This a a roll up of about a weekends worth of work done over a month (due to school consuming all my time) Now that the temp have been increasing and summer is here I have have been having problems keep the oil temp down to a reasonable level. It has been slowly increasing from 220 deg to back in Late April on a particularly hot day it hit 240 degrees flying aerobatics. This was the final straw that caused me to figure this out.
It turns out that my front baffle is seeing some rather high pressures at normal flight speeds and really high pressures flying aerobatics. It was blowing the baffle back about 1.5 inches braking the seal between the silicone baffle seal and the cowling and allowing air under my motor. This caused really poor airflow to my oil cooler and to my cylinders thus causing the high temps. I also had problems with the silicone baffle seal to staying forward.
I relocated the oil cooler back to the front on the right side of the cowling just in front of the #1 cylinder. I beefed up the baffle to accept the cooler and then added a bracket back the engine sump bolts. Now the entire right side of the forward baffle is rigid. The left side was stiffened up by installed a 3/4″ by 3/4″ 0.32 angle riveted diagonally from the air intake to the top of the forward baffle. I then installed another bracket off the injection servo to the lower lip of the baffle to support the baffle and keep it rigid. Finally I took a 3 inch by 3/32 silicone baffle seal and caused it to conform to the elliptical shape of the forward baffle I made a 3/4″ by 1/2 ” 0.32 angle and stretch the outside edge of the 3/4″ angle to make the shape of the curve. This acts like a long washer and allows the baffle seal to conform to the shape without puckering where it attaches. Here are some pictures…
I went out a flew the plane for a 1.1. in 75 deg day and the highest temps I saw was 193 degrees flying nothing but Aerobatics. Cruise flight I see 183-185 deg oil temp.
Furthermore. Conducted a conditional inspection of the plane all seemed well.
Total time spent 25 hours.
Posted by acropilotbret 