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-   -   FAI fuel (https://www.rcuniverse.com/forum/glow-engines-114/9000059-fai-fuel.html)

Walther 08-08-2009 01:51 PM

FAI fuel
 
Is there a glow engine that you can buy in the US that will run correctly on 0% nitro? I was told that the engines that you can buy in say the UK are set up to run on 0% because the US is the only country that makes nitro.

w8ye 08-08-2009 02:05 PM

RE: FAI fuel
 
Just straight methanol and castor oil does not run as good as we are used to with our model engines in the USA.

Typically the needle valve is difficult to adjust. one click will be the difference between too rich or too lean

The solution is to use 3-5% Acetone in the FAI type mixture

You can also just buy 5% nitro fuel

Anymore we are also not accustomed to all castor oil for lubrication. Most of use are used to a 80% synthetic and 20% castor oil ratio for the lubrication package.

estradajae 08-08-2009 02:06 PM

RE: FAI fuel
 
Many countries produces Nitro, but it is usually cheaper in the USA.
here in Germany you can get also nitromethane, but it cost about 20EU a liter....

I would say most sport engines like O.S and similar will run O.K with no nitro, maybe you won't get every bit of maximum power, but they will run fine.

I run an o.s 46 fx, magnum xls 46 and tower 75 with no nitro and no problems, they run fine and reliable.

I'm living in germany since last year, and I've run here only a 4 stroke engine, with nitro, so I don't know how it runs with no nitro.

saludos,

Jorge

Rodney 08-08-2009 02:31 PM

RE: FAI fuel
 
With the proper adjustment of the compression ratio, most engines will run almost as well with no nitro as they do with it.

wjvail 08-08-2009 03:23 PM

RE: FAI fuel
 
As a point of clarification, "FAI Fuel" is 80% methanol and 20% castor. Notice there in no provision for nitro but also no allowance for synthetic oil. The term "FAI fuel" is often used to simply mean no nitro fuel and while that is correct, FAI fuel really is 80% Methanol - 20% Castor... no exceptions. This is per the FAI sporting code. It must be 20% oil and all 1st pressing castor.

In general, this is not a good modern fuel blend. Even EU engines set up to run on low/no nitro do not need 20% oil and no modern engine needs an all castor fuel package. Modern competition engines optimized for classic FAI fuel do run well but are not easy to set up and tune and, in general, would be better off with at least some nitro and far less castor.


Many countries produces Nitro, but it is usually cheaper in the USA.
While it is usually cheaper in the US, most of the nitro the US uses come from China. To the best of my knowledge only the US and China produce Nitromethane.


Cheers,



Bill

MJD 08-08-2009 03:38 PM

RE: FAI fuel
 


ORIGINAL: wjvail
In general, this is not a good modern fuel blend. Even EU engines set up to run on low/no nitro do not need 20% oil and no modern engine needs an all castor fuel package. Modern competition engines optimized for classic FAI fuel do run well but are not easy to set up and tune and, in general, would be better off with at least some nitro and far less castor.
Agreed; if the metallurgy/design is so outdated that 1/5 castor oil is required to keep the thing alive, I'd want to see if I had suffered a time warp anomaly and accidentally bought it 40 years ago then returned in a puff of smoke. It has been said many times that I can recall by assorted engine columnists and others, that current engines designed for no nitro fuel respond very favorably to current syn/cas fuels and that the idle and throttle response are noticably improved on 5% nitro. My own observati0ons agree so far.

As to the OP's question, certainly you can buy engines over here that will run well on these blends - MVVS, Rossi are two names that comes to mind. If the engine has head shims installed you can always bump compression if it seems necessary. Or, run the engines you are used to on 5% fuel or FAI fuel and see how things go. Many folks do and are happy. Is it your goal to use FAI fuel, or are you just curious?

MJD

JoeAirPort 08-08-2009 05:01 PM

RE: FAI fuel
 
My Moki 1.8 and 2.10 loved Morgan FAI fuel.

estradajae 08-08-2009 05:38 PM

RE: FAI fuel
 
Normally the engines that run with low(5% max)/no nitro are (from what is usually said here)

MVVS
Webra
Super Tigre
Moki
Laser
Rossi
MDS

Do you see something in common there?

At home (Colombia) for me no nitro fuel was the choice between flying and staying at home...I had to pay too much for a gallon of fuel, where I could mix my own about the 20% of the cost. The same for the oil....there I can only get castor, eventually I could see klotz at the hoby shop, but it costed too much to make it usable for me... we have a problem there...and is the dollar course....it is about 2000 pesos to 1 dollar...and in Colombia you buy a coke with 1 dollar...we buy it with 1000 pesos....just like here in Germany, a coke is about 1EU [:'(], so in my country you just have to pay about the double of the price plus what the poor owner of the LHS earns...


