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Conference vmszoo::rc

Title:Welcome To The Radio Control Conference
Notice:dir's in 11, who's who in 4, sales in 6, auctions 19
Moderator:VMSSG::FRIEDRICHS
Created:Tue Jan 13 1987
Last Modified:Thu Jun 05 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:1706
Total number of notes:27193

1554.0. "Fuel - why what when etc" by WELCLU::WOOLCOCK () Wed Sep 08 1993 09:35

Hi,

I am new to powered model flying, although I have been flying gliders for many
years. I went to my local model shop recently to get some more fuel for my 
Gloplug engines. There was a vast array of fuel to choose from. I had been
using a mix containing 5% nitro, but this was unavailable so I bought some
10% mix. I asked what difference it would make and was told that my engine
would run cooler. 

I tested the engine yesterday and it does run much cooler, I don't burn my
fingers on the cylinder head anymore.

What are the other advantages/disadvantages of the various fuel mixes available 
?

Keep on Flying
Steve
T.RTitleUserPersonal
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1554.1A few fuellish answersBAHTAT::EATON_NStupid English Ker-nigg-itWed Sep 08 1993 10:2236
    
    At Last!!!
     
    (I told Steve about this notesfile months ago, he *claims* to be "too
    busy". Pah!)  8^)
    
    OK, I'll chuck in what I've picked up:
    
    More nitro means:
    
    A) Your fuel costs more!
    
    B) Your engine's likely to be easier to start (especially on a cold
       day).
    
    C) You need to watch out for corrosion problems after the run. As I
       understand it the nitro leaves nitric acid kicking about in the
       engine. You need to run the engine dry, and use some sort of after
       run oil. There's a commercially available after run that I use
       which seems pretty good, but doubtless there will be about 300
       private recipes from the good folks in here! (Try note 64).
    
    D) Needle valve settings become less critical.
    
    E) You get more power.
    
    I hadn't heard of cooler running as a benefit, but maybe this is a
    consequence of D) ?
    
    	
    That's all folks!
    
    Nigel
    
    PS> Steve, put a note in 4 to tell us what you're flying!
    
1554.2CXDOCS::TAVARESHave Pen, Will TravelWed Sep 08 1993 11:422
A former DEC employee, John Chadd, entered quite a few notes on fuel
into this conference.  Check around and you'll find some good info.
1554.3Nitro = more O2LEDS::WATTThu Sep 09 1993 09:0415
    My experience is that smaller engines need more nitro to run well. 
    Nitro improves idle as well as what's stated above.  Most sport engines
    in the 25-60 size run best on 10-15% nitro.  With ABC engines it's best
    to stick with the same nitro content fuel to keep running temperatures
    more constant.  Nitro provides additional oxygen to aid in combustion
    which is why you can get more power.  More O2 plus more fuel = more
    power.  Always run your engine dry and use an after-run oil at the end
    of every flying session.  To run it dry, drain the tank and leave the
    fuel line off.  Start the engine and let it run until it won't fire
    anymore.  Then add after-run oil down the carb and spin it over to
    distribute it around the bearings.  I use Mobil-1 motor oil for
    after-run oil.  A quart will last you a lifetime.
    
    Charlie
    
1554.4my .02 cents worthGALVIA::ECULLENIt will never fly, Wright !Thu Sep 09 1993 12:0110
    My experience is that when using Nitro on 4 bangers is that with the
    larger pitched props (> 11") it helps the low idle be more consistant. 
    I went from using a home brew a few years ago, to a 5% Nitro by Flair,
    to 15% nitro (Morgan fuels). The latter has been the most successful
    for moi ! 
    
    There was an interesting article in MAN maybe in the middle of last
    year on Nitro, what you got, etc. 
    
    Alt-E.