psgugrad

My Feedback: (2)

has anyone here seen/heard anything about or seen one run at your flying field? It seems like an interesting concept and I want one, I just want to make sure I'm not buying a $200 paperweight. I've heard people knock gas engines this size, but after my first gas engine (a DLE 20 in a 4*120) I'm pretty much abandoning glow. I like the 4*120, but have to carry it in my company cargo van as it won't fit well in the car and it's a pain as I have to unload the van first, etc.... I have a well-worn 4*40 that I love, but the covering is coming off from castor oil.

In a 40-sizer, the cost of glow fuel isn't really a concern, but the gas engines don't get slop all over your plane, plus they run soooooo much better. Glow engines only run great when the compression, carb settings, fuel, and glow plug are all 100% perfect...move any one of those 4 factors even slightly from ideal and all bets are of. THe gas motors are so much less sensitive. I would be curious to know:

How does the thing run?
Is it powerful...really as powerful as a .46 glow...at least a plain-bearing one like an LA .46?
are parts available? are they reasonable priced, or does NGH try to pull an OS Max on us with regards to parts pricing?
what is the cylinder construction? steel sleeve? chrome-plated brass?

any input appreciated

Mike Norris

w8ye

My Feedback: (16)

The DLE 20 is a truly great engine value

Turk1

Hi Mike,check
http://www.rcgroups.com/forums/showthread.php?t=1555659
I have one on bench.Im trying to have good adjust.I saw 12300+ RPM s with APC 11-7 prop.
With more than 1:20 full mineral oil.
For parts.Refer to http://www.agaperacingandhobby.com/v...?productid=450

mpascual

My Feedback: (1)

I'm testing one GT9 for our local distributor .
Engine is very powerful if you have in mind the fuel it uses (no nitro) , much more powerful than the OS46LA.
Needles settings process is more similar to a glow engine than a Walbro fitted gas engine, but on mine i have no problem to get a reliable and low rpm on idle and very good transition.
Also i've tested on this engine a new spark plug 1/4*32 with iridium tip. I must make more test, but i'm satisfied with performance with this new spark plug.
Sleeve construction with steel sleeve, no ABC or ABN construction.
If you have in mind the engine comes with a true RCEXL ignition, a special and a costly spark plug, the fuel delivery system pump-regulator, i think is well priced.
But also you must think where you want to mount this engine. The CDI , battery for the CDI and FDS, opto kill switch and or a switch will increase the total weight of your model, not a good idea if you want for extreme 3D. But there are much more airplane models for this engine.
Only remember to use a good quality oil mixed at the correct ratio needed by this engine ( no less than 25:1) .

Best regards

earlwb

I have one and after working with it for a while now, figuring out its idiosyncracies I am right on the edge of flying it. I have it in a plane and I almost flew it today, but my allergies got the best of me, so i didn't try flying it today. having a sneezing episode while flying a airplane is not a good experience to have. Noty just one or two sneezed but more than ten or twenty sneezes and then the eyes start to get all watery and swelling up on me too.

here are pics of mine

























I measured about 357 degrees F at the base of the spark plug on the head after a fairly long full throttle engine run on the test bench using a APC 11x6 prop. At the flying field using a Master Airscrew prop I measured about 330 degrees F. The back of the cylinder just below the head measured about 200 degrees F and the muffler about 1 inch or so away from the engine measured about 400 degrees F,

earlwb

The issues I had was the the fuel pump did not like being mounted on the back of the engine. The engine vibration and engine heat caused the gasoline to vaporize into gas bubbles that played havoc with the engine running smoothly. So having the fuel pump mounted nearby and protected more from the vibrations and heat cleared up that problem. I have two different NGH fuel pumps and both of them did not like being mounted to the back of the engine directly. They both exhibited the same gas bubble problem when I did mount them on the engine right behind it.

The carburetor is a NGH design. It is quite similar to a small Walbro carb but the carb and the fuel pump have been separated into two units instead of one integrated carburetor unit. The carb is a floatless design that uses a valve that is controlled by a diaphragm to handle the fuel demands of the engine. The valve and diaphragm inside the carb sort of serves as a pressure regulator for the fuel going to the carb. But the diaphragm is really acting more like a float in a carb and controls the fuel inlet valve aloowing fuel into the carb for the engine. The fuel pump simply provides the fuel for the engine. At full throttle the engine can draw fuel from the fuel tank without the pump operating off of crankcase pressure from the engine.

