Posts: 5
Joined: 6/27/2008 From: Glendale Heights, IL, USA Status: offline
I'm new to R/C, and wish to make my own fuel to save money, but nitro is so EXPENSIVE! I heard that people make their own fuel, and was wondering. Would a Cen NX 76 motor run with a 0% nitro/18% oil/82% methanol fuel mixture? If not, whats the minimum amount of nitro required to get the engine going smoothly without hurting it. and finally, where could i buy the methanol, oil, and nitro(if needed) to make this mixture? I live near chicago, illinois.
Posts: 3198
Joined: 10/10/2002 From: Adelaide, AUSTRALIA Status: offline
Your engine is the same size as what would be called a .46 in plane engines and they'll all work perfectly well with zero nitro. I'd suggest using either all castor or a blend with synthetics somewhere around 50/50 and use a hot plug. The needles will be a bit more sensitive to tune so you need to be more delicate with them.
Posts: 5
Joined: 6/27/2008 From: Glendale Heights, IL, USA Status: offline
thank you for that! glad to know it doesn't require nitro. Now, do you know where i could buy the methanol locally cheap, or somewhere online cheap where they'll ship it to me? i've been looking at like 50 a liter and it just don't seem worth it. And what brand of oil do you recommend? Moneys not an objective if it keeps my engine clean and makes it last longer.
Posts: 3198
Joined: 10/10/2002 From: Adelaide, AUSTRALIA Status: offline
The brand of oil I'd recommend is Castrol M castor but that's not available in America. You'll have to wait for one of the locals to reply as to where you can buy the ingredients. Sorry about that .
Posts: 156
Joined: 8/17/2002 From: Ogden,
UT, USA Status: offline
Mitch I usually buy my methanol from one of the oil distributors around here. Most have it avail in a 55 gal barrel or 5 gal bucket. Some we even fill your own container for a little less cost. I have been running klotz supertechniplate without any problem. It is a synthetic/caster blend and usually available at motorcycle shops or online.
Posts: 5
Joined: 6/27/2008 From: Glendale Heights, IL, USA Status: offline
I heard that when the methanol gets exposed to air it degrades. Should i buy only as much as i'm going to use in a timeframe? or can i buy a lot and use it slowly?
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Joined: 3/31/2003 From: Tokoroa, NEW ZEALAND Status: offline
Here's what the manufacturer says:
quote:
There are many good brands of fuels on the market. You may use any of them as long as they meet the basic minimum requirements. However, avoid Traxxas Top fuel, HPI Fuel and Blue Thunder.
1. Fuel must be a castor and synthetic oil blend with total oil content of 12-15% 2. Nitro methane (Nitro) content should be around 20-30%.
The best fuels on the market today are castor/synthetic blends. The castor provides high temperature lubrication while the synthetic oils help prevent varnish build up inside the engine. The higher quality fuels also contain anti-wear agents, anti-foaming agents, lubrication additives, and rust and corrosion inhibitors. Use fuels that are made for use in cars, not airplanes. (Airplane/boat fuel is ok for marine engines) Car fuel will give better performance with easier tuning, and longer run times.
I suspect that running on 0% nitro will see your engine perform with significantly less power than you are used to and it may also be a *lot* harder to tune.
Note also that the manufacturer doesn't recommend using straight-castor, suggesting a synth/castor blend instead.
You *might* get away with the blend Downunder has suggested but if I were you I'd look at getting some methanol locally and then contacting Brian Cooper at Cooper Fuels for some of his Plus-C oil (synth/castor blend). He may be able to send you a bottle with at least a little nitro already mixed in with the oil. I gather that if the percentage is low enough it doesn't qualify as a dangerous product and can be shipped more easily.
The Coopers oil also has the advantage that you can run it at much lower percentages than straight castor (we run 12% here) without risking the health of your engine.
Alternatively I think Klotz make a product called "Nitroil" which is designed for upping the nitro ratio of fuel and it contains a blend of oil and nitro.
You can try some 0% nitro first but I think you'll be *much* happier with just a little nitro in there. And if you opt for 20% castor then be prepared for a *lot* of mess and the possibility of fairly rapid carbon build-up in what is sometimes a poorly cooled engine (truck with a heat-sink).
Posts: 5
Joined: 6/27/2008 From: Glendale Heights, IL, USA Status: offline
so what should the blend of the 18% oil be? i want to completely strip nitro because anything containing it lately seems to make it so....expensive... Is there a good ratio of castor to synthetic? 30/70? Someone mentioned to me that there was "refined" castor oil, that is a lot cleaner and really doesn't gum up the engine.
Posts: 3465
Joined: 3/31/2003 From: Tokoroa, NEW ZEALAND Status: offline
I've found that anywhere from 2%-4% of castor by volume (of the total fuel) is pretty good.
If you're running 20% oil then that means 10%-20% of the *oil* will be castor.
If you're running 12% oil then 16%-32% of the oil will be castor.
Morgan's castor/synth blend is about 30% castor and Klotz SuperTechniplate is (from memory) 20% castor.
I'm not sure what Cooper's Plus-C is but I know that it's more than enough.
This provides the benefits of castor (rust-protection, hi-temp protection) without the nasty effects such as carbon or varnish build-up.
I also found that running 12%-14% of a *good* quality synth/castor blend (such as Cooper's Plus-C) with 0% nitro gives me about the same power as a fuel with 5% nitro and 20% of a lesser quality oil.
Our club fuel (which is 5% nitro, 12% Coopers Plus C and 83% methanol) produces almost identical RPMs as store-bought (Omega) fuel that claims 10% nitro.
