Curiosity question

[uk_figs]

I have an 0-360 in my -7 and at each condition inspection I remove the oil screen on the back of the engine. I have not found anything in this screen and it is a pain to get to to remove and replace. I am curious how this screen relates to the oil flow through the engine and in particular to the spin on oil filter that I replace each oil change and cut open to check for metal.
Thanks
Figs

[cajunwings]

It is at the inlet of the path to the oil pump. It is for big pieces. I have found parts of mag bearings and once part of the drive gear on the back the crank in this screen. In each case there were no metal flakes in the spin on filter.

Don Broussard
RV9 Rebuild in Progress
57 Pacer

[Aggie78]

Figs,

I think there are two screens in the engine...a suction one on the oil pickup that you can't access, and the pressure screen that you are cleaning designed to catch the big chunks after the oil pump.

Here's a schematic I found online that may help:

https://www.google.com/search?q=o-36...C1KxdBH_pz9MM:

Not a mechanic, so could be totally off base on my understanding of the system...

Rob

[Don Jones]

Originally Posted by Aggie78

Figs,

I think there are two screens in the engine...a suction one on the oil pickup that you can't access, and the pressure screen that you are cleaning designed to catch the big chunks after the oil pump.

Here's a schematic I found online that may help:

https://www.google.com/search?q=o-36...C1KxdBH_pz9MM:

Not a mechanic, so could be totally off base on my understanding of the system...

Rob

Actually, the one you access through the plug on the oil pan is the suction screen, it is there to keep big chunks from going into the oil pump and locking it up. The only other thing in the system is the spin on filter. (with the exception of early lycomings that have a screen in place of the spin on oil filter)

[Walt]

Originally Posted by cajunwings

It is at the inlet of the path to the oil pump. It is for big pieces. I have found parts of mag bearings and once part of the drive gear on the back the crank in this screen. In each case there were no metal flakes in the spin on filter.

I too have found chunks there, some lifter bodies that broke on a very low time Lycoming (which they would not cover under warranty). Filter was clean. Expensive annual

[Aggie78]

Originally Posted by Don Jones

Actually, the one you access through the plug on the oil pan is the suction screen, it is there to keep big chunks from going into the oil pump and locking it up. The only other thing in the system is the spin on filter. (with the exception of early lycomings that have a screen in place of the spin on oil filter)

Don,

Thanks for clarifying, I learned something!

50/50 chance of guessing the right way, and missed it!

But, the right info got out there to the OP, so all good!

Rob

[uk_figs]

Thanks for the info, very helpful. As a follow up question is it recommended to check the suction screen every oil change or at the annual condition inspection? I send oil samples to Blackstone at each oil change so I would think that a change in metal content would give clues to impending problems.
Figs

[DanH]

Originally Posted by uk_figs

Thanks for the info, very helpful. As a follow up question is it recommended to check the suction screen every oil change or at the annual condition inspection? I send oil samples to Blackstone at each oil change so I would think that a change in metal content would give clues to impending problems.
Figs

Yes, every change.

Think of it this way...Blackstone analysis is for detection and measurement of wear. The suction screen is there to detect broken parts.

[Don Jones]

Originally Posted by DanH

Yes, every change.

Think of it this way...Blackstone analysis is for detection and measurement of wear. The suction screen is there to detect broken parts.

My IA buddy says to look in the suction screen for things with part #'s stamped on them...

[Walt]

Originally Posted by DanH

Yes, every change.

Think of it this way...Blackstone analysis is for detection and measurement of wear. The suction screen is there to detect broken parts.

I almost always agree with Dan but in this case with an average of 100 hrs/yr being flown doing it every annual seems prudent.

From the Lycoming operating manual:

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