The other issue is that the engine instructions are correct, Idle speed is a little under 1/2 throttle at about 1/3 throttle. Full throttle is like normal with it fully open all the way. So you need to adjust your throttle servo end point adjustments to take that into account. The carb or engine tends to spit fuel out of the carb at low speed, quite a bit too, so be prepared for some messiness there. It cam be a bit difficult to get the fuel pump going so the fuel is being pumped so using a electric starter to get it going is a big plus. After you have it running some OK and dialed in better hand flippling the prop to start it is no problem. You can actually see it spitting fuel after 1 min and 20 seconds of the first video I posted below here.

You want to use the small spiral spring wire clip for the base of the spark plug cap, it really does help lock the spark plug cap onto the spark plug. I didn't use it when running the engine on the test stand, but after a while the spark plug cap tended to want to come loose.

In the airplane pic where I show the RCexl ignition module inside the plane, I actually used velcro to fasten the ignition module into the plane. the velcro helps dampen engine vibrations and isolate the module from the vibrations but allows it to be open for air circulation so it doesn't overheat. You can't just wrap it with foam padding and stick it inside the fuselage as it will over heat if you do so.

I used black neoprene rubber tubing for the crankcase pressure fitting to run a tube to the fuel pump. The Tygon tubing became soft over time and would slip off the engine pressure fitting. But the black neoprine tubing doesn't have that problem. The neoprene tubing tends to naturally glue itself to the pressure fitting, so it tends to stay on there much better.

You do not have to use the stock in cowl muffler that comes with the engine. A OS 46 style muffler fits oK too. I used a Mac's one piece muffler designed for a OS 55AX engine on my NGH 9cc engine and it fits just fine. The screw hole spacing and exhaust outlet supports a wide variety of different mufflers and brands that will just bolt right on no trouble.

I also didn't want to take any chances with our modern ethanol laced gasolines here in the USA causing the rubber parts inside of the fuel pump or carburetor causing problems. So I used the Tru-Fuel or SEF fuel which is a more simple, non-ethanol gasoline in my engine. I really like the stuff as it leaves little to no gasoline odor or smell behind. Our ethanol laced gasolines simply make me a bit nauseous and it stinks up the house if I bring a plane or engine inside to work on it. My family quickly starts complaining about it. But the Tru-Fuel or SEF fuels are great, it doesn't stink up the car or home. Tru-Fuel is sold at Home Depot or Lowes and the SEF fuel is made by the Powermaster fuel company and it can be found in some of the larger hobby shops too. The fuel is more expensive than pump gasoline though. So that could be a detractor against using it for sure.

Here are a couple of videos I made when I was running the engine.

[youtube]http://www.youtube.com/watch?v=PlwJAU3fnUw[/youtube]

[youtube]http://www.youtube.com/watch?v=UKGoRC2hWaE[/youtube]

psgugrad

My Feedback: (2)

Some great input...thanks guys! I like the steel sleeve, no chrome to peel. With a ringed piston this should mean that unless you're one of the 8 or 9 people on earth who fly model airplanes for a living the thing should last forever, or at least until it's obsolete.

For me, the weight's not a real issue as I'm not flyinging high-performance planes. The weight issue seems to stem from the fact that no matter how small the engine is, the ignition battery pack and ignition are going to weigh the same. This means that gas engines can only get so small, at least until some breakthrough occurs in batteries and/or the ignition packaging.

As I'm eyeballing the inside of my 4*40, I'm also seeing that packaging is going to be a bit tricky with this engine, stuffing 2 battery packs and an ignition into a 40-size fuselage.