About the countries that produce Nitromethane....I really don't know, I guess I meant that nitro is available in many countries.... not quite easy thought.


Saludos,

Jorge

jib 08-08-2009 05:39 PM

RE: FAI fuel
 
Super Tigre!

jack

blw 08-08-2009 06:41 PM

RE: FAI fuel
 
Castor still provides the best protection against lean runs, but it doesn't take all castor to do the job. You also get rust protection with it.

Nitro is also made in large quantities in India.

The price of nitro in most European countries is mostly a tax driven issue. We have the same tax increased prices on other hobby items here, but fortunately not nitro.

Walther 08-08-2009 08:30 PM

RE: FAI fuel
 
Why I asked the question is that I mix my own fuel and I was going to give FAI a try, that is with 20% castor oil. I have some new ST ABC engines that are 20+ years old that I would run on it.

captinjohn 08-08-2009 09:09 PM

RE: FAI fuel
 


ORIGINAL: JoeAirPort

My Moki 1.8 and 2.10 loved Morgan FAI fuel.
Is the Morgan FAI fuel you talk about 20% Castor oil? Thanks capt,n

jeffie8696 08-08-2009 11:51 PM

RE: FAI fuel
 
Ihave found most engines in my collection will run OK on FAI fuel. If Isimply increase the compression a little. And use a hot plug. Merlins work great.

downunder 08-09-2009 12:06 AM

RE: FAI fuel
 
Morgan doesn't have a clue what real FAI fuel is but that goes for most American fuel manufacturers where it's just become a generic term for any fuel with zero nitro. There's a reason why FAI fuel is 80/20 methanol/castor. To keep a level playing field in events where power is an absolute requirement (CL speed, RC Pylon. FF power) the only fuel allowed is methanol, no spiking with nitro or any other additive that can burn and possibly add to the power output. Castor was chosen as the oil because it doesn't burn and is well known for its lubricating ability under extreme conditions. Also it's cheap and readily available.

Engines available in the UK are exactly the same as similar engines available in the USA (OS, Enya, ST, you name it) and they'll all run perfectly well with zero nitro. As a for instance, my old (second hand) ST GS45 ABC with its low compression of 8.5:1 turns an APC 10x6 at 14,600 on 75/25 castor so it's no slouch and tuning is dead easy.

Luna_Rendezvous 08-09-2009 02:42 AM

RE: FAI fuel
 
Add Enya engines to the list, my SS30 c/l loves FAI as does my 46-4C in fact when use a synth blended lube my Enya's generaly lose 300 RPM here's a vid of the 46 with one head shim 12x6 mas on FAI...

[youtube]http://www.youtube.com/watch?v=O6q358B260I[/youtube]

Iflyglow 08-09-2009 11:11 AM

RE: FAI fuel
 
Luna,
You sure could here the rpm drop when you disconnected the glow power though. The idle did not seem very stable.:eek: I am looking for performance that does not sacrifice the ability to idle. I have two early era race planes, and a reliable idle is important enorder for you to land them.;)

wjvail 08-09-2009 02:12 PM

RE: FAI fuel
 

Morgan doesn't have a clue what real FAI fuel is but that goes for most American fuel manufacturers where it's just become a generic term for any fuel with zero nitro. There's a reason why FAI fuel is 80/20 methanol/castor. To keep a level playing field in events where power is an absolute requirement (CL speed, RC Pylon. FF power) the only fuel allowed is methanol, no spiking with nitro or any other additive that can burn and possibly add to the power output. Castor was chosen as the oil because it doesn't burn and is well known for its lubricating ability under extreme conditions. Also it's cheap and readily available.
All true... but I'll add... FAI fuel, as described by the sporting code, has not changed in the 40 plus years that I've been modeling and I believe it was "created" decades before that. Taken in the context of the time true FAI fuel was defined, it makes more since. At the time of "FAI fuel's" creation, "glow" engines were relatively new, fuel additives included many that were very dangerous, liners were steel, piston were iron, and the only oil KNOWN to keep engines running over time was castor. At the creation of FAI fuel, model Schnuerle engines didn't exist. Neither did ABC/ABN/AAC engines. Synthetic oils were potentially faster but poor lubricants, and the sky was the limit for additives. Nitro was one of them but others existed that were explosive or carcinogenic or both.

Fast forward to todays world of comparitably readily available Nitromethane, the invention of (good) synthetic oil, and chromed brass or aluminium liners with very high silicone/low expansion pistons and the best reason for continuing to use FAI fuel is that it allows you to compare model performance over time. Yes, prohibiting the use of nitro reduces cost considerably for most/all modelers but that doesn't explain the requirement for 20% all castor oil.

