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General control line discussion => Open Forum => Topic started by: Dennis Toth on November 26, 2019, 12:39:51 PM
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Guys,
Was getting very low on fuel, had been using Brodak 5%N, 29% Castor mixed equal with 10%N, 23%Syn, giving 7.5%N and 26% oil. Worked good in my Fox. I wanted to push the nitro to at least 10%, Brodak was out of 10%N, 29%Castor so I went to LH and bought some Byron 15%N and mixed it with the 7.5%N. Well power when way down even though the %N went up. Had to go in on the needle to get the power up. Then I looked as the MSDS sheets for the Byron fuel they have nitromethane listed (I thought it was Nitroethane, miss read) but why does the power go down?
My question is for those familiar with or that use the Byron fuel, what is the equivalent % nitro in Byron to match the power of 10% SIG nitromethane fuel?
Best, DennisT
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Dennis,
Which exact Byron fuel was added during the second reformulation cycle? Was it Aero Gen II? If so, what oil content and mix? They make several different mixes.
With what you have given us to work with so far, my first thought is that lubricant system keeps getting altered to lower and lower viscosity. This would be due to the ratio of castor to synthetic going down each time you mix it as I suspect that their synthetic has less viscosity than their castor. Since the jet in your needle valve is the same diameter as it was with real Fox fuel, you have to go in on the needle or too much fuel (the reformulated mix) is being drawn by the venturi. If, by turning the needle in, you got at least one run where the power was the same, then that seems consistent to me. If, however turning the needle in did not improve the power back to the previous level, then the new added Byron fuel may have had something wrong with it. For example, if it had absorbed too much water.
But the fuel would not need to be defective to cause what you are describing. If you had to run more than one tank of the stuff thru a Fox Stunt to try to find your setting again, then you are altering more variables since you are removing the "Fox varnish" from the P/L. (If you've been running a mix with synthetic all along, you probably don't have this issue.) And, you may also be changing the heat balance by fooling around simultaneously with the nitro levels (burn rate), and the oil level and type (heat absorption). And running a different fuel but the same plug means whatever the magic setting that went with that plug (and compression ratio) is now different.
If you change fuel mix you have to expect to change the needle. How much you change the needle is a good indication of how consistent your fuel supplier is from batch to batch of even the same fuel mix.
Of course, we are assuming that the only thing that changed was the fuel. No change to the engine, the prop, the tank, the plug, the density altitude, etc.
Dave
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My question is for those familiar with or that use the Byron fuel, what is the equivalent % nitro in Byron to match the power of 10% SIG nitromethane fuel?
I was running 15% Byron and it was still a bit short of SIG 10%. It was good enough at the time, so I didn't experiment further than that.
I have very good results with Byron fuel when I was running it - it definitively solved the "quit like you flipped a switch" problem in every case I found. I qualified at 3 Nationals using Byron that I had poured into an old SIG jug to hide its origin, so as to hold down on the snide comments.
Bret
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Hi Dennis,
I've been using Byrons fuel for 20 years along with several other brands. When I use fuel with castor the brands that had the most power were Sig , Red Max, Powermaster , Taffinders. Byrons was a bit anemic. Probably 5% off 15% Byrons = 10% Sig. However around 1999 I started using Heli Fuels. Byrons Heli will work as well or better as any other Heli or YS 20/20 brands I've tried. And I've tried a few.
I prefer Byrons but its hard to get now so I use other Heli fuel.
Not sure this answers the question but it is my finding.
Best of luck , John L.
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Thanks for the input. Dave, I had not thought about the lower viscosity with the Syn oils but it makes some senses. As Brett and John remarked the Byron nitro level seems a bit weak. Could be they are not getting pure nitromethane, awhile back we could get nitro from the local speed shop but it was always cut with 10% menthol, maybe they are getting something like that. Anyway my flying partner has been using Byron's in his ABC/ANC engines for the past year because that is what the LHS has, he has been getting great runs.
Last night I ran the numbers for the mix I had and it seems I was down around 23 -24% oil with more than half syn. I added castor to bring the mix up to 27%.
Today we got to fly and without changing anything, just fueled the ship and flew. The run was totally consistent and motor was happy. I changed the prop from an APC 9 1/2 x 6 to a Brodak BYO 10x6 and flew again. This added load and leaned the motor but it was again totally consistent and motor was happy, could go a few clicks richer as we had plenty of speed for the El Diablo. All in all a good day and I feel I have a set-up that will work.
Best, DennisT
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Glad you're going good again, Dennis. I know that a happy engine makes me a happy modeler....
I hadn't thought about whether the nitromethane had been cut. I assume they are doing that to stabilize it for safety reasons. From my point of view, if you are selling something, you need to know what your ingredients are, and represent that correctly on your labels. I'm very curious why apparently a number of people have found a Byron fuel mix to run well, but with consistently lower power than another known brand. I have only run a couple of gallons of Byron's Aero Gen II 10% in a sport plane and didn't notice any real difference. Of course, I didn't benchmark the test, so I probably wouldn't notice on a basically over-powered plane.....
Dave
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This is THE website for adding either nitro, oil, or both to existing fuel
been using it for years and is THE best.
http://nitrorc.com/fuelws/