Pre fill

[201Steve]

 Pre fill

[A64Pilot]

Can’t, if it was remote mounted so I could, I would.

[Guest]

For those engines which have the filter installed upside down, I pre fill the filter.

[Hank]

I've never prefilled any oil filter on any engine, ever.

On my Mooney, the filter is horizontal and can't be prefilled. 

[Fly Boomer]

44 minutes ago, M20Doc said:

For those engines which have the filter installed upside down, I pre fill the filter.

Upside down meaning threaded end up?

[Pinecone]

13 hours ago, Fly Boomer said:

Upside down meaning threaded end up?

I hope so.

Prefilling one with the threaded end down could be a bit messy.

 

[Fly Boomer]

20 minutes ago, Pinecone said:

I hope so.

Prefilling one with the threaded end down could be a bit messy.

 

 

[Pinecone]

How do you pre-fill it?

[Fly Boomer]

Just now, Pinecone said:

How do you pre-fill it?

I haven't figured it out, but @M20Doc has a technique.

[Fly Boomer]

14 hours ago, M20Doc said:

For those engines which have the filter installed upside down, I pre fill the filter.

 

[Guest]

8 hours ago, Pinecone said:

How do you pre-fill it?

For your TSIO 360, assuming that yours isn’t a Rocket, just fill the filter with clean oil before you thread it on.  For 520 and 550 Continentals you can pre fill the filter.  For Lycomings the filter also can’t be filled, unless is has a remote filter installed vertically.

[BDPetersen]

Maybe the larger question is “why”. Certainly an empty filter doesn’t create a fatal air bubble. I just put in 7 quarts instead of 6.

Now, the fuel filters on my diesel tractor are a different story, but even there I have a work around.

[kortopates]

It essentially eliminates the time the engine is running without oil pressure as it fills up the filter with oil before it can go into the engine.
I don’t really know how many seconds that may be, not long, but they say starts can be when our engines see the most wear; especially with cold oil.
It’s a good suggestion.


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[201Steve]

On 10/18/2022 at 7:03 PM, Hank said:

On my Mooney, the filter is horizontal and can't be prefilled. 

I thought I replied to this but I don’t see it. 
 

The filter on my io360 is also horizontal. You can’t fill it to the brim, but it will take way more than you’d think before it starts spilling out sideways. Pour, tilt, pour, tilt. When it starts dribbling out, done. Install. Half pre-filled. 

[201Steve]

You would think with all the people in here that freak out over half degree egt changes, there would be more passion about gaining oil pressure one second sooner! As mentioned above, the most abusive operation of the engine. Startup

[EricJ]

1 hour ago, 201Steve said:

I thought I replied to this but I don’t see it. 
 

The filter on my io360 is also horizontal. You can’t fill it to the brim, but it will take way more than you’d think before it starts spilling out sideways. Pour, tilt, pour, tilt. When it starts dribbling out, done. Install. Half pre-filled. 

This is what I do.   You can partially fill it without any coming out during installation.   I think it's a little better than leaving it empty.

[RLCarter]

I’ve always pre filled to the top in one pour, then let it sit, most of the oil is absorbed into the filter media and you can turn it upside down and very little if any will come out before you get screwed on. I’ve never looked but if Aircraft engines are like all other engines, the filter is on the return side of the system, that being said pre filling or not wouldn’t matter as far as oil pressure on start up. The only engine that I know of that has to be pre filled is the 7.3L Power Stroke Diesel, it has a high pressure oil pump that fires the fuel injectors, if that pump cavitates the injectors won’t fire (open), other diesels might be the same .. not sure 

[Shadrach]

I have never prefilled the filter on my plane.

I have seen the inside of my engine at ~900hrs.

I’m skeptical that it makes a difference.

I have a horizontal filter that mounts between the mags on the accessory case.  Trying to thread a semi filled filter though the engine mount and onto the engine would be almost as messy as removing the old one.

 

[A64Pilot]

7 hours ago, RLCarter said:

I’ve always pre filled to the top in one pour, then let it sit, most of the oil is absorbed into the filter media and you can turn it upside down and very little if any will come out before you get screwed on. I’ve never looked but if Aircraft engines are like all other engines, the filter is on the return side of the system, that being said pre filling or not wouldn’t matter as far as oil pressure on start up. The only engine that I know of that has to be pre filled is the 7.3L Power Stroke Diesel, it has a high pressure oil pump that fires the fuel injectors, if that pump cavitates the injectors won’t fire (open), other diesels might be the same .. not sure 

Ford is the only one that uses the HEUI injectors, in PU trucks, but I think it was a Caterpillar invention, pretty slick, it takes a lot of oil at low pressure and uses it to pump a tiny bit of fuel to extreme pressures, each injector is it’s own pump, everybody else I believe uses essentially a hydraulic pump to jack fuel pressure to 30,000 to 50,000 PSI and keeps it an accumulator and calls it common rail.

