Oil Temperature during Climb

Roger;

As an example the Flight Design CTSW oil hose from the oil cooler to the oil pump makes a 180 degree bend and squeezes down on the I.D.of the hose. This reduces the oil flow and causes higher temps. I place a spring in the hose at the bend to keep the hose wide open and I can drop temps 15F - 20F.

I am struggling with elevated temperatures in my new Sonex Legacy. All hoses have gentle/wide radius bends,  except the one between oil cooler & pump, where I have a short (115mm) length of hose that turn's 90 degrees - have been wondering if it may be partially  "collapsing" in flight. I was going to fit it with a  "Unicoil", which is an external anti kink spring - what think you?

Howdy Sean,

Hope the weather and flying down under is good.

Your idea would work, but I have grown to prefer internal springs. They can't move and you can turn the hose into a pretzel and it will keep its shape. I use springs in some of the 17mm coolant hoses too. This is usually because some aircraft Mfg's make hose routing changes vs the stock Rotax setup.

Even if you try the spring and it doesn't work like you want, it can be left there and at least that bend can be ruled out as the issue. The spring doesn't have to be anything special. It's immersed in oil and won't corrode. I just take a magic marker and put a mark on the fire sleeve where I want the spring to be centered. Then I pull the hose off the cooler fitting and leave the fitting alone. Then I apply some oil to the spring, take a 12" long 1/4" socket extension and turn it around backwards so the open end is going into the oil hose to push the spring down in place. The 1/4 socket end is a perfect fit to slide the spring down in place. No oil is lost here. Just keep the hose end up. Then I just push the hose back on the fitting and tighten the clamp. This method has helped me many times from aircraft Mfg's when they over bend a hose.

You have nothing to lose if you give it a try.