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HomeAircraftHelicopterGasser Model RC HelicoptersOther › Campers Fuel vs Gasoline
06-04-2009 06:00 PM  9 years agoPost 81
Dr. Fibinotchi

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Sioux Falls SD

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hmmm
Pinecone.

Here is a man that knows his stuff and has hit the nail on the head with multiple blows.

-C

If you want others to be happy, practice compassion. If you want to be happy, practice compassion.

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06-04-2009 06:14 PM  9 years agoPost 82
copperclad

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NY

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Hi
one thing i am curious about , if anyone knows , i have always heard that octane is needed in high compression engines , with a car high compression can mean 11 to 1 or higher , if i remember correctly

what is the compression ratio of these little two cycle Zenoah engines we are using , thanks

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06-04-2009 06:16 PM  9 years agoPost 83
Hotwings

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Florida, West Palm Beach.

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i run coleman or ozark with 4oz amsoil 100:1 synthetic oil, this equals 32:1, i used to use 2.6oz 49:1,but was not sure it was enough oil.
i fly every weekend and it's hot here in florida, my hanson md 260puh engine starts easily and runs great, never a blip so far, knock on wood. Ron

Please cancel my clearance, I have the field in sight. Got my RW Turbine Waiver, need lottery!

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06-04-2009 06:57 PM  9 years agoPost 84
Hellsiege

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Colorado Springs, CO

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Zenoah 26cc here running 91 octane with Amsoil 100:1 pre-mix @ an 85:1 ratio (1.5oz / gal)and so far have a gallon through the engine and it's running great. Previous owner was from TX so I had to obviously adjust the Hi/Lo for this altitude but I'm really impressed with this engine. Getting smoother and running better with every few tanks (Previous own had only ran 4 or so tanks through it). So regular gas for me

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06-04-2009 07:12 PM  9 years agoPost 85
MikeSherman

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Racine, WI

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Zenoah 26cc here running 91 octane with Amsoil 100:1 pre-mix @ an 85:1 ratio
Wow - I didn't think anyone ran less than 64:1!

You must be good with the needles....

-Mike

Team QuickUK Pilot
Team Heliproz

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06-04-2009 07:13 PM  9 years agoPost 86
shawmcky

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Isle of Wight,United Kingdom

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Compression ratio
copperclad,the standard compression ratio as shown in the manual is 8.4-1 showing 90 octane as the recommended grade of fuel.

Team- unbiased opinion.K.I.S.S principle upheld here

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06-04-2009 07:35 PM  9 years agoPost 87
TaleGunner

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Deer Park WA

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Wow - I didn't think anyone ran less than 64:1!
AmsOil sabre is designed to run at 100 to 1 in 2 stoke engines but there seems to very little increase in performance after 50 to 1 so why risk it

CRASH! GLUE! REPEAT!
Spectra-G, Ion X-2

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06-04-2009 07:38 PM  9 years agoPost 88
Justin Stuart (RIP)

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Plano, Texas

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so why risk it
Yeah, why risk it?

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06-04-2009 08:20 PM  9 years agoPost 89
copperclad

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NY

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Hi shawmcky

8.4/1 , thanks

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06-04-2009 08:52 PM  9 years agoPost 90
Hellsiege

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Colorado Springs, CO

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Wow - I didn't think anyone ran less than 64:1!

You must be good with the needles....
Good or ignorant may be interchangeable in my case. The more I read the more I found out people running the more oil (40:1 - 65:1 for example) were using fossil based oil with amsoil it's synthetic hence myself using the higher ratio...

*edit*
Also 91 octane is the same as 93 octane at sea level. Highest we can get out of the pump out here is 91.

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06-04-2009 10:40 PM  9 years agoPost 91
Wayne Parrish

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Apex,NC,USA

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Well for what its worth,I use Honda HP-2 ,2 stroke oil and have for over 12 years in all my 3W's and other engines . It has run flawlessly without a single issue of any sort.I also use straight from the nozzle regular fuel that I burn in my auto's and trucks,without incidence also.I run 2.5 oz. of oil to a gallon of gas. I just checked the temp of my 230 engine in my Vario Bell 47 G3 and it was 203 degrees. I also just pulled the plug and it is a very nice tan as it should be.Since these things are running well I sure don't see the need in spending 10-12 bucks a gallon on fuel.Also,why do you suppose that Hanson wants you to use regular fuel ? Maybe he's got a lot of stock in the oil co.'s ?? Just food for thought,"If it ain't broke,don't fix it ". Have a great weekend

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06-05-2009 03:48 PM  9 years agoPost 92
Pinecone

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Maryalnd

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Compression ratio is only one aspect of the reuired octane of the fuel. Timing, both ignition and intake/exhaust, and temperatures (intake, engine, head) are other common factors that effect required octane.

Basically it is more on cylinder pressures and temperatures. Higher copression ratio increases cylinder pressure and temp. Intake/exhuast timing can increase the cylinder pressure temp. Engine temps and intake temps can inrease the cylinder pressure and temp.

Intake timing, if too soon, can increase the cylinder pressure.

