Power setting M20C

[brndiar]

7 hours ago, carusoam said:

Could be the TopProp efficiency?

Best regards,

-a-

Hi,

Should be HC-C3YR-1RF/F7282 (do not have dokumentation at hand). The engine before general overhaul did not have bad kompressons. I did not fly any other M20C than mine, so I do not have anything to compare with.  But now it is completely another bird.  Besides more speed also less noisy and more smooth (the last two just my first impressions). Because the wings are low I removed "fix step".

 

m

[cliffy]

That's IT! You removed the step That's good for 10 or so Knots!!   "-) "-)

[Tcraft938]

On 4/14/2020 at 11:26 PM, cliffy said:

The point at which the oil consumption stabilized was where the engine was basically fully broken in.

Your speeds and temps are remarkable.  Have you double checked the speeds with a 3 or 4 way GPS run? 

I presume most of this flying was solo so I have to ask about your CG and where it is sitting. Can you mention say what 25 pound block you weight fits into  150-175    175 - 200     200-225 etc    Just trying to get a handle on CG position.

All flights start with full fuel. I like to keep tanks wet for the sealant. All early flights just me 172lbs. A few had a passenger of 220 lbs. one flight had a third in back at 180 lbs but I did not take copious notes on that flight. The numbers I gave were backed up by 3 way gps runs. One flight was 240 miles east and turn around come home. Strong tail/headwind. Going out was fun seeing 211 mph over the ground. Coming home took a bit longer. My empty CG is a bit forward, battery in the front. No speed mods. Rigged well engine shimmed per Maxwell and corrected a gear door that sagged. Gained some speed with those adjustments. 

[brndiar]

On 4/15/2020 at 3:14 AM, cliffy said:

I"ve dropped in the Lycoming SI for engine break in after overhaul if you don't have it

Follow this for your break in   Pay attention to the ground run in instructions at first also. 

Go to 7500' altitude (actually density altitude but 7500' is close enough) with full power and you are turning 75% power Any higher and you won't get 75% 

https://www.lycoming.com/sites/default/files/Lycoming Reciprocating engine Break-In and Oil Consumption.pdf

 

BTW, there was an A&P several years ago dinged by the FAA for doing an overhaul and doing his own run in procedure, seems the FAA asked him if he knew more than the engine manufacturer.

One more comment- you will notice that the SI speaks to having the engine gauges calibrated before the break in. In truth, it can't be called "an OVERHAUL" unless it follows the factory instructions including calibrated gauges. Without calibration its in reality a "repaired" engine. Small bit of trivia but if you don't believe me go ask the FAA.  I've had this discussion a couple of times with them. Nobody does it but its just a bit of trivia. 

 

...Go to 7500' altitude (actually density altitude but 7500' is close enough) with full power and you are turning 75% power Any higher and you won't get 75% ...

 

7500 ft "Pressure Altitude" Could be theoretically cca 5200 Ft Density Altitude bei ambient Temperature -20C (-4F), on the other site cca 9500 Ft Density Altitude at +20C (68F) ambient Temperature.

Fortunately, nowadays we have in Europe almost "standard atmosphere" with about 0C in 7500 Ft :-)))). For case,

Does anyone knows how to use that "user friendly"  Chart for cerrecture to "non standard temperature"? 

 

thanks,

m