Fuel for COX .049

[Mike Griffin]

What is the best brand and mixture fuel for the COX .049 engines and where can you buy it?

Thank you
Mike

[Ty Marcucci]

Anything with 35% nitro and 20% oil. Norvel fuel is for 1/2A engines, but has only 18% oil.   I have used it for 7 years in my Cox  engines with NO problems..  I used to use Missile Mist by Fox, which was 25% nitro. I got mine at my local hobby shop.

[kenneth cook]

             I personally prefer 25% nitro because it's a lot easier on plugs. Glowplug Boy offers terrific fuel now made by Fitz. The original owner of Glowplug Boy passed away and Fitz took over for him. Excellent fuel which offers different nitro levels . His fuels contain a touch more castor. If you've been out of touch with the cost of 1/2A fuel, your going to be a bit sticker shocked as not only is the fuel expensive, so is the shipping. Ritch's brew also offers terrific fuel for 1/2A. Don't e-mail him, call him direct. Brodak also offers 1/2A fuel which I've used with good success. You also have Stan from S&W fuels which will make any fuel you ask of him.

[Dennis Toth]

Mike,
Brodak offers suitable 1/2A fuel in small containers (https://brodak.com/catalogsearch/result/?q=Fuel+%28Qt%29). They will run on anything with 10% nitro and 20% total oil (50/50 ok), they run this in the 1/2 speed events.

Best,   DennisT

[Gary Dowler]

15-25% nitro makes them happy. As to oil, I conducted a test involving several Cox 049’s and their response to oil content. Started with 18% oil 50/50 mix. Runs were difficult and frequently shut down prior to running out of fuel. Began upping the oil by adding castor. At 25% I got consistent runs and 30% total was the sweet spot.  Above that it just made a bigger mess.

Fuel with Castor and nitro in generous quantities is your 049’s best friend.

Side note, one was a dual port, the other a single port. Duel port was consistently 1500 rpm faster.

[944_Jim]

Mr.Ty,

What is the name of the hobby shop up there? You are about 3.25 hours NNE of me, I think.

[Ty Marcucci]

 Here in Huntsville, Alabama we go to RC Hobbies on Meridian Blvd.. The RC stand for Rick Chambers, not Rocket City or Radio Control.. Rick's brother was the owner of Rocket City stuff until he closed in 1998.

They are closed on Sundays and Monday.

[John Rist]

Here in Huntsville, Alabama we go to RC Hobbies on Meridian Blvd.. The RC stand for Rick Chambers, not Rocket City or Radio Control.. Rick's brother was the owner of Rocket City stuff until he closed in 1998.

They are closed on Sundays and Monday.

RC Hobbies carries high nitro fuel for the RC cars. Works but you need to add caster oil.

[Motorman]

Nitro should be minimized for sport use due to the limitations of the ball socket joint of the piston. They run just fine with 20% nitro 20% castor. Also, with that mix, it's easy to make a standard fuel for most other engines by adding an equal amount of 0% nitro 20% synthetic oil for 10% - 50/50 mix.

MM

[GallopingGhostler]

I personally prefer 25% nitro because it's a lot easier on plugs. Glowplug Boy offers terrific fuel now made by Fitz. The original owner of Glowplug Boy passed away and Fitz took over for him. Excellent fuel which offers different nitro levels . His fuels contain a touch more castor. If you've been out of touch with the cost of 1/2A fuel, your going to be a bit sticker shocked as not only is the fuel expensive, so is the shipping. Ritch's brew also offers terrific fuel for 1/2A. Don't e-mail him, call him direct. Brodak also offers 1/2A fuel which I've used with good success. You also have Stan from S&W fuels which will make any fuel you ask of him.

Thanks, Ken. There used to be long time hobby shops near me - 95 miles away either Amarillo or Lubbock, Texas. But they closed up a while back. After I was going to another in Amarillo, don't know if they survived Covid. Still got 4 gallon jugs of fuel, mostly a 15% nitro R/C fuel with a pint of Castor (Benol Racing Castor) added to give me 25% oil with 10% as Castor.

I recall that Peter Chinn, the UK engine guru recommended no more than 25% oil for the Cox reed engines, because their fuel passageways could not satisfactorily handle the viscosity of higher percentage oil (like the famed 29% preferred by some - especially for their Fox engines).

One stating 30% oil satisfactory use, perhaps used a lighter grade of synthetic oil?

I know my fuel mix, mostly for the legacy say, .35's - K&B Stallions, Testor McCoy .19 and .35 Red Heads, OS's Enyas work fine along with the Cox reedies. Yet my Norvel .061 Big Mig didn't seem happy with it.

Regarding ball and socket, I was flying with 25% nitro 20% oil (100% Castor) SIG Champion fuel back in the day, my Golden Bees, Babe Bees, .020 Pee Wees and R/C Bee were all happy on it, never had a problem. However, I was resetting the piston-con rod joint periodically on the .049's, when de-varnishing the cylinders coated with Castor residue. (Didn't have one for my Pee Wees. Now I do.)

Anyway, I hope the OP finds the fuel needed to make his Cox engines happy.

[Mike Griffin]

Thanks everyone for the replies.

Mike