stunthanger.com
Engine basics => Engine set up tips => Topic started by: Dave Moritz on May 01, 2018, 01:54:48 PM
-
Gents:
I run Byron Gen2 fuels, mainly because they are readily available in gallons at the LHS. Their labels claim that the oil content is a synthetic/castor blend (a good characteristic for my fleet of somewhat vintage OS and Enya motors). However the highest oil concentration in these fuels carried by the LHS is 18%. Thus I end up having to spike the fuel with a 50-50 blend of castor and synthetic to bring it up to higher levels recommended for each of my engines.
There seems to some confusion (at least in my mind) about whether the Byron oil portions stated on the label reflect volume or weight. I've read varying claims. Some state that the content is spot on for volume while others suggest the oil content is weight-based and thus overstated by two percentage points.
Can anyone provide an answer with some degree of confidence? Does this really matter for a sport flyer learning stunt?
Thanks.
Dave Mo...
-
Dave, I use Byron fuels and they are excellent. My fuel is different than yours as I run a RO Jett 67 which is an ABC or similar piston and liner.
I use the Heli Fuel which says 21% Oil . I have heard from reputable sources that the OIL is by Volume which is good. ABC piston and liner can use less oil. If it is a Fox 35 or Old OS 35S or McCoy 35 you will need more oil content.(28-29 %) Read Randy Smith information about Care and Feeding of Stunt engines on this Forum he has listed it many times. He explains in detail about fuel for different kinds of engines. The only reason I am responding to this question is that for the last 3 years I have been using Byrons fuel and it has been excellent and other reputable people have also stated that.
Hopefully Randy Smith or Brett Buck will chime in here and answer your question in detail.
-
Walter:
Yup, I too like their fuel and will go ahead and trust their stated measurements as volumes.
Right now, I am bench running for break-in a new/old stock OS Max 35 S. The 10% nitro Byron fuel with the oil blend boosted to 24% seems to do the job with a 9x4 APC prop for break-in. So far, it's got one hour running time with another hour to go. I tried a higher oil ratio (approx. 28%), and the motor didn't seem to like it.
The LHS guy stocking the Byron fuel says that he will only stock the 15% nitro juice from here on out. Not sure what (if anything) that'll mean for these older motors. I've been using 5% and 10% from their line.
But as they say, it's all good!
Thanks.
Dave...
-
The last 2 years I used the 15% Gen 2 traditional with additional castor (6oz per gal) in everything. La 46/40, 35/40fp and newer foxes. After adding castor the nitro was at 12%.I had good runs, no overheating. If I hadn't bought 2 gal. of Ritches Brew I'd be mixing some more. I never added syn. oil, so I'm not sure what my results would have been if I had.
Steve
-
Steve:
Thank-you for the benefit of your experience. I'll just keep an eye on temperatures to see if the 50-50 supplement needs more castor.
Dave...
-
During break-in sessions running rich, I found that I've had to increase the oil content in order to keep the heat down. I might well make it to that recommended 29% after all!
Dave...
-
Walter:
Yup, I too like their fuel and will go ahead and trust their stated measurements as volumes.
Right now, I am bench running for break-in a new/old stock OS Max 35 S. The 10% nitro Byron fuel with the oil blend boosted to 24% seems to do the job with a 9x4 APC prop for break-in. So far, it's got one hour running time with another hour to go. I tried a higher oil ratio (approx. 28%), and the motor didn't seem to like it.
The LHS guy stocking the Byron fuel says that he will only stock the 15% nitro juice from here on out. Not sure what (if anything) that'll mean for these older motors. I've been using 5% and 10% from their line.
But as they say, it's all good!
Thanks.
Dave...
I would be very leery of the fuel blend, The last time i tested Byron's Fuel it was 12% oil, at best what they call 10% maybe 14.7 percent. I would use the fuel and add at least 12.8 ounces to the fuel, roughly 1 percent is 1.28 ounces, this will get you close to 25%, and 15% fuel will be no more than 9 to 10 percent after you mx it
Randy
-
Randy:
Speaking here of oil only. That 12.8-ounce boost in a gallon of Byron Aero Fuel listing 18% oil would give us a nominal 31.6% of oil in the mix. I say "nominal" because you suggest that the Bryon oil percentage shown on the jug might be overstated. If so then the 31.6% final blend might too be overstated, with the true oil percentage falling a bit lower (but likely within safe running parameters). Comprendo?
You know this business well enough that I'm going with your suggestion. Thanks.
Dave Mo...
-
Randy:
Speaking here of oil only. That 12.8-ounce boost in a gallon of Byron Aero Fuel listing 18% oil would give us a nominal 31.6% of oil in the mix. I say "nominal" because you suggest that the Bryon oil percentage shown on the jug might be overstated. If so then the 31.6% final blend might too be overstated, with the true oil percentage falling a bit lower (but likely within safe running parameters). Comprendo?
You know this business well enough that I'm going with your suggestion. Thanks.
Dave Mo...
Hi Dave
No its not going to make 31.6% oil, 12.8 ounces wll boost it 10%, if the fuel really has 15% oil , it will boost it to 25%, IF it still has 12% oil , it will only take it to 22%, and IF.. It really has 18% then it will take it to 28% oil
Remember, 1 percent of a gallon is 1.28 ounces, or just over 1 and a quarter ounce
Randy
-
Wowza, but you are correct. My figuring was erroneously based on 64 ounces in a gallon - duh!
Thanks for taking the time to correct my snafu.
Dave Mo...