Leadtrumpet

It is quite common on small gassers to run the ignition and flight pack from one battery...

earlwb

Yes it can be a problem trying to cram in all the extra stuff, especially with some airplanes that have smaller fuselages.
They do have a special BEC device that can use a single battery pack to power both the ignition system and RC system. it uses RFI filters and adjustable voltage regulators. Here is one such device http://www.tech-aero.net/ultra-ibec

The NGH engines use a RCexl ignition system. The RCexl ignition unit has a maximum voltage input of 6.0v. They really mean it too. You cannot use a 5 cell nicad or NMH pack with it, as a fully charged 5 cell pack exceeds 6.0v. The ignition unit will burn out if the voltage exceeds 6.0v. I use a four cell 4.8v battery pack for the ignition system, which when fully charged outputs a little over 5v too. But it stays under the 6.0v limit. So if you just have to use a Lipo or LiFe battery pack or something like that then you will need to use a voltage regulator to supply 5.0v to the ignition module. The RCexl ignition systems are designed for 4.8v battery packs, so they have their best performance at that voltage level anyway. Trying to power them with higher voltages does not make them work any better.

ggraham500

My Feedback: (4)

Actually the url is http://www.tech-aero.net/ultra-ibec (without the extra spaces at the end). Looks like a decent product, but I have no experience with it.

earlwb

graham500, Thanks I correct it.

psgugrad, Yes the main limiting factor is the weight of the ignition system and battery to power it with.
It is possible to build a .049 gasoline spark ignition engine. But the CDI unit can only get so small. One could use a smaller battery pack to power it with though. Or a single battery pack with a iBEC to power the ignition unit with. So maybe something along the lines of a 1/2a Q-Tee plane or similar might be doable as a gasoline spark ignition engine powered RC plane. I doubt a high performance plane and or engine combination would work as a gasoline 1/2a engine is not going to have a lot of RPMs to it. But maybe I am wrong. I haven't gotten around to making one yet myself. I do have some really small spark plugs though. I have been thinking about it. I did get some micro-size spark plugs too. If Iremeber someone did make a gasoline spark ignition .12 engine many years ago and they did sell pretty well. So maybe a bigger 1/2a plane with a .09 to .12 engine would be the way to go. Since we now have 1/4x32 spark plugs and they have 1/4x32 glow plug heads for 1/2a engines it is easier to make one a spark ignition engine nowadays.

Dale Deitrich makes these little 8x40 size threaded micro spark plugs. Here is a pic of them next to a couple of 1/4x32 size spark plugs.

w8ye

My Feedback: (16)

Dale lives in the next town over and frequents the flying field. He's truly devoted to small engines and makes the parts himself. i've been to his house and had him make some custom parts for me.

geeter

My Feedback: (110)

with all the problems with these small engines from china. why not get an os and avoid the problem in the first place. they just came out with a 22 cc gas engine. they cost alittle more but run very good. any engine less than 22 cc is not worth it anyway IMHO. if you can't offord nitro for a .40.50 maybe you shouldn't be flying. i like small gas engines but i think they have a limit. the weight of another battery pack plus the cdi is just not feasable to me. anything besides an xcell ignition is pretty much junk anyway. don't waste you time and money on junk gas engines, buy something good. besides you risk your plane and electronics to boot, just to save a few bucks.............GEETER

earlwb

OS doesn't make a small 9cc spark ignition gasoline engine. It could be several months or more for the new 22cc OS engine to show up in the USA too.
It depends on the importer Great Planes as to how soon they'll bring them in.

Magnum was supposed to come out with a .50 size gas engine, but they apparently cancelled it.
Fox Manufacturing has a .50 size gas engine too, but I don't know if they are shipping them out yet.

Besides there are places in this world where model engine glow fuel and even model engine diesel fuel are extremely difficult to impossible to get. I know of some places in the USA where you would have a heck of a time trying to get glow fuel too. But gasoline is right there and easy to get. In some of these places you could get glow fuel but they charge like two to three to four times the cost of the same glow fuel in a large metropolitan area.

