Hobbico's "Cox Super Fuel"

How about this for a conspiracy theory -

A collector of Cox engines is a major model fuel manufacturer. The manufacturer creates a fuel at a reasonably low price that wrecks Cox engines.

His collection increases in value as engines and parts become rarer.

Here it is easy to get fuel made up or the liquids to make your own - but difficult to get it delivered. Buy and collect - either from the manufacturer or make an arrangement to collect at a show where they are exhibiting.

"Buggy" fuel (non castor) is easy to get in model shops, diesel fuel is difficult along with castor based fuel. (Diesel fuel is usually castor only because of the higher temperatures)

From what we understand the Hobbico (rebranded Cox) fuel is 20% oil, of which 1/2 is castor oil; so it should be fine for Cox engines.

Cox International wrote:From what we understand the Hobbico (rebranded Cox) fuel is 20% oil, of which 1/2 is castor oil; so it should be fine for Cox engines.

Following is stated from Tower Hobbies Tower Hobbies: Cox Super Power 1/2A Fuel 25% Nitro Quart

Tower Hobbies wrote:NOTES FROM OUR TECH DEPARTMENT
This is the quart (946ml) Bottle of Super Power 1/2A Fuel from Cox. FEATURES

• Premium blend 25% nitro formula is ideal for model airplane, car, or boat use
  
• Special 18% oil package consists of 90% synthetic, and 10% castor lubricant blend
  
• Latest high-tech synthetics combined with castor protects and lubricates the aluminum journals and plain steel bearings used in small displacement engines
  

Cox International wrote:From what we understand the Hobbico (rebranded Cox) fuel is 20% oil, of which 1/2 is castor oil; so it should be fine for Cox engines.

http://www3.towerhobbies.com/cgi-bin/WTI0001P?I=LXDBNH&P=8

If you scroll down to the product features, it states "Special 18% oil package consists of 90% synthetic, and 10% castor lubricant blend"


**Oops, GallopingGhostler beat me to it!

OUCH!

I thought they once told me the mix had 10% castor oil. I guess what they meant was 10% of the oil was castor. Definitely DO NOT use this fuel on Cox engines.

I just called them and will follow up with an email.

Pete,

I guess you are the gent that sent us the mail re. fuel you bought from us. Theresa responded to let you know that we do not sell fuel; hence we could not have supplied it to you.

We would like to make it clear that we are in no way involved with Hobbico and / or the fuel they sell. If the mix of their fuel is indeed 10% castor / 90% synthetic then we would not recommend it, as it will invariably lead to engine damage.

We are currently compiling an email to Hobbico to make them aware of the fuel issue.

PeterJGregory wrote:

Cox engines are rather peculiar in lacking a wrist pin.  The required motion is done with a ball and socket joint, and the socket part of that bearing is the piston.  Very few other engines do this.  The piston gets very hot, and it will cook out any oil other than castor.

Thank you for a clear explanation about this castor oil issue.
I am absolutely mesmorized by this discussion. I paid almost $50 for a gallon of Cox Super Fuel from Tower, to find out it doesn't work!!!
I just sent Tower a question about why they sell this stuff when it destroys Cox engines.
Very interesting that the ultimate problem is not the cylinder wall varnishing, but the breakdown of the ball-and-socket.

Now to hear back what Tower has to say about this.
Better yet, I need to contact the Cox people putting this stuff out.

What can you use the Cox Super Fuel for if not for Cox engines? The other small engines are OK with this stuff?

Thanks, Poughkeepsie Pete

I guess it never really dawned on me, but even though this is a Cox brand (sort of) it only says 1/2A fuel on the bottle.

1/2A is a pretty broad spectrum and on some engines that mix may work just fine.

Cribbs74 wrote:I guess it never really dawned on me, but even though this is a Cox brand (sort of) it only says 1/2A fuel on the bottle.

1/2A is a pretty broad spectrum and on some engines that mix may work just fine.

That's true, if not for the ball socket they might be okay with less castor. Out of curiosity I just looked at NVengines.com and they say, "Use the proper oil mixture. Requirements - minimum 18-22% oil in the fuel with 50% being Castor oil in engines smaller than .15 and at least 25% castor in larger." The MP Jets say no less that 20% castor too, so Cox isn't alone in the high castor requirements.
Rusty

We sent the following email to  airsupport@hobbico.com

Hello Justin,

As discussed on the phone with you, Hobbico product # COXP1005 Cox Super Power 1/2A Fuel, if indeed a mix of 90% synthetic and 10% castor oil, will almost certainly damage Cox engines if used in such.

