What fuel should I use for a Mccoy 35.

Picked up a Red Head 35 and 29 at the local R/C swap meet this weekend.(30 bucks for both). I have some Sig Champion 5% nitro,25% all castor. Is this the proper fuel for these particular engines? Thanks for the help.

That Sig fuel worked fine for me in a Mccoy redhead 35.

If the engines are loose, that fuel is perfect. If they are still tight, Fox Superfuel is called for.

>If the engines are loose, that fuel is perfect. If they are
>still tight, Fox Superfuel is called for.

What exactly makes Fox Superfuel better for running in ? What is the difference with the standard fuel?

I'm with Gerben here. Brand names mean nothing in other parts of the world. What is the oil. nitro and methanol content. Also, in the days of these engines, mostly castor oil was used as there was very little use of any synthetic. Is this an OLD Fox brew or some "modern" mix with the Fox name?

Fox Superfuel--5% nitro--29% castor--66% methanol.

Thanks Jim. Does make you wonder when manufacturers state the 29% and 66% in their brews. Why not 30% and 65%. Just like some modellers who give us 22 1/2% oil. I doubt if any of us are that particular to go that accurate and it wouldn't gain any noticeable properties.

For a single gallon it would be hard to mix 29% and 66% fuel. Manufacturers of fuel mix large batches at once, for a 1000 gallon batch the percentages are easy, 290gallons caster, 660gallong alky.
I am sure they make much larger batches this this so the %'s are even easier to adjust. Fox superfuel has been the same since at least 1955 when I first started using it. The percentages are shown on the can or jug.

Fox Superfuel is one of those "Made in the USA" things which actually lives up to its reputation.

The 29% was determined by the maker of the engine Duke Fox.

I talked to Duke shortly before he left us. He said he added 1% synthetic to superfuel to act as a detergent. This may account for the 29% castor.

Phil,

I'd thought it was because the original Superfuel,back in the '40's and '50's listed about 1% 'prope' (was that propylene oxide??) as ignition booster.

Good reasoning on large batches being easier to do stuff like this with.

I started buying Superfuel back in the early 60's and at that time it was 29% castor. Then, somewhere in the 70's I think it went to 28% for a while. Then later still, it went back to 29% again, and has stayed there so far. Sets the standard for old cast or steel piston's and steel sleeves. I used to break in my ringed Enya's on it also.

The Fox Superfuel cans say 29% Castor oil, 5% nitro methane, and 1% ignitors. The balance was presumably methanol. If the ignitors were propylene oxide, they would evaporate rather quickly. Probably after half the gallon is gone, so is the prope. But the fuel still worked OK.
I find that the McCoy's wear out faster than the Fox's. The K&B Green heads wear out even faster. Use plenty of castor for these engines.
Happy Landings