Ed,

I believe that the only purpose of the oil thermostat in the cooler is for emissions.

It allows the engine to heat up to operating temperature more quickly by by-passing the cooler. If you were to permanently plug the by-pass hole in the cooler the only difference would be the time it takes to get the engine up to running temp. Now if you had a cowl flap on the oil cooler then the thermostat would be redundant as you could control the oil temp with the cowl flap. Just a thought.

Jim

Ed Anderson <eanderson@carolina.rr.com> wrote:

When I drained my oil in preparation for the flight to the Rotary Flyin, I decided to do it a bit different.  My oil cooler is the lowest point in the system and I decided that since the oil thermostat housing was on the bottom of the cooler that draining it from there would be the smart thing to do.

 

So I proceeded to unscrew the plug - but, it wasn't until everything shot into the oil bucket that I realized that the innards had a strong spring incorporated.  So SPLASH! everything into the oil bucket - not problem I fish out the components and then realize that the thermostat pellet will fit either way.  Of course, I did not have my Mazda engine manual since it was only a simply oil change.

 

In my minds eye I recall seeing the spring hit the bottom of the bucket before I heard the heavy "Clunk" of the thermostat hit.  So I finally decided that the spring must have come out of the housing first(forgetting that light travels faster than sound).  After all I had a 50/50 chance of being correct. 

 

So I replaced the thermostat back in the housing and screwed the plug on.  Fired up the engine - and noticed that while oil pressure was fine - the oil temperature did not budge off the bottom of the gauge even after a couple of minutes of running but that the coolant was already up to 120F.  Hummmm.

 

Decided not to put the cowling back on until after going home and consulting a manual.  Sure enough I had installed it backwards.

 

So went back out to day reverse the thermostat and oil temps once more responding normally.

 

This got me to thinking that I fly without a coolant thermostat and wondering whether oil temps would lower if the thermostat was removed or wedge permanently closed.  I know you can not just remove it or the oil will by-pass the cooler.

 

 

My question to those (Lynn?) who have more experience is what effect would removing the oil thermostat on oil temperature??

 

 

Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com