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FUEL QUESTION.

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FUEL QUESTION.

Post  SCROWOASH on Thu Sep 21, 2017 9:14 am

Hi Everyone,

Hope i am not being a pain and asking a common question. I managed to buy 4 litres of MORGAN FUELS COOL POWER 20% NITRO fuel (GREEN) that i would like to run in my COX engines. It contains 17% synthetic lubrication. How much castor oil do i need to add to make it safe to use with COX engines? (TD 051/BLACK WIDOW).
i.e How much castor will 2 litres of fuel require?

Help on this will be much appreciated!!

Thanks in advance.

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Re: FUEL QUESTION.

Post  Marleysky on Thu Sep 21, 2017 9:34 am

There is a web page that will do those calculations for you. I'll do a quick search, but someone else will chime in with the answer before I find it.  

Hey, WELCOME TO THE FORUM! Small Cox Logo Babe Bee .049

Ok, here is one:

http://www.nitrorc.com/default2.asp?Introduction=http://www.nitrorc.com/fuelws


Last edited by Marleysky on Thu Sep 21, 2017 9:41 am; edited 1 time in total (Reason for editing : Found it!)
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Re: FUEL QUESTION.

Post  balogh on Thu Sep 21, 2017 9:53 am

SCROWOASH wrote:Hi Everyone,

Hope i am not being a pain and asking a common question. I managed to buy 4 litres of MORGAN FUELS COOL POWER 20% NITRO fuel (GREEN) that i would like to run in my COX engines. It contains 17% synthetic lubrication. How much castor oil do i need to add to make it safe to use with COX engines? (TD 051/BLACK WIDOW).
i.e How much castor will 2 litres of fuel require?

Help on this will be much appreciated!!

Thanks in advance.


The longevity of COX engines depends on the ratio of castor oil in the lubricant. I always use castor only in a ratio of at least 20% of the fuel.
Some folks here say half of the lubricatant should be castor, so that would mean for you to add of 0.17 x 4 = 0.68l of castor (= the same, 17% of the 4l) to your fuel, but  that would then have too much lubricant relative to the methanol and nitro content. So you either compromise on a lower castor content than 50% of the lubricant, or, try to add some methanol and nitro, not just castor, in order to retain the strength of the fuel...

All the rest is just simple mathematics.

If you cannot add meth and nitro, only castor, then with 0,68l of castor  added, you would have 4,68l fuel altogether, in which 0,8l (20% of the original 4l)  nitro makes 17% nitro, and the 2,52l meth (= 63% of the 4l fuel containing already 17% synt plus 20% nitro =37%)  makes 54% meth content. So the lubricant content is 100-17%(nitro) - 54% (meth) = 29%  lubricant...a bit thick on oil, so you may want to compromise on the castor content, and add only 0,34l i.e.half. (then you would have a lube containing 2/3 synt and 1/3 castor instead of 50/50)

Then you have 4,34l fuel in which you have roughly 18,4% nitro, 58% meth, and 23,6% lubricant (i.e. 15,8% synt and 7,8% castor). It is good for recreational flying.
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FUEL QUESTION

Post  SCROWOASH on Thu Sep 21, 2017 10:28 am

Thank you.

I was hoping when i bought the fuel it had a castor/synthetic blend. It was an online purchase and it was the only option(every other blend was out of stock).
The type of flying is recreational. i have a small amount of nitro that is about 6 years old. Could it be off by now? Might be enough to treat the 4 litres depending how much i need.
I also have methanol, so i could add these if the nitro is ok. Next fuel purchase i make i will buy fuel with higher nitro and castor/synthetic blend.
Will the 8% castor content i end up with really be ok or will i harm my engines over time?

Thanks again to all for the great advice.
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Re: FUEL QUESTION.

Post  balogh on Thu Sep 21, 2017 11:06 am

You are welcome.

The 8% castor content is only a tad less than half of the 20% lube content that I think is the minimum required, and I might as well say should be enough...but I do not have the experience with so low castor content.

On the other hand I believe COX engines, these tiny gems deserve the best lubrication possible that I think is castor. Castor, forming a varnish layer on the hot metal surfaces, not only saves the balljoint of the conrod, but deposits in the micro-scratches on the cylinder wall, and keeps a quasi-constant, accurate piston-to-cylinder fit that is crucial for the small swept-volume engines like COX that are more sensitive to compression loss than the larger engines. Synt oil, to the contrary will burn with the fuel, and leaves your plane cleaner than castor, but will not do so much good to the engine as castor.

I have a well used TD051 with estimated near 300 hours runtime on it, exclusively with castor as lube, and it still starts easily and runs well, albeit with some performance/rpm loss while the plane is climbing.

Nitro and methanol both are higroscopic fluids that tend to absorb the moisture of ambient air, thus losing their strengths as fuel component.

