How long to let an engine warm up?

[Bluepilot2003]

I've read on here that people let their engines warm up. How long should you warm up your engine before taking it airborne? I don't think I have ever seen anyone at my club do much more than start it, run it up a couple times to make sure the engine transitions smoothly and it sounds correct, and then fly. I fly out of Tucson... so maybe the heat here has something to do with that??

 

[acerc]

After starting, I taxi to the runway, just prior to entering the runway I do one run up just to ensure there is no loading, then I go fly.

 

[jamesrxx951]

A properly tuned low end needle will not allow for a good transition till you run it for 30 or so seconds.

 

[TazmanianDevil]

To make the engine worm the first flight of the day I just nail the throttle stick after the engine starts in the middle position for 15 sec' after that I play with the stick up and down a little bit to get is wormer, 3 - 5 sec full throttle and to the air.
It still spits gas through the cans when I take off, but after the first trimming line it's gone.

The next flights I just kick it and fly.

 

[ryan_m]

I've got telemetry on my motor, and I find that it only takes about 15-20 seconds of it running at a fast idle, maybe 2000 rpm or so for the temp of the motor to get up to about 150 degrees. After that I'll run it up a few times, check the transition and if all is well go fly.

 

[Bluepilot2003]

So it is almost impossible to not let it warmup as long as you make sure it runs well before takeoff. Good to know. Thanks gents!

 

[garlandk]

Its always a good idea once the engine is crank to let it idle for a good 10-20 second. Then give it a few clicks of throttle and let it stay there another 10 to 20 seconds. Then smoothly do a full throttle run up.

 

[thurmma]

I have always let my engines run at a few clicks above idle for about 30 seconds before transitioning to a full throttle run to clean them out. They seem to be happier this way I know, they tell me so every time I fly

 

[Jetpainter]

I wear a glove, so by the time I start it, walk behind the plane, take off the glove and hang it on the fence, its warm enough to clean out, check the idle and fly. On a cold day I'll let it idle a little longer.

 

[stangflyer]

I have always let my engines run at a few clicks above idle for about 30 seconds before transitioning to a full throttle run to clean them out. They seem to be happier this way I know, they tell me so every time I fly

Apparently my planes have been talking to your planes. They tell me the same thing.
I do my first flight of the day start ups the same way on all my motors. Start, kick it just above idle a click or two for 30 or so seconds. As @jamesrxx951 pointed out, a properly tuned engine really doesn't transition too well until warmed a bit. Cylinder heat is important to get the fuel to atomize correctly. Each flight after the first of the day, I let them idle just a few seconds less and away I go.