Rc Fuel Faq
#101
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RE: Changes?
Dart,
If its working for you, great! Make sure you richen that needle up when going up 20% of nitro, you don't want to damage the engine. Other than that, you should not be doing any damage to the engine as long as it is kept rich. I feel that 30% may be a little over what ASP recommends and the engine may not have low enough compression to effectively utilize that much nitro.
You went straight from 10 to 30, you may find that you would have been perfectly satisfied with 15 or 20% nitro and save the high cost of 30.
I see no need to add oil to any commercial helicopter fuel.
Hope this helps.
If its working for you, great! Make sure you richen that needle up when going up 20% of nitro, you don't want to damage the engine. Other than that, you should not be doing any damage to the engine as long as it is kept rich. I feel that 30% may be a little over what ASP recommends and the engine may not have low enough compression to effectively utilize that much nitro.
You went straight from 10 to 30, you may find that you would have been perfectly satisfied with 15 or 20% nitro and save the high cost of 30.
I see no need to add oil to any commercial helicopter fuel.
Hope this helps.
#102
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RE: Changes?
I looked all over for 15% fuel, with no luck. So, I just went to the 30%. I noticed after breaking in ASP #2 on another plane......... I get some detonation. I tried everything. Nothing, still high end knock with this fuel. I broke it in on 10% . My other ASP 61 on my Seamaster loves this fuel. What gives?
#103
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RE: Changes?
Dart,
it is not uncommon for there to be variations in manufacturing where one engine has a touch different tolerance than the next. You can try mixing equal parts of your 30% with your 10% and that will yield you 20% fuel.
If you are getting detonation, it is indicating that you have too much compression in that engine, or too hot of a plug, or too much prop load, or too much nitro, or too lean of a needle setting. OR a small combination of more than one of the above. Teh easiest solution is to richen up the needles, if that does not cure it, lower the nitro content or go to a different brand or heat range plug (cooler).
Hope this helps
it is not uncommon for there to be variations in manufacturing where one engine has a touch different tolerance than the next. You can try mixing equal parts of your 30% with your 10% and that will yield you 20% fuel.
If you are getting detonation, it is indicating that you have too much compression in that engine, or too hot of a plug, or too much prop load, or too much nitro, or too lean of a needle setting. OR a small combination of more than one of the above. Teh easiest solution is to richen up the needles, if that does not cure it, lower the nitro content or go to a different brand or heat range plug (cooler).
Hope this helps
#104
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RE: Rc Fuel Faq
I would like to know the answer once and for all to the question; DO FOX ENGINES ABSOLUTELY REQUIRE FUEL BLENDED ONLY WITH CASTOR OIL? The cost of all castor fuel tends to be twice that of the synthetic types. At least that's what I've found. I have two brand new FOX engines that I feel like I should sell off and replace with some other make that will use the less expensive fuel.
#105
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RE: Changes?
Lunbom,
Depends on the engine.
The Fox 35 control line (lapped iron) engine runs the best on 5% nitro, 25% to 29% all castor fuel. The other early design lapped iron, bushing (non ball bearing) control line engines run best on the all castor fuels, at least at first, then can be run on a 50/50 blend, still of high total oil (20-23% total oil).
The modern ABC and Ringed ball bearing Fox engines run just fine on nearly any 5% to 10% nitro, castor / synthetic blend fuel.
I have numerous Fox engines, from the older ringed big frame 40's to the current 74's. I run all of them on whatever 10% or 15% fuel I have extra laying around. The Ringed engines run just fine on all synthetic fuels as long as you have enough oil, the ABC engines will like a castor/ synthetic blend.
Hope this helps.
Depends on the engine.
The Fox 35 control line (lapped iron) engine runs the best on 5% nitro, 25% to 29% all castor fuel. The other early design lapped iron, bushing (non ball bearing) control line engines run best on the all castor fuels, at least at first, then can be run on a 50/50 blend, still of high total oil (20-23% total oil).
