Engine Oil Temps

[207WF]

Oh, to complete that: I use AV-9 from Cal Power systems and Rotax oil filters from the same source. WF

[Roger Lee]

Sometimes the littlest things can make a small enough change to help. Try these things.

1. Switch to Amsoil motorcycle oil if you use 91 Oct. If you are using 100LL use Aero Shell. I am not a big fan of RV9.

2. Pop the top on your carbs and move the needle from position 3 to position 4. Your engine oil ought to run at least 15F cooler.

3. This can make a bigger difference than some believe. If you use the standard paper air filter by Mann throw it away and use a good K&N 33-2092. I have seen this change on

planes make a 100F difference in EGT's and cooler CHT's.

4. Make sure your prop can turn at least 5500 rpm WOT in flat and level cruise. Running to little throttle in the mid 4000's or above 5200 rpm will cause the temps to rise. The

best cooling is at around 5000-5200. Prop pitch plays a huge part here and a small change in pitch can make a big difference for your temps. Too course or to flat will hurt

temps.

 

I don't think your temps are caused by any one thing, but a combination of a few different things.

I live in hotter country than most and I never see over 240F on the worst day in a climb, but I do all the above. In cruise I usually see 215F-230F during the hottest days in cruise and never over 235F during climb.

[GlennM]

I would not use a K&N if I lived in a dusty area. The K&N passes more dirt than the paper filter. On the ground in diesel trucks, the turbo impeller leading edges get worn and the cylinders get scored from dirt passed by K&N filters. I would never buy a truck with one previously installed. I would think an airplane would not have so much trouble with dirt while flying, but they have to be on the ground eventually.

[207WF]

I have the K+N filter and the prop is set to run 5600 rpm WOT at sea level. So, maybe a different oil will help. I run a mix of 100LL and autogas, running more mogas in town and 100LL when travelling. WF