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Curiosity question

uk_figs

uk_figs

Well Known Member
Friend
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
 
Suction Screen

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 said:
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-3...&imgdii=RnArqCurEJZX5M:&imgrc=mC1KxdBH_pz9MM:

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

Rob
Click to expand...

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)
 
cajunwings said:
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.
Click to expand...

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 :eek:
 
Don Jones said:
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)
Click to expand...

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
 
Follow up question

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
 
uk_figs said:
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
Click to expand...

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.
 
DanH said:
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.
Click to expand...

My IA buddy says to look in the suction screen for things with part #'s stamped on them...:eek:
 
DanH said:
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.
Click to expand...

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.
 
Walt said:
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.
Click to expand...

I agree with Walt on this one. The sump screen Is a hold over from the days when these engines did not have oil filters as we know them today and yes it does catch those big bits so you don't let them get up into the oil pump. On this side of the pump that's what you want so the pump does not get stopped while in action. Dirty oil flowing to lube the engine is better than no oil flowing if the oil pump gets stopped by a peace of something from inside the engine or sometimes something the owner dropped in the oil filler hole, ( yes it does happen ). With the addition of the good oil filters we have now days on the pressure side of the systems in these engines you can go for 2-3 times longer than we used to with out them between oil changes. So if you are flying a lot of hours per year it stands to reason that you may wish to check that screen at an annual. If you are only flying a few hours it would be reasonable to check it every oil change. There are a number of different oil filtering set ups out there on these engines. Even knowing this we like to check our screen at each oil change. It may take in some cases an extra 30 minutes on that job, but we feel it is worth the extra effort while the cowl is off and we are looking at every thing in the hamster wheel area anyway.
Just 2 cents from the peanut gallery here. Yours, R.E.A. III #80888
 
The suction screen is there to detect instantanious failure - the kind that can change in a single flight - not wear trends. I check mine at every oil change. It only takes an extra 5 minutes, so why not?
 
Toobuilder said:
The suction screen is there to detect instantanious failure - the kind that can change in a single flight - not wear trends. I check mine at every oil change. It only takes an extra 5 minutes, so why not?
Click to expand...

Maybe you should be checkng it after every flight then!

But realy it depends on what sump you have, A model vs TD, inverted systems installed, etc.. Yours may take 5 minutes but most take quite a bit more effort than that. Some are a real bear.
 
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