Whats all this about fuel?

[carey shurley]

I see a lot of posts about folks asking about fuel choices. Yeah I know its a gasoline helicopter but there are still some options. For example

1. 87 octane gasoline
2. higher octane gasoline
3. aviation or racing gasoline
4. methanol
5. camper fuel
6. specialized fuels like SEF (small engine fuel)

Its a gasoline motor after all so using gasoline seems like a no brainer. couple of caveats to this logic.

• first off, pump gas likely has ethanol in it now. ethanol is hard on certain types of rubber (sort of like that rubberized diaphragm in a walbro carburetor).
• secondly because of the additives and custom blends (an environmental consideration) it can smell really bad both before and after being burned. Its also often quite dirty. Its a really good idea to install a fuel filter on your fill mechanism to keep junk out of the fuel tank. you can get around these by using aviation or racing gas but they are hard to find and more expensive than straight pump gas.

now having said this, I've personally found that the motors idle better and run more smoothly with gasoline. even with that, I don't use it because of the smell. I keep my models in my house and if you're not careful gasoline residue can really smell up the place. More on that in a couple of paragraphs

Gasoline

If odors are not an issue you still have the choice of regular vs premium (lower vs higher octane) fuel. Unless you're running a custom modifed motor which specifies the use of higher octane fuel due to a higher compression ratio, there's just no practical reason to use higher octane fuel. These things are just industrial motors typical of yard implements. In fact if you buy a Red Max weedeater , trimmer or blower............you're buying a zenoah motor. It will run fine on low octane fuel.

Methanol

an interesting choice is methanol. this is the same stuff thats the basis for glow fuel. use this and the motor will run cooler and make more power. but you'll have to get a methanol ported carburetor (larger internal jets). This will use more fuel because relative to your .55 or .90 size motor this has at least twice the displacement (9 or 10cc vs 23cc) so either you have to use a bigger tank or your flight times will go down. You'll also have to use a different oil, most oils that are formulated for pre-mix with gasoline don't mix with gasoline. Finally, pure methanol isnt that expensive but its hard to find. If race facilities are in your area you may have easy access otherwise not so easy. And just using 0% nitro glow fuel? whats the point? the motor uses more, the fuel costs more and the model is still heavier.

Camper Fuel

There's another alternative, camper/lantern fuel. This stuff is a derivative of naptha so its a petroleum based product. but it has no ethanol or other additives in it so its clean and has very little odor. I don't know who first came up with the idea of using this, as far as I know Bill Meador in mississippi first ran this but I'm not sure. What I do know is that the motors run quite well with it. It is more expensive than gasoline, right now about $10 per gallon but you can usually find it a Walmart/K-Mart or other sporting good stores. Unfortunately it is apparently an ingredient in certain types of illegal narcotic manufacture so its getting harder to find in gallon sizes.

SEF

Finally another fuel is starting to surface targeted towards small engines, it can be found in some outlets and goes by the name SEF or Small Engine Fuel. This comes in several sized containers and may come pre-mixed with a two stroke oil in 40:1 and 50:1 ratios or in an oil-less version where you can mix your own oil. This fuel has a controlled octane rating at 94 and doesn't have any ethanol in it. I personally have not used it so I'm not prepared to provide any real report on it other than it exists. I know that it smells very similar to camper fuel and many of the folks who ARE using it are impressed. If you should want to try this be prepared for a couple of things, its not that easy to get and its a bit more expensive than camper fuel.

Whats the bottom line?