So providing you have stored the nitro and meth in an airtight container without frequent opening/contact with ambient air, they may still serve well as fuel.
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Re: FUEL QUESTION.

Post  RknRusty on Thu Sep 21, 2017 11:13 pm

Hi, Scrow,
Morgan, as I'm told, measures their fuel components by weight rather than volume. While a valid method for a chemist, it seems most of the suppliers of model engine fuel opt for measuring the components by volume, which is a considerable difference in amounts(probably because it's easier to do in a garage shop). Oil is heavy, so the weight method makes it sound like higher oil content compared to our traditional suppliers. The only way to convert weight to volume that I know of is to cook down(evaporate) a measured amount of fuel so that nothing but oil remains. Now you know how Morgan's volume would compare to all of our traditional blends; Sig, Byron, VP Powermaster, Fritz, etc.

Sorry, I just thought I would up the frustration factor.
Rusty

P.S.
SCROWOASH wrote:Hi Everyone,
Hope i am not being a pain and asking a common question...

Heck no, the smartest thing to do is question the contents of an unlabeled or questionable fuel. If they do not label it, and aren't perfectly clear when asked, it's even smarter to seek knowledge.

Our top competitive Cox engine builder, Paul Gibeault claims to have destroyed more than one Cox engine in a very short time with (un-doctored)Morgan Cool Power.
Welcome to CEF... even after 3 years, Lol.

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Re: FUEL QUESTION.

Post  Oldenginerod on Fri Sep 22, 2017 12:12 am

The calculator in Rene's link is a good one & takes out the guesswork. Unless of course Rusty throws us a curve ball by mentioning the weight to volume question. Rolling Eyes If they say it's got 17% oil, that's pretty close to the volume you'd expect in most commercial blends, so I'd say you'll still be pretty safe to use the calculator. If you want to add another 8% by volume oil to bring it up to 25% (theoretically) total lube, then that 8% is still a significant amount of castor and your engine should still be well protected. Even if you up the oil content as suggested it only drops the nitro content to 18.2%, so that's still enough to get a pretty decent run on a Cox, so if you don't trust the old nitro you have, don't worry about using it in the initial test phase.
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FUEL QUESTION.

Post  SCROWOASH on Fri Sep 22, 2017 9:24 am

Hi Everyone and thanks again for the valuable information.

I think i feel better now after what everyone has said as this whole business was bugging me due to concern of damage to these little gems. I will pay better attention to the fuel details when i buy next time. i went back to the website where i bought this coolpower green fuel and found they had a product called OMEGA FUEL PINK 30%. The description had this to say:

*Ideal for Cox and 1/2A engines

Omega Fuel is the worldwide #1 selling castor/synthetic blend, because of its unique balance of reliability, performance and protection. Due to its excellent idle, acceleration and top end, Omega's formula is the benchmark for the industry. It has remarkable performance characteristics in A.B.C. and A.B.N. engines particularly in hot installations. Omega Fuel uses our CleanCastorTM, the cleanest burning castor oil with superb lubricating properties as well as an ability to disperse inside your engine for added protection.

*This 100ml bottle contains 30% Nitromethane and 17% lubrication

Does anyone disagree with the above? Does the fuel still need more castor. Perhaps it will be a good idea to add 3% castor oil to make it 20% total lube content and it wont affect the nitro/methanol too much.
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Re: FUEL QUESTION.

Post  balogh on Fri Sep 22, 2017 9:29 am

Unless the castor to synt ratio is specified by Omega as 50%/50% or more to the castor, I would add that 3% additional castor.

The castor-obsessed balogh...
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FUEL QUESTION

Post  SCROWOASH on Fri Sep 22, 2017 9:49 am

Hi Balogh

Once again, looking at the image of the fuel bottle label, there is no indication of the synthetic to castor ratio. The closest product i can find with ratio details is OMEGA 25% which states a ratio of 70% synthetic to 30% castor. i can only assume this is the same.
With that ratio, is 3% enough or would it be better to push the castor up 8% again to 25% total lube content?

This stuff just blows my mind - so fascinating!
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Re: FUEL QUESTION.

Post  pkrankow on Fri Sep 22, 2017 10:00 am

25% total lube is fine. You will start loosing some power from too much lubricant, but for most applications it will be fine.

You may wish to consider ordering Sig Champion in quarts as that is not hazardous shipping like gallons are. This saves the mixing fuel problems.

Tower also makes a Cox blend that is correct for these engines. It is the "new" formula.

Glowplugboy also blends appropriate fuels.

Phil
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FUEL QUESTION

Post  SCROWOASH on Fri Sep 22, 2017 10:44 am

Thanks Phil,

let me have a look at those options. My problem is that i live in Zambia, Africa!! So fuel that needs to be airfreighted is a no no.
The coolpower fuel that i recently obtained was from an online shop in South Africa and therefore i was able to use a land based courier to ship it to me. You guys don't know how lucky you have it! lol.
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Re: FUEL QUESTION.