The modern ABC and Ringed ball bearing Fox engines run just fine on nearly any 5% to 10% nitro, castor / synthetic blend fuel.
I have numerous Fox engines, from the older ringed big frame 40's to the current 74's. I run all of them on whatever 10% or 15% fuel I have extra laying around. The Ringed engines run just fine on all synthetic fuels as long as you have enough oil, the ABC engines will like a castor/ synthetic blend.
Hope this helps.
#106
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RE: Changes?
Thanks for the reply, I'm not quite sure what category the engines I have fall into. One is a .19 R/C, bushed, non ringed, and a .29 and .36 that are R/C, bushed and non-ring and purchased new in 1980 from TOWER. The latter don't have the displacement stamped on them. The .29 and .36 are brand new. Incidentally, other engines I have include an ENYA 35, K@B 40 and MDS 46. I would like to be able to use one type fuel for all, if possible, but not the $26 gal stuff. I'm not into competition, so getting max power is not important.
#107
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RE: Changes?
Lunbom,
The Fox engines you listed would definatly benefit from some castor in the fuel. They are lapped iron piston and sleeve type engines. The castor buildup on the piston helps create the compression seal.
Most of the popular 2-stroke fuels contain a fair amount of castor and should be suitable. As added insurance, you could always get a pint of castor and add a few ounces per gallon (of a two stroke fuel) for the first dozen runs or so to help with the break in process.
To get any longevity and user friendlyness out of the listed Fox engines, some castor is necessary.
The Fox engines you listed would definatly benefit from some castor in the fuel. They are lapped iron piston and sleeve type engines. The castor buildup on the piston helps create the compression seal.
Most of the popular 2-stroke fuels contain a fair amount of castor and should be suitable. As added insurance, you could always get a pint of castor and add a few ounces per gallon (of a two stroke fuel) for the first dozen runs or so to help with the break in process.
To get any longevity and user friendlyness out of the listed Fox engines, some castor is necessary.
#108
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RE: Water in fuel
Hi.. my LHS does their own home brew fuel... i normally get 30% nitro.... but i have no idea what the other 70% consists of....
can you recommend me the the mix of the other 70%
if you can recommend me something... i can take to the Hobby shop for them to mix up for me..
cheers
thnaks
can you recommend me the the mix of the other 70%
if you can recommend me something... i can take to the Hobby shop for them to mix up for me..
cheers
thnaks
#110
RE: Changes?
Fuelman,
Thanks for taking time with posting such great information.Thats so amazing how much knoweledge in this forum.
HOwever i got a question for your expertice...
I want to homebrew my own fuel just because i want it to be cheap .I am not in any competition or superpreformance stuff and fly just for fun.So tons of power are really not required for my planes.
I can buy methanol @ about 3$/gal at local race shop and i need an oil that i can buy online because seems to me that only oil i can find locally is benol by klotz.I searched on the internet for baker's oil but it didn't do any good.
Can you recomend any sources for CHEAP stuff ?
Thanks ahead.
Mitty.
PS.I think i settle for 80%methanol and 18-22% oil
Thanks for taking time with posting such great information.Thats so amazing how much knoweledge in this forum.
HOwever i got a question for your expertice...
I want to homebrew my own fuel just because i want it to be cheap .I am not in any competition or superpreformance stuff and fly just for fun.So tons of power are really not required for my planes.
I can buy methanol @ about 3$/gal at local race shop and i need an oil that i can buy online because seems to me that only oil i can find locally is benol by klotz.I searched on the internet for baker's oil but it didn't do any good.
Can you recomend any sources for CHEAP stuff ?
Thanks ahead.
Mitty.
PS.I think i settle for 80%methanol and 18-22% oil
#113
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RE: Changes?