There have been extensive tests performed with various castor / synthetic oil mixes and although, under some ideal circumstances, one could use as little as 25% castor / 75% synthetic mix, the consensus is that a 50% castor / 50% synthetic mix or better should be used to prevent engine damage.

This is due to the unique nature of Cox engines, with no piston rings, OEM tolerances of 2 /1,000,000” on cylinder / piston fit and Cox’s unique ball and socket joint for the piston / conrod assembly. Basically, Cox engines were engineered to require castor oil and no synthetic oil currently available (that we are aware of) would be a good substitute for castor oil.

In 2009 we purchased over 25,000 Cox engines, together with several pallets of other Cox items and are currently the world’s largest distributor of legacy Cox products. We would be most happy to include Hobbico as a recommended vendor for Cox engine fuel but can only recommend fuel that does not potentially lead to premature engine failure.

Perhaps you could forward our email to the person or persons in charge of fuel procurement. Please feel free to contact the undersigned at any time should you or someone else have any questions. FYI, there is an ongoing thread about your fuel on the Cox Engine Forum, located here:  https://www.coxengineforum.com/t5113-hobbico-s-cox-super-fuel  which should give you more technical insight as to why synthetic oils alone should not be used with Cox engines.

Thanks in advance and have a great day!

Bernie
For Cox International

Cribbs74 wrote:I guess it never really dawned on me, but even though this is a Cox brand (sort of) it only says 1/2A fuel on the bottle. 1/2A is a pretty broad spectrum and on some engines that mix may work just fine.

My Mehanite iron piston steel sleeve Enya instructions state 20% all Castor oil, but those are at least 35 years old. My ABC Fuji instructions, 30 years old, state 25% all Castor oil for general (CL stunt I imagine) and 20% for other uses (RC, speed, free flight). My Mehanite iron piston steel sleeve OS Max .10 RC cross scavenge engine instructions of 40 years ago states 25% Castor oil. My OS FP ABN Schneurle manual of 20 years ago states 25% Castor for (FAI fuel) general use, 20% Castor with 10% nitro.

Overall for engine health, whether steel or ABC/ABN, I gather that 20% oil is a standard. Use of 50% Castor and 50% synthetic is reasonable. Older engines with softer metals, such as the Testors McCoy's should use 25% oil.

Granted we oft don't find ideal fuels. I'm still learning, but I'm adding Castor oil to the standard hobby store shelf blends for aircraft. Couldn't hurt and I have nothing to lose and all to gain.  

Cox International wrote:We sent the following email to  airsupport@hobbico.com Hello Justin, As discussed on the phone with you, Hobbico product # COXP1005 Cox Super Power 1/2A Fuel, if indeed a mix of 90% synthetic and 10% castor oil, will almost certainly damage Cox engines if used in such. [...]

Thanks Bernie, I missed your message while complying mine, then got side tracked in a discussion with someone else meanwhile.

I'm glad that you are taking the lead in contact Hobbico. I hope they reformulate to standards or focus on another supplier for fuel. That basically leaves Sig Champion 25% fuel as meeting the requirement.

Here is our list of recommended vendors (from our on-line fuel guide). Ritch's Brew seems to be a favourite.

Cox International wrote:We sent the following email to  airsupport@hobbico.com

Hello Justin,

As discussed on the phone with you, Hobbico product # COXP1005 Cox Super Power 1/2A Fuel, if indeed a mix of 90% synthetic and 10% castor oil, will almost certainly damage Cox engines if used in such.

There have been extensive tests performed with various castor / synthetic oil mixes and although, under some ideal circumstances, one could use as little as 25% castor / 75% synthetic mix, the consensus is that a 50% castor / 50% synthetic mix or better should be used to prevent engine damage.

This is due to the unique nature of Cox engines, with no piston rings, OEM tolerances of 2 /1,000,000” on cylinder / piston fit and Cox’s unique ball and socket joint for the piston / conrod assembly. Basically, Cox engines were engineered to require castor oil and no synthetic oil currently available (that we are aware of) would be a good substitute for castor oil.

