corbystarlet11

g-day

i'd like to know what are some good 46-55 size gas engines (not nitro) im converting to gas and have got rid of all the nitro garbage, i have heard of the NGH9cc engine the Saito 14cc 4stroke. The NGH are not to flash and i had a FG20 saito whichs is also crap, is there anything else out there worth a go?

Darcy

Mr67Stang

I had a buddy put an NGH 17cc on a 40 sized Space Walker. It was a BRICK. It did fly but did not look like fun. The plane had to have an excesive amount of weight added tothe tail to ballance. My sujestion would be to increase the size of the planes and engines you are looking at unless it is a larger trainer. You will not be happy with the performance of a 9cc-17cc on a 40 size aerobatic/sport plane.

20-26cc on 60 size planes seem to be the blending point where some airframes are still not suitable for the gas conversion but others are.

ahicks

My Feedback: (2)

Yup, I agree. Nothing that small seems to be working well. Really looking forward to the possibility. NGH9cc looks promising, but from what I understand is having fuel issues. The smallest I see that seems to make good numbers reliably is the RCGF 15cc, but the weight of that engine is not that far off a DLE20? I'm looking for an excuse to try one, but can't find an airframe where it makes sense?

earlwb

The NGH 9cc engine works OK. I know a couple of folks with the NGH 17cc engine and it is working good for them too. I haven't tried using my NGH 17cc engine yet.
I clocked one of my NGH 9cc engines on a Great Planes Escapade using the Doppler shift method at 65mph.
Our grass runway is rather thick and lush with the grass on it, so take offs tend to be longer.
Power output is similar to a 40 to 45 glow engine. I am using a 11x7 prop on the engine at present.
Actually the engine develops about the same power as the old baffled cross flow scavenged 2 stroke .60 glow engines like the Fox .60Eagle I, K&B Veco .61, HB .61, etc. They didn't turn a 11x7 prop any better than the NGH 9cc gasoine engine does.

I will say there were some trials and tribulations until I got used to the engines and figured them out. They are not glow engines and do not really behave or act like glow engines. So that may take some getting used to from people.

The only mods to the engine that were done was to change the pressure fitting on the engine and pump to the larger 8x32 threaded size and use larger 1/8" fuel tubing. The other fittings are still stock using 3/32" tubing. The pump/regulator is also placed close to the carb as well.

Now the NGH pump/regulator uses Walbro carb parts too. I did replace the pump diaphragm and regulator diaphragm after a short while as the rubber seemed to stretch out and get soft. I suspect our USA pump gasoline doesn't agree with the rubber parts in the pump.regulator. But since it uses standard Walbro carb parts, it isn't a big deal to fix the carbs.

NGH 9cc engine in a Escapade 45
[youtube]http://www.youtube.com/watch?v=0HkMYRiLhPQ[/youtube]


Of course this NGH 9cc engine was modified to use a Walbro carb, as an experiment, but it works OK too.
[youtube]http://www.youtube.com/watch?v=mR2N4IM3nCM[/youtube]


I remember reading a lot of peoples opinions of the SV-17cc engine and how bad it was. No power, overweight, etc. But the one example I have works quite well though. Here it is on a Great Planes Escapade .60 plane and it flies the plane well too. I suspect the stock Walbro carb had too large of a venturi on them, I replaced my engine's carb with a smaller venturi carb and it then started running great. But since it is the only example of the engine I have dealt with, I can't say what they used for carbs on the other engines.

SV 17cc engine in a Escapade 60
[youtube]http://www.youtube.com/watch?v=CdkSeeCk9pg[/youtube]

karolh

I have two friends that have the RCGF 15cc beam mount engines in their GP and H9 60 size Sticks and they perform very well having unlimited verticals.

Karol

corbystarlet11

Thats the go!, i guess the best to go is about the 15cc-20cc mark for reliability. I'm mainly looking for a cheap plane and gas engine, for something to have endless fun with, do some ribbin cutting and something easy to land and glides well, none of that scale. That big Stik idea is the best so far and i here those rcgf engines are the go. I'm tossing between the Big Stik and a boomerang trainer but a Stik looks more fun to fly. Those NGH9cc engines look good, but haven't seen anyone say they are good.

Thanks

Darcy

acerc

I also have a couple 20cc engine's as well, RCGF. One in a GP Super Stearman and one on a 65" ws profile. I love them both. I also have a couple 26cc's as well, RCGF. One in a 1/5 scale Waco and one in a 1/4 scale Clipped wing Cub. Both very appropriate for the airframe's.

ahicks

My Feedback: (2)

Have a DLE 20 in a profile. That pretty much defines the max performance for anything I've ever flown. Then there's a rail mount 20cc RCG in a Great Planes Revolver. That's a blast as well. Much more docile than it looks when slowed down (not a trainer though!), sturdy, awesome all around sport plane with plug in wings and compact dimensions for easy transportation. Prior to a couple of price jumps recently, it was a pretty economical gasser - that looks like a real plane. There's a pretty active forum here for guys with that plane (Larger Revolver - http://www.rcuniverse.com/forum/m_9143970/tm.htm)
-Al

karolh

One of the best deals around is Value Hobby's 60 size ARF Big Stick for $88.00.