Full scale piston aircraft engines require a good bit higher octane than one would expect just based on compression ratio.

Terry
Blade CP Trex 450 SE
QJ EP8v2 EX Gaui Hurricane 550
Vibe 50 Bergen Intrepid Gasser

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06-05-2009 04:43 PM  9 years agoPost 93
imnxtc

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BC.Canada

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Full scale piston aircraft engines require a good bit higher octane than one would expect just based on compression ratio.
Yes, and the four cycle Lycoming engine in my Grumman, with its' valves and its' timed magneto driven ignition system, is very different, with more critical fuel demands, to the far more simple Zenoah two cycle in my Predator.

Ditto for the four cycle engine in any modern automobile with their valve train, computer controlled fuel injection systems and computer controlled electronic ignition systems.

So if my Zenoah can perform dependably, with little to no maintenance, year after year, using relatively odor free Camper fuel then all the power to it.

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06-05-2009 09:38 PM  9 years agoPost 94
Pinecone

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Maryalnd

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Which Grumman?

I did my Private in an AA-5B. Have flown most of them, including the GA-7, except the AA-1.

And the "timed" magnetos of your Lycoming are pretty primitive devices, with normally only two timing settings. Hmm, not unlike our helis (which have only one).

And like a full scale aircraft engine, we pull higher percent power for most of the operation. With a engine that runs at very low % power for most of its life, the short time at high power settings can live with some detonation.

Terry
Blade CP Trex 450 SE
QJ EP8v2 EX Gaui Hurricane 550
Vibe 50 Bergen Intrepid Gasser

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06-05-2009 10:45 PM  9 years agoPost 95
Justin Stuart (RIP)

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Plano, Texas

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Terry, what kind of fuel do you recommend?

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06-05-2009 11:27 PM  9 years agoPost 96
copperclad

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NY

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Hi Pinecone
thanks for the info on compression , i know that Octane can't be a huge factor in our small engines , or the 55 octane camper fuel would simply not work

it is also easy to see that people are getting good results whether they use gasoline or camper fuel , so there has to be more to it than just the octane factor , thanks again , it is all very interesting

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06-06-2009 03:12 PM  9 years agoPost 97
turboomni

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East of the Equator

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Have there been any reported issues using Coleman fuel in extremely hot conditions? Also under the same conditions has anyone went from 87 octane gas to 90+ octane gasoline with an improvement in performance? It would be interesting if it was possible to hookup a knock sensor to the motor and be able to read what the motor is up too.

Setup is everything, All my heli's can fly far better than I can pilot them

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06-06-2009 03:31 PM  9 years agoPost 98
Justin Stuart (RIP)

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Plano, Texas

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I did a crude side by side comparsion of 93 octane gasoline and Coleman fuel in my weed wacker. I filled the tank with one fuel, ran it, emptied the tank, filled the tank with the other fuel, ran it, and then repeated this a few times until I had made sufficient observations.

I felt that the 93 octane gasoline made the weed wacker engine run smoother, but the RPMs didn't get as high at full throttle as it did with the Coleman fuel. I could tell as soon as the new fuel hit the carburetor because the smell of the exhaust changed and the full throttle RPMs either went up or down.

It is my unproven hypothesis that the Coleman fuel explodes inside the cylinder much quicker than the 93 octane fuel does, thus forcing the piston down quicker. This seems to explain the higher RPMs I obtained with the Coleman fuel, and it also explains the somewhat higher vibrations I obtained with the Coleman fuel.

The exhaust sound between the two fuels was also somewhat different at idle with the Coleman fuel producing a more pronounced "snap" with each combustion cycle.

I love Coleman fuel for its physical properties. It doesn't stink when you get it on your hands, and it never creates varnish in the tank no matter how long you store it for. However I want my engine to run as smooth as possible, and overall power output is secondary. I think that using higher octane fuel (if coupled with a large enough fan to provide sufficient cooling) will help the engine to run smoother.

With these very simple Zenoah engines that have fixed magneto timing and fixed intake and exhaust valves, varying the burn rate of the fuel is pretty much the only adjustment we can make to advance or retard the timing. The ideal fuel would be odorless, store indefinitely, create good power output in the engine, run cool, and not produce any vibrations.

Someone with actual laboratory instruments need so run a similar comparsion bench test using a Zenoah engine, but instead just listening for differences, rather taking measurements in verifiable and scientific way using a knock sensor, a tachometer, and a temperature sensor to determine which fuel is really best. Otherwise this speculation and hyperbole will continue indefinitely.

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06-06-2009 04:52 PM  9 years agoPost 99
Flying Tivo

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Monterrey,NL,Mexico

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coleman fuel at 105 degrees
I ran coleman on hot summer days peaking the 105-110 degrees and no problem at all. The engine ran good and at a steady 190 degrees.

Felipe

If life throws at you lemons......Squirt some lemon juice in the eye of your enemy!!!!

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06-06-2009 10:52 PM  9 years agoPost 100
Wayne Parrish

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Apex,NC,USA

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Did you re-needle the carb each time you switched the fuel mixture ? If not ,why would you not think that each differnt mixture would not need to be re-needled ?

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