In 2009 we purchased over 25,000 Cox engines, together with several pallets of other Cox items and are currently the world’s largest distributor of legacy Cox products. We would be most happy to include Hobbico as a recommended vendor for Cox engine fuel but can only recommend fuel that does not potentially lead to premature engine failure.

Perhaps you could forward our email to the person or persons in charge of fuel procurement. Please feel free to contact the undersigned at any time should you or someone else have any questions. FYI, there is an ongoing thread about your fuel on the Cox Engine Forum, located here:  https://www.coxengineforum.com/t5113-hobbico-s-cox-super-fuel  which should give you more technical insight as to why synthetic oils alone should not be used with Cox engines.

Thanks in advance and have a great day!

Bernie
For Cox International

Thank you Bernie. A very well written letter IMHO. Hobbico could easily re-brand the stock that they have out there; by contacting their distributors with a letter of explanation.. and instructions to temporarily remove stock from inventory, until a new "label package" is sent out. Hobbico could also offer some incentives to these distributors.. for this inconvenience. It's a small price to pay, to protect their modeling reputation. The fuel that's already out there is certainly useful.. but it's irresponsible for them to continue to use the "Cox Super Fuel" trademark packaging.. if their product prematurely destroys "Cox" engines.

Towerhobbies still selling cox super fuel. From their info, coxmodels.com supply them.
I think we should email to coxmodels.com about this?

tru168 wrote:Towerhobbies still selling cox super fuel. From their info, coxmodels.com supply them.
I think we should email to coxmodels.com about this?

I believe they are a company of the Hobbico consortium. Since as far as I know, Hobbico bought O'Donnell Fuels, I think it may be a product from them.

coxmodels.com is a domain of Hobbico and was registered by them after they bought Estes/Cox.

It is pretty amazing how fuel sensitive these things are. The first Cox engine I had flown in decades was a Hyper Viper back when those first came out. It didn't even occur to me to use any special fuel, so I flew it on the Powermaster 15% that I was using in my ABC stunt motors. After three flights it became impossible to start and the plane got shelved

I now use that motor as a set up motor when I'm building a new plane because it is basically ruined. The crank wobbles, the rod has something like ten to fifteen thou worth of play and there is very little compression. I won't make that mistake again...

Mike

Mike Mulligan wrote:It is pretty amazing how fuel sensitive these things are. The first Cox engine I had flown in decades was a Hyper Viper back when those first came out. It didn't even occur to me to use any special fuel, so I flew it on the Powermaster 15% that I was using in my ABC stunt motors. After three flights it became impossible to start and the plane got shelved. I now use that motor as a set up motor when I'm building a new plane because it is basically ruined. The crank wobbles, the rod has around 25 thousandths play and there is very little compression. I won't make that mistake again... Mike

You probably already know this, but http://www.coxinternational.ca has parts for your engine to restore it.

Since coxmodels.com is actually under Hobbico, they still keep selling the same fuel even knowing that low castor contain will harm our Cox engine. Really hope Hobbico will change their ingredients to proper one.

Some of the best info on Cox Super Fuel (CSF) I have found on the internet is in this thread.
Some of you here have related ACTUAL personal experience with low- or no-castor oil fuels destroying your engines.
Well, as a test of how appropriate CSF is, I just ordered up two new SureStart engines from eBay to perform an experiment .
I'll run Sig 25% Champion Fuel in one, CSF in the other. Both will be broken in per Cox's old guidelines - 3 tanks of fuel with the engines set rich.
No mention was made in the Cox guidelines about how big a tank - I'll use an ounce for each run.

Cheers-

Considering the instructions are the same for a baby bee, 5ml is a tank full, 60ml is a long run.

Phil

Larger Golden Bee / Black Widow tank is 8 cc. 1 oz. is 30 cc. That it 6 times the volume of the 5 cc Babe Bee tank. Depended upon prop, if run time is 2.5 minutes on 5 cc, that is 15 minutes on 30 cc. 48 flights would be eight 1 oz. tank fulls, about 2 hours. It would be interesting to see what tankful the engine would start to lose compression on the Cox fuel.

YMMV (Your mileage may vary)  

I'll be interested to see your results Peter. More proof adds to our credibility on this issue, thanks for your sacrifice. If you can document it on video that will be even better.
Rusty