• Its a gasoline helicopter - if you don't mind the odor use gasoline
• unless explicitly requested by the motor mfgr - don't use high octane fuel, its not needed
• if storage odor is a consideration - use camper fuel or experiment with SEF

[kenh]

I used to sell gasoline and diesel fuel. I worked for CHS (Cenex) as a "Certified Energy Specilist". A fancy name for sales person Now I'm a mechanic for a local power sports dealer. Anyway, IMO the use of ethanol in fuel is a good thing, but you have to watch where you buy it. It is perfectly legal for a fuel retailer to buy what is called "sub octane" fuel and use ethanol to bring the octane up to the minimum standard. It seems that most of this fuel also does not have any additional additives (detergents) in it to prevent varnish and others things from happening. If you purchase your fuel from one of the major bands you should be OK. It's the "off brands" and private retailers I would worry about. Today's gasoline has a shelf life of about 60 days. This clock starts from the moment the gasoline is distilled. In my area, our gasoline comes via pipeline to the distribution terminal. It spends almost 30 days in the pipe. (little know fact... You can walk as fast as fluid moves in a pipeline!). It may spend a week at the refinary and it certianly will spend some time at the terminal before being delivered to your friendly neighborhood gas station. The moral of the story is to burn what you use as quickly as possible. If you don't get is used up in a couple of weeks dump the remains in your car and buy fresh. The little bit of oil in the fuel will not hurt anything in your engine or it's sensors.

OK back to ethanol.... Ethanol will help to keep your fuel system clean. I see this every time I take a carburetor apart. It is very obvious which customers use ethanol. The non-ethanol carb WILL be dirtier inside. The down side to ethanol is , it will attract some moisture. So if you mix small quantities and get it burned up soon you should have no problems. Now with the above said my motorcycle just sat all winter with ethanol in it OK, I did use some Seafoam for a fuel stabilizer though. I use ethonal in all my engiens. From my chainsaw to my motorcycle and I have very few problems. It may help that I live in the heart of ethanol country so it should be about as fresh as it gets. I like ethonal enhanced gasoline. I have good luck with it. If you understand its positives and negatives it will treat you right.

This is my take on ethanol. Do your own research if you like. Your "mileage" may vary from mine.

[kopterkat]

Question:
Can I put octane boost in Coleman fuel to use it in my high compression 30.5cc engine. I currently use coleman in my TRM231 with great success. I tried it in my 30.5cc and it didn't work so well. Sounded like a hammer.

[Dr_Fibinotchi]

Great post. Not sure if you could touch on compression as well or not. A modded engine runs diffrent than a none modded from the coleman to a 89 gas, and running a Methanol your compression would benifit from being changed from stock.


-Cody

[kenh]

IMO.... Coleman fuel has no need for knock suppression. Colman fuel belongs in a Coleman lantern, my opinion again. I know a lot of people use it though. An octane booster may be in order. Or just buy some 91 octane fuel, which is what I would do.


From Wikipedia;

Coleman fuel is a petroleum naphtha product marketed by The Coleman Company. Historically called white gas, it is a liquid petroleum fuel (100% light hydrotreated distillate) sold in one gallon cans.[1] It is used primarily for fueling lanterns and camp stoves. Originally, it was simply casing-head gas or drip gas which has similar properties.
Coleman fuel has an octane rating of 50 to 55 and none of the additives found in modern gasoline.[2] It has a lower molecular weight than gasoline, kerosene and diesel fuel and cannot be used as a substitute for any of those fuels in modern engines.[2]
The flammability of Coleman Fuel is similar to gasoline; however, it should never be used in modern era gasoline engines. Its high heat of combustion and lack of octane boosting additives like tetra-ethyl lead will destroy engine valves, and its low octane rating would produce knocking.[2]

[kopterkat]

I know what coleman fuel is. I been using it for years without an issue. I asked the question if octane booster could be used.

[kenh]

With an octane rating of only 55, I would think an octane booster would be mandentory. Your engine owners manule should give you a minimun octane rating for the fuel used in your engine. A good detergent additive package would also be in order. My understanding is Coleman fuel is "dirty" fuel in that it has a good amount of varnish causing agents in it. Coleman fuel also burns hotter than gasoline. This this will compound problems assosiated with preignition and detonation.

[Rototerrier]

I have been around long enough to see a lot of threads from very educated people discuss camper fuel. You guys should search that stuff out rather than hashing out opinions. The camper fuel, octane, pinging, detonation, stuff has all been hashed out and discussed.