Bill

Luna_Rendezvous 08-09-2009 10:39 PM

RE: FAI fuel
 

ORIGINAL: MOTORMAN37

Luna,
You sure could here the rpm drop when you disconnected the glow power though. The idle did not seem very stable.:eek: I am looking for performance that does not sacrifice the ability to idle. I have two early era race planes, and a reliable idle is important enorder for you to land them.;)

You are kidding right?

The engine was stone cold, 2 flips and it starts right up and 5 seconds later the glow driver was removed, I wonder why it stumbled gee let me think....

downunder 08-09-2009 11:22 PM

RE: FAI fuel
 

ORIGINAL: wjvail
Yes, prohibiting the use of nitro reduces cost considerably for most/all modelers but that doesn't explain the requirement for 20% all castor oil.
In the competition arena cost doesn't play any part but standardisation of fuel components does. Sure, the rules could be changed to say that FAI fuel will be 83% methanol and 17% Klotz oil but what if Klotz change their formula or go out of business? Castor has been and always will be simply castor. Some people will try to push the rules to the limit to gain the slightest edge over their competitors and if they could find a synthetic that would not only lubricate but also have a powerful burnable component then they'd use it, even if it cost $100 a quart. Under FAI rules (for the 3 events that require it) you can use your own fuel to practise and find the best tune but in any competition flight the organisers supply the fuel.

As you said, the best (and only) reason for using FAI fuel is to compare performance over time. That's the level playing field thing again.

Iflyglow 08-10-2009 12:00 AM

RE: FAI fuel
 


ORIGINAL: Luna_Rendezvous


ORIGINAL: MOTORMAN37

Luna,
You sure could here the rpm drop when you disconnected the glow power though. The idle did not seem very stable.:eek: I am looking for performance that does not sacrifice the ability to idle. I have two early era race planes, and a reliable idle is important enorder for you to land them.;)

You are kidding right?

The engine was stone cold, 2 flips and it starts right up and 5 seconds later the glow driver was removed, I wonder why it stumbled gee let me think....

It should not drop rpm like that when pulling the glow power cold or hot. Maybe I am just to used to my YS 1.10's 2000 rpm. Even my Tower .75's on 10% do not drop like that, and I do not even let the glow power on 5 seconds. The needing to clean out is normal though.

Luna_Rendezvous 08-10-2009 01:02 AM

RE: FAI fuel
 
The idle is fine on the enya once it has warmed up I wonder why you failed to notice that?

Bone 08-10-2009 01:09 AM

RE: FAI fuel
 
Also bear in mind that most 2 stroke model aero engines are "designed for sale in the USA" - by that I mean that the compression ratio is on the low side 'coz the manufacturers know that most (USA) people will run a nitro based fuel.

Therefore, to run a 2 stroke engine on zero nitro fuel, a quick & often very effective solution is to remove the head & take out one or both of the head shims, thereby increasing compression. Take the usual care of course to ensure the plug does not come into contact with the piston plus ensure correct prop selection.......and off you go.

Luna_Rendezvous 08-10-2009 01:22 AM

RE: FAI fuel
 
Also note too, that most carbies are designed for nitro fuel, that's why the transition can be less smooth than it should when running nil nitro. If you’re handy you can re-profile the low speed needle, and the transition will come back.

mike.

David Bathe 08-10-2009 03:10 AM

RE: FAI fuel
 
I used 80/20 for many years.
Ran OS, Enya, Webra, HP and HB.
They worked... but thinking back, they where a great deal more finicky than today.
Mind you, my Moki runs just perfect.

Apart from the YS engines (and the Moki), I've dropped the oil content down to 15% on everthing else.
Perfect.

mk1spitfire 08-10-2009 04:33 AM

RE: FAI fuel
 
I've been running fai for the first time this season on my moki and give some of the following comments.

1.How come its working without Nitro? Its a myth all engines need nitro.
2.ok you need an engine with high compression and moki sure are that.
3.The cost!! I pay about£8.50 a uk gallon and petrol is over £5 a gallon, so only slighlt more than gas and MORE power,less weight,ok bigger tank but its light when you land
4.The nitro costs,say for good 16 sythn fuel costs about £22 so BIG glows that need nitro could hurt the wallet.
5. The smell is lovely.!! Castor has a nice whiff compared to sythns
6. Castor residue sucks, but extentending the exhausts furher, makes for a cleaner model and meths/water is a great cheap cleaner.
7.The exhaust will go black, but if its hidden in the cowl,it doesn't matter.
8.leaner runs with all that castor.!! More power
9.Once you know how to set a needle,you don't need the nitro to help you. My tolerance is half a turn,too lean-rich
10.Other engines have you by the balls,once they comit you to nitro

I think the comment about fai fuel being a test over a period of time rings true


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