Phillips 20w-50 (conventional)

[Robster]

Our mechanic suggested we switch from AeroShell 15w-50 (semi syn) to Phillips 20w-50 (conventional) in an attempt to reduce excessive crankcase venting of the oil / consumption. Engine is a TIO-540 Lycoming--crankcase venting of oil has been a problem with this engine since new. I've used AeroShell in practically every aircraft I've flown and have run several of them to TBO a few times on it with no oil issues.

I've never used Phillips before, but it DOES seem to be slowing consumption--I'll know better as we approach the end of the OCI. Have any of you used Phillips for this reason? One thing I noticed right off is that it blackened very quickly, compared to the AeroShell.

 

[BigCahuna]

I'm no plane person but, I think I read somewhere that oil for planes is designed to be more resistant to plug fouling. So I guess my question is , is the Phillips oil your using designed for plane use?.,,,

 

[2004tdigls]

Originally Posted By: BigCahuna
I'm no plane person but, I think I read somewhere that oil for planes is designed to be more resistant to plug fouling. So I guess my question is , is the Phillips oil your using designed for plane use?.,,,


this is my thought also, unless the Phillips oil is approved for aircraft, i would use something like this. Note some engine manufacturers require specific additives.

"AeroShell W 15 W 50 has become very popular amongst engine manufacturers and operators alike. In order to cater for those Lycoming engines that need improved load carrying, the Lycoming LW 16702 antiwear additive has been incorporated into the formulation thus eliminating the need for supplemental additive addition."

http://www.shell.com/business-customers/aviation/aeroshell/piston-engine-oil/w15w50.html

 

[seanf]

I worked at a piston engine overhaul shop for almost 10 years, one of the guys who had been building Lycomings for years says he thought the Aero Shell was too slick causing the cylinder barrels to slick out giving you increased consumption and crank case pressure. However we were also a Phillips distributor as well. When was the last leakdown performed and were the cylinders new or overhauled.

 

[LoneRanger]

The flight school where I earned my vfr ticket used only Phillips 20W50 in the two trainer 152's (Lyc O-235) and two 172's (Lyc O-320). They always made it to tbo or whatever hour threshold the part 135 stuff held them to. I used Aeroshell 15W50 in the '67 PA-28 we had and had to put a cylinder on it before selling it.

 

[OPR4H]

Phillip 66 is the first Aviation multigrade engine oil. A heavier base has less volativity. The branched molecules of mineral base makes it, initially, get to do more dispersion of the dirt, so it blackens very early. Appart from that, mineral oil is also more prone to oxidation, by the exact same branches.

 

[wings&wheels]

Our A&P suggested the exact same change a few years ago after some odd, for our engine, readings with Aeroshell. I switched to Phillips, but did an overhaul not long after as we hit TBO (w/ no major issues). Still breaking in the new engine, but will probably keep using 20w-50. Can't add any actual results yet, other than my mechanic giving similar guidance. Happy flying.

 

[Robster]

Thanks for the replies. . . I'm keeping an open mind about the claim of reduced oil consumption, although I'm dubious. We do UOAs at every oil change--it will be interesting to see if any of the numbers change. As of today, it seems like it's using slightly less, but still hovering around the 1 qt. in 7 / 1 qt. in 8 hrs. range. Lycoming will officially declare that "normal", but I think it's excessive for a mid-life engine.

 

[Robster]

. . .oh, forgot to mention, the compressions are good / normal and haven't changed much since new. I flew this aircraft from delivery and it was blowing oil from the git-go. We'll be trying an air/oil separator (again) at the next inspection. We'd tried that shortly after delivery, but couldn't get the air/oil separator to work right--it actually INCREASED venting of oil, so we scrapped it. Our new mechanic wants to try it again. We recently tested crankcase pressure at Lycoming's recommendation (attached airspeed indicator VIA hoses to modified oil cap) with negative results of excessive pressures. I'm thinking that there's something unique about the cowling that's causing a negative pressure at the vent, causing it to "siphon", but we've played with the vent pipe location with no real improvement. Stay tuned. . .

 

[FastLane]

That's all I run in my Cessna 150. It runs cooler than Shell. The big flight school here runs it too. Some of their engines are running to 3500-4000 hours.

 

[Cujet]

Originally Posted By: Robster
Thanks for the replies. . . I'm keeping an open mind about the claim of reduced oil consumption, although I'm dubious. We do UOAs at every oil change--it will be interesting to see if any of the numbers change. As of today, it seems like it's using slightly less, but still hovering around the 1 qt. in 7 / 1 qt. in 8 hrs. range. Lycoming will officially declare that "normal", but I think it's excessive for a mid-life engine.


1 quart in 7 is excellent in a lycoming. Those air cooled cylinders really don't seal all that well. Only the Conti's with their non nitrided cylinders seal well, due to rapid wear.....

As for 20W-50, it's an excellent oil and will protect your engine properly.

 

[Robster]

Quote:
1 quart in 7 is excellent in a lycoming. Those air cooled cylinders really don't seal all that well. Only the Conti's with their non nitrided cylinders seal well, due to rapid wear.....

As for 20W-50, it's an excellent oil and will protect your engine properly.


Thanks for the comments CuJet. Yeah, I get all that, but was hoping for closer to 1 in 10. The problem for me is that our ship's mission is aerial photos / video and the camera is slung underneath. That means me crawling under it to clean oil off the lenses after every sortie--was hoping to cut back on that! It's going in for inspection next week and hopefully the mechanics will work some magic with the air / oil separator. I'll keep y'all posted on how that works out. --Rob

 

[Cujet]

I think it's simply "blowby" that causes the breather to discharge oil vapors at a high rate. Our Extra 300L, has the breather tube run all the way to the back of the airplane. That way it never affects the belly.

I know that some camera aircraft run the exhaust all the way to the back for optical clarity.

Unfortunately, Lycoming's are this way. We had 4 new cylinders "warp" slightly, causing a lot of blowby and less than ideal compression. Took 'em off, rigid honed them, and re-installed with new rings. Problem solved.