Here is a quick summary, based on many very knowledgable people. For these engines, Camper fuel works just fine. There are many technical reasons as to why it works and why these engines don't suffer from the negatives that you guys are assuming. I am not an expert and am not going to go into it...but I have read all the threads and am educated enough on the facts and data to say...do a search and educate yourselves.

It's good stuff and serves a purpose for many people.

I have tried it and only had one problem. It also didn't cooperate with my fuel pump. Same pump would work fine with gas but leak like crazy with the camper fuel. I swapped back to pump gas after only running 1 gallon of camper fuel.

[Toxic Al]

I will agree with Roto on this, people ask me all the time what to run in my engines and i have tested a great deal of fuels in the past. I like the camper fuel because of a few reasons, 1 it does not have any real odor, which is great because i keep my helis in my Bedroom and my wife has no idea they have fuel in them. 2 the fuel is super consistant from batch to batch as are needle settings. 3 smells like I am about to cook hotdogs when it does burn. lol. The problem i have with etanol fuel is you don't know how old it is, how good it is(quality wise) and it's consistancy. the additives in the fuel are horrible for any longevity and when it does clog the carbs which it will if left long terms, they are a pain to deal with. If you use it use small amount mixed and from stations that move a lot of gas so the freshness is better. Peace, Al

[Pinecone]

1) We don't actually use octane as a rating in the US. We use AKI (Anti Knock Index) which is the average to two different octane ratings. RON (Research Octane Number) and MON (Motor Octane Number). RON is used through most of the rest of the world, and was used in the US up until the early 70s.

Both are derived from running a single cylinder test engine under very controlled conditions. The engine has variable compression. The compression is adjusted until the test fuel knocks (detonates). The engine is then run on fuels made up of a mixture of n-heptane (octane rating of 0) and iso-octane (octane rating fo 100). The mixture that knocks at the same compression as the test fuel tells the octane. A 90 octane fuel, knocks at the same compression ratio as a mixture of 90% iso-octane and 10% n-heptane.

MON has tougher conditions than RON (higher temps, etc). There is no direct relationship between RON and MON of a fuel. However, due to some issues with proper RON fuels destroying engines under certain operating conditions, most modern fuels have an MON not lower than 10 points below the RON. This means also, that European 98 RON fuel is basically the same as US 93 AKI fuel.

2) The US mandates ethanol in street fuel. You can de-ethanol gasoline by mixing a substantial amount of water, shaking, and after settling, decanting the gasoline off the top of the water. Doing so will reduce the AKI of the fuel, but if 50 octane naptha runs fine, de-ethanoled 87 AKI should be more than fine. If you are worried, use 93 AKI to start. Some premium (93 AKI) fuels are billed as not containing ethanol. Do not use mid grades, as they are mixture of regular and premium, done at the pump. This also means, you should run some fuel from the pump first, to elminate any regular from the hose. So start filling your vehicle with premium, after a few gallons, fill your model jug.

There is also a product marketed to the modeling market that is added to gasoline to reduce the issues with the ethanol. I will have to find my bottle to get the info. Not sure how it works, but you add a small amount to the gasoline.

3) All US aviation gasoline at this time are leaded. And VERY highly leaded compared to what auto fuels used to be. Many race fuels are also leaded. Leaded fuel have many issues. One of which is highy increased toxicity. Also, modern engines are not designed for leaded fuels, and that can cause internal issues in the engine.

There are unleaded race fuels (and unleaded aviation fuels are in the works). You can find unleaded race fuels in some gas stations (Sunoco for one) and at most tracks. All the fuels at the track will be without ethanol, even the track 93 AKI fuel. Sunoco makes 93 and 98 AKI unleaded race fuels without ethanol. Higher AKI fuels are leaded.

VP race fuels also makes several unleaded, no ethanol fuels. They are even marketing one to the model aviation market ( http://seffuels.com/ ). It is available as straight fuel or as pre-mix with Motul two stroke oil.

