickly.  I laid out the lines last night and today I drilled and cut the openings.

Next I filled and deburred the openings.  I cut out a ‘T’ shaped  actuator  and a connection arm.  I made modifications to the shutter door so I can mount the actuator to the base plate.  I drilled holes in the arm and a the actuator and connected them to the shutter door.  I then assembled the mechanism.  

By putting a rivet in the edge of the base plate and installing the actuator arm the shutter door is limited in how far it can slide in both directions.  I will connect it to a push pull cable the will be attached under the instrument shelf in the cockpit. 

I tried putting it in place in the front of the cowling over the opening for the oil cooler.  It appears to work great.  I will need to determine where and how I will run the control cable.  I think I will attach a section of tubing inside of the cowl duct to run the control cable through.  That way when I remove and reinstall the lower cowling I can push and/or pull the cable through the tubing and then connect the end to the actuator arm.  I ordered some control cable swivels from Wicks Aircraft Supply.  They should be here the first of next week.  However, with Christmas, who knows when they will get here.

I then turned my attention to the radiator shutter.  It will be an aluminum door inside of the duct in front of the radiator.  I cut a piece of mat board the shape of the door.  I will need to get some hardware, tubing, angles, etc. so I can continue with the installation.

I will continue to work on the radiator damper tomorrow.