Question Idle rpm for Lycoming IO-360?

[Tsquared]

I'm rarely in idle as well other than just a test, however, the other time I'm at idle is in some pattern work where I'm doing practice engine out or just trying to keep speed under control. So base and final may see idle throttle position, although windmilling will keep it around 1100-1300 I believe, and then on roll out and other rare scenarios. Good to know that your engine will remain running at any throttle position even if minimally used.

I read something about cold weather starts not to go to 1000 RPM right away. I welcome any feedback from your northerners about this. Should you keep the throttle full aft until you start to see oil temp rise for example? Or is it okay to go straight to 1000 RPM after start in any outside air temperature condition?

Don't forget that you will be in idle when your practicing power off stalls.... you guys do practice stalls right? My most recent flight had my RPM's at idle around 1300rpm while practicing my engine out landings. 1100-1300 rpm sounds right to me coming in to land at idle.

To the second point/question - Define "cold weather" please

I've heard the same story about keeping RPM's below 1000 on a cold start, just keep in mind that Lycoming recommends a preheat system anytime it's "cold". I've seen cold defined as temps below 10F. In some cases cold is defined as temps below 40F.

With the Tanis preheat (cylinder heads and engine oil) my cylinder heads are typically 80F warmer than ambient temp and oil is 35-40F warmer as well. For me I plug in my Tanis when temps start to hover around 40F or lower consistently. That said I still keep close eye on my oil temp after start and don't taxi or operate above 1000rpm until my oil temp is at least 120F in the winter. I know with some of the radial engined warbirds I've flown in, we don't taxi (ie rpm >1000) until the engine oil is up to temp regardless of the outside temp.

 

[Neal]

From the Lycoming manual: