100LL AVGAS - Help! Need Advice

ptynning · Post by **ptynning** » Mon May 24, 2004 2:12 am

I can't buy 80/87 any more so I am now forced to use 100LL Avgas.

I only have a simple EGT and CHT Gauge.

Need some advice on how to operate with 100LL Avgas!

TCP? Leaning Techniques ?

I am Teaching my 16 Year old boy to Fly my Cessna 170B

Lots of slow flight - stalls - Power off landings

Not the Best operating Enviorment to keep LEAD off my Plugs and Valves!

All Advice and Opinions wanted! Don't hold anything Back!

Thanks!

Pete

blueldr · Post by **blueldr** » Mon May 24, 2004 3:54 am

Switching to 100 LL? Don't change any of your operating procedures. Plan to clean your spark plugs at about 50 hours to keep from having any problems with lead fouling.
My personal choice was to change to MOGAS, but that seems to rattle the gourd on too many people.
Another choice is to throw more money at it and put some TCP in the 100 LL to raise the price. After all, it's only money and flying is supposed to be expensive! If it was cheap, the guys driving the $300,000 motor homes would all be flying!

russfarris · Post by **russfarris** » Mon May 24, 2004 4:41 am

So, who cares if running mogas rattles some people! With the STC, it's perfectly safe AND legal! I've been using it for over a year and 150 hours now, and quite frankly, cannot tell ANY difference operationally, except it's a buck a gallon cheaper, leaves virtually no exhaust stains and stinks more than avgas. The biggest downside I've found is the hassle factor - either pouring from cans or finding airports with it. My solution is a 110 gallon tank on a trailer, with electric pump, filters and meter. I'm not trying to start a range war here

, but my experience has been totally
positive. BTW, Superior says mogas does not void their warranty, and so does G & N engines; not sure about Mattituck and Lycon, I think I'll call just to check. You'll never see TCM and Lycoming endorse it because of their bloodsucking lawyers advice (Not you, Jerry E. ! ) Russ Farris

zero.one.victor · Post by **zero.one.victor** » Mon May 24, 2004 6:11 am

Pete,I found a real good additive for 100LL. I've been using it for over 1100 hours in my 170 with good results. I add 87 octane car gas to the 100LL,in a 3-to-1 ratio--3 gallons of cargas to 1 gallon of 100LL. You'll need an STC to make it legal-- sold by both the EAA & Petersen Aviation (check Trade a Plane),it costs a buck a horsepower plus some money to your IA for "installation".
I've never had a stuck valve,or a fouled plug. The money-saving aspect of it is going away fast--cargas is only about 50 or 60 cents a gallon cheaper nowadays where I live-- but the other advantages just keep on keeping on.
I don't want to spark a debate with the anti-mogas camp-- all I can say is that it works for me. If you don't like it or don't feel comfortable with it--don't use it.

Eric

Post by **GAHorn** » Tue May 25, 2004 9:25 pm

When using 100LL lean as aggressively as will permit smooth engine operation to reduce lead fouling. ( I never cruise above 65% so leaning exactly as the Owner's Manual says works perfectly for me. Lean to max rpm, continue leaning until first indication of rpm drop, enrichen back to max rpm.) No need for EGTs that are overkill for this carbureted engine anyway. My 2 cents.
Otherwise I operate just like most of the car-gas guys do....never bother to check for fuel quality, alcohol, octane, proper ASTM standards, etc. etc. (JUST KIDDING GUYS !!!!!!!)

Post by **GAHorn** » Sat May 29, 2004 2:06 pm

I doubt this will adversely affect our mechanical gauges.

http://www.chron.com/cs/CDA/ssistory.mp ... ss/2598677

Dave Clark · Post by **Dave Clark** » Tue Jun 01, 2004 1:41 pm

"Otherwise I operate just like most of the car-gas guys do....never bother to check for fuel quality, alcohol, octane, proper ASTM standards, etc. etc"

That cracked me up George, good one!

Post by **GAHorn** » Tue Jun 01, 2004 5:52 pm

Well, that silly comment had the potential to start the Peloponesian Wars so I probably shouldn't have said it just like I did....
The real comment behind the little kidding is....a reminder to be careful what you're putting in your tanks when you buy mogas. I used to use the stuff myself and it did OK most of the time. A couple of incidents with alcohol and absorbed water sneaked up on me as after awhile I quit checking for it....I just began to trust the place I'd always bought it.
The final straw for me was a fuel system leak that was caused by damaged seals and dumped a lot of fuel into the belly of my fabric Aeronca and onto the ground beneath my tie-down neighbors. I had no insurance at the time and that liability to the airport and the other airplane owners had the potential of ruining me. Now I carry insurance ALL the time and stick with avgas. (It's more expensive in the short run and the leaded avgas is no good for valves and outrageously expensive but ...what the hey? We don't own these things because they're cheap do we?)

Mogas is OK if it really does meet the STC, if it's fresh, and if the pilot really does do his homework. I just never did my homework and don't think I know anybody who does.

mrpibb · Post by **mrpibb** » Wed Jun 02, 2004 1:20 am

MoGas is too stinky, everything was starting to smell. Now with 100LL everything smells airplaney

Serious, with the cabin top vent, on hot days or while taxi I would get wiffs of mogas, also during winter months they oxygenate the fuels here so if a warm day happens upon us there's a good chance of vapor lock, happens on my car and especially my motorcycle since I ride infrequently to where there will be winter gas in the tank. Avgas evaporates pretty quick and leaves hardly any odor, plus I like the smell, as for a operational stand point I lean when nessesary, use tcp when available allthough not lately

and during my checkout there was 16 hours of everything but cruise. with this all said and done tomorrow i'll goto the airport to find I have a Stuck valve

Chao

Harold Holiman · Post by **Harold Holiman** » Wed Jun 02, 2004 1:53 am

For the last several years, since I could no longer get 80 octane avgas, I sometimes put mogas in my plane, probably about 20% of the time. This spring I convinced my self not to do it any more except in an emergency. What changed my mind is this. I have a tiller that I used in 02 but not in 03. When I was getting it ready to use this spring, I accidentally bent the rubber gas line while getting it ready to use. It had 02 gas in it and had not even been started during 03. The gas line broke and started leaking. I took it off and it was very gummy and soft. The rubber of the gas line was almost like chewing gum. I decided if mogas did this to the rubber parts of a tiller engine it would do the same thing to the rubber lines and other parts of the airplane if it sat for a period of time. This softened/weakended tiller gas line made me decide no more mogas in my airplane. I'll stick with 100LL with an ocassional dose of MMO. Looking forward to Tehachapi.

Harold
N92CP