Run-Up RPM's Turbo Mooney

[stormflyer]

A 1981 M20K's POH says run-up at 1700 RPM

A 1980 M20K POH says run-up at 2000 RPM

What says Mooneyspace M20K owners with the TSIO360 engine?

 

Edited October 23, 2021 by stormflyer

[spistora]

My 79 POH says 2000, I was instructed in transition training to use 1800.

[milotron]

HI, not sure that is matters. I think 1800 gets into governor RPM range so that it can be exercised with some effect. 2000 rpm gives a bit more authority for excercising the prop.

 

I use 1800 as I think that is what my 262 mod POH supplement calls for.

[Marc_B]

Just to add another M20K variation...97 Encore POH recommends 1700 RPM for run-up.

Marc.

[Will.iam]

I don’t pick an exact number, anythibg over 1700 and i start the mag check and proc cycle and be done with it. No more time than absolutely necessary since cooling is so poor on the ground. 

[PeteMc]

I was taught that there was no need to put excessive pressure on the prop, but you did want to make sure you were doing a good Mag check with clean plugs and under power.

So Mag check is done at 1800-2000, not that critical, just get the RPMs up.  Then reduce to 1600 RPMs which is still in the range of the prop governor, and slowly pull the Prop Control back.  The reaction is a little slower than at a higher RPM, but you will still get a noticeable change to confirm good operation.  But the mechanical pressure of pulling the prop all the way back will be much less. 

[anthonydesmet]

Below is a snip from Phil Corman’s article “Love Your Engine For Pennies on the Dollar” in this month’s Mooney Flyer:

“Runup
I hate those really long runups; runups at higher RPMs with zero airspeed and minimal airflow. For the runup, you don’t need to set your RPM to the exact number mentioned in your POH. Just get close. When you check your prop, as soon as you see about a 100 RPM drop, push the
lever back and your done. There is no need to check it three times unless it’s very cold and your prop had a sluggish drop.
During the mag check, switch to the left and wait about ten seconds, then back to both, then right for ten seconds, then back to both. If you have acceptable drops, you are done. No need to take a long time. It’s not good for your engine and it gives you no more info than a ten second check.
If you have no drop in one or both mags, then you have a short and you should address that.
Since we are discussing Mag Checks, if you want to do a “real” mag check, then get the engine up to some significant power setting, (which is hard on the engine, airplane, and prop). Run it up to 2000 RPM, lean the mixture until the RPM rises a bit, then falls on the lean side, and check each mag for 10 seconds or more, while watching the EGT bars on your engine monitor. All EGTs should rise on one mag, and fall back to the starting point on BOTH, and the engine should run smoothly, assuming you have very good fuel distribution.
Before Takeoff – Ensure that you have set the mixture appropriately for your density altitude. If you don’t, your engine will be too rich, and you will not be
getting optimal power. You’ll also foul the inside of your
engine.”
 

[Hank]

Wait, the mag check is supposed to be 10 seconds on each side? I generally wait long enough for RPMs to stabilize, generally about 3 seconds on each side with about a second on Both in between. 

When checking the prop, there's no need to let it fall more than about 200 RPM.

[81X]

I like 2,000 RPM. The main reason being a more complete systems check at a power setting that is closer to what you’re about to ask the engine to do vs 1700rpm or so.   It’s not just a mag check, it’s also a fuel systems check of sorts.  in a Cherokee 180 I was once in, that higher power setting on run up caught that the left seat person cycled the fuel to “off” and that was just enough to drain the bowl during run up vs on takeoff.

 

just my thoughts, no hard science behind it