Personally I pre fill when I can, figure it can’t hurt. But back in the 70’s pre-oilers we’re pretty common, sold of course because they would make your engine last forever because it was an accepted fact that almost all wear occurs at start up on dry parts with no oil pressure.

Well unfortunately that didn’t turn out to be true or said another way pre lubing didn’t seem to make an engine last longer for some reason, I for one thought it would.

So maybe pre-lubing isn’t significant?

[RLCarter]

24 minutes ago, A64Pilot said:

Ford is the only one that uses the HEUI injectors, in PU trucks, but I think it was a Caterpillar invention, pretty slick, it takes a lot of oil at low …………..

Well unfortunately that didn’t turn out to be true or said another way pre lubing didn’t seem to make an engine last longer for some reason, I for one thought it would.

So maybe pre-lubing isn’t significant?

I had a 7.3 for 20 years, the 1st gen were an International engine, 300k on it when I sold it with no issues. The older Chrysler/ Dodge has a very unique sound when starting, by design the engine would crank over with the ignition dead to help build oil pressure before firing off.. I’ve torn down engines that haven’t run in years and the oil pumps still have oil in them along with the rod / mains & cam bearings. Pre oiling an engine before firing it up can’t hurt just as pre filling an oil filter but I doubt either is necessary. 

[Hank]

So prefilling the oil filter can't hurt but likely won't help.

I'll keep mounting them with no oil except on the gasket, to keep everything clean(er).

[EricJ]

10 hours ago, RLCarter said:

I’ve always pre filled to the top in one pour, then let it sit, most of the oil is absorbed into the filter media and you can turn it upside down and very little if any will come out before you get screwed on. I’ve never looked but if Aircraft engines are like all other engines, the filter is on the return side of the system, that being said pre filling or not wouldn’t matter as far as oil pressure on start up. The only engine that I know of that has to be pre filled is the 7.3L Power Stroke Diesel, it has a high pressure oil pump that fires the fuel injectors, if that pump cavitates the injectors won’t fire (open), other diesels might be the same .. not sure 

The media holds some oil, but not nearly enough to fill the filter volume, as evidenced by how much comes out when you remove one.

Lycoming and Continental engines both send oil through the filter before it gets to the galleries and bearings.

Typical Lycoming (pressure screen = filter):

Example Continental (from TCM "Tips on Engine Care"):

[Shadrach]

10 hours ago, RLCarter said:

I’ve always pre filled to the top in one pour, then let it sit, most of the oil is absorbed into the filter media and you can turn it upside down and very little if any will come out before you get screwed on. I’ve never looked but if Aircraft engines are like all other engines, the filter is on the return side of the system, that being said pre filling or not wouldn’t matter as far as oil pressure on start up. The only engine that I know of that has to be pre filled is the 7.3L Power Stroke Diesel, it has a high pressure oil pump that fires the fuel injectors, if that pump cavitates the injectors won’t fire (open), other diesels might be the same .. not sure 

I don't think the filter is on the return side for a Lycoming, but that may vary with installation. The flow diagram is no exactly easy to read and does not show the filter (attached). One of the guys on the RV board created a simplified version (attached).  Either way, I don't think the difference amounts to much. Doubt it is measurable with the naked eye and a stop watch. I think almost all bearing wear occurs as a result of parts going from stationary to moving. Pressure or no pressure, hydrodynamic separation between parts requires that those parts move.  Metal is contacting metal until hydrodynamic separation is achieved.  No amount of filter filling or preoiling will prevent it.  That explains why engines perform so well in endurance tests where they run for the duration of the test. Virtually no wear. Would be better to do 2000 stops and starts to demonstrate durability.

 

 

 

[Shadrach]

5 minutes ago, EricJ said:

The media holds some oil, but not nearly enough to fill the filter volume, as evidenced by how much comes out when you remove one.

Lycoming and Continental engines both send oil through the filter before it gets to the galleries and bearings.

Typical Lycoming (pressure screen = filter):

Example Continental (from TCM "Tips on Engine Care"):

beat me by 4 minutes...

[Dream to fly]

There are a few commercial truck engine companies that actually state that prefilling any liquid filter prior to installation is not a good idea.  That said when dealing with small volume filters of less than a quart it really is a mute point on an engine that ran just before the service because the previous oil in the crankcase had some adhesion to the metal and on start up the oil pump can produce way more volume to overcome the short air pocket.  That said on larger filter systems with big cans or multiple cans manufactures still caution against prefilling but personally I struggle with it.  Brand new engines under warranty I don't prefill, after warranty I do but only on the oil lubrication side.   I NEVER prefill on a fuel side.  The contamination on a fuel side is way more critical and causes massive engine issues.  Most fuel system filters installed today are positioned in a way or built so prefilling is almost impossible.   This is all for normal running engines but in the case of an engine that has been sitting for years I do prefill and prime the oil system and on the fuel side I have made a 10 micron fill system that can pre charge the fuel system with clean filtered fuel to lesson the crank time.  Just my half cent passing time waiting for parts.