Karol

captinjohn

Value city .60 ARF http://www.youtube.com/watch?v=IgTOOK0xDkc

http://www.youtube.com/watch?v=xofQR...feature=relmfu with onboard camera!!!

dirtybird

My Feedback: (5)

What we need is a smaller ignition.

earlwb

I can agree with that too, as it was a challenge trying to figure out where to put the CDI module on the Escapade .40.
Of course the vintage engines used ignition points and a coil with battery pack, and that is arguably smaller, but I don't really want to deal with finicky ignition points on a RC plane.

dirtybird

My Feedback: (5)

You wouldn't need points. You could place a small coil next to the same small magnet used for current CDI systems. The charge generated by the magnet passing the coil would trigger a FET that would take the place of the points.
With this you could run it on three volts. A hall effect trigger needs 3.7 volts.

captinjohn

Please post a photo of this system you tell about. Thanks, Capt,n

dirtybird

My Feedback: (5)

I don't have a system that uses this.
I think 3W uses a coil pick up system. This is nothing new. Your hard drive uses a coil pick up to read the data off the plate. This data has been placed there by another coil called the write head.
I could design such a system but I don't have the ambition to work out the kinks.

OliverJacob

My Feedback: (12)

The smallest gasser I have is a JBA 15cc. After replacing the stock carb with a DLE it has lots of power, but it's heavy.
I had this in a 60 size Extra, but it was no fun to fly with all the weight.
Now I have it in a Value Hobby Stick 60 and it's a great combination.

But I would not get another gasser under 20cc. There are not many planes which handle the weight well.
 

earlwb

I found that instead of using two separate NMH battery packs for the CDI and radio, that I could combine them, using a single LiFePo4 2 cell pack (6.6v) and run the radio unregulated directly off the pack and use a Tech Aero Ultra-IBec to power the CDI. That saved a fair amount of weight in the airplane. So I could squeeze the 9cc gas engine into a fairly small .45 size airplane then. But your radio has to be able to handle 6.0v or so.

I'll have to think about the electronic ignition system dirtybird was mentioning. Using a transistor ignition for vintage engines might do the trick. It is coming up with a way to bypass the points and use a hall effect transistor instead. But that would shrink it down more in size and weight. But it then becomes a fixed timing setup with no ignition retard then. But with a small engine, it may not matter too much. It is another thing to try out and test. If I ever get the time to do so. But maybe a rotating timing setup could still be used like they do with the vintage engines too.

corbystarlet11

I just bought a GT33 today with a Phoenix Sbach, i picked em' up cheap at a scale fly in show. I'm still intersted in one of those RCGF 15cc engines in a big stick or a trainer, but i can get a Seagulls Edge540 50 for about the same price, you think that engine would go well, or is it to heavy? i had one of these planes before with a os55ax and it was such a great plane to fly, til i forgot to plug in one of the alrine servos Bugger it!.

Darcy

earlwb

The DLE 20cc or RCGF 15cc are really meant for .60 size planes where one could use a .60 to .91 two stroke or a .91 to 1.20 size four stroke engine in the plane.  A Extra .50 size plane would not work with the engines as they are too heavy for a plane intended to use the big bore .50 size engines. I know it is a big plane though, not much smaller than a .60 size actually. So it is mighty tempting to put on the bigger, heavier engine. But that messes up the wing loading, overall weight and CG. You really want the plane to be as light as possible for a low wing loading.

ahicks

My Feedback: (2)

For some help/guidance deciding on a 15-20cc gas powered airframe, I think I would want nothing less than about 800-850 sq.in. of wing, if that's any help? Much below that and the low speed performance drops off pretty quickly due to the wing loading Earl is talking about. Not that it won't fly. The military planes fly great for instance - but can be a hand full (maybe not so predictable?) around stall speed when landing. Not something a sport flyer would have fun with for long....

OliverJacob

My Feedback: (12)

Agree. The Stick has a huge wing surface and handles the weight very well. A 50 or 60 size aerobatic plane will likely fly like a brick with the gasser.
I replaced my 15cc gasser with a 15cc four stroke in the Seagull Extra and it's a whole different plane.

Another problem in these small airframes is that you don't have much room for the ignition box, hard to keep enough distance to the radio equipment. Interference still happens, even with a 2.4 Ghz radio. Ask me how I know.
Then you will more then likely have to beef up the engine mount, gassers vibrate a lot. Also check the airframe often for cracks.

jeffk464

In my opinion if you want to fly .40-.55 sized planes and don't like glow, electric is the best option. DLE 20cc seems to be the smallest gasser that people are happy with.

I personally think the best gasser starting point is probably DLE 30cc with a 68"-72" wingspan.

ahicks

My Feedback: (2)

Not saying your opinion regarding a "starter" gasser is wrong, only that mine is different. I generally suggest one of the 20's....

Here's the thought behind that. The DLE 20 and 30 are both over achievers, but there's 8oz difference in their weights? That's enough to make a noticeable difference in many/most airframes. In a Funtana for instance, it carries either engine nicely (both engines are popular!), but the 30 is WAY too much power (after that initial big grin wears off!). You'll find yourself flying most of the time at/around 1/4 throttle? You can't possibly use much more unless you're pointed straight up because of the flutter potential. Why not have a plane that's 8oz lighter, and just as capable at anything but vertical acceleration? You'll be able to fly slower without dropping a wing as easily, and still have PLENTY of vertical performance? That 8oz difference will also let you get down into some of the smaller (less expensive?) planes without overloading them as well (the Revolvers are a blast!). The props used on the 20's are smaller, giving increased clearance too. That get's to be an important point as you go into the smaller airframes as well.

corbystarlet11

I was looking on youtube before and seen a Harmon Rocket with the saito fg14, it looked great, but i don't think the trouble you get with these saito FG's is worth the money. I hope O.S bring out a GT11 . i Just took the saio fg20 out of my Seagulls christen eagle and im going to store it away. I am looking at the OS gt22 as replacement, they wiegh a bit more then the DLE20 but my plane needs the nose wieght. i Have heard that those DLE's didn't last very long, they had a weak Rod or something like that. i Maybe Wrong

[email protected]

man i got a rcgf 15 cc that so dependable about the same as my dle 20