Percentage of Nitro in the Fuel
 

What are the advantages or problems of running a higher nitro percentage than necessary if any, disregarding cost factors?

For example the difference in running say 30% vs 10% nitro if all that is required is 10%.

RE: Percentage of Nitro in the Fuel
 

when i was running ducted fans 25% was what evertbody said you needed.I was able to run 10% nitro and still get 24,000 rpm the 25 % nitro I would get 24,500 and about 2 oz more thrust.the cost os the fuel did not make sense for such a small gain.

RE: Percentage of Nitro in the Fuel
 

Disadvantage of higher nitro: higher fuel consumption rate.

Advantages of higher nitro: slight (sometimes very slight) increase in power, sometimes improved idle.

RE: Percentage of Nitro in the Fuel
 

high nitro will increas the fuel usage probably increas the rpm somewhat and theroreticly cool the engine but you should add a bit of oil note if you use alot of nitro watch for a lean run motor wont last 3 flights if your really lean...

RE: Percentage of Nitro in the Fuel
 

JPMacG hit the nail on the head!

RE: Percentage of Nitro in the Fuel
 

small Nitro increases make no difference to engine performance. From 0 to 10% a small increase in performance will be noticed. However a much better idle will be noticed. For a noticeable extra increase in performance the next step would have to be up to about 30%. When Formula 1 Pylon Racing was popular we ran 60% nitro.

Do not ever believe that nitro cools the engine. It does not. The higher the Nitro content the higher the engines operating temperature. Most sport engines meant for use in North America are set up for app 10% nitro. Most European engines are set up for 0% nitro. For average sport flying 10% is adequate. If the nitro content is increased then it may be necessary to add head shims to prevent over heating. Extra oil is not necessary. Again when I flew Formula 1 pylon Racers I used 60% Nitro, 15% oil, all synthetic.

If one is going to play with high nitro fuel then an understanding of inlet and exhaust timing, deck height and head clearances to determine combustion chamber volume is required.

Ed S

RE: Percentage of Nitro in the Fuel
 

I fly a UCANDO .60 size with a Saito 100 on it. I started using 10% nitro then switched to 30% Wildcat just to try it. There was a noticable increase in power (like I took a pound off the plane) and the idle was smoother. Needle settings remained the same but I had to lower the idle a few clicks. I didn't notice any change in fuel consumption.

Don't get me wrong, this setup didn't need any more power but it made it that much better punching out of a bad 3-D move.

One other advantage is that I don't need to install a smoke system-with the extra oil, 30% has it built in!

RE: Percentage of Nitro in the Fuel
 

I run 15% nitro 18$ oil in everything except Saito. In Saito I run YS20/20,,, not really for the extra nitro but I want the extra lube.

RE: Percentage of Nitro in the Fuel
 

hi

from all I have read on this you do have an advantage from 0% to 5%.
you then gain less and less with each increase of 5%. also you engine rpm will be higher and will run hotter than with lower nitro.
also glow plugs won't last as long. some advantage however if cold weather. I usually use 5% on my 2strokes and 15% in 4 strokes.
lower nitro...cheaper fuel

good luck and happy flying

pt19 flyer

RE: Percentage of Nitro in the Fuel
 

A K&B 21 ducted fan motor won't run on anything less than 25 %. On 15 % you can't get it past half throttle. Very advanced port timing is the reason for it. Mind you this is an exception to the rule. Also, the smaller the motor , the more the improvement with higher nitro. The little Cox motors like the high nitro.

RE: Percentage of Nitro in the Fuel
 

My Saito engines give noticeably more power going from 15% to 30%. Four-strokes seem to benefit from higher nitro much more than two-strokes.

RE: Percentage of Nitro in the Fuel
 

I will second that....