going gas???
 

don't get me wrong, I love my electric planes but...I've been wanting to get into larger models and for the cost to get I big brushless motor ESC and 4+ cell lipo would be more then buying a gas engine. I'm looking at planes with 80" + wingspan and more for scale like flight then aerobatics. http://www3.towerhobbies.com/cgi-bin...&I=LXLWH2&P=ML something like that. which brings me to my question. on the 4 stroke motors, are they running regular "pump" gas or still model fuel? do they have spark plugs and valves like a traditional gasoline motor? my questions may sound dumb to some but if there still running the same fuel, and still basically a glow motor, why would you run a 4 stroke? is there any model engines that run regular gasoline? I look at it like $3.95 a gallon vs $34.00 a gallon.

RE: going gas???
 

There are two distinct motors out there that most people mistake as "gas." Glow, and true gas.
For your application (80 inch wingspan), I would recommend you go with a gas engine. This will burn a mixture of gas and oil, just like a weed eater engine would. In fact, lots of people (myself included) have converted weed eater engines for use on airplanes.
You can get a large glow engine, but the cost of glow fuel coupled with the consumption of said fuel in these large glow engines make them very expensive.
Saito does have a four stroke gas engine that has valves and spark ignition. Don't know much about it, other than it is expensive. It would still have to have oil mixed in the fuel, just like any other two stroke. Only the delivery of the fuel is different.
On the other four stroke glow engines, yes, they have valves just like a car. You can usually tell the four strokes from the two strokes becuase they will have external pushrod tubes, and usually a rocker arm cap on top of the jug. That, and they sound awesome.
However, they burn glow fuel, not gasoline, and they do not use spark ignition. Instead, they use a glow plug that keeps the cylinder hot between combustions, and the fuel/air ignites off of compression temperaturesmuch like a diesel engine.
Hope this helps.

RE: going gas???
 

For that plane you do NOT need a gas engine. A glow fuel engine will do. A friend of mine has that plane and it flies great with an OS .70 four stroke.

RE: going gas???
 

Yes the airplane you linked is intended for .46 glow two strokes or about .70 glow four strokes anything more is overkill for what you want and may actually reduce overall performance.

Heavy gasolene fueled spark ignition two strokes which are comonly called gassers are a bit inappropriate for the airplane you linked.

John

RE: going gas???
 

I have this plane myself. An OS 46 FX is almost too much engine for this plane. I swear this plane would fly well on a 25!

Ken

RE: going gas???
 

Depending on the glow engine type you pick you should be able to keep your fuel cost down under 20$ a gallon. I was paying 17 a gal for 15% in my 2 stroke and could of got away with 10%. I just switched to 30% heli for my new 4 stroke that is 34$ a gal [:@] Not all 4 strokes need expensive fuel though and for the cub your looking at even if you went with a 4 stroke there is no need to get one that needs high nitro fuel.

RE: going gas???
 

Oops,
Sorry, I didn't follow the link. I saw 80 inch wingspan and assumed too much.
Sorry. You absolutely would NOT want to put a gasser in that thing.
Once you get up to around the 12 to 15 lb range, glow engines become very expensive to operate. That one, however, will fly on an engine that will sip fuel. As suggested, a 70 class four stroke will fly it just fine. A .91 four stroke will give you all kinds of power. I have a clipped wing cub that flies great on a saito .56. My dad has one with a .91 magnum fs on it.

RE: going gas???
 

Hey Sport Rider.


You are right that gasoline is a check of a lot cheaper than glow fuel. (at least now, they way things are going lately that might not always be the case [X(]) But if a glow engine can pull your plane that is usually the best choice. Glow engines are easier to run and maintain. You only need one battery, you don't need to worry about interference as much.


For a summary of glow engines vs gas engines (pros and cons) take a look [link=http://www.hooked-on-rc-airplanes.com/rc-gas-engines.html]here[/link].

RE: going gas???
 

You can't get glow fuel here in Vermont for under $28 a gallon, unless you buy a bunch of cases.

RE: going gas???
 

Wow 28$ is the cheapest? What kind of fuel is it? The most expensive stuff at my lhs is 34$ and that is cool power heli 30%. I think he has 10% for 15$ or cheaper.

RE: going gas???
 

BME has a .90 Supertigre engine that has been converted to spark ignition for gasoline use. It also comes with a special gasoline carburettor and needle bearing crank/con rod which allows for a 32:1 fuel/oil mix. At 15 cc, it is probably the smallest gas engine commercially available, although you can convert any glow engine, even a .40, to spark ignition with an aftermarket electronic ignition module, however, without needle bearing con rods, you will still need to run a really oily fuel, something like 10:1.
http://www.bmeengine.com/point90.htm

That might be a good combo with a 1/4 scale Cub if you absolutely hate the idea of glow engines.

RE: going gas???
 

Agree with most above. Gasoline is best on models over 10 lbs. Has less to do with wingspan than overall weight. But the engines for gas are getting smaller all the time. Most gassers are two stroke and need an Amsoil or similar mix, just like a weedwacket or chainsaw. Still a lot cheaper than glow (especially at the volumes they suck down in large sizes). Some have electronic igniition and need a seperate dedicated sparkplug/ignition battery and circuit. Because of the spark and accompanying EMI they require a little more thought and care in where your servos and receiver can be located. The reward is that you don't need to diddle around with a seperate hand-held electric starter, flieldbox battery or glow driver. Radio switches on, prime and choke the carb, ignition switch on, put on a leather glove and flip the prop by hand. And the sound is right.

In the alcohol glow fuel two and four strokes the fuel is basically the same - alcohol, some percentage nitromethane instead of methanol and castor oil or synthetic oil as a lubricant. $17 to $20 per gallon hereabouts. Gasoline may catch up at the present rate!

RE: going gas???
 

thanks all for the info, this will be my first non-electric powered plane. I've basically come to the conclusion that if I go glow I plan on running an OS motor. from what I've read they seem to be the easiest for break in and tuning, and most reliable. I've thought about converting my Magiser to glow before committing to a plane that would need to be glow/gas (or very costly to be electric) to get a feel for a glow plane (seeing how the stock magister is pretty underpowered anyhow) . I guess I need to make up my mind, but I'm always thinking about the next addition to my hanger:D

RE: going gas???
 

I have nothing but good things to say about OS engines. Also, a .40~.46 glow (nitro if you must) engine doesn't use very much fuel. A gallon should see you through at least 16 flights at 8 ounces per flight. If you fly every weekend on both days, that's about a gallon every other week. Most of us are ready to land with only 1/2 of the tank used up. Driving your car to the field and back probably costs more.
Now, when you start flying glow engines in the 1.00 + range, you definitely will join the gallon-a-day club and should consider gasoline. Gasoline is not only cheaper than glow fuel, but gas engines burn fewer ounces per minute to make the same power. The smaller fuel tank needed partially cancels out the extra weight of the gas engine in a large plane.

RE: going gas???
 

makes me want to go to my hobby shop and buy their stock of fuel and stock it in my pantry at home. They sell 15% for $11(Cool power, Omega). Time to hit them up today.

RE: going gas???
 

Not tring to hijack danny. I have all electric planes, stryker c, electristar, pz spitfire, and a freedom. I have been thinking about going glow power. I have been into nitro trucks for years. Going glow seems cheaper in the big birds. Is this a good setup to run. http://www.hobbypeople.net/combos/999002.asp