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O-320 oil screen to oil filter retrofit recommendations?

NM Doug

Well Known Member
The O-320 in my relatively-new-to-me 9A is from 1954 - even pre suffixes like A1A, etc - and has an oil screen instead of an oil filter. I'm considering having a retrofit kit put on for a filter (I would welcome a 50 hour interval between changes instead of the 25 hours for the oil screen setup), but there are several kits available, and I'm looking for recommendations - both in terms of what to expect or look out for generally, and for any specific models.

Thanks!
 
Same situation

I have the same situation and fave considered switching. I guess any remote type that is approved for the engine you have should be good.
 
If the standard Lycoming oil filter will not interfere with your engine mount, then why not use the Lycoming part number?

This lycoming SSP gives the numbers and installation details...

http://www.7ts0.com/manuals/lycoming/EMOFK.pdf

A PMA part is $158 and only needs a short stud, gasket and nuts/washers to complete the kit...

http://www.aeroinstock.com/products/AERO_ADAPTER/6174/11519/product_detail/index.html

The one stud needed is oversize at one end and is fairly pricey at $32

http://www.titancylinders.com/pages/products_detail.aspx?in=273

Every thing else is standard, cheap and easy to get...
 
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There are several styles available, the choice is will they all fit? Beyond that, the difference is the amount of mess each makes when the filter is changed.

The straight Lycoming version - filter sticks out horizontally backwards - can usually only be fitted if the recess in the firewall has been fitted.
straight_filter.jpg


The 90* offset version - filter points to (usually) the left side of the engine - can interfere with the engine mount, so sometimes needs a spacer (say 1.5"), filter adapter and spacer are made by ECi, B&C and others. I think these adapters use 2 angles for the filter - when viewed from the rear of the engine. I have used one that puts the filter at the 11 o'clock position.
This isn't an RV engine - there is more space between the engine and firewall on most RVs
eci_filter_adapter.jpg

eci_filter_adapter2.jpg


Remote filter, as sold by Airwolf. This is probably the most expensive as a pair of high pressure -8 hoses are required to connect the adapter that bolts to the engine to the remote filter head. The benefit is that the filter can mounted anywhere (within reason). Note - in this photo the 2 oil fittings in the adapter have not been aligned to their final position - they should both point in about the same direction!
This isn't the same engine as the one above
back_of_engine2.jpg

remote_filter.jpg


I have used all 3. The 90* offset type makes the least mess at oil change time, as long as a plastic bag with no vent holes in the bottom is used to catch the filter.

Peter
 
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On my old O-290-D2 I changed the screen to a filter, like you want to do.

The O-290 uses the same accessory case as the O-235, O-320, & O-360 so the change should have been simple. Only one problem, the first accessory case I installed was set up for a fuel pump and a screen. At that time, I had not decided on switching to a filter, so no big deal.

Bad mistake because that accessory case could not accommodate the oil filter adapter.

So, what I'm saying is that you MAY have to change the accessory case. Also, when I installed my filter adapter, I didn't need a spacer but I did need a restrictor plate. Mahlon helped me out with the part numbers, all of which Here is the link to my engine page, check it out for some details included in the conversion.

The angle adapters I used on the O-290 and the new O-360 were both from ECi and did not require a spacer to get around the engine mount. The O-290 was a conical mount and the O-360 is a Dynofocal 1 mount.
 
Thanks - I will make some measurements and see if that pushes me toward one solution or another.

Outside of differing messes during the oil changes and different intervals between changes, are there any operational difference between having a screen, the horizontal filter, or the 90* filter? It looks like the 90* arrangement may allow oil to drain out of the filter when the engine isn't running - does this affect lubrication one way or the other during engine start?
 
My view is that the important thing is to have a filter, it is only installation issues that decide which type of adapter. With a filter the oil will be much cleaner and your engine will much longer - the screen doesn't really filter out the small stuff that does the damage over time. Your oil temps may also drop slightly with a filter. I haven't seen a particular delay in oil pressure coming up on start with a 90* adapter - there are valves to prevent the oil running out of the filter.

Pete
 
I've seen several engines go past TBO with nothing but screens. The mesh is fine enough to catch the junk that matters. So I would hesitate to change. That said you could give me a right-angle filter adapter for free, and I wouldn't use it. Almost would rather have the screen.
 
