Fuel for 1/2 A engines

[Tom Rounds]

I haven't done much with 1/2 A engines in years. I have a couple of Baby Flight Streaks for the grandkids and wondering what fuel I can get. What do I need for Nitro content? I guess that the fuel that the car guys use would probably fill the bill. I have a Golden Bee, Black Widow and a TD .51. Thanks in advance.
Tom

[John_Craig]

I would add some Caster oil to car fuel.  The C*x engines are plain bearing & enjoyed 22-25% oil.  Then it was all Caster.  Search the 1/2A site for more info.

http://stunthanger.com/smf/index.php?topic=20309.0

[Bill Little]

Cox recommended castor oil in the fuel.. Larry Renger who was at Cox recommends castor oil.  I have decided you should use castor oil in the fuel  17%-20% oil is what I have seen called for.

Nitro in the 25% + - range for a starting point.  Most available fuels don't meet these precise criteria, but a lot of people use Sig 25% nitro "Champion with good results.  Glowplugboy sells a specific 1/2A fuel on ebay.  it is configured to "Cox" standards, it appears.  I have some, but at $10 plus $8 shipping a quart, some feel it is too expensive.  I have to drive at least an hour to get to a hobby shop (and it the best around!), so I don't mind to add the shipping.

To get the best reliable usage out of the Cox engines, if you run them a LOT, a bit of regular maintenance is required.

Big Bear

[Dwayne]

Our LHS only sells Omega so I buy a quart of 20% Basher car fuel and add 2 oz. of castor, works fine.

[Larry Renger]

Cox fuel was either 15% nitro for sport or 30% nitro for racing fuel.  Oil was 18% all castor.  Cox engines varnished up a lot on this mix.  I now use 15% nitro 10% castor and 10% synthetic, get good performance and life and no varnishing.  The extra oil content only increases fuel consumption a bit without hurting performance.

[Tom Rounds]

Thanks for the information

[John Crocker]

I've had good success with Powermaster 20/20

[Bill Little]

Cox fuel was either 15% nitro for sport or 30% nitro for racing fuel.  Oil was 18% all castor.  Cox engines varnished up a lot on this mix.  I now use 15% nitro 10% castor and 10% synthetic, get good performance and life and no varnishing.  The extra oil content only increases fuel consumption a bit without hurting performance.

HJI LArry,

I am thinking of adding an ounce of Klotz to the quart of the 17% all castor fuel.  What do you think?  Too much?  I just want the cleaning effects of the synthetic.

Thanks for your help!
Bill

[Brian Hampton]

Last Father's Day my son gave me about 10 various Cox engines he'd found at a LHS that was closing down. I'd never used a Cox before and had never even contemplated using one because I'd read they absolutely needed nitro to run or they'd cool down as soon as plug power was removed and stop running. But I got curious not long ago so I decided to see what happened with my usual 80/20 all castor fuel.

First up was a Babe Bee (single transfer) with a 5x3 Cox prop which started very easily by hand. I didn't bother with the spring, I was more intersted in a hand start. It held a steady 13,000 for the full tank. Next was what apparently is called a Product engine (two transfers), same prop, which gave 15,800 and was also very east to hand start. The last one was a Tee Dee .049, same prop again, which started very easily by hand and hummed away at a steady 18,300.

I know they'd all give more revs with nitro but at least now I know they don't need it to keep running .

[john e. holliday]

I flew 1/2A's for years with the same fuel I used in my .35's and bigger engines.   Then I started flying Mouse and it does make a difference to have a little nitro in competition set ups.   

[Dave Adamisin]

TD head, 1 washer, k&B speed fuel...... oh wait you can't get that anymore...... never mind......

[Bill Hodges]

Tom:

Take a ride over to Graves.  I believe he still has some Norvel 1/2A fuel in quarts.  It was back in the far left corner where the wheels and tanks are located.

I was in there a couple of weeks back and I think I remember seeing some on the shelf.  If you don't see any on the shelf, ask Neal or Marker if they have any in the back room.

Bill Hodges

[Andrew Borgogna]

What I have learned about 1/2a engines from Larry Renger is "Nitro is good", and the more nitro the more head gaskets you need.  Larry can tell by how the engine is running if it needs more or less gaskets, but I can tell you this he keeps a large supply of head gaskets in his flight box.
Andy

[Dave Adamisin]

What I have learned about 1/2a engines from Larry Renger is "Nitro is good", and the more nitro the more head gaskets you need.  Larry can tell by how the engine is running if it needs more or less gaskets, but I can tell you this he keeps a large supply of head gaskets in his flight box.
Andy

Nitro is REAL good. I was serious about the k&b speed fuel. (50% nitro) I even ran a few r/c flights (TD 049 1/2a pylon) on straight nitro. As in 82-16-2 Nitro, ucon, and propylene oxide. It needles perfectly and the engine loved it. I still have the engine..

[Bill Little]

Nitro is REAL good. I was serious about the k&b speed fuel. (50% nitro) I even ran a few r/c flights (TD 049 1/2a pylon) on straight nitro. As in 82-16-2 Nitro, ucon, and propylene oxide. It needles perfectly and the engine loved it. I still have the engine..

    

My luck, the glow head would have blown off and put my eye out! LOL!!

Big Bear

[Dave Adamisin]

   

My luck, the glow head would have blown off and put my eye out! LOL!!

Big Bear

Just call me blinky....

[Bill Little]

Just call me blinky....

 

[Larry Renger]

HJI LArry,

I am thinking of adding an ounce of Klotz to the quart of the 17% all castor fuel.  What do you think?  Too much?  I just want the cleaning effects of the synthetic.

Thanks for your help!
Bill

You would be up to 20% Oil, which is probably ideal.  I think it is a good idea.

Larry

[Bill Little]

You would be up to 20% Oil, which is probably ideal.  I think it is a good idea.

Larry

Thanks, Larry!

One more question (for now! LOL!!): what was the intake hole size in the .051 Killer Bee back plate, or better yet, what "size" hole would you *recommend* for one with a SPI, milled/lightened piston w/ twin ports and two boost ports?

Okay, two questions: (LOL!!)  What would be the best "head" set up to run on an engine equipped as I said above?

Thanks!
Bill