Fuel without nitro
 

Hello. Do any of you have experience with nitromethane-free fuel? Today we saw a partner who used acetone instead of nitromethane. A .46 engine worked just like he had nitro. 13500 rpm and at a temperature of 113 degrees Celsius. Will this have negative effects on engine life? The mixture was 4% acetone, 16% beaver oil and 80% methanol. Thank you for your answers

Never heard of it and would be very careful of using it. I was told that the purpose of the nitro was to act as a catalyst with the glow wire. I don't think acetone will do the same thing. In fact it may even eat your seals.

I've used zero-percent(0% also known as FAI) nitro fuel, which is straight methanol(alcohol or alky in the kart world)...mixed with about 17% castor/synthetic oil which is used in high compression glow engines,

My guess is your partners engine would run without any acetone additive just fine as well.. and yes even though the engine runs, it would be interesting to note the long term affects. How long will a glow plug last?.. How long will seals or even rings last in a ringed engine?... Could the acetone attack any plating within the bore/engine? etc.. many questions as to long term affects.

I guess I have no desire to experiment with acetone, but your question was about experience with nitromethane-free fuel..and yes I've used it in a few of my high compression engines that don't require nitro.

I'd have to say there's probably many chemicals that can be an additive. Come back and report on how that engine runs in a year... that will be your real test. We all have glow engines that have lasted 30yrs and more and still run like new with conventional glow fuels. Therein will be the test on acetone though.

Just a question, what is Beaver oil? Where can you get it? 2% acetone is common, it improves the transition on throttled RC motors much like nitro does. I would not be concerned with that percentage. It will not give the same performance as nitro but the motor will run better than with no nitro with no modification to the motor. Sometimes no nitro fuel requires a bit higher compression than fuel with nitro, especially to get a reliable idle. Usually just removing a shim under the head is enough. I doubt that most people would notice the performance drop with 0% nitro to 5 or 10%. Might just get mad if it cuts on idle. That is the main reason for the acetone. I don't think acetone is any harder on an engine than nitro. Nitro is also a strong solvent with similar properties to acetone, and is used at much more than 2%. I found anything over 15% nitro to be corrosive on motors and they need after run oil very quickly after a day of flying. In Europe 0% fuel is more common than North America.. I used it for fuel in the FAI class with no problems in control line flying. I think when done flying that any acetone would evaporate quickly enough to not damage the insides of a motor. I will admit to not using acetone....yet.

Fuel without nitro
 

Hello. Beaver oil or ricino oil is extracted from the seeds of the ricino plant . It is widely used in Mexico as medicinal plant, is very cheap and is easily purchased in many commercial buildings where they sell chemical or solvent products. When I got nitromethane, I make my fuel with this oil as a lubricant, at 17%. Now it's very difficult to get the nitro in Mexico, so we're seeing options for a nitro-free fuel.

I have tried 5% acetone, 18% castor oil and the rest with domestic ethanol, with bad results, but I've heard some engine are made for low nitro % ( as some webra ), some other engine for high nitro %.

But in case of crisis, at least I will be happy to bench run my engines with that fuel...

I have read that ethanol has trouble keeping lit without constant battery on the plug, methanol is the way to go. There is no problem getting it in this country although it is $12 for 4 litres.

I have managed to get a plane flying with ethanol, but with idling a 5000rpm at least ;)

On my island methanol is hard to find and for example we have to order a year of glow fuel consumption as we don't have hobby shop here and the shippment is really expensive if your order 5L by 5L....

I get my methanol from the paint thinner aisle at the hardware store. Fuel at the hobby shops here is pretty expensive too mostly because of shipping. I am not on an island though.

It is methanol, not nitromethane, that supports the catalytic reaction. I run 80% methanol, 20% oil in some of my engines. It runs just fine. Nitromethane is not necessary, although it produces a bit more power and improves the idle on some engines. I use a mixture of castor oil and synthetic (PAG) oil. Note that methanol is not the same as ethanol. Our glow plugs are intended to work with methanol.

Thank you for your Info.

Just rereading this. The Ricin bean is the Castor bean, so that is fine. As mentioned you would be fine with the acetone for ignition improver.

Thanks again, I'll treat mixture methanol and castor oil for my MDS. I'll coment you the results.

The acetone is a good additive but remember to use a good fuel proof paint topcoat and be careful with raw fuel getting on the finish, wipe off quickly.

Best, DennisT