AJsToyz

I have to agree with the size and availability of the small engines, I would wait for long term test results though. As for the OS, there are other good running 20cc engines on the market. I just picked up the new Mintor 22cc and am going to see how that works out. I am
keeping an eye on the GT9 though.

clivemc

have you had an OS 22 that you know it runs so well? dont think so.... 5 years ago a light enough 22cc gasser was unheard of
, today you have a choice. the 9cc engines will come...........
nothing pees me off more when someone says if you cant afford X you shouldnt be flying at all. everyone is different but everyone is also entitled to fly what they want. where do you buy xcell ignitions that are so great? or are you referring rather to the RCEXL units i think.......
for all the NGH problems and previous brand history, i give michael credit for at least thinking outside the box, if he pursues itwith the right testing prior to releasehe may just get it right

dirtybird

My Feedback: (5)

I have a Super Cyclone replica engine in my closet.
It has a small coil and it runs on 3V. its quite light for an ignition system. The only drawback is it requires points on the engine.
In my misspent youth I used this system. It was the only system we had. It was quite reliable.
I just wonder why a modern system could not be made using this system. You could use just one 1100mah A123 battery for it.

geeter

My Feedback: (110)

hey clivemc, i hope your right, yes everyone has the right to spend or waste there time and money the way they want, i'm not saying that. just trying to give advice to people who don't know. they are called xcell ign for short,if you didn't know. i'm just not the type to sucked into some crap because i know better................ been there done that..........HAPPY LANDINGS...............GEETER

earlwb

How can you bad mouth something when you never even used or owned it?
What does a OS 22cc engine that no one can buy have to do with a thread about 9cc engines?
I am a big glow engine user myself, but I found the little 9cc gasser to be extremely fascinating.
They actually designed their own pumper carburetor for the engine, they didn't copy it because no one makes one that small. They had to make the carb in two parts as it is too big to fit on the front of the engine like the Walbro style carbs. Granted they had a lot of pumper carbs to use as a guide, but they still had to design it, make it etc. They even committed to having molds done for the castings too. Those molds aren't cheap to make well. Plus they needed little diaphragms made for it too. The carb us a floatless carb design with a diaphragm and little fuel inlet valve in it too. The pump of course is separate.

Years ago, i remember someone at the flying field was bad mouthing some engines and espousing his views on the others as to which engine was best. He also went on about how bad Fox engines were, blah blah blah. So after I finish another flight, as I wanted to fly not talk, he loudly tells everyone that they need to use engines like what I use, as those engines are running so good. But he then asks me, "What brand engines are you using, I don't recognize them"? So I look at him hard, and reply, "All the engines here on my planes are Fox engines, I only fly what works." He stood there shocked, and shut up after that. I don't think I ever saw him at the flying field again while I was there either.

My main problem with the little 9cc gasser engine was I was still thinking glow engine instead of gas engine. it does not behave like a glow engine, it behaves like a gasoline engine. So I had to get my brain working correctly for a gasser engine again. Years ago, i quit flying gassers when the gasoline formulas changed and the fuel started stinking or smelling real bad. i really can't stand the modern gasoline odors as it tends to make me nauseous. Plus my family almost causes a riot at home if I bring a gasoline engine inside to work on it for whatever reason, not just RC engines but trimmers, etc. The gasoline smell just lingers on everything and you can't even get it to wash off the hands well either. But when i discovered I could find some other gasolines that didn't have all those noxious aromatic hydrocarbons like today;s gasolines use, I became much more interested in having a go as gassers again.

earlwb

I have a couple three old vintage spark ignition engines that are missing timer units. I plan on putting a CDI system on them to run them again. it wouldn't weigh any more than the old points, condensor, coil and battery pack would. They might even run better as it would generate a much nicer spark too.

dirtybird

My Feedback: (5)

Points and condenser weigh very little-about the same as the hall effect sensor. The battery required is 1/2 required for CDI. The coil is about 1/4 the CDI units I have.(RCXEL)

geeter

My Feedback: (110)

i am afraid he was right about fox engines. but you have to know how to use them first off. most people don't and turn them into paperweights.............RON

earlwb

The guy was bad mouthing the Fox engines and he didn't even know what they looked like.

dirtybird

My Feedback: (5)

Fox is advertising a .50 size gas engine. The picture shows a standard Fox carb. I wonder if it has needle bearings on the rod. The price is about double of its glow equivalent.

AJsToyz

They have had it listed for quite some time but have not heard anything more about it.