Post  balogh on Fri Sep 22, 2017 10:47 am

SCROWOASH wrote: engine for added protection.

*This 100ml bottle contains 30% Nitromethane and 17% lubrication

Does anyone disagree with the above? Does the fuel still need more castor. Perhaps it will be a good idea to add 3% castor oil to make it 20% total lube content and it wont affect the nitro/methanol too much.

Assuming the 70/30 synt to castor ratio is true in your 53/30/17 blend, the current castor content with 17% total lube is 0,3 x 17 = 5,1%..I would find it on the low side. The hot crown at the piston underside causes synt oil to burn even there not only insde the cylinder: I see in my engines that even the castor is coked around the balljoint socket area, especially in the Tee Dee-s. And the balljoint is where you typically need the castor that will be less in a 70/30 synt/castor mix than in an all-castor lube. So you may end up with poor lubrication in the balljoint area.

You may want to ramp the 17% total lube up to about 20% by adding some castor.From the original 30% nitro blend you still will near 29% nitro which is strong enough:

For each 100ml of 53/30/17 original blend you add 3,6ml of castor to reach a total 20% lube content. This will leave you with a 51/29/20 new blend.

The total castor content grows from the original 5,1% to about 8.4%

But this is only my uneducated opinion as I have never used synt/castor mix, only all-castor.
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Re: FUEL QUESTION.

Post  balogh on Fri Sep 22, 2017 10:49 am

SCROWOASH wrote:Thanks Phil,

let me have a look at those options. My problem is that i live in Zambia, Africa!! So fuel that needs to be airfreighted is a no no.
The coolpower fuel that i recently obtained was from an online shop in South Africa and therefore i was able to use a land based courier to ship it to me. You guys don't know how lucky you have it!  lol.

I live in Hungary and if I want nitro I drive 250km-s one way to neighboring Slovakia as nitro is no longer sold here. So much about my luckiness !!! Sad
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FUEL QUESTION

Post  SCROWOASH on Fri Sep 22, 2017 11:21 am

If i could just find nitro in South Africa which is about 1500 km away, i would be able to get it to me with a land based courier. There is just nobody stocking it as a seperate ingredient! Sad Sad

Looks like we unlucky together. I am impressed though, that you can get it 250 km away...thats cool!
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Re: FUEL QUESTION.

Post  roddie on Fri Sep 22, 2017 12:33 pm

SCROWOASH wrote:Thanks Phil,

let me have a look at those options. My problem is that i live in Zambia, Africa!! So fuel that needs to be airfreighted is a no no.
The coolpower fuel that i recently obtained was from an online shop in South Africa and therefore i was able to use a land based courier to ship it to me. You guys don't know how lucky you have it!  lol.

Yes.. we do have some advantages here in the U.S... As for fuel.. I'd heard that the "SIG-brand" was backordered.. and figured that you'd explored that option. I don't know what the current fuel-situation is with Sig.. but their 1/2A (small glow engine) "Champion" fuels were available in pints and quarts.. non-applicable to a "Hazardous-Material" (Hazmat) designation.. as are the "gallons". Many of us use this fuel.. because it has a 50/50 Synth. (Klotz)/castor (Baker AA) oil-content and is available in 25 and 35% nitro blends.

The domestic hobby-shop that "you've" been dealing with may be able to order fuel in pint/quarts from the U.S. without too much.. if any red tape .

"Tower Hobbies" (owned by Hobbico) sells and has actually "re-blended" the fuel that they were selling under the name of Cox "Super-Fuel". This was accomplished through intervention from the Cox Engine Forum. Hobbico had been offering Cox-branded fuel that was deficient of castor-oil. The Hobbico "Rep." worked with CEF to have the glow-fuel re-blended. There was a test-group set up.. and Hobbico sent their "newly-blended" fuel to some forum members who volunteered to be test-subjects. The "new" blend was found to be satisfactory. The fuel is currently offered in quarts.. through Tower Hobbies in 25% and 35% nitro formulas.

I would contact your hobby-shop and ask if they can make inquiries to Tower Hobbies and/or Sig Manufacturing Co. who both sell fuel in quarts.. and both have 25% and 35% formulas. These two blends are quite similar to what used to be available direct from Cox.. and will yield easy-starting and top-performance from your Cox glow-engines.

Don't discount converting your engine(s) to "compression-ignition" (diesel) if you have trouble sourcing glow-fuel. Model diesel-fuel may be easier to obtain. It's not the diesel-fuel you'd find at the pump for your automobile. Model diesel fuel has an oil-package for two-stroke combustion.. just as the glow-fuel does. We (the forum) have threads on how to mix your own diesel-fuel. A "conversion-head" is required which replaces the glow-head.. and has a "screw/contra-piston" similar in function to purpose-designed 2-stroke diesel model-engines.. which were/are very popular outside of the United States.

