Synthetic Oil

Barnstormer · #1 12-14-2009, 08:49 PM

Does anyone use synthetic oil in there Lyc's successfully?

Pat

PCHunt · #2 12-14-2009, 09:22 PM

My guess is: "No".
Recommend a visit to Lyc's website and see what they recommend.
Try searching this forum, as well.

Kyle Boatright · #3 12-14-2009, 09:27 PM

Many of today's aviation oils are semi-synthetic, which means a blend of synthetics and mineral oils. When pure synthetics were tried (Mobile, if I recall correctly), they ended up with some serious problems because the synthetic oil couldn't suspend the lead combustion byproducts, and all the lead ended up as sludge in the crankcase. That, in turn, led to Mobile paying to rebuild quite a few engines.

So, none of the commercial sources sell pure synthetics for aviation. However, if you were running unleaded fuel, a synthetic might work. Or might not... ;-)

rocketbob · #4 12-14-2009, 09:44 PM

Yep.

Some friends of mine have run Amsoil 5W30 with no problems.

F1Boss · #5 12-15-2009, 12:41 PM

I run Amsoil 20W-50 at about 25% in my TCM 550. I know of past problems with lead deposits & sludge, but I'm not running the stuff at 100% in this engine. I'm expecting the Phillips X-CY (@ 75%) to scavenge the lead. I'm expecting the Amsoil to reduce or eliminate internal rust in this application.

I did run this Amsoil straight (100% synth) in a 540 -- no oil changes in about 140 hrs after puttiing the stuff in. Dropped it at a mech's place for HP upgrade (cyls/pistons/cold air) -- he called when he opened 'er up and asked me how many hrs were on it and what oil did I use. He related that the inside looked new, and very clean. The engine had about 500 hrs on it then, and as I mentioned the oil had 140 hrs on it. I did change filters every 50 hrs....

Amsoil is an ashless dispersant oil, so I wouldn't expect any problems if you did decide to run it straight.

You can get on their distributor program, and get the stuff for far less than full retail. The extended change interval available with this type of oil is a good thing -- be sure to figure that into your cost equation.

Carry on!
Mark

Geico266 · #6 12-15-2009, 03:19 PM

Quote:

Originally Posted by rocketbob

Yep.

Some friends of mine have run Amsoil 5W30 with no problems.

What kind of fuel are they running?

rocketbob · #7 12-15-2009, 03:22 PM

blend of mogas/avgas

hevansrv7a · #8 12-15-2009, 04:51 PM

I have no particular view on Amsoil, but the idea of running 140 hours on one oil change seems not very wise. It is not an issue of the oil "wearing out". It is an issue of chemical pollution. Filters remove gross particles in the multiple micron size range. Some say that our clearances are so loose that the smaller particles are thus OK. None of this, however, deals with the issue of the pollution of the oil by by-products of combustion and the consequent formation of, for example, acids. Even the elimination of water vapor from the engine during non-running periods can't prevent that. Water vapor is a result of burning gasoline. It gets into the crankcase by getting past the rings; then it gets into the oil. And, of course, some the oil is burnt and the burnt stuff lodges in the oil, too.

Would any of you who do run long oil-change intervals like to help me understand this from your perspective?

RV6_flyer · #9 12-15-2009, 05:35 PM

Quote:

Originally Posted by Barnstormer

Does anyone use synthetic oil in there Lyc's successfully?

Pat

After the Mobil 1 aviation oil lawsuit, I will not even try a full synthetic aviation oil but have no problem running the semi-synthetic aviation oils that are approved for aircraft engines.

Info on the lawsuit and Mobil 1 Aviation oil can be found at the following two links.

http://www.avweb.com/news/news/182891-1.html

http://www.avweb.com/news/news/182892-1.html

I will not use any oil that is not approved for the engine and fuel that I am using regardless of the application that I use the engine in.

BTW. I use a manufacturer recommended Rotella synthetic diesel oil in my diesel car. It is recommended to be changed every 10,000 miles. I forgot at the last change and went 14,000 before change. It was down one quart when I changed and I did not add any between change.

I like synthetic oil, I do not exceed manufacturer recommend change intervals on purpose, I do not have a issue with paying a little more, and I have a BIG issue with paying a LOT more for it.

rocketbob · #10 12-15-2009, 06:23 PM

A friend of mine bought every bit of Mobil 1 synthetic aircraft oil he could find when they discontinued it, and continued running it in his Aerostar for hundreds of hours with no problems. Still has cases of it in his hangar. He ended up trading the Aerostar for a Cheyenne 400LS, otherwise the oil would be used up by now.