DDriver

I have converted a Super Tiger G.90 to operate with Gasoline using the C.H. Ignition Module System.
Initial Test was made using regular 5% Glow Fuel....and it worked A-OK.

Then I converted over to Regular unleaded car gasoline with a 10:1 air cooled 2 stroke oil mix.
Engine runs great after initial difficulty, caused by high speed needle valve set for glow fuel at 1 1/2 turns out.
Engine now operated at at approx. 1/4~3/8 turn out only!!
BTW. Getting almost identical rpm as operation on glow fuel before conversion (13 x 6 wooden prop.)

I would like to operate the engine using AV100 LL gas (aviation 100 low lead).
Is this possible??
What are the Pros & Cons of using AV gas over regular car gas??

Any advice would be most welcome.

DDriver.

av8tor1977

My Feedback: (6)

Avgas is more consistent in quality, but your engine doesn't need the octane rating nor the lead in Avgas. It will most likely have a little less power, and definitely cause plug fouling problems. I would stick with auto gas, or alcohol.

w8ye

My Feedback: (16)

There has been mention of a altered carb on these for use with gas where the needle is not so sensitive.

Enjoy,

Jim

DDriver

Thanks for the info Guys.

The reason for desiring to use AV Gas is simply because it's nowhere near as stinky/smelly as regular car gasoline & in addition, is very much cleaner also. Regular gas is pretty dirty in comparision!

You mentioned glug fouling which I presume is caused by the lead could be a problem though?!?
A pilot told me that the aviation fuel available down here is the low lead type .......I just wonder how much of a problem I might end up having with the plugs though??

As far a power increase or decrease, the only real way to really tell is by a real test.

I have a flying buddy who is presently setting up a Kangle CAP 232 120 size 3D plane with a Brison 2.4 Gas Engine who is definitely planning to run it strictly on AV100 LL.

Nevertheless your comments are very much appreciated.


DDriver.

w8ye

My Feedback: (16)

Why not just use Coleman lantern fuel? It works rather well in a model gas engine. It has almost no smell. Try it and see if you like it?

Enjoy,

Jim

av8tor1977

My Feedback: (6)

Even "Low Lead" avgas has a significant amount of lead in it. When they discontinued regular leaded 80/87 avgas and we all had to use 100 Low Lead, we had lots of problems with lead fouling of the plugs. I would imagine you would have a lot of problems with lead fouling in a model engine. It is a common misconception that higher octane fuel, or avgas, is "hotter" or more powerful. The truth is, the higher the octane, the slower the gas burns, and it actually has a little less potential energy.

Good luck
Av8tor

DDriver

Thanks for the info Jim,

Never though about using Coleman lantern fuel.

I remember reading about the first successful trans-Atlantic flight by a model plane....it was powered by an old 60 size four stroke glow engine using Coleman Lantern Fuel.

I will have to check our local hardware stores to see if its availabe and the cost!!

I have taken the engine off the test stand and am presently installing it into my new Bill Evans Simitar Flying Wing
( Future Shock Model ).
I am almost ready, just awaiting my 3 month old order for a Iron Bay fuel regulator. (Fuel Tank over C.G.)
I hear that all back orders have finally shipped earlier this month which is good news!!!

DDriver.

w8ye

My Feedback: (16)

Coleman fuel may not be as common in the stores as it once was? There has been a trend by the lantern makers to use different vaporizers that work with pump gas now that the lead has been removed.

Enjoy,

Jim

DDriver

Hi Jim, Hi All,

Thanks again for your input.

I took the liberty to check into Coleman Fuels as it relates & differs from regular unleaded car gasoline and here are a few interesting comments that I found.

a.
"Coleman Fuel was developed in the early 50's as a replacement for "white gas" which in the US was readily available at hardware stores and gas stations. This was the original motor fuel, no tetraeythlead, or additives, also know as casing head gas, water white color. Was also used as a cleaning agent for mostly white materials, also a fuel for outboard motors and early powered lawnmowers. This source started to disappear in the 50's due to technology.
The Coleman fuel of today has not changed in years, it is a blended naphtha with no lead compounds, and a paraffinic type. The benzene content is controlled to .5% by wt. or less and we add a rust inhibitor along with a green dye for identification."
(Frank Schmidt, Senior Project Engineer, Appliances-Fuels-Patio Grills, The Coleman Co.)

