Skip Oil filter change

[texasclouds]

It’s your funeral.

 

[Skymac]

I routinely do 100 hour oil changes every 5 weeks. Great oil sample data, if you’re flying often, I wouldn’t worry about it. A/S 15w-50.

 

[Timbeck2]

I think you can go every other oil change to change the filter on a known healthy engine.
I am not suggesting this for a high performance engine or engines not flown a lot.
You can remove it and let it drain a bit so you do change all the oil if you want to reuse it.
I do oil analysis and get that back in a week or so to help track metal in the oil.
I did run oil and filter to close to 100 hours in my last 0-320 right before I returned it as a core. I sent a oil sample for analysis and the metal numbers were all within averages.
The silicon numbers were from new valve cover gaskets...

I fly a lot and have been thinking of extending my 55 hr oil changes to maybe 65-70 hours?

I cut and inspect every filter at oil change. Luckily I have never found metal. I did find a few paint chips after reinstalling 4 cylinders on my old engine.

I have 2 more filters and then I am switching to Challenger reusable filters. I have used these type filters on racing engines. It is a very good filter.

View attachment 109794 View attachment 109795

Gary, can you confirm the Challenger part number for your O-320 is: CP48103C

This is the one I'm going to get although the website is a bit confusing on it's application chart. I'm planning on switching to the Challenger for my next oil change but at least on the Spruce site, it's on backorder until October.

 

[Pinecone]

I change the oil and filter every 3000 in my '71 Volvo. I attribute that to the fact I have 570,000 miles on the original engine.

What oil are you using?

With a full synthetic, you can go much longer between changes.

 

[Pinecone]

Mobil one oil says something like they guarantee 15,000-20,000 miles between changes. I guess as long as you have enough oil that won’t be a huge problem. Anything else is bad luck.

Our 90 Jeep Cherokee 4.0 ran 300,000 miles with good compression, starting and gas mileage. Only problem was rear main seal was leaking.

The last 70K miles, I never changed the oil. I would run until the oil pressure gauge started bouncing, and stop and add a couple of quarts.

 

[Pinecone]

Mobil one oil says something like they guarantee 15,000-20,000 miles between changes. I guess as long as you have enough oil that won’t be a huge problem. Anything else is bad luck.

BMW went to a baseline 15,525, miles between changes. Up from the previous 9,000 miles in about 2001.

But the oil change interval is dynamic. And it seems that the best predictor is fuel used. So for my car, if I drive very carefully, the miles between oil changes actually goes up.

 

[the dude]

I think its ass backwards to dump the oil and not change inspect the filter. I would rather change the filter and reuse the oil and believe that is the practice on extend oil intervals. Have a analysis done and swap the filter.

 

[MooneyDriver78]

I think its *** backwards to dump the oil and not change inspect the filter. I would rather change the filter and reuse the oil and believe that is the practice on extend oil intervals. Have a analysis done and swap the filter.

Why? Do you think the filter stops working after so many hours?

 

[the dude]

Why? Do you think the filter stops working after so many hours?

I didn't say it does, it will keep working until no more oil will pass through. A oil analysis will report the condition of the oil, but if the filters getting crap in it, you wont know. If you dump the oil at the regular interval and its clean, how do you know the filter isn't holding the debris.

 

[Pinecone]

On airplanes, the oil change interval is based on the amount of blowby that an air cooled engine has. This leads to compounds that, when mixed with water, create corrosive mixtures. So the oil gets changed often.

Car engines, especially ones in the last 25 - 30 years or so, don't have much blowby. So less corrosive compounds.

Both aircraft and auto oils have additives to boost the TBN (Total Base Number) that neutralize the acids. You can add this to your oil analysis to see if you are changing it to early or too late, or just right.

Autos also benefit from full synthetic oils to get the extended change internals. BTW, checking my average speeds, I average for the low 30s to maybe 40 MPH per tank. So a 15,000 mile change intervals is more than 375 hours between changes.

I think it is highly unlikely that you will have issues with skipping the filter change, every other oil change, on an aircraft engine. Although, as always, check your POH.

My Mooney allows 100 hours on oil changes, but the filter needs to be changed every 50 hours. I use 35 hour change intervals, so would be good with skipping the filter every other change.

All that said, I have plenty of filters, so will not be skipping any changes. They are available, you just have to look. And possibly wait. If you need one now, you may pay a premium price.

 

[MooneyDriver78]

I didn't say it does, it will keep working until no more oil will pass through. A oil analysis will report the condition of the oil, but if the filters getting crap in it, you wont know. If you dump the oil at the regular interval and its clean, how do you know the filter isn't holding the debris.

You don’t, if the engine hasn’t been making metal your probably good.
I drain the oil through a screen to check for metal in the oil.
Don’t forget the acids and other chemicals in the oil that’s bad for metals.

 

[the dude]

A lot of the metals you cannot see with the naked eye. Our nickel was down and it just picked up on the last sample, bore scoped and found a issue with a valve guide starting to burn a valve. Couldn't tell on the engine monitor and never physically seen by eye that nickel in the oil. Wouldn't have known until it was too late.I still wouldn't chance not changing the filter but that's JMO.

 

[SoonerAviator]

On airplanes, the oil change interval is based on the amount of blowby that an air cooled engine has. This leads to compounds that, when mixed with water, create corrosive mixtures. So the oil gets changed often.

Car engines, especially ones in the last 25 - 30 years or so, don't have much blowby. So less corrosive compounds.

Both aircraft and auto oils have additives to boost the TBN (Total Base Number) that neutralize the acids. You can add this to your oil analysis to see if you are changing it to early or too late, or just right.

Autos also benefit from full synthetic oils to get the extended change internals. BTW, checking my average speeds, I average for the low 30s to maybe 40 MPH per tank. So a 15,000 mile change intervals is more than 375 hours between changes.

I think it is highly unlikely that you will have issues with skipping the filter change, every other oil change, on an aircraft engine. Although, as always, check your POH.

My Mooney allows 100 hours on oil changes, but the filter needs to be changed every 50 hours. I use 35 hour change intervals, so would be good with skipping the filter every other change.

All that said, I have plenty of filters, so will not be skipping any changes. They are available, you just have to look. And possibly wait. If you need one now, you may pay a premium price.

Yup, I feel like just running a Blackstone analysis on the oil will probably help cure some of the "filter crisis" paranoia. I run them on my diesel just for peace of mind. I do 5K-mile oil intervals even with full-synthetic because the high-pressure oil pump that runs the fuel injectors (using oil) is notorious for shearing down oil over time. A 5w-40 semi-synthetic can often be sheared down to a 30w by 5K miles in the Powerstrokes. Running an oil analysis shows me the TBN as well as a host of other metals/contaminants, and gives a historical trend of my engine as well as a reference to other Blackstone customer average analysis results as a datum.

 

[Gary Ward]

Gary, can you confirm the Challenger part number for your O-320 is: CP48103C

This is the one I'm going to get although the website is a bit confusing on it's application chart. I'm planning on switching to the Challenger for my next oil change but at least on the Spruce site, it's on backorder until October.

Yes that is the number I ordered... crap I do see that the filters and Challenger oil filters are out of stock now! Wow I figured it would get better by now. WTH.

 

[pfarber]

I think for me, in seriousness, the question isn't how much dirt is it trapping, it's "how soon do I want to know if my motor is making metal?" -- 100 hours seems like a long time to get meaningful warning.

If there was a way to inspect the element without destroying the can, that'd be a victory for re-use. Someone should come up with some sort of fine mesh screen that can be inspected periodically.

There is nothing special about an aviation oil filter other than the hole for the safety wire.

You would think that there would be more STCs for cartridge filters but the FAA can't rub two brain cells together and allow anything newer than 1950s technology near a certificated engine.

 

[Arrow76R]

What oil are you using?

With a full synthetic, you can go much longer between changes.

I use Quaker State 10W40 but it is hard to find here lately. Otherwise Pennzoil, both "high mileage". Synthetic, I have been told, will leak quickly past seals that have had nothing but organic oil for 51+ years.

 

[Jeff767]

Aircraft engines have enormous tolerances compared to modern auto engines. We change the oil at 50 hours not because the oil is degraded but because it’s contaminated with combustion byproducts that never get to the oil in a auto engine. Don’t compare between the two.

 

[Pinecone]

I use Quaker State 10W40 but it is hard to find here lately. Otherwise Pennzoil, both "high mileage". Synthetic, I have been told, will leak quickly past seals that have had nothing but organic oil for 51+ years.

An auto OWT.

That was true in the 60s and early 70s. The synthetics did not have short chain solvent type molecules that swelling the seals. So they shrank. But the just added a tiny bit to the synthetics and problem solved.

Should be no problem switching to a full synthetic now.

 

[Pinecone]

Aircraft engines have enormous tolerances compared to modern auto engines. We change the oil at 50 hours not because the oil is degraded but because it’s contaminated with combustion byproducts that never get to the oil in a auto engine. Don’t compare between the two.

They are comparable, if you compare aircraft engines to auto engines of the 50s and 60s.

But there is also the added complication of leaded fuel and lead in the blowby with aircraft engines. Unleaded fuels are going to be a very good thing for aircraft engines.