Mobil One, Anyone?

[TXFlyGuy]

Originally Posted by chaskuss

Myron,
This would be a much better choice, if 100 LL will be used. It has the correct "ash-less dispersant" additive package.
Charlie

Thank you, Charlie!

[rocketbob]

You could run Mobil 1 if you take care of the ring and piston clearances. When was the last time you've seen a gasoline car engine oil turn black?

[TXFlyGuy]

Originally Posted by rocketbob

You could run Mobil 1 if you take care of the ring and piston clearances. When was the last time you've seen a gasoline car engine oil turn black?

Never seen black oil. And I change oil (Mobil One) every 7,500 miles on my wife's Explorer, 5.0 V8. Been using Mobil One for over 160,000 trouble free miles. And the oil consumption is minimal today. For the first 100,000 the engine did not burn a drop between changes. Now it will use a quart every 7,500 miles. I attribute this to the oil and the religious break in procedure we employed when the engine was factory new.

[hevansrv7a]

As I now understand the question, it relates to the best oil for a Chevrolet engine used in an airplane. Let's admit that there is no oil on the market that was formulated for this application.

The obvious choices are:
1. Aero-Shell or Exxon-Mobil partly synthetic.
2. Mobil-1 or comparable synthetic for automotive
3. Whatever is the best oil for marine gas engines which often use automotive blocks.

Given that marine applications of car engines are meant to run long periods at high power settings and car engines are not, that would be worth a look.

I don't want to start a war over additives, but it's worth considering a non-synthetic car oil with a really good, patented oil additive which I will only name in a PM or email. I ran my 78 Toyota >230k miles on that and the cam lobes were still within specs when I sold it. That would solve part of the problem with lead. Of course, you still would have plug fouling and such.

Aviation oil, IMHO, is a poor choice simply because it is not designed for that kind of engine. When Mooney had a Porsche engine option, it used car oil, IIRC. AvOil does not contain, the last I heard, the comparable anti-wear package(s) because we don't want deposits in the combustion chambers which might encourage detonation at high, continuous power settings. Aviation oil is also higher in viscosity than what is normally used in an auto engine. The clearances are likely the reason, but the idea of running higher viscosity oil than that for which the engine was designed needs some careful thought, too.

A related question that bears careful decision making is the fuel to be used. If the fuel does not have lead, then the lead issue goes away. However, I don't mean to start a war over car gas vs. av gas. Everything about that has already been written. That said, car engines and even marine engines are no longer designed to run on leaded fuel. Of course, cars and boats don't have the same issues with altitude, seasonal blends and so on.

So there may not be a really good choice in this situation, but given that the decision was made to use an auto engine conversion, then the fuel and lube questions must be decided. It may come down to the least-bad choice.

[jetdriven]

Originally Posted by TXFlyGuy

Never seen black oil. And I change oil (Mobil One) every 7,500 miles on my wife's Explorer, 5.0 V8. Been using Mobil One for over 160,000 trouble free miles. And the oil consumption is minimal today. For the first 100,000 the engine did not burn a drop between changes. Now it will use a quart every 7,500 miles. I attribute this to the oil and the religious break in procedure we employed when the engine was factory new.

i ran my 2005 Honda Accord V6 33,000 (thirty-three thousand) miles one one Mobil 1 oil change and sent it in for oil analysis to Blackstone. Viscosity, metals, everything was within limits.

[RV6_flyer]

The following is a copy paste from:
http://www.lieffcabraser.com/defecti...aft-engine-oil

Mobil Aircraft Engine Oil

• Issue: Defective product
• Result: $12.5 million settlement
• 1995

Gross v. Mobil

Lieff Cabraser served as Plaintiffs' Class Counsel in this nationwide action involving an estimated 2,500 aircraft engine owners whose engines were affected by Mobil AV-1, an aircraft engine oil. Plaintiffs alleged claims for strict liability, negligence, misrepresentation, violation of consumer protection statutes, and for injunctive relief.
Plaintiffs obtained a preliminary injunction requiring Defendant Mobil Corporation to provide notice to all potential class members of the risks associated with past use of Defendants' aircraft engine oil. In addition, Plaintiffs negotiated a proposed Settlement, granted final approval by the Court in November 1995, valued at over $12.5 million, under which all Class Members were eligible to participate in an engine inspection and repair program, and receive compensation for past repairs and for the loss of use of their aircraft associated with damage caused by Mobil AV-1.




For some old but good reading on oil, try this link.


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



For safety reasons, 100% synthetic oil should never be used in an aircraft engine that uses lead in its fuel. Semi-Synthetic oils have proven very effective in aviation engines that use lead. IF you want more info, I recommend using Google and spending a little time reading what you find.

[TSwezey]

I used Mobil 1. I used car gas most of the time and 100LL not to often.

[TXFlyGuy]

These class action suits make for interesting reading. The question is, will a synthetic oil operated in an auto-conversion engine burning 93 octane pump gas present a problem. And lets say that 30% of the time the only fuel available is 100LL. Are you still going to have the sludge problem? Is the problem related in the class action suit due to the fact that certified aircraft engines are rather loose (sloppy?) in the tolerance department and the result is much more contamination in the case? Auto engines are built to much closer tolerances and I would think this would abate the sludge issue to a certain degree.

Aeroshell 15-50 is a semi-synthetic blend. What is the ratio? Is it 10% synthetic, 20%, more, less? All the auto oil brands have syn-blends as well. I would be curious to know the ratio.

[jetdriven]

I have read somewhere it is 50% synthetic. Some people blame AS 15W50 for Lycoming's epidemic of cam failures.

[RV6_flyer]

Originally Posted by TXFlyGuy

These class action suits make for interesting reading. The question is, will a synthetic oil operated in an auto-conversion engine burning 93 octane pump gas present a problem. And lets say that 30% of the time the only fuel available is 100LL. Are you still going to have the sludge problem? Is the problem related in the class action suit due to the fact that certified aircraft engines are rather loose (sloppy?) in the tolerance department and the result is much more contamination in the case? Auto engines are built to much closer tolerances and I would think this would abate the sludge issue to a certain degree.

Aeroshell 15-50 is a semi-synthetic blend. What is the ratio? Is it 10% synthetic, 20%, more, less? All the auto oil brands have syn-blends as well. I would be curious to know the ratio.

I am not willing to risk my safety trying to find out.




Some people like to do dangerous things. I will not risk my life, money, or time going down that path.