Synthetic oils

[pierre smith]

Yesterday at the Southern National drag boat races, my wife asked me how synthetic oil is made and I didn't have a clue. I researched a little and found this very informative article. I also learned that our Lyc redline oil temp at 250 F is because above that, dinosaur oil breaks down fast while synthetics run all day long in excess of 302F without breaking down.

Do any of you guys run synthetic oil in your Lycs?

Here's the article:

http://www.pelicanparts.com/techarti...thetic_faq.htm

Pierre

[Mel]

Synthetic oils do not tolerate lead. Mobil bought a lot of engines several years ago before they found this anomaly.
Do not use fully synthetic oils in conjunction with leaded fuel. The "blends" don't seem to have the problem.

[cytoxin]

neeed to be ashless dispersant.

"Ashless Dispersant oils are formulated from base stocks blended with additives designed with a range of objectives which may include enhancing low temperature fluidity, high temperature stability, corrosion inhibition and anti-wear protection. The additive system is ashless and of a dispersant nature offering greater engine cleanliness. Ashless means that the product does not contain any metallic components - this is important because it reduces the formation of harmful metallic ash deposits within the engine. Dispersant means it will hold small particles in suspension if they do not dissolve, allowing these particles to be carried away from critical areas and filtered out. This helps keep the engine clean. Ashless Dispersant piston engine oils are approved against SAE J1899 specification (superseding MIL-L-22851D)."

[rv6ejguy]

I've run Mobil 1 with 100/130 and 100LL in race engines for over 20 years and now in my Subaru RV6A on 100LL with no issues. Frequent oil changes in the race engines of course and zero lead deposits in the oiling system.

In the RV, oil is changed at 40-50 hour intervals and I run Decalin lead scavenger in the fuel (1/4 oz per 10 gallons). I just had the pan off to fix an annoying oil seep around the turbo drain fitting. There were zero lead deposits anywhere and everything looked brand new.

Rotax says if you run full synthetics with 100LL to halve the oil change intervals.

Eggenfellner recommends Decalin or Marvel Mystery Oil added to the fuel when running 100LL. Several users are nearing the 1000 hour mark with no issues although he does not recommend synthetic oils for the reasons stated in other posts. Might be better to be safe than sorry.

Now will a Lycoming like Mobil 1? Who knows with all the whacky break in procedures required. I have been breaking in my auto engines on Mobil 1. The "experts" say it can't be done- nonsense. Just requires a proper wall finish and a hard breakin. My oil consumption on about the last 30 engines is almost nil.

If the Lycoming will tolerate Mobil 1, it undoubtedly provides far superior protection to dinosaur oils.