If the standard Lycoming oil filter will not interfere with your engine mount, then why not use the Lycoming part number?

This lycoming SSP gives the numbers and installation details...

A PMA part is $158 and only needs a short stud, gasket and nuts/washers to complete the kit...

The one stud needed is oversize at one end and is fairly pricey at $32

Every thing else is standard, cheap and easy to get...

Gil,

Thank you for posting these links, especially the one to the Lycoming SSP! This is helpful to a newbie like me. My engine came with a bare mounting pad on the accessory case and I need an adapter. I've been wondering where the best place is to get one. The only one Vans offers is the 90? adapter, and by the time you add the spacer, the sticker shock bowls you over.

I will still need the Vernatherm, though, correct? Any ideas where to get one of those for a good price? The only ones I've found ran over $400.
 
I remember, but can't find an article from the nineties that compared filtering efficiency of the screen, a champion filter, and the Airwolf remote. There was hardly any difference.
 
Gil,

Thank you for posting these links, especially the one to the Lycoming SSP! This is helpful to a newbie like me. My engine came with a bare mounting pad on the accessory case and I need an adapter. I've been wondering where the best place is to get one. The only one Vans offers is the 90? adapter, and by the time you add the spacer, the sticker shock bowls you over.

I will still need the Vernatherm, though, correct? Any ideas where to get one of those for a good price? The only ones I've found ran over $400.

In a O-320 and an O-360 you should have a Vernatherm in the screen assembly you are taking out. You just re-use it.
 
I've seen several engines go past TBO with nothing but screens. The mesh is fine enough to catch the junk that matters. So I would hesitate to change. That said you could give me a right-angle filter adapter for free, and I wouldn't use it. Almost would rather have the screen.

I respect your experience so I am curious what your reservation to the 90 deg filter adapters is based on.
 
I remember, but can't find an article from the nineties that compared filtering efficiency of the screen, a champion filter, and the Airwolf remote. There was hardly any difference.

Then why would engine manufactures (Lycoming) double the oil change interval for engines with filters?
 
I just had the O-300-A in our Cessna 172 overhauled.
The rebuilder said (in his experience) engines with oil screens do just as well as engines with filters provided the oil is changed on schedule.
My T-18 has an oil screen, and so does my son's RV-4.
Weight is a serious issue in a small plane, and all these filter adapters, hoses, remote mounts and even the filter canister adds considerable weight.
For Peter, who does aerobatics, and my T-18 with an 86 Sq-ft wing, we look at things to take out of the plane instead of things to add.
I would like a 50 hour oil change instead of 25 hours.
Oh well.
 
I respect your experience so I am curious what your reservation to the 90 deg filter adapters is based on.

1. They make a mess due to the way the filter is oriented when removing it.
2. Dirty oil drains back into the engine on shutdown especially if filters used have no drainback valve.
3. Vernatherm doesn't seat properly since there's not a good way to index it to the accy. case.
 
Bob,
I think you are under some misconceptions. Maybe I can try to help.
The angled oil filter adapters use a different oil filter assembly then does the horizontal adapters. The difference is that the angled adapters use a filter that has a bypass valve incorporated in the oil filter and not the oil filter adapter. When the filter is static or not in a bypass condition, this valve is closed. Thus, when removing the oil filter from an angled oil filter adapter, the only substantial oil that can leak out is when the filter is actually removed from the adapter as it is flipped right side up. My experience is that about 1-3 ounces of oil spills. With the horizontal adapter the filter leaks as soon as it is started to be turned to be loosened. which leaks a lot of oil during the entire unscrewing process. The oil lands on things below the filter rather then the engine but I think it makes a bigger mess to clean up then the angled adapter. Secondly, because the filter has the bypass valve in it , that valve helps prevents oil from back draining just like the valve that is in the horizontal adapter. The valve, coupled with proper clearances within engine, keeps the oil in the filter at shutdown; and keeps it there until the next start regardless of which adapter is used, horizontal or vertical.
In the case of vernatherm seating; the indexing of the valve is no different then the way the valve is indexed with an oil screen. Granted the index is dependent on the exact position of the adapter housing or screen housing on it's mounting studs, but the vernatherm valve poppet has the ability to swivel slightly to correct for any minor misalignment that could be possible.
So all in all, I think your reservations are a little bit misguided. Personally, I am a real fan of the angled adapters due to the ease of access they normally present. Not always but most times. Not all nacelles are the same and granted some suit them selves better to the horizontal adapter and some suit the angled adapter better. To each his own as they say.
I really believe that using an oil filter verses an oil screen, with proper oil change intervals, will help the long term life of the engine. So I guess to me it doesn't really matter which adapter you use, just that you use one.
Good luck and Merry Christmas,
Mahlon
 