Hi. I am in the middle of reading the entire thread, and I hope this question has not come up. I run the pink Omega fuel. Some castor and some synthetic. I know what the nitro is because it is plastered right on the side of the container. Since this is the only fuel my LHS carries, that I am comfortabel with, I want to keep using it, however, I can't find anywhere what the oil content is. I am going to purchase a ST-2300 and they want you to run 18% oil, and I haven't a clue how much oil is in my fuel. Could there be info on this somewhere? Everything I see refers to Nitro content. People talk about oil content, but it seems this info is much harder to come by. Thanks.
#115
RE: Changes?
According to Morgan's web site almost all their fuels have 17% oil but I've heard they mix by weight which makes it actually about 14% (feel free to correct me if I'm wrong). If you must use Morgan fuel then the only one I'd use would be the Jet 7% which they say has 20% oil (30/70 castor/synthetic) which if mixed by weight gives around 17% actual oil content. But seeing oil is the life blood of an engine I wouldn't use anything that didn't specify exactly what the oil content was.
http://www.morganfuel.com/omega.htm
http://www.morganfuel.com/omega.htm
#116
My Feedback: (1)
RE: Rc Fuel Faq
Fuelman
I've always had a question about whether fuel is mixed by weight or by volume. I have a graph that compares nitromethane percentage by weight vs. percentage by volume. There appears to be a substantial difference. For example, if I mix 15% nitromethane by weight I will only get 10% nitro by volume. Based on this I must assume that the fuel manufacturers will chose to mix by weight, thereby using less nitromethane per gallon for an advertised percentage. It seems that there is a mixed bag of literature on what criteria they use. Some will tell you that they mix by volume while others don't mention it. Your thoughts or comments?
I've always had a question about whether fuel is mixed by weight or by volume. I have a graph that compares nitromethane percentage by weight vs. percentage by volume. There appears to be a substantial difference. For example, if I mix 15% nitromethane by weight I will only get 10% nitro by volume. Based on this I must assume that the fuel manufacturers will chose to mix by weight, thereby using less nitromethane per gallon for an advertised percentage. It seems that there is a mixed bag of literature on what criteria they use. Some will tell you that they mix by volume while others don't mention it. Your thoughts or comments?
#117
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RE: Changes?
Can engines be converted to use real diesel? Would it be a waste because of the potential in the fuel or is there some other reason? I've seen gas conversions and Davis heads (faux diesel), but what about the pump kind?
#118
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RE: Changes?
By weight or by volume. John, many modelers have asked the question. My fuel company as well as most others measure by volume. At least one company I know of measures by weight. Your numbers are a little off but the idea is correct: equal percentages of nitro, measured by weight and by volume where the remaining components are fuel ingredients, the one measured by volume will contain more nitro than the one measured by weight. Keep in mind that the company I know of does disclose their measurement method and are hiding absolutly nothing, you are getting exactly what they are telling you, its just measured by weight rather than volume. No industry standard exists and it is up to the company making the fuel to determine the method that best suits them.
It is my professional opinion that the percentages of oil, nitro and methanol were determined by volume by the founding fathers of glow engines. I don't believe that any of them weighed out the fuel components on lab scales when they were experimenting on the best percentages of fuel components when trying to make an engine run the best. Reality tells me that the founding fathers of glow had an old jug of some sort and a couple "borrowed" measuring cups from the kitchen. They made fuel, based on volumetric measurement and thats where it all started.
It is my professional opinion that the percentages of oil, nitro and methanol were determined by volume by the founding fathers of glow engines. I don't believe that any of them weighed out the fuel components on lab scales when they were experimenting on the best percentages of fuel components when trying to make an engine run the best. Reality tells me that the founding fathers of glow had an old jug of some sort and a couple "borrowed" measuring cups from the kitchen. They made fuel, based on volumetric measurement and thats where it all started.
#120
My Feedback: (1)
RE: Changes?
Fuelman,
Thanks for the reply. I have inquired of a few of the manufacturers on their method of measure after searching their web sites for the answer. One responded that they mix by weight. Seems that the ones that mix by volume state so in their literature. I've not seen the one that states that they formulate the fuel using the weight method.
