Holy Cow!!!

batjac Thu Sep 10, 2020 5:55 am

As I said in an earlier post, I was given a quart of nitro by a club member. I decided to figure out how to best use it to doctor up some of the other fuels I have. My choices are a quart each of Traxxas 20% and 33% Top Fuel Power Plus, which has 16% oil and 50/50 castor/synthtetic per the Traxxas rep. I have a gallon of Omega 4-cycle which is 15% nitro and 17% oil at 50/50. And I have a gallon of Omega 15% heli fuel. Now, Omega is sold as a Castor/synthetic mix, usually 30% Castor and 70% Synthetic. The 4-cycle is an exception at 50/50 mix. The other exception is the 15% heli. The heli oil is a 1/99 mix.

????? ONE percent castor!!! Holy Cow! There's no saving that fuel for control line...

Ah, well. With the quart of nitro and a quart of SIG castor I can bring the Omega 4-cycle to 25% nitro and 20% oil, the Traxxas 20% to 25% nitro and 20% oil, and the Traxxas 33% to 31.5% nitro and 20% oil, and still have 18 ounces of caster and 9 ounces of nitro left for future doctoring.

I used this website to do the calculations because it's late and I don't have any scratch paper to hand:

Fuel Calculator page

But, since I'm going to be doing some Cox .09 flying in the next couple of weeks, maybe I'll just up the oil content of the 20% Traxxas and settle for essentially 20/20 fuel for the .09. Hmmm. I'll have to sleep on that one.

The Mixologist Mark

davidll1984 Thu Sep 10, 2020 7:52 am

Y use same méthodes mixing 4 difrent fuel To get the right fuel and 4cycle fuel is hi in
Méthanol and lower oil lets say is Good To have som just To refrech old fuel y ad som aditive To the mix and adjustment To weather condition

getback Thu Sep 10, 2020 8:37 am

I guess my question is why do you have all those different FUELS? Small Cox Logo

Good you can save them for use with the Coxes though. Cool

fredvon4 Thu Sep 10, 2020 9:34 am

Mark
I am NOT buying the 1:99 Heli mix....I have seen some Car racing blends a low as 11% lube most of the time all synth

When I am in our only local Hobby shop (RC Car oriented with a race track complex in the back yard) I usually can find RC car fuels with high nitro but low oil for what I consider cheap, at under $20 per gallon

I got two gallons a while back for $17 each...25% N and 14% lube and no idea the lube synth/castor amount so just assume it is all synth

I have 2 gallons of Torco Nitro and local sourced Methanol and a bunch of various synth and Castor oils

Using 25% cheap nitro gallon to make Higher (20%~25%) oil content for 2 stroke aircraft use is relatively inexpensive and the math in Metric Millilitres is real easy

batjac Thu Sep 10, 2020 7:42 pm

getback wrote:I guess my question is why do you have all those different FUELS? Good you can save them for use with the Coxes though.

I bought the gallon of 4-stroke to run in my Saitos before I bit the bullet and bought YS-Saito 20/20 fuel by Powermaster. The heli fuel I bought for a heli that I never got around to flying. The Traxxas stuff I bought because it's the only thing the local shop carries.

The Obvious Mark

944_Jim Thu Sep 10, 2020 7:58 pm

Hi Mark,

See here:
http://web2.murraystate.edu/andy.batts/ps/fuel.htm

The Excel spreadsheet is built for quarts. I edited my local copy for 8 ounce total blend. Play the numbers for two different pairs (fuels A/B and fuels C/D of fuels, then grind those two resultants to get your final blend.

For me, I use hi nitro/low synth oil heli fuel, lower-nitro mid-castor content truggie fuel, and a shot of castor. My final has about 22% nitro, and 20% 50/50 synth/castor. The engines make good power, don't overheat, and splatter the model with a light layer of castor/exhaust mess (easily cleaned up).

andrew Thu Sep 10, 2020 11:24 pm

I'm glad that spreadsheet was of some use for you. I wrote that over 15 years ago simply because I got tired of doing the calculations by hand. At the time I was mixing Sidewinder 20/10 and Sidewinder 30/10 with BeNol to get the blend I wanted. I also have an Excel calculator for one mix that is a little easier to use. Later I wrote a Windows application that uses a slider to allow selecting the desired castor percentage after entering the original fuel mixture. It allows the user to drag the slider with their mouse and spontaneously recalculates the values. Unfortunately, all I have is the executable which my email provider will block. The original code was on my office computer, but I guess I failed to migrate it when I retired.

I am attaching a screen shot of the Windows product -- it worked well.

944_Jim Fri Sep 11, 2020 7:54 am

Andrew,
Any time someone wants to blend two fuels, I point them to your Excel spreadsheet. I've been doing that here, on RCG, and StuntHanger for at least four years. Or for almost as long as my comeback to the hobby.

I appreciate the Excel one specifically because it does the math for a two-fuel blend. I appreciate the ability to input two fuels with known nitro and oil content, and computing/outputting the combined values. In my case, I get high N/Low C fuel, and straight methanol to reduce the nitro/increase the castor for my needs.

You have advertised your newer GUI-version the last few times I mention your "old tool," but your screenshot looks like it is for doctoring-up the castor content of one fuel.

I hope the new one can do two fuels. I guess I need to try the new tool.

Thanks for sharing your tools.

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