Mahlon, I modify my filter housings to accept an automotive filter and in the process of doing that I shorten the 3/4"-16 stud to make it 1/3 as long as a stock filter and screw/locktite it into the housing. What this does is make changing a filter a completely unmessy affair. I fold up a paper towel underneath the filter and oh, in maybe 2-3 seconds I have it off and vertical. Four or so turns and its off. Why on earth a stock filter has a half inch long thread is beyond me, because if a filter unthreaded that far every drop of oil in the engine would be gone. Spending a couple hundred bucks on something I can fix with a little bit of common sense and about 10 minutes of work seems best to me. And I haven't dropped a drop of oil in quite some time changing filters.

And yes I agree, the angled filter shares the same poor design as the screen. The alignment of the vernatherm needs to be precise and neither offer that.
 
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I took off the top cowl today to take a look, and I'm not sure if the angle adapter will work or not. In the following photo, 1 is the oil screen holder, 2 is the oil pressure sensor, 3 runs from the oil cooler, 4 is the breather tube, and 5 are wires that go to the MGL box mounted on the firewall. The labeled photo is so you can see where you are, and the second photo is more of a top view.

2ighvtd.jpg


20ro9vk.jpg


To my untrained eye, it looks like installing an angle oil filter adapter, even with a spacer, would require moving the breather tube, maybe putting another fitting on the hose from the oil cooler to steer it out of the way, and maybe moving or replacing the wiring to the MGL box.

Here's my latest list of questions:

1. is that true, about what would probably need to be moved or modified?

2. if so, do these modifications fall into the "can of worms" category, suggesting it might be better to go for either the horizontal screw-on filter adapter or the remote filter? Or would the necessary modifications be more in the "piece of cake" category for an A&P?

3. Oh, and where does the oil pressure sensor end up?

Thanks,
Doug
 
I took off the top cowl today to take a look, and I'm not sure if the angle adapter will work or not. In the following photo, 1 is the oil screen holder, 2 is the oil pressure sensor, 3 runs from the oil cooler, 4 is the breather tube, and 5 are wires that go to the MGL box mounted on the firewall. The labeled photo is so you can see where you are, and the second photo is more of a top view.

<snip>

To my untrained eye, it looks like installing an angle oil filter adapter, even with a spacer, would require moving the breather tube, maybe putting another fitting on the hose from the oil cooler to steer it out of the way, and maybe moving or replacing the wiring to the MGL box.

Here's my latest list of questions:

1. is that true, about what would probably need to be moved or modified?

2. if so, do these modifications fall into the "can of worms" category, suggesting it might be better to go for either the horizontal screw-on filter adapter or the remote filter? Or would the necessary modifications be more in the "piece of cake" category for an A&P?

3. Oh, and where does the oil pressure sensor end up?

Thanks,
Doug

Doug,

You probably should move the oil pressure sender. They are typically not attached with a hard connection to the engine for vibration reasons.

The MGL installation instructions recommend a hose from the engine to a remote mounted sender. Page 10 here -

http://www.mglavionics.com/MGL_Avionics_Lycoming_Engine_Sender_Installation.pdf

Moving that will give you quite a bit of extra room.
 
Thanks, Gil -

The fitting currently used for the oil pressure sender was a little mysterious to the A&P who helped me with a recent oil change. It looks like some kind of pipe fitting that can rotate some even while tightened. It doesn't leak right now. I'll put moving the sensor on my list of recommended modifications.

Doug
 
Rocket Bob has a point !

Multiple times I have discussed filtration with oil company Reps at Oshkosh. They tell me that filters just take out the ROCKS,( Bob;s point). The 25 hour change schedule refreshes the addatives that deteriorate with temperature, water etc. Don't SHOOT THE MESSENGER, I am just passing on what they tell me for your consideration.
 
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