Engine run with top of cowl off?

[Toobuilder]

Originally Posted by joe gremlin

Doing ground idle and runups with the top cowl off is one thing. Going flying with it that way it something else entirely...

I didnt get the impression the OP or subsequent replies were discussing flying the airplane with any part of the cowl removed.

[joe gremlin]

Originally Posted by Toobuilder

I didnt get the impression the OP or subsequent replies were discussing flying the airplane with any part of the cowl removed.

By George you're right. Shows what happens when I try to read before my brain is warmed up. Oops.

[Snowflake]

Originally Posted by Toobuilder

I didnt get the impression the OP or subsequent replies were discussing flying the airplane with any part of the cowl removed.

True, but while balancing a prop you will go to full throttle to get a complete vibration profile.

The point someone made about vibration readings changing with/without the cowl may be valid... If nothing else a lower cowl vibrating on its own may add noise to the reading.

That all said, when I did my dynamic balance, I did it with top cowl removed, bottom in place, and had no issues. It feels smoother now.

[skylor]

Originally Posted by kkmarshall

I do it after every oil change to ck for a possible leak at the filter. No issues rubbing against the spinner or flopping around.

Thread drift, but...

I'm curious why you don't do the leak check before replacing the lower cowl?

Skylor

[kkmarshall]

I don't pull the bottom cowl/sump screen for a routine oil change,just at CI time. I can fish a drain hose to my quick drain from the cowl exit so that is why the bottom cowl is still on. I know that may be heresy to some to only pull the sump screen every other oil change!

[az_gila]

Originally Posted by kkmarshall

I don't pull the bottom cowl/sump screen for a routine oil change,just at CI time. I can fish a drain hose to my quick drain from the cowl exit so that is why the bottom cowl is still on. I know that may be heresy to some to only pull the sump screen every other oil change!

That sounds to me like you are only doing a visual inspection of the lower engine area once a year.

The few minutes extra to remove the lower cowl every oil change for a good "look-see" down there would seem to be a wise thing to do.


PS - per Lycoming, the oil suction screen is a 100 hr item -

Oil Suction and Oil Pressure Screens – At each 100-hour inspection remove suction screen. Inspect
for metal particles; clean and reinstall.

[scsmith]

Originally Posted by az_gila

That sounds to me like you are only doing a visual inspection of the lower engine area once a year.

The few minutes extra to remove the lower cowl every oil change for a good "look-see" down there would seem to be a wise thing to do.


PS - per Lycoming, the oil suction screen is a 100 hr item -

Oil Suction and Oil Pressure Screens ? At each 100-hour inspection remove suction screen. Inspect
for metal particles; clean and reinstall.

Gil beat me to it. +1.

[Whitman]

Originally Posted by az_gila

That sounds to me like you are only doing a visual inspection of the lower engine area once a year.

The few minutes extra to remove the lower cowl every oil change for a good "look-see" down there would seem to be a wise thing to do.


PS - per Lycoming, the oil suction screen is a 100 hr item -

Oil Suction and Oil Pressure Screens ? At each 100-hour inspection remove suction screen. Inspect
for metal particles; clean and reinstall.

Also I?m fairly certain this crush washer must be replaced each time the screen is removed per Lycoming.

https://m.aircraftspruce.com/pages/ha/washers/an900.php

[FLTENG]

How does it go from running the engine with the top cowl off to crush washers.....

[lr172]

Originally Posted by az_gila

That sounds to me like you are only doing a visual inspection of the lower engine area once a year.

The few minutes extra to remove the lower cowl every oil change for a good "look-see" down there would seem to be a wise thing to do.


PS - per Lycoming, the oil suction screen is a 100 hr item -

Oil Suction and Oil Pressure Screens ? At each 100-hour inspection remove suction screen. Inspect
for metal particles; clean and reinstall.

+2
I also don't check the suction screen every oil change, however, I always pull the cowl and do a visual check. I have been able to catch numerous issues early. This is especially important in the first 100+ hours as many bolts/nuts need to be snugged early on as heat does its thing.

Larry