A diesel-conversion may be a good choice for you. Diesel engines (or conversions) generally will utilize a larger propeller than a glow-engine of the same displacement. A starting battery is not required. There's a learning-curve associated with running/tuning compression-ignition engines.. but it's well worth knowing about if your a model-engine enthusiast.



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FUEL QUESTION

Post  SCROWOASH on Sat Sep 23, 2017 3:30 am

Hi Roddie,

Thanks for those great ideas. i have looked into the diesel option and in fact have a few diesel motors...PAW, WEBRA, MILLS, and ED. Unfortunately, trying to obtain ETHER is just as difficult!! But, i am still trying and will hopefully find a source soon!

Thanks all for the encouraging comments again.
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Re: FUEL QUESTION.

Post  Oldenginerod on Sat Sep 23, 2017 4:12 am

Your best option may be to just buy the highest nitro fuel you can, and if you can get castor & methanol separately just blend it down to the nitro % you want.
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FUEL QUESTION

Post  SCROWOASH on Sat Sep 23, 2017 6:00 am

That seems to be the option most likely to yield the best results. i am waiting on the shop i deal with as they claim to have 30% nitro and a 70/30 synthetic to castor mix in 100ml bottles in stock. (OMEGA PINK 30%) I have asked them for 5 bottles for now. Based on the success of this, i will order more.
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Re: FUEL QUESTION.

Post  pkrankow on Sat Sep 23, 2017 7:54 am

Write a little spreadsheet to convert the percentages to volumes.  Then add another section to take the volumes required to make to the percentages desired.  The math isn't very hard, just simple algebra, but it ends up quite a few calculations so the spreadsheet is the way to go.

Just make sure you put the instructions in like it is for someone else since you will likely save the file and use it only a couple times a year. I have located my old spreadsheets if you want them. One is light on comments. Huh...

Phil
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Re: FUEL QUESTION.

Post  RknRusty on Sat Sep 23, 2017 9:16 am

SCROWOASH wrote:If I could just find nitro in South Africa which is about 1500 km away, I would be able to get it to me with a land-based courier....
If you could look up Keith Renecle in South Africa, I bet he could help you fast track fuel and other items. Sorry I do not have his email address, but if you need, I can put you in touch with him via email or PM through Stunthangar.com. If you want me to do that, PM me your name and email address, or phone number.
Rusty

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FUEL QUESTION

Post  SCROWOASH on Sun Sep 24, 2017 2:46 am

Hi Phil,

I think you are right...the spreadsheet is definitely a good idea. i have a pocket notebook that is riddled with fuel mix calculations and gets quite tedious! One of the most useful things i see someone getting out of a spreadsheet based calculation is what Nitro percentage you would end up with when doctoring the other ingredients.

Thanks for the great tip.
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FUEL QUESTION

Post  SCROWOASH on Sun Sep 24, 2017 2:50 am

Hi Rusty,

I cannot believe i never gave Keith Renecle a thought! I actually know Keith personally and i think it is a great idea to speak to him about this. Thanks for the brilliant idea!
As a matter of fact, i e-mailed him a couple months ago to catch up. Although i know he converted his top stunt plane to Diesel and is also getting quite big into electric power these days. However, a good contact to speak to.

Thanks again.
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Re: FUEL QUESTION.

Post  RknRusty on Sun Sep 24, 2017 10:25 am

SCROWOASH wrote:Hi Rusty,

Thanks for the brilliant idea!
You're quite welcome, Scrow. That's why a buncha heads... allbeit mostly gray... are better than one, Lol.
Rusty the head.

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Re: FUEL QUESTION.

Post  roddie on Sun Sep 24, 2017 11:26 am

That's definitely encouraging! Resources are everything when it comes to running model engines these days! I hope that Keith can provide some good leads. Sometimes we forget about certain acquaintances when it comes to tracking down a needed item. I fly (or I used to.. Rolling Eyes ) C/L.. and there's only a handful of established clubs remaining in the U.S. One of them; "N.E.S.T." (New England Stunt Team Precision-Aerobatics) fly's at a nearby field in Wrentham, Massachusetts, on state-owned land that's shared with several other various community organizations. I used to be a member back in the early 90's.. and have kept in touch with a few members.

I've seen a recent shift toward electric-power amongst several of its members. It's a sad thing to me.. but I understand the movement. It's "plug and play".. "clean and quiet". No fuel-proofing of the model is needed.. rock-steady "timed" motor-runs.. and the airplane's paint/finish stays nice.

I suppose I'll completely accept it when "full-scale" aircraft are powered by electric-motors.. but until then; petrol model-engines will still offer the utmost in scale-realism.
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