Oil Filter Cart

[8434]

Hi All,

Now I know there are a few STCs out there to add an Oil Filter to the C85, 90, 200's but has anyone considered just filtering the oil and putting it back in? It all came up in a discussion with a reliability engineer at work, he pointed out that most pieces of equipment like gear boxes and pumps don't have filters. Instead every so often an mechanic drags a filter cart out to the equipment and runs the oil through the filter cart. The cart consists of a pump and a set of filters, the type of filter used depends on the desired cleanness of the oil being filtered. The industrial models are expensive however I figure I could build one for 100$ or so. I'd be able to filter the oil every few hours which would be better than running for 25 hours with no filtration at all.

Has anyone ever heard of doing this?

Thoughts?

Marshall

[2066]

Interesting. Some related readings over the years seem to support the claim that oil molecules are "sheared"/damaged gradually so that lubrication and protection properties are significantly diminished. Some others suggest that oil doesn't "wear out". Of course, "naturally" accumulating contaminants to oil may contribute to engine wear. Randy Thompson makes a very good assumption (based on LOTS of experience and expertise) that a filter isn't "needed" and that retaining the OEM oil screen and adhering to recommended oil changes is all that's "needed" for our little Continentals. With the cost of AV oil (and, filters) the idea of filtering and re-using at some(?) normal change intervals might be an interesting (practical?) project, 'though the jury would probably be out for quite a while to make any valid comparisons & conclusions. Keep us posted. Mac

[8474]

I agree with Randy, the cheapest maintenance you can do for any engine is frequent oil changes. Filtering just takes out the (relatively) big chunks, but there are a lot of other contaminates such as acids that filtering won't remove. The screen will tell you if something is coming apart or as we like to say making metal. Change that oil, even more so if you don't fly regularly or get the oil good and hot.

[8434]

I did some further thinking about it. The limitation on what filter is installed on an engine is the oil pressure, pick a filter that is too fine and your oil pump won't achieve the required flow to lubricate the engine. Since a filter cart doesn't have this constraint, one could select a pump and a multi stage filter and remove virtually every contaminate.

Mac, I agree, the oil will degrade and oxidize so I won't be saving anything in longer oil life. I might however do my engine a favor by removing more carbon and metal before it has a chance to get somewhere it shouldn't.

Marshall

[6183]

I'm going to parachute in here on this one.

From my youngest brother, a retired Shell Oil Chemical Engineer who manufactured aviation oils, lubricants, and fuels for 30 years
Oil used in an internal combustion engine collects acids due to the combustion process. Those acidic compounds along with other contaminates(due to the combustion process in the engine) can cause damage to internal engine components if the oil is not changed on a regular basis. Filtering any oil will not remove the damaging acidic compounds from the oil; however, filtering is a media that removes dirt and carbon particles that can lead to engine wear. Changing oil on a 25 hour basis or every 90 days will help eliminate the acids from doing further damage.

Randy makes a good point about the use of the OEM oil strainer screen and regular oil changes. Key here is to make regular oil changes at 25 hours or every 90 days with fresh new oil. Lot of folks won't fly 25 hours in 6 months and will not change oil until that 25 hour time is met. That's poor practice just as is starting up an engine on your aircraft and running it for 5 minutes to warm it up then shutting it down. Moisture in the oil will start to boil, and will mist up to the top of the engine components. That mist will contain those damaging acids which will fall back down onto the engine components during cool down to start the rusting process. If you need to run the engine, fly the airplane for at least 30 minutes to boil off the moisture in the oil.

Oil is really relatively economical when one considers the cost of a complete engine overhaul. Just my 2 cents

[8359]

I made a thread about this on PoA a while back. The general consensus was just change every 25 or get the filter and move to 50.

https://www.pilotsofamerica.com/communi ... il.119343/

Getting an oil filter is still on my to-do list.