4) There are poducts (Stabil for one) that reduce the issues with longer term storage of gasoline. You can find them in most any auot parts store or in hardware or home warehouse stores. You add a small amount (and ounce or two per gallon) and it reduces the gum formation from storage. I have run gasoline in my generator that has been stored for years using Stabil.

5) Actually the term"white gas" originally refered to unleaded gasoline. Early gasoline did not contain lead. Later, higher octane needs were met by adding lead. Very old timers will remember that premium was called Ethyl. Ethtyl refered to tetra-ethyl-lead, which is the form of lead in gasoline. Regulations required that leaded fuels contain a dye indicating that is is leaded. In the old days of leaded vehicle fuels, Amoco sold unleaded fuels, that did not contain dye. They marketed it as being purer. Also, for aviation fuels, the dye color indicates the grade of fuel. So for a period of time, premium fuel was leaded and regular was not. So things like Coleman lanterns, stoves, and even cigarette lighters (like Zippo type) used unleaded gasoline.

Later, all fuels got lead, so they could no longer be used in these alternative uses. So Coleman had to start selling a fuel that would work in their products. And they called that fuel generically "white gas" as most people were familiar with using "white gas" in the products already.

If you are interested, here are the color codes of aviation fuels. Aviation fuels are normally rated with two numbers. The first number is Aviation Lean and the second Aviation Rich. They are very close to, or the same, depending on the information source, to MON and RON conditions.

Early

Red - 80/87
Blue - 91/96
Green - 100/130
Purple - 115/145

Current

Red - 80/87
Blue - 100LL (Low Lead - lower than the old 100/130, but still very high lead content).

They are working on 96UL, which will be unleaded. It is pretty much 100LL without the lead. Many of the aircraft engines run today on 100LL were actually designed for 91/96 fuel, so 96UL should be fine. As I understand it, the aviation world has already been in the process of making the internal engines changes needed to support unleaded fuels (mainly valves and valve seats).

[Seasick78]

http://pure-gas.org/index.jsp

There are also free iPhone/Android ( http://itunes.apple.com/us/app/pure-...9068?ls=1&mt=8 ) apps that will show you the nearest ethanol free gas stations near a given location. Users can also contribute (expand) the list by sending in a notification of a station not currently listed. Just an FYI.

[blackbeard]

This is what i use trufuel50.com Useing 40:1 did 4-5 cans and yes i keep my heli in the house.

[turboomni]

It seems to me that if at least a stock Zenoah engine can work well on Coleman which is 50 octane then the compression ratio and porting is such that it will work on most budget fuel that is available in every part of the world. This is why I found SEF does NOT improve on this situation. Why would an engine manufacturer make an engine that would make bigger power on other than rather primitive fuel? [real low octane] ,,Happy with 50 Octane be happier with 94 Octane and up?
It does not make sense Especially with fixed timing,,,there is no room to improve on any fuel even if it is so called better[Octane] or not. The best fuel is the octane that it was designed for. With only ONE timing point,,and one compression ratio and port timing ,,who would you want to please? The Americans with Race gas or the majority with low octane crap and makes them all happy. Let me guess,,,,
Zenoah is dealing with the world market and the present world market quality of gas. Do you really think they are catering to anyone with race gas or SEF??
NO,,,,,,,,,,,,,,,,,,,,,,

[James Kovach]

It seems you are under the impression that the higher the octane, the higher the power. Octane does not create power.

I believe Carey stated in another thread that on the dyno, Coleman was making less power than gasoline. This is not solely because of the octane level.

The benefits of Race Gas/SEF is not that they make more power. They are a cleaner fuel. Which will give a cleaner and more efficient burn. This give you a better overall performing engine.

In the next week or so, we will have a couple of guys from VP Racing/Powermaster fuels on the RCTodayShow Podcast. Be sure to check it out as they can explain it better.

[carey shurley]

This is an informational forum, given the history of this discussion on other forums, I'm going to close this thread before it turns into something else