"b.
White gas or Coleman Fuel, is basically a highly refined version of auto gas. In particular, unleaded gasoline oxidizes more quickly than white gas, resulting in the formation of gums, varnishes, and other crud that can foul a spark plug.

c.
Model Stationary Engine Fuels by Jerry E. Howell of Colorado Springs, CO.
"Fuel selection for our engines can be a problem. Some use the same gasoline that is used in their cars. My friends and I have tried this, but for some reason it really stinks when burned in our hit-and-miss engines. This is probably due to the low temperature that these engines operate at and the somewhat rich mixture required by small engines. We came to the conclusion that it also carbons up the valves and spark plugs worse than the camp fuel we had been using."

"Most engine owners are using Coleman Camp fuel with good results. My Plunket Jr. engine has higher compression than most model engines and I noticed that it made some strange knocking sounds that were not mechanical, so I decided it must be detonation. Wondering what the octane rating is, a friend called Coleman and was informed that the octane rating is only 53. No wonder that it knocks!"

"Over time, I finally became disgusted at the fine lint particles in the fuel which was causing all manner of problems maintaining a proper needle setting over a period of time. I began filtering the fuel and installing in line fuel filters on my engines. One day while at a Walmart store several years ago, I noticed they had camp fuel called Ozark Trails on the shelf next to the Coleman fuel. I decided to try a can and see how it compared to the Coleman fuel. Upon checking, I discovered that it was clear as water and had no trace of lint particles. It ran just fine in all my hit-and-miss engines. I told my friends about the Ozark Trails fuel and they gave it a try. Now they use it too and we all agree that it even has a better exhaust smell than the Coleman."

"I discovered that up to 30 parts Ozark Trails camp fuel will blend with 70 parts of methanol. Any amount of camp fuel over 30 percent will not mix and will stay seperate. An engine will start just as easily with this blend as with straight camp fuel. After running the 70/30 methanol/Ozark Trails fuel for more than 100 hours, I found that the valves and plugs stay really clean. The spark plugs in my Plunket Jr. and PowerHouse engines run almost a frosty white, no carbon deposits at all! The fuel needle setting needs to be a little richer and a tank of fuel will not run quite as long as camp fuel, but this could hardly be of concern. I can't find anything negative with using this fuel blend, only positives. I think it is the best of both worlds, as they say. If you try it, please let me know what you think of it. Don't use these fuels in your lawn mower or car, models only!"

I sincerely hope that the above info will be of some positive benefit to all.

DDriver.

aero nut

What kind of oil and in what ratio do you use on your blend?

DDriver

I am presently blending with 10:1 ratio using Quaker State - Small Engines - 2 Cycle Universal Engine Oil (For Air-Cooled Engines).
The quart bottle specifies on the back the following info:
Quaker State 2 cycle Universal Engine Oil is a premium formulation fully compatible with low octane, oxygenated/gasoline fuels.
Provides outstanding anti-scuff, anti-wear, rust and corrosion protection.'
Helps keeps ports clean for maximUm output.

BTW. The ratios recommended for oil in the glow converted engines like Super Tiger G.90, 2300 (1.4) or O.S. 1.08 seem to vary a lot from anywhere between 8% to 15% depending who you speak to.

For example, I origionalLy had decided to purchase the Pro Spark Ignition system, until I read a post at RCU wher a guy installed 6 systems and strongly recommended the C.H. Ignition over the Pro Spark. (Better Transition).

Now the Pro Spark Ignition recommends 15:1 whereas the C.H. Ignition recommends 10:1.
I have personally seem post of various ignition users as low as 8:1, or 12:1 etc.

Nelson HobbY website use to sell the Pro Spark & there is a photo of a O.S. 1.08 which has run for 150 hours using 15:1 with no sign of wear. Gerry Yarrish back in 1999 MAN mag ran a review of the Pro Spark Ignition and he used Havoline 2 cycle oil at 15:1.

I origionally broke my SuperTiger G.90 as a glow with methanol/5% Nitro for about 35 minutes before converting to Ignition.
Then started with 10:1 After its fully broken in I will move to 12:1 then later to 15:1.

DDriver.

lightnin62

i would guess, sense the engine is running on 2- cycle oil only, no caster, that it smokes excessively. would this be the case?