C-145 Fuel Additives

Robert Eilers · Post by **Robert Eilers** » Sat Jul 30, 2005 6:01 pm

Is anyone using fuel additives in the C-145, i.e., MMO, TCP, Synthetic 2 cycle oil? I have been using 100% synthetic 2 cycle oil (4 oz to 10 gals) in my Champ C-85 for the past 18 months or so. The 2 cycle oil is supposed to improve valve lubrication. I have been unable to find auto gas without alcohol in it lately, so I am running 100LL and adding TCP as recommneded. Any suggestions, cautions regarding the C-145 and fuel additives?

Post by **Bruce Fenstermacher** » Sat Jul 30, 2005 7:18 pm

Thooonk -sound of can opening

slllurrrrp plooop -sound of a wad of worms falling from open can and hitting the floor

Robert
I can't say for sure if anyone here on the forum would use any un-approved additives like MMO and 2 cycle oil but I seem to remember someone talking about snake oil once.

OK enough of the fun.
Out of the nearly 20,000 posts here I think 18,000 of them mention MMO or TCP. There have been a few mentions of 2 cycle oil as well.

Do a search on "MMO" you will get 40 threads including 1 with the subject "Marvel Mystery Oil". Do a search for TCP and snake oil as well.

After reading all of that if you still would like to discuss fuel additives I'm sure at least a few of us would be happy to step up on our soap box one more time and tell you all about our secret fuel formula.

blueldr · Post by **blueldr** » Sun Jul 31, 2005 1:59 am

Out here in California, all the mogas I've tried tests out at about 5% alcohol. My solution has been to fill the ranks almost full with mogas then dump in a couple of quarts of water, shake the airplane vigorously, let it stand over night, and the alcohol will amalgamate with the water. Drain the sumps in the morning and go flying!
I'm working on a STC for this procedure.

Robert Eilers · Post by **Robert Eilers** » Sun Jul 31, 2005 2:45 am

Ok, OK - Ive learned my lesson. I hope the mixing water with fuel alcohol removal solution was a joke.

Post by **GAHorn** » Sun Jul 31, 2005 4:55 am

Yes, it was a joke that blu elder was playing. By the way....one reason alcohol is a bad idea for aircraft fuels is the affinity for water that it has. While it may sound like a good idea to absorb water out of the fuel....the real problem is when you have alcohol in your fuel and go fly. When you climb up away from Mother Earth the temperature falls. The fuel cools. The water precipitates back out. The fuel strainer may become overloaded with the stuff. The engine sputters.....
Notice also that the FAA Type Certificate for Cessnas specifically prohibits the use of fuels with alcohol in them. (I know, I know. The FAA also allows generally, the addition in the field of isopropyl to aircraft fuels as an anti-freeze....but that Advisory Circular is generic.....the Type Certificate prohibition is overriding because it is specific.)
Alcohol also damages/deteriorates some fuel system components. It's a bad idea for any fuel system, IMHO.
Two-Cycle oils for "valve lubrication" is a potential problem, IMHO. First, it makes for increased carbon fouling which creates hot-spots/glowing embers which can cause pre-ignition. The incomplete combustion by-products caused by the burning of the added 2-stroke oil also adds to dirt in the engine's oil system. It also may contain other additives not approved for aircraft engines such as metallic compounds that can be deposited in the combustion chamber, also causing pre-ignition. (The reason av-oils have different additive packages than automotive oils is specifically to avoid such metallic compounds. An example is that Av-oil additives are not "detergent" like auto-oils...they are "dispersant".) Why don't 2-stroke engines suffer from pre-ignition then? Because 2-stroke engines run at higher cycles (hence the term 2-stoke) and their combustion chambers are scavenged differently than 4-stroke engines. In fact, some 2-strokes actually have glow-plug ignition because they benefit from the continuous-temp ignition source. An extra little bit glowing here and there has no ill effect on them. (Remember your model airplane engines? And certain 2-stroke diesels?)
The normal clearances in your aircraft engine already allow crankcase oils to reach the areas needful of lubrication. (Air cooled engines are considerably "looser" than liquid cooled engines such as your car. In our C145/O300 engines, the valve-stem to valve-guide clearance is specifically intended to allow oil from the rocker-box to lubricate the valve.) If your valves/guides are properly sized, no additional additives are necessary or adviseable.
Some operators swear by MMO for various reasons. As a fuel additive it is analagous (IMHO) to adding dyed jet fuel to your gas. If jet fuel is bad in avgas systems, then MMO has to be just as hazardous. But there they are, the many owners who use the stuff and tell stories about how great it works for them. I personally believe that MMO probably softens lead deposits somewhat. (It's going to be funny as H--- when some day someone reveals that the "mystery" in MMO....is that it has TCP in it.)

(I just thought/made that one up.)

There's quite a few folks who tell convincing stories about how it solved their engine's stuck valve habits. All I can say is.... if it's so good, then I don't know why MMO hasn't gotten it approved. They must know something that we don't. And the engine mfr's have fought off a lot of lawsuits centered on failed/stuck valves. You'd think TCM would have packaged the stuff as a special TCM-valve additive if it had any merit. Think of all the extra money they could reap if they had an additive like Lycoming sells for their tappet-galling problem. Alcor-TCP also gets rid of lead problems and it is approved so that's what I use.

Other's use MMO in their oil sumps, I suppose either to satisfy an imagined need for "thinner oil" for lubrication of equally imagined delicate/fine mechanisms, or to keep the engine insides clean, since it's also a solvent. I think that's an especially bad idea. If thinner oil was good or necessary then simply using a lighter viscosity oil would solve that need. But I suspect if the same owners thought about it, they'd disapprove of adding something that actually thinned out their oil. Yet that's exactly what it does.
As for cleaning out the engine, I believe that deposits already there in places that aren't in close/sliding contact with other internal moving engine parts serve a good purpose in situ. They insulate against corrosion just like a coat of varnish or paint would. Washing that stuff off and circulating it around in close-tolerance areas seems injurious to me. I've seen inside some engines that were pretty-well coated with junk on walls, sumps, etc., and they were running just fine. I can't imagine loosening that stuff up and pushing it thru the moving parts of an engine without it damaging something. Aviation Consumer magazine had MMO tested at a lab that reported it was kerosene/naptha/distillate with red dye and perfume.
I believe clean, pure, purpose-designed/refined fuels and oils are best for our engines. I also believe additives are usually attractive to us only because we have active imaginations and our well-intentioned buddies do too.

Finally, a quote from one of the best articles ever written about "snake oils" aka: additives. "The major oil companies are some of the richest, most powerful and aggressive corporations in the world. They own multi-million dollar research facilities manned by some of the best chemical engineers money can hire. It is probably safe to say that any one of them has the capabilities and resources at hand in marketing, distribution, advertising, research and product development equal to 20 times that of any of the independent additive companies. It therefore stands to reason that if any of these additive products were actually capable of improving the capabilities of engine lubricants, the major oil companies would have been able to determine that and to find some way to cash in on it.
Yet of all the oil additives we found, none carried the name or endorsement of any of the major oil producers.

In addition, all of the major vehicle and engine manufacturers spend millions of dollars each year trying to increase the longevity of their products, and millions more paying off warranty claims when their products fail. Again, it only stands to reason that if they thought any of these additives would increase the life or improve the performance of their engines, they would be actively using and selling them - or at least endorsing their use.

Instead, many of them advise against the use of these additives and, in some cases, threaten to void their warranty coverage if such things are found to be used in their products."

Want to read the entire, informative, well-researched article on additives? http://www.thegsresources.com/garage/gs_additive.htm

Post by **Bruce Fenstermacher** » Sun Jul 31, 2005 5:02 pm

George I really have to commend you for typing all that one more time.
Whether one agrees with you or not I for one appreciate you taking the time to do it. (Or have yo learned to "cut and paste". I sure hope so.

)

While I can't argue any of your points MMO in gas has "seemed" to work for me with regards to sticking valves. Other than not being approved and lightening my wallet to purchase what seems to be a solution I otherwise wouldn't put in my tank, I have seen no harm.

Harold Holiman · Post by **Harold Holiman** » Sun Jul 31, 2005 5:20 pm

George,

That is an excellent post and I don't dispute anything you say. However, I am one of those who "Believes" that MMO in the fuel does good, wether it really does or not. Never in the oil though.

Harold
N92CP

Post by **GAHorn** » Sun Jul 31, 2005 7:51 pm

Hey, guys, remember,..... it was one of my personal mentors who related the story to me of his experience as an early Delta Air Lines mx chief and how Delta attempted to solve their dispatch problems with the turbo-compound radials with MMO....until they were caught at it one day.

(At the quantities suggested by the can's instructions, it's a pretty small amount of product that is actually being dispensed into the gas tanks.....so I personaly expect in such quantities it has little detrimental effect on avgas....and about the same amount of benefit. What is referred to in some professional circles as the "placebo" effect.

blueldr · Post by **blueldr** » Mon Aug 01, 2005 3:34 am

What the heck! When you test the mogas for alcohol the test tube is filled to about 10% with water then filled with the fuel. The mixture is then shaken vigorously and then allowed to settle out. The amount of increase it the water level determines the alcohol content percentage in the fuel. Works in the test tube---must work in the airplane! C-170 airplanes with the old, early style gear legs are a lot easier to shake vigorously.

(If I could type as loquaciously as George, my answers would fill a lot more space.)

johneeb · Post by **johneeb** » Mon Aug 01, 2005 4:20 am

Ah jeez Ma do I have to look it up?

3 entries found for loquacious.
loÂ·quaÂ·cious ( P ) Pronunciation Key (l-kwshs)
adj.
Very talkative; garrulous.

--------------------------------------------------------------------------------
[From Latin loqux, loquc-, from loqu, to speak. See tolkw- in Indo-European Roots.]
--------------------------------------------------------------------------------
loÂ·quaciousÂ·ly adv.
loÂ·quaciousÂ·ness or loÂ·quaciÂ·ty (l-kws-t) n.

Source: The American HeritageÂ® Dictionary of the English Language, Fourth Edition
Copyright Â© 2000 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.

loquacious

loquacious was Word of the Day on February 24, 2002.

Source: Dictionary.com Word of the Day

loquacious

adj : full of trivial conversation; "kept from her housework by gabby neighbors" [syn: chatty, gabby, garrulous, talkative, talky]

Source: WordNet Â® 2.0, Â© 2003 Princeton University

Blue Leader is George keeping you from your housework?

N1277D · Post by **N1277D** » Mon Aug 01, 2005 1:42 pm

FYI - Chevron markets a fuel additive and even adds small amounts of it to their auto gasoline. I wonder if they add it to their AvGas ? Since their auto gas can be used with an STC'd; does it follow that the FAA approves of their additive

in certified aircraft; since they have a huge budget and can hire the best chemists does it follow that George secretly uses the stuff ?

Post by **GAHorn** » Mon Aug 01, 2005 4:39 pm

N1277D wrote:FYI - Chevron markets a fuel additive and even adds small amounts of it to their auto gasoline. I wonder if they add it to their AvGas ? Since their auto gas can be used with an STC'd; does it follow that the FAA approves of their additive in certified aircraft; since they have a huge budget and can hire the best chemists does it follow that George secretly uses the stuff ?

That IS funny.

(Of course, what Chevron calls their additive "Techron"....for cleaning fuel injectors...has no application to our 170 engines. It also is another example of the power of marketing. All modern auto gasolines have "cleaners" that flow through fuel injector-equipped engines. It's not called "Techron" ...because Chevron already trade-marked that moniker...but its in 'em all. It's usually simply referred to as "aromatics", meaning highly evaporative solvents. Auto gas makes an excellent, if somewhat dangerous, parts cleaner, as we all know. (In fact, it's no secret. I do sometimes use it as that's what it does best.....cleans aircraft parts, like wheel bearings, in a bucket.)

spiro · Post by **spiro** » Wed Aug 03, 2005 8:45 am

A very experienced refinery engineer I know told me that the major brands of gas were all pretty much the same - except Chevron. He says it's a given in the industry that the proprietary fomulation of Techron/Techroline is much better than the cleaners used by anybody else. I've heard this elsewhere too.

While I don't believe in or use MMO or any other additives in my cars or airplanes, I do burn Chevron exclusively in my cars, whether w/ carbs or FI. So in this particular case I think Techron is a lot more than just marketing hype.

I have no affiliation w/ Chevron, I used to work for a competitor.

jon s blocker · Post by **jon s blocker** » Wed Aug 03, 2005 1:24 pm

I agree with Spiro, I have used Chevron in my cars for years and have never had a problem with it. I have used several other brands but have always come back to Chevron. I have owned several Porsches and have raced most of them. never a problem. My wife uses a different brand of fuel in her Vette, and when it starts to stumble a little, I put Techron in it and it smoothes out. I have used other products but really believe Techron has worked the best for me. If it Is just marketing hype, I would like to meet and shake the hand of the man hyping it, he has my vote. I would love to be able to use Chevron in the plane, but we don't have any around here for aircraft. Jon

N170CT · Post by **N170CT** » Wed Aug 03, 2005 2:30 pm

Jon,

I have owned two Porsches and Vettes always "stumbled" around either.

So it probably ain't the gas.

Chuck

The International Cessna 170 Association