Say hello to Tony the Tiger for me.
Thanks again
John Palica
Thanks for the reply. I have inquired of a few of the manufacturers on their method of measure after searching their web sites for the answer. One responded that they mix by weight. Seems that the ones that mix by volume state so in their literature. I've not seen the one that states that they formulate the fuel using the weight method.
Say hello to Tony the Tiger for me.
Thanks again
John Palica
#121
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RE: Changes?
Out of curiousity, I have a question since nitro-methane is sold in solution with an alcohol.
Shouldn't the homebrewer make adjustments to their recipes, because using whatever percentage of Nitro-methane alcohol solution yeilds a lower percentage of nitro in their fuel. The basic recipe is as follows:
nitro-methane% + oil% + methanol% = 100% total fuel
Now what I have realized from some research is as follows:
Nitro_methane solution is actually ( Nitro-methane + alcohol) not pure nitro. If the nitro solution is equal parts from the container, then a 15% nitro is actually 7.5% nitro-methane and 7.5% alcohol. So you would have to use more Nitro-methane to actually get to 15% or whatever percentage you want.
Is this correct thinking? If not what is the truth about purchasing nitro-methane from speed shops or petroleum distributors?
Will
Shouldn't the homebrewer make adjustments to their recipes, because using whatever percentage of Nitro-methane alcohol solution yeilds a lower percentage of nitro in their fuel. The basic recipe is as follows:
nitro-methane% + oil% + methanol% = 100% total fuel
Now what I have realized from some research is as follows:
Nitro_methane solution is actually ( Nitro-methane + alcohol) not pure nitro. If the nitro solution is equal parts from the container, then a 15% nitro is actually 7.5% nitro-methane and 7.5% alcohol. So you would have to use more Nitro-methane to actually get to 15% or whatever percentage you want.
Is this correct thinking? If not what is the truth about purchasing nitro-methane from speed shops or petroleum distributors?
Will
#122
My Feedback: (1)
RE: Changes?
Will
It seems to me that in your container of mix, if equal parts nitro and methanol, you have a 50% mix to start with. Adding oil will reduce that mix depending on how much oil you add and you would want to add methanol to further reduce the nitro percentage to what ever % you want.
It seems to me that in your container of mix, if equal parts nitro and methanol, you have a 50% mix to start with. Adding oil will reduce that mix depending on how much oil you add and you would want to add methanol to further reduce the nitro percentage to what ever % you want.
#123
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RE: Changes?
Will,
When buying nitromethane, you need to know what the contents of the container are that you are buying. It should be disclosed if it is a mixture of nitro and alcohol.
All fuel makers buy pure nitro in drums, it is not diluted with anything and the purity generally exceeds 99.5%.
When buying nitromethane, you need to know what the contents of the container are that you are buying. It should be disclosed if it is a mixture of nitro and alcohol.
All fuel makers buy pure nitro in drums, it is not diluted with anything and the purity generally exceeds 99.5%.
#124
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RE: Changes?
Fuelman, I have wondered many times if the %'s of oil nitro & meth are buy weight or volume and I have never seen anyone answer all the questions of this subject. I do not intend to mix my own, just intrested to know. The fuel I purchase from the LHS works great and I do not fix what is not broken HI HI.
fly the airplane first
73 Lee K5MRC
fly the airplane first
73 Lee K5MRC
#125
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RE: Changes?
Lee,
What questions do you have? If you have specific questions, I would be glad to offer what I know.
I thought it has been fairly well covered within the previous posts.
Weight vs. volume is nothing more than the prefrence of the company. I feel that neither way is wrong. the more important thing to consider is; are you getting good service from what you are running assuming you are running it correctly.
What questions do you have? If you have specific questions, I would be glad to offer what I know.
I thought it has been fairly well covered within the previous posts.
Weight vs. volume is nothing more than the prefrence of the company. I feel that neither way is wrong. the more important thing to consider is; are you getting good service from what you are running assuming you are running it correctly.