How to make your own 2-Stroke fuel

I am just getting back in to Flying and and having a hard time finding fuel with suitable Castor OIL content for my Cox .049 Babe Bee etc.   I thought I might try to mix my own, but the posted link will not let me access.

Thanks in advance for your help.

Bigdaddy0442

bigdaddy0442 wrote:I am just getting back in to Flying and and having a hard time finding fuel with suitable Castor OIL content for my Cox .049 Babe Bee etc.   I thought I might try to mix my own, but the posted link will not let me access.

Thanks in advance for your help.

Bigdaddy0442

Welcome Bigdaddy0442. Because members here are from all around the globe, access to suitable fuels varies from country to country. It would be helpful to know where you hail from and I'm sure someone will head you in the right direction.

Rod.

bigdaddy0442 wrote: I thought I might try to mix my own, but the posted link will not let me access.

Thanks in advance for your help.

Bigdaddy0442

Hmmm...  The link doesn't work for me either.  Try this:

https://coxengines.ca/public/files/Gibeault.pdf

I love the Cox Mixing Formula for the 15% nitro Flight Power Fuel.  6,000 gallons of methanol, 1,661 gallons of castor oil, 1,384 gallons of nitro, and 185 gallons of synthetic.  Easy-peasy.  I’ll just mix up a batch for this year’s flying season in the garage...

The Traffic Cop Mark

It's pretty simple to do it yourself, but you will have to find the necessary ingredients. Starting with oil important not to use more sintetic oil than castor oil if its just castor oil The engine gives a very good performance but becomes sticky with time the varnish accumulates A little trick is to mix small quantity To begin You can use hardware products A source of methanol use methyl hydrate best for oil is To mix klotz benol wit pur castor oil It is possible to convert to use diesel or gasoline But gasoline is much harder to obtain a good result and the performance is very poor It is doable but it is better with bigger engine equipped with crank bearing Gasoline has difficulty absorbing the oil necessary for proper operation of a small engine I myself did some testing The best and easy is to find nitro fuel for buggy with as little oil as possible and add castor oil To it klotz benol is Good stuf But not 100% castor oil Some use drugstore castor oil Not a good idea in my opinion the best is to find a type made for motorcycle engine automotive oil is a bit different than the pharmacie drugstore castor oil Who is subject to the phase separation and Who is degummed To Not Good oil You need a pure non-degummed oil

If you're buying pre-mixed fuel, the important thing is that you use fuel specified for 1/2A, which is generally acknowledging that Cox engines dominate this class. SIG sell it. Brodak sell it. There are a few others in the United States. They also sell castor oil separately.
The best I can do here is AUS is mix my own. As David suggested, I often buy car fuel which is high nitro low oil, and I add enough castor oil to get the % up over 20%. Seems to work fine.

Here is a link to our fuel guide: https://coxengines.ca/public/files/FG.pdf

Bigdaddy,

Welcome to the CEF!
Please take a moment to give us a bio, or introduction. Including your country of residence will help for any regional differences that may come up.

I'll assume you live stateside, so if you don't, toss the following out.

Regarding fuel, for your first few "crank-em-ups," I recommend getting a starter pack from SIG or visit eBay and look for Glowplug Boy fuel. Sure, the cost per quart will pinch your eyes like a tart lemonade, but unless you are planning on staying in the hobby, this is a fast and convenient way to fuel your needs temporarily and quickly. Besides, it takes the guess work out of the equation.

Once you know you will do this for at least a gallon, then you can go into experimenting with fuels.

With that last one said, keep in mind I have to mail order or travel 2.5 hours each way for commercial fuel. I learned to mix high nitro/low oil (synthetic) helicopter fuel with medium nitro/low oil (again, synthetic) truggie fuel and castor oil. I was using medicinal grade castor from Walmart, or the apothecary around the corner from my house. I wanted the heat of nitro, but needed to temper it with the desire to keep from blowing glowplugs...If you think fuel is hard to get, keep in mind any...no, all engine parts are mail order for me.

A few of my engines will run just fine on 15% nitro, and one needs only 10%. Clearly, I had to learn some chemistry skills, or buy stock in a fuel company!

Later, I bought a quart of Benol castor oil from Walmart for $20 a year or so ago. Methanol is available from a race engine shop 30 minutes away. I continue to use high nitro heli fuel for the nitro content, use the methanol to cut the nitro content down, and spike the mix with castor oil to raise the castor content up.

Most fuel blenders will describe their mixes as nitro, methanol, and oil blend by percentages. Sometimes you have to dig deep to get their numbers. Traxxas truggie fuel doesn't declare the numbers (that's my "low test"). I assumed/gleened their mix values by assuming they package their fuel as their manual suggests.

This is the calculator I use...I'll let the author describe how to use it. I later edited the Excel spreadsheet to mix in 8 ounce batches versus the original quart values, since I had been flying 1/2A exclusively. I just didn't need to store in quarts.
http://web2.murraystate.edu/andy.batts/ps/fuel.htm

I mix 4 oz of "high test" with 3.5 oz of "low test," with a 1/2 oz of castor. The oil goes first, followed by "high test" to wash the oil out of the measuring cup (small graduated shot glass), and finished with the low test or methanol to rinse out the glaas. These are dumped into the mixing jar through a coffee filter to catch air-borne dust/junk and/or trash, then shaken to mix. The mix is funneled/filtered one more time into a stainless liquor flask, or a glass bottle (both chosen for fitment in my flight box). The calculator says I have about 22% nitro, with the oil right at 20% (half synthetic/half castor). None of my engines appear to hate the mix, except I admit to NOT trying it in my lone Fox (that one gets 10% nitro). I run my Norvels (.061, .074) and all Cox engines on this Brew, and none complain. I may cut the castor content later since all of the engines are getting that Castrol tint on their exteriors. My one Babe Bee with Merlin plug does seem a bit over-compressed, but I don't run it enough to worry about it. I should just add another head gasket or two. In fact, I do have videos off these engines running my brew, so I think I can claim this works just fine. Don't use my numbers since I didn't indicate the exact fuels I use. Others will chime in with their experiences...YMMV!