< Message edited by XJet -- 6/29/2008 1:53:49 AM >
Posts: 3198
Joined: 10/10/2002 From: Adelaide, AUSTRALIA Status: offline
This is hands on experience using 0% nitro and 20% castor in a car (Hyper 7 with Mach 28 engine). Starting and tuning was easy and the car ran extremely well but slightly down in performance compared to those using 25% nitro. Lack of performance showed mainly along the main straight where it'd lose maybe 10 feet to the others if they came out of the hairpin turn onto the straight side by side. A slight mod to the head gave it identical performance to the others. For general bashing around with a stock engine I doubt you'd notice any loss of performance.
The easiest way around using a low nitro fuel is simply to buy normal plane fuel with the lowest nitro content available to you. Some companies sell a zero nitro but the most common would be a 5% nitro blend. Sig, Powermaster and Morgan all sell a fuel with no or low nitro and use some castor in the blend. There are other companies too of course. Making the fuel yourself is cheaper if you can find a regular supplier.
Posts: 5
Joined: 6/27/2008 From: Glendale Heights, IL, USA Status: offline
turns out my dads friend at work owns his own drag strip car(he's running 8 seconds, i was really surprised at that) and he said he would sell me some, dollar more than the company charges him. thought that sounded fair. now just need a reliable(cheap) source of oil. Plus, i think i'm getting a Baja. Anyone have any recommendations for what brand of 2 cycle oil to blend for the fuel?
Posts: 3465
Joined: 3/31/2003 From: Tokoroa, NEW ZEALAND Status: offline
quote:
ORIGINAL: mitch_b
turns out my dads friend at work owns his own drag strip car(he's running 8 seconds, i was really surprised at that) and he said he would sell me some, dollar more than the company charges him. thought that sounded fair. now just need a reliable(cheap) source of oil. Plus, i think i'm getting a Baja. Anyone have any recommendations for what brand of 2 cycle oil to blend for the fuel?
As I said.. Cooper's Plus C.
Coopers is (to the best of my knowledge) the only advanced ester-based synthetic oil made in the USA, the others (from Morgan and Klotz) are PAG I believe.
Go to Coopers' website and read a little about their product.
You won't see oil listed there but if you contact them and ask, they'll gladly sell you the oil they use. Ask Brian Cooper what he recommends for your application. I think he may even have some oil specifically designed for buggy use.
Or if you want to wait, I'm in the middle of writing up an "oil shootout" article on RCModelReviews.com which will compare the oils from the major manufacturers for protection, performance, price and corrosion-resistance but that's still a few weeks away.
Posts: 1604
Joined: 6/24/2003 From: Crystal Lake,
IL, USA Status: online
I found a guy in McHenry that sold Methanol. As Brian says nitromethane is not absolutely necessary, but increasing compression ratio is needed to keep the same performance. If you want to run castor oil walk into a motorcycle shop and ask for Klotz Benol or Maxima Castor 927. If you want to run a top end synthetic, ask for Motul Micro, they might have a hard time getting the Motul.
The Baja, which is a 20+CC gasoline engine will do well on any TC3 or higher spec oil for air cooled two stroke engines. The same stuff you pump into the weedwacker.
Posts: 1571
Joined: 10/2/2002 From: Portage,
IN, USA Status: offline
Small quantities of Methanol can be found at most any gas statioin or any place that sells HEET gas line anti-freeze in the yellow and blue bottle. It is straight methanol, no magic ingredients.
As far as oil, be sure it can mix with alcohol...some only mix with gasoline and won't stay suspended.
If you want to experiment without buying a huge quantity of fuel you possibly might not like running, I would try mixing up some HEET and castor oil from the pharmacy first, but if you think you're going to keep running it, switch to AA grade castor (usually labeled *first pressing*) or any others that were mentioned, and switch to that. It will burn with less deposits, but for experimenting, the pharmacy kind will work fine.
Try experimenting with head shims also. Usually when you change over to no-nitro, the engine will be down a little on power but will pick up if you raise the compression a little by lowering the head. If you start blowing glow plugs you went to far and means it's pre-detonating and you should add back a shim, or of course your too lean. Alky takes a shorter needle setting (leaner) than nitro. You'll see longer run times because of that.
Good luck and let's hear back from you how it went
A little bit of engine tuning experience will help a bunch, and bit of nitro will help with that. It gives easier starts and needle settings.
Taking away all the ntiro will make everything more sensitive to tune and probably will be frustrating at first finding the right combination of compression, glow plug, needle setting and possibly pipe adjustments, and still leave you wondering if your making the best power or if your hurting the engine, but it is possible to have the best of both worlds running without nitro.
Due to alky burning different than nitro mix, in Europe the manufactures over time have even had "europe and US versions" of the same motor. The difference being in the head designed for europe is a high compression head for no-nitro because in europe, our exotic nitro had either been too expensive or unobtainable to them.
Here's some head buttons. The two OPS heads (Italy), the one on the left is for nitro and next to it is for alcohol, both are for the same engine. The last one is a Webra (Austria) and designed mostly for alcohol, but instructions say nitro can be added in your own descretion, but basically is designed for no nitro or what is called "FAI" fuel - 80/20 mix, castor only. The squish band area is much larger and flatter on the alky heads compared to the nitro head, and the bubbles are a lot smaller, less volume in the head. Something you might consider looking into if you stay with alcohol.
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CEN 7.7 motor + 0% nitro? - 
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