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clean oil, I'm impressed

A5555

Well Known Member
engine 980 hrs, 30 hrs since oil change. the oil stays cleaner than I would have expected.

IMG_20211203_124417.jpg
 
Looks good, but how does it taste? A little soapy?(oxides); bitey?(silica); gritty?(metal). Let us know how it tastes…….
 
My original break-in oil and first couple of oil changes on fixed-weight mineral oil also looked very clean. I then switched to normal oil with ashless dispersant and it got a bit darker quicker, and I understand this is because the oil is holding contaminants in suspension, not necessarily a bad thing.
 
Mmm sweet sweet ice cream toppings. That's why it's called light sweet crude oil, right? Caramel with a hint of smoke. Could be dark chocolate like I like my ice cream topping. ;)
 
Usually, if the oil is black early, it is caused by running too rich, a really bad thing for the engine, as it leads to build up on valves (poor valve to seat cooling and sticking valves); piston rings "carboned up" and poor ring to cylinder seal, and lastly, overly rich mixture washing off lubricants from the cylinder wall, destroying the dynamic seal, and allowing potential ring to cylinder contact (scuffing). I lean every 1000' in the climb, and lean to peak at 65% cruise, higher EGT, but lower CHT. Been running over 40 engines that way, and they still look good at TBO!

DAR Gary


It’s black after several hours in my engine :)
 
Usually, if the oil is black early, it is caused by running too rich, a really bad thing for the engine, as it leads to build up on valves (poor valve to seat cooling and sticking valves); piston rings "carboned up" and poor ring to cylinder seal, and lastly, overly rich mixture washing off lubricants from the cylinder wall, destroying the dynamic seal, and allowing potential ring to cylinder contact (scuffing). I lean every 1000' in the climb, and lean to peak at 65% cruise, higher EGT, but lower CHT. Been running over 40 engines that way, and they still look good at TBO!

DAR Gary

Dark oil early on can be a sign of blow by …..
 
Interesting discussion. My M1B has ~200 hrs now and the oil seems to begin darkening after 30hrs. I stopped tasting a while back with black stains on my lips but still smell it and notice the odor change about the same time . . . . an elevated "cooking" smell , not burned, just a little brown. Analyses have always showed low oxidation and metal content, but I keep looking anyway JIC.

Honestly, I stopped judging colors of oil as an absolute after looking a good black diesel oils that tested and performed well. And engine sounds too, aircraft engines mechanical sounds like **** compared to a sewing machine sound of an automotive. Sound is a relative thing, relative to the original sounds and whether it is running or not. Gotta be able to pick out that one french horn in the background. Like the symphony really... OK you got me started now . . time to withdraw.

Hmmm, the censor did not like that word, where is George Carlin when you need him. It was not one of the 7 either. Oh well.
 
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Oil color vs oil type question ?

I was so proud of my crystal clear dipstick even at 30 + hours.
Dual EI leaned religiously, mogas (ie. no lead) , phillips 20x50 from first start.
250hr with perfect compression.
But when oil was changed, it drained black.

So, the oil does not suspend carbon etc, yet 20x50 is considered a dispersant for use from break-in to TBO.

How does this work ?
 
A very good, cheap option

This is from the Camguard guys. If you ever get to hear Mr. Kollin speak, it's usually a good lesson.

It works very well for stuck rings which could be the root cause of high oil consumption and or quick-to-dirty oil. Helped a Hangar neighbor with this; had to hang weight from the prop. His oil consumption dropped